grumpyvette

Ive built dozens of 383 and 396 sbc engines and the clearancing can be done BY YOUR OWN HANDS with a standard HAND HELD drill and a few CARBIDE BURRS OR GRIND STONES in that drill in well under two hours if you take your time and total expence even if you need to buy that drill and burrs will be well under $50 total http://www.click-onsource.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=OVAL_1-4_Shank buy a 1/2" burr and a cheap drill http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=20776&item=4358782476&rd=1 place you old bearings in the block an place the crank in those bearings after coating them with axle grease slowly rotate the crank and grind a minimum of .060 clearance anywhere the counter weights might touch the block and try NOT to grind more than about .070 any place it touches the block (use a JUMBO size paper clip as a gauge if you don,t have feeler gauges) next assemble two connecting rods and pistons, one connecting rod and piston for the left one connecting rod and piston for the right, use old bearings coated with axle grease and no rings on the pistons, assemble them to the crank and grind anyplace the rods touch the block, grind minimum of .060 clearance and try NOT to grind more than about .070 any place the rods touche the block (use a LARGE size paper clip as a gauge if you don,t have feeler gauges)move them to the next journal and repeat untill all 4 journals and 8 connecting rods clear. now assemble all eight rods and pistons without rings and install them in thier correct locations and recheck everthing carefully. next intall the cam and index it correctly with the timeing chain/gears, rotate the engine slowly and look for clearance issues, between the cam and rods/rod bolts ,youll need to use a small base cam if there are major clearance issues but in most cases if your cams lift and duration is under about 230 at .05 and .500 lift there should be minor if any clearance issues, usually the outside edge of a rod bolt head is the only area needing a touch up. once everything clears, [color:"blue"] wash all the parts VERY CAREFULLY ,TWICE and re-oil then send out to be ballanced [/color]now you might ask why do that! well, first youll know its done correctly, and that a correctly built 383 will have a very significant hp and torque advantage over any similar 327 or 350[/b] http://www.bracketmasters.com/small_block_stroker_383_cu.htm http://www.prewittracing.com/newpage2.htm http://www.chevytalk.org/threads/showfla...true#Post676922 "Pardon me for being dense GRUMPY ..but what is being grinded upon, the block?" this may help the comon areas are the area near the block oil pan rail where the rod bolts touch and the lower inner cylinder walls and where the cam lobes touch the rod bolts upper shoulder on some types of rods, now you can,t grind on the cam, but you can grind the edge of the rod bolt and you can use a small base circle cam to give greater clearances http://www.karl-ellwein.org/2005engineprojects/388project.htm

personally Id move the battery and re-install the current ignition

if its clearance problems your solving, then yeah, the newer built in ignitions are much smaller and compact, yet work reasonably well, just don,t expect a major hp increase

"Do You Think I Should Stick With What I Got Or Use That?" swapping from a correctly set up MSD ignition running the suggested ignition wires,coil, and distributor (which I think is what you have now) is not likely to show any noticable improvement swapping to a controller built into the distributor

the one function of any spark plug is to ignite the compressed air/fuel mix efficiently as the piston approaches tdc, the number of degrees before varies with the application, octane, cpr,fuel atomization, cylinder heat,quench and other factors in your combo.if your current ignition does that (ignites the compressed air/fuel mix efficiently as the piston approaches tdc,) (youll not be improving it with a unique plug! they claim a 44%-50 increase in MPG, right there you know this guys full of B.S with a neon B.S. flashing before your eyes this is the same class of crap as the magnets that IONISE YOUR GAS or the TORANADO that swirls more power into your engine! theres a SUCKKER BORN EVERY MINUTE, and thats what they count on! if your looking for better ignition get a MSD ignition or a NOLOGY IGNITION that gives far hotter spark, much improved energy and MULTIPLE sparks, both increase the burn efficincy far more than ANY spark plug swap can potentially do! http://www.nology.com/products.html http://www.msdignition.com/ BTW if you do buy it youll need these to get it to work correctly http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7967383856&category=33741 a $24 fan that sells for $95 (above) http://www.accupressurecaps.com/family.asp?fam_id=ZTFS&CAT= a $35 roof turbine impeller (sells for $70) http://www.magnetcity.net/fuel.htm 3 magnets,you cuold buy for under $12 http://store.yahoo.com/engineionizer-store/

"what usually limits power at higher RPM " do a search on ...REDLINE..... IM sure youll get several posts on the subject like these It basically comes down to several factors, valve float rpm, rod strength rpm and the increasingly shorter time available for the cylinders to fill as the RPMS increase, Im sure youve noticed that power increases with rpms due to the greater number of power strokes per second at higher rpms , but a some point the voluumetric effiecincy falls off due to the cylinders not filling completely due to time.(the valves just don,t have the open flow time necessary),( usually by 4500rpm-5500rpm, DEPENDS ON THE COMBO)voluumetric efficiency starts to fall off rapidly theres a whole bunch of factors involved , like the cam, type of lifters, valve springs,etc. but if the engines a stock 350-383 youll be reasonably safe keeping it at about 6000rpm above that your likely to be getting into stress that could dammage your engine that figure is found by keeting the engines piston speed under 4000fpm max and below valve float rpm levels Maximum Average Piston Speed (redline) is the rpm level where stress starts to damage parts,both the engines lower end strength and the engines valve float limits will have a huge effect on the engine ability to safely operate in the upper rpm ranges, most stock hydrolic lifter engines tend to float the valves by about 6000rpm due to weak stock springs and lifter pump-up so even if the bottom end can take the strain the piston smacking a valve will destroy the engine, keep that in mind! Crank stroke x rpm divided by 6 = Piston speed in feet per minute. Conservative speed is 4000fpm, but lightweight aftermarket parts can hit 5000fpm. http://users.erols.com/srweiss/calcrpm.htm 4000 feet per minute (FPM) of piston speed is generally considered max useing basically stock parts in a chevy v8. now no one in their right mind will tell you you can,t exceed that speed slightly but STRESS IS CUMULATIVE and if you EXCEED that speed regularly ,sooner or later IT WILL eventually FAIL! 4000fpm=48000 inches per minute your crank stroke X 2= distance travelled bye the piston in ONE REVOLUTION while its very true that its unlikely to fail the first or even the 100th time you exceed redline you are stressing the parts and the strain on those parts due to rpm levels climbs MUCH FASTER AS THE RPMS INCREASE than the RPMS,example the strain on parts spining 6000rpm is not double the strain imparted by 3000rpm, its more like 4-8 times higher (rod angles , rod stroke ratios, total stroke length, piston weight, crank counter weights, internal verus external ballance, etc. vary the results) examples 327=7384 rpm 350=6857 rpm 383=6400 rpm 454=6000 rpm (454 big blocks with the 3/8 rods should not push that limit too hard, the aftermarket 7/16 rods and lighter weight pistons, can easily handle 7000rpm in a CORRECTLY set up engine) I would have to say most blown engines that are brought to me are caused by (no particular order) (1) lube problems (2) overheating (3) rod bolt failure(streched or not torqued correctly) (4) broken pistons due to detonation or valve float (5) broken rods due to spun bearings or trying to compress busted valves rod bolts normally stretch and break on the exhaust stroke when they are not compressing anything to slow their inertia as they play crack the whip approching tdc OR most comonly,when they have been over reved, exceeding the valvetrains rpm limits, then the valves float, the piston smacks the valves bending them , locking them in place, from then on each successive impact (hitting with 300-500ft lbs of energy at 50-70 times a second) further bends the valve,untill the valve breaks off, the piston , unable to compress the broken valve causes the rod to bend, rods comonly bend then break, now you have a bent rod slaming everything it can reach at 5000-7000rpm with 300-500ft lbs 50-70 times a second untill something breaks,it locks up when something jams, at that rpm, the result is normally a long list of destroyed parts we have all heard it, " you need massive low rpm tq" "you need a screaming high rpm hp peak" well heres some info, More in-depth description: http://www.revsearch.com/dynamometer/torque_vs_horsepower.html http://www.dynacam.com/Product/Torque_vs__Horsepower/torque_vs__horsepower.html http://vettenet.org/torquehp.html http://auto.howstuffworks.com/horsepower4.htm http://homepage.mac.com/dgiessel/engine/hpvstq.html first thing to keep in mind is that theres no such "thing" as horsepower, horsepower is a mathmatical formula for the RATE at which TORQUE can be applied the formula for hp is (tq x rpm/5252=hp example 450 ft lbs of torque at 3000rpm=257hp 450 ft lbs of torque at 6000rpm=514hp because the torque at the higher rpm useing gearing can be applied faster here read this http://www.69mustang.com/hp_torque.htm http://www.ubermensch.org/Cars/Technical/hp-tq/ http://vette.ohioracing.com/hp.html where most guys go wrong is in not correctly matching the cars stall speed and gearing to the cars tq curve, if you mod the engine for increased high rpm performance but fail to also match the stall speed and gearing to that higher rpm tq curve much of the potential improvement is wasted. example in the close to stock engine above, the engine should be geared to stay in the 3500rpm-5000rpm range for max acceleration (lower in the rpm range if mileage is a big factor) in the moded engine above the rpm range moved to 4000rpm-6500rpm requireing differant rear gears and slightly higher stall speeds to gain max acceleration in the same car, you should readily see that a trans that shifts at 5000rpm will work in the first example but would waste most of the power curve in the second example,where shifting at 6500rpm under full power acelleration would make more sence. a 3.08 rear gear and 700r4 trans matches the first example well but it would take a swap to a 3.73-4.11 gear to allow the engine in the second example to keep its most effective power band matching that second power curve well. links youll need to figure out correct rear gear ratios http://www.miata.net/garage/tirecalc.html http://www.wallaceracing.com/reargear.htm http://users.erols.com/srweiss/calcmph.htm http://users.erols.com/srweiss/calcrpm.htm http://users.erols.com/srweiss/calcrgr.htm http://www.geocities.com/z28esser/speed.html http://server3003.freeyellow.com/gparts/speedo.htm http://www.pontiacracing.net/trannyratios.htm http://www.tciauto.com/tech_info/gear_ratios.htm torque is the force your engine produces, rpm is the rate at which it can be applied, the correct combo will almost always be the combo that supplies the best AVERAGE torque curve within the HIGHEST possiable RPM RANGE that the cars engine and GEARING can sustain so that the greatest advantage from gearing can be used effectively , using the above torque curve Id want to shift so the rpms fell aproximately back at 4400rpm and I shifted at aproximately 6200rpm if I could. you might want to play with these http://users.erols.com/srweiss/calcrpm.htm

a few factors you might want to look into are the fact that the cam timing and the compression ratio and boost curve MUST ALL match the application, and then the voluumetric efficincy falls rapidly after about 4500-5000rpm simply due to the TIME available to fill the CYLINDERS, ESPECIALLY if the exhaust is restricted or the compressor flow map does not provide the voluum necessary and the cylinders dont scavage correctly. at 5000rpm theres about 42 intake strokes per second per cylinder, you just don,t have a great deal of TIME to fill the cylinders above 5000rpm as the time available gets shorter and on a boosted engine the booost pressure tends to make closing the intake valve harder and without more spring pressure valve float comes in at a lower rpm

always glad to help out BTW in some applications http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=47928 these also come in handy, for tighting header bolts (youll need BOTH SAE and METRIC sets if you do ALOT of this work as the bolts vary)

first make VERY sure the hole in the header flange and the heads bolt holes align correctly and the exhaust gasket is not partly blocking the hole which are VERY comon problems, next make sure the bolts your useing are the correct thread type/pitch and length and before starting make sure the threads in the head are clear/clean, USE ANTI-SEIZE on the threads and make very sure the gaskets are correctly placed once your TOTALLY SURE thats correct...a sidewinder wrachet and wiggle/wobble extension makes the rest reasonably (DO-ABLE) http://www.jcwhitney.com/webapp/wcs/stor...catalogId=10101 http://www.jcwhitney.com/autoparts/Produ...ble%20extension many times simply drilling out that particular hole in the header flange to the next larger drill size gives you enough room to get the bolt in much easier BTW on those applications where the bolt heads are so close to the header tube that turning the bolt becomes very difficult theres several ways to make that far easier (1) socket head cap screw bolts (2)studs with a nut, rather than a bolt (3) (long studs with a nut or bolt and use a 1" or 1.5" long section of the correct size pipe or tubing slipped over the bolt or stud as a spacer to get the nut out away from the header pipe, this tends to work wonders when the clearance next to the flange is really tight http://www.stockcarproducts.com/exhaust3.htm

as much as you wish you did......you might want to read thru these http://www.newcovenant.com/speedcrafter/tech/camshaft/1.htm http://www.oregoncamshaft.com/cam-basics.html http://tru-442.tripod.com/camselect.htm http://www.rpmoutlet.com/camfac.htm http://www.chevytalk.com/tech/engine/Cam_Selection.html http://www.auto-ware.com/combust_bytes/camspecs.html http://www.chevyhiperformance.com/techarticles/95298/ http://www.rbracing-rsr.com/camshaft.html http://www.babcox.com/editorial/ar/eb30228.htm http://www.crower.com/misc/valve_timing_chart.html http://www.2quicknovas.com/happycams.html http://www.hotrod.com/techarticles/18218/

for $40 I can,t see how you can go wrong, provided you take the effort and time to CORRECTLY,CLEAN,CHECK,AND INSTALL THEM

go to http://www.midwestmotorsportsinc.com/ then (order online) (search BY DISCRIPTION) (OIL PAN) PART# MWM 15120 or MWM 15121 look at the picture (it can be enlarged) this is a very good starting place for a high performance oil pan, and check for clearance issures with your frame, headers,ETC. then simply extend the pans sump forward to the max your application allows and weld a door hinge over the 4-5 1/2" holes you drill in the orriginal forward sump so that it swings very easily to allow oil flow towards the pump but swings with the oil to block flow away from the pump oil pan capacity can be easily custom made between 8 and 10 qts and for under $100 if you do the mods BTW use a sheet of poster board to mock up your sheet metal sump mods and tape to simulate welds to trial fit and make a pattern to use before cutting the sheet metal with the pan temp bolted to the block while your under the car to avoid clearance issues...I usually use 12 ga steel sheet for good impact strength but its up to you! and a TIG weld distorts the pan far less than oxy-acetolene or mig __________________keep in mind your pump and main caps/crank extend about 5" below the block so you can,t get an EFFECTIVE OIL CONTROL DESIGN in a shallower oil pan than about 6.75"-7.25" unless you get a DRY SUMP application

1255806298......350..........L31 Vortec, truck, 64cc chambers, 1.94/1.5, 170cc intake port.. 10243880...350...95-00...2 or 4...Vortec truck, Gen.I crate motors and "ZZ4", roller cam, one piece rear seal . http://www.goautocenter.com/zz4_420hp.htm CAM SPEC'S FOR 420 HP ROLLER ENGINE Duration @ .050" Lift Lobe Int. Exh. Int. Exh. Centerline 230 230 .560" .560" 110 http://www.cranecams.com/?show=browseParts&action=partSpec&partNumber=109831&lvl=2&prt=5 one of us (probably me in this case) is confused simply because part # for that block/engine shows the ZZ4 cam that comes with it is noticeably hotter than the crane cam your looking at???

I build easily 5 big blocks for every small block that goes thru the shop,youll be way ahead buying and reading these books and links below FIRST before spending your money , youll save THOUSAND$ of DOLLARS if you KNOW what your doing VS just wadeing in with a check book and with $800 it is going to be really hard to build even a stock small block,big block parts tend to cost slightly more but then you can make better power levels , so it averages out, especially if the goal is over 500hp http://www.camaros.net/racing/BBCombo.html http://www.camaros.net/racing/BBCombo.html http://www.racingengines.com/public/sales/wrldprd1.htm [ http://www.amazon.com/exec/obidos/ASIN/1557882169/qid=1075079777/sr=2-1/ref=sr_2_1/102-1234339-0571324 http://www.amazon.com/exec/obidos/tg/detail/-/0912656042/ref=pd_bxgy_img_2/102-1234339-0571324?v=glance&s=books http://www.amazon.com/exec/obidos/tg/detail/-/0895861755/ref=pd_bxgy_img_2/102-1234339-0571324?v=glance&s=books http://www.amazon.com/exec/obidos/tg/detail/-/1884089208/ref=pd_sim_books_1/102-1234339-0571324?v=glance&s=books http://www.amazon.com/exec/obidos/tg/detail/-/1557883572/ref=pd_sim_books_3/102-1234339-0571324?v=glance&s=books http://www.amazon.com/exec/obidos/tg/detail/-/0760302030/qid=1075080362/sr=1-2/ref=sr_1_2/102-1234339-0571324?v=glance&s=books something to read http://www.popularhotrodding.com/enginemasters/articles/bigblockshootout/ heres more bbc info, but don,t let the guys make you think only oval port heads work well! it totally depends on your combo,s rpm range,displacement,gearing,weight,cam timeing,etc http://www.idavette.net/hib/vette_bbfh.htm http://www.protopline.com/racingaluminumbbc.asp http://fteufert1.home.att.net/bbchevy/bbchevy.htm http://roadsters.com/bbc/#prep http://roadsters.com/bbc/#bore http://roadsters.com/bbc/#oval http://www.chevelles.com/racing/BBCombo.html http://www.edelbrock.com/automotive/raceheadbbchev.html http://www.dragraceresults.com/worldcastings/ http://www.nastyz28.com/bbcmenu.html general big block info! http://www.amotion.com/cbb.html http://www.edelbrock.com/automotive/headbbchev.html http://roadsters.com/bbc/ http://www.teufert.net/bbchevy/bbchevy.htm http://www.chevelles.com/racing/BBCombo.html http://www.racingengines.com/public/sales/wrldprd1.htm http://www.holley.com/HiOctn/ProdLine/Products/IEC/IECP/Chevy30.html http://www.mortec.com/location.htm http://home.hiwaay.net/~ppatter/patrick_budd_article.htm http://www.bigblockchevy.com/BittnerBoyz/460Alky1500Hp.html http://www.edelbrock.com/automotive/7161pp.html http://www.onlineperformanceparts.com/public/sales/ablock1.htm http://www.off-road.com/chevy/tech/454engine/ http://www.directhits.com/ChevyDynoReport.asp http://www.theengineshop.com/techinfo7.shtml http://www.dodgeram.org/tech/gas/specs/crank.html http://www.diabolicalperformance.com/diabolical540.html http://avs.epix.net/schorrperformance/cams/_ChevyBB_290+.htm http://avs.epix.net/schorrperformance/cams/_ChevyBB_290.htm http://www.diabolicalperformance.com/extremevalue468.html http://chevyhiperformance.com/techarticles/93650/ big blocks like more compression, bigger carbs and a slightly larger cam than small blocks if thats what your used to building btw http://maliburacing.com/patrick_budd_article.htm HERES AFRs 345cc head AFR 345cc As Cast Magnum BBC Head AFR’s Magnum Series If “Dirty Harry†drove a racecar, it would certainly be fitted with a pair of our 345 or 357 “Magnum†cylinder heads. If huge horsepower is what you are searching for, either of these castings will certainly deliver. With our Race Ready “As Cast†345cc flirting with 400 CFM and our fully CNC ported 357cc flowing 425 CFM, these heads represent the ultimate in airflow for your BB Chevrolet. Our 357 “Magnum†flows over 415 CFM @ .700 valve lift! No other production style BB Chevy head even comes close. Both of these heads were targeted at larger cubic inch engines (509-632 CID) looking for maximum horsepower and rpm capability with a primary operating range of 3500-8000 rpm’s (This range is an average and will vary with engine displacement and component selection). These heads will also provide impressive torque figures at higher rpm levels. Blown, turbo, and nitrous engines will especially like the larger, higher flowing intake ports.Both of these heads will work best with camshafts exceeding .750 gross valve lift to make better use of the substantial airflow found in the higher lift range. Both the 345cc and the 357cc come standard with AFR’s trademark .750†thick head deck, reinforced rocker stud bosses, and are equipped with premium one piece stainless steel 2.300†intake valves and 1.880†exhaust valves. Standard combustion chamber volume is 119cc’s on the 345 “As Cast†pieces, while our fully CNC ported 357 version comes with a 121cc chamber. Both are available with an optional 114cc combustion chamber as well. Properly selecting the correct cylinder head depends on a large number of variables. Please consult with one of our sales technicians to assist you in making the best decision for your particular application. Note: Optional stud girdle required for 2° rolled valve angles and 1†longer head bolts needed on four bottom exhaust bolt holes. new EDELBROCK big block heads Victor 24° As-Cast Rectangular Port The Victor 24° is the best standard port location head available for large bore (4.470" and larger) big-block Chevys. Based on the Victor head #77609, it features a rolled over deck, altered valve locations, and revised 115cc combustion chamber. The head has been angle machined 2.4° and the valve locations moved to improve flow and combustion efficiency. The new valve spread accommodates valve sizes up to 2.45" intake or 1.92" exhaust. The 345cc ports are significantly smaller than the 77609 but flow 400+ cfm, producing a higher velocity flow for improved throttle response. All geometry has been developed using Pro/E 3-D software to ensure the ultimate valve train tracking and stability. #77409 is finished with a valve job, port match and bowl blending, and comes with 2.30" intake and 1.82" exhaust valves. #77419 is a bare head without port matching or bowl blending. Other features include: spring pockets cut for 1.625" springs; 11/32" diameter bronze valve guides; ductile iron interlocking valve seats; heli-coiled exhaust bolt holes; and raised exhaust ports capable of flowing 300+ cfm. The valve cover rail is raised an additional .25" to retain the oil during valve adjustments. Matching stud girdle #7796 is available for use with stud mounted rocker arms. Victor 24° (as-cast) Chamber Size Bare (single) With Valves (single) 115cc #77419 #77409 notice the EDELBROCK HEADS CLAIM A 400CFM/300CFM flow rateing that equals or betters the AFR flow numbers on their new heads!!

http://www.cranecams.com/?show=browseParts&action=partSpec&partNumber=109831&lvl=2&prt=5 heres the cam btw you did not post the rest of the combo in your question, gear ratio,trans stall speed, cpr, displacement, ETC and most of us DON,T keep track of your combo so the question is very difficult to answer correctly

first let me say (GOOD REPLY POST) to answer your question, AND keep anyone reading this up to speed on what we are talking about I think we need to explain a few factors that also need to be looked at. look here these are the valve timeing overlap ranges that are most likely to work correctly trucks/good mileage towing 10-35 degs overlap daily driven low rpm performance 30-55degs overlap hot street performance 50-75 degs overlap oval track racing 70-95degs overlap dragster/comp eliminator engines 90-115 degs overlap torque is basically the result of cylinder pressure (dynamic compression) and leverage (stroke) plus the NUMBER OF POWER STROKES PER MINUTE (rpm) from the cylinders that are efficiently filled (volumetric efficiency). up to a certain rpm level the cylinders don,t efficiently fill due to low port air speed, above that level the valves and pistons move too fast to effectively fill the cylinders due to lack of time. your highest torque will be at the point where the engine spins the fastest it can while still packing the cylinders to the max efficiency. here read this info on cams http://www.newcovenant.com/speedcrafter/tech/camshaft/1.htm (lessons 1-8) then look at the chart to get a rough idea as to the duration necessary to fill the cylinders effectively . duration , lift and LSA are all a combo that must match compression, displacement, rod length to stroke ratio,port size and length,exhaust scavageing effectiveness, ETC. look here http://www.iskycams.com/ART/techinfo/ncrank1.pdf then look at your cam spec sheet, the piston compresses nothing untill the piston has reached the point where both valves are closed, from that point on your compressing the voluum in the cylinder. look at this cam http://www.compcams.com/information/search/CamDetails.asp?PartNumber=12-433-8 the pistons not compressing anything untill 77 degrees past BDC, looking at the other chart we see that the piston is about 2.4" down the bore on a 350 chevy not the 3.5 inches that the engines static compression in theory could compress heres the answer to a similar post that fits here very closely first is that the port can only flow when the valve is open......and THAT depends on the cam timing and displacement and rod to stroke ratio,.and .050 lift is a good place to judge or compare port flow from so you have some basis to compare from when looking into potential changes. next, the chevy v8 operates on a 720 degree repetative cycle of which ,if we measure from .050 lift we find ONLY about 200-250 of those 720 degrees are potentially flowing air thru the port or 28% to 35% of the time PORT SIZE FLOW AND THE RELATION TO CAM DURATION FIRST, This will not be anything more that a brief glimpse into a subject that takes years to understand fully and I’m sure there are a few people on the site that can give more exact info! This is meant to apply to the 350-383 sbc engines most of us are useing My purpose is merely to give an idea as to the relationship between the factors and yes IM ignoring several minor factors to make things easier to understand like dynamic compression and valve timing overlap But lets look a a few concepts (1) There are 720 degrees in a 4 cycle engines repetitive cycle of which between about 200degrees to about 250 degrees actually allow air to pass into the cylinder, (the valves open far enough to flow meaningful air flow) and the piston has a maximum ability to draw air into that cylinder based mostly on the engines displacement and the inertia of column of air in both the intake port and the suction (or negative pressure the PROPERLY designed headers provide) this produced a max air flow thru the ports, the greater the volume of fuel/air mix effectively burn per power stroke the greater the engines potential torque production, the faster you spin an engine the greater the NUMBER OF POWER STROKES PER MINUTE, and up to the point where the cylinder filling effectiveness starts falling off due to not enough time available to fill that cylinder the torque increases, above that rpm or peak torque it’s a race between more power stokes and lower power per stroke (2) look at this diagram (3) As air enters an engine it normally travels thru both an intake system and the cylinder heads intake port to eventually pass into the cylinder thru the valve. The valves in a normal small block corvette engine are between 1.94 and 2.08 in diameter, that’s between 2.9sq inches and 3.4 sq inches of area, but because the valves require a seat that at a minimum are about 85%-90% of that flow area we find that the intake port even with out any valve has a max flow of not more than about 90% of the flow thru a port of valve size. Or in this case 2.46 sq inches-2.9 sq inches of port area, Since you gain little if any flow having a port that’s substantially larger than the valves AT NORMAL ATMOSPHERIC pressures and since you can’t substantially increase the valve sizes for several mechanical reasons you must improve efficiency, this is done in two major ways, you can match the intake port length and cross sectional area to the engines most efficient rpm range on the intake side, to build a positive pressure behind the intake valve as it opens and match the exhaust length and diameter on the exhaust side to provide a negative pressure to help draw in more volume this will require the cam timing match that same rpm range of course. By experimentation its been found that air flow port speeds in the 200-320 cubic feet per minute range are about the best for a chevy V-8 now lets say you have a 383. 383/8=47.875 cubic inches per cylinder, the rpm range most used is 1500rpm-6000rpm so that’s where are cam and port size must match, you can do the math , (47.875 x ½ engine rpms = cubic inches, divided by your cams effective flow duration, (use 210-235) as a default for a stock cam) x 720 degrees/1728 (the number of cubic inches in a cubic foot) to get the theoretical max port flow required (I will save you the trouble its 250cfm-275cfm at max rpms and about 2.4-2.9 sq inches of port cross section, depending on where you want the torque peak, or use this handy calculator, Intake Runner Area = Cylinder Volume X Peak Torque RPM 88200 Or this helpful site http://www.newcovenant.com/speedcrafter/calculators/intake.htm Either way you’ll find that you’ll want a port size in the 2.4sq –2.9 sq inch area Now use this calculator to figure ideal port length, REMEMBER youll need to add the 6†in the cylinder head to the intake runner length to get the total length and you can,t exceed the engines REDLINE RPM which with hydrolic lifters seldom is higher than 6400rpm http://www.bgsoflex.com/intakeln.html Ever wonder why your engines torque curve gets higher with the engines rpm level until about 4000rpm-5500rpm(DEPENDING ON YOUR COMBO) but fades above that rpm level? well it depends on several factors, first as long as the cylinders can fill completely you get a good fuel/air burn so you get a good cylinder pressure curve against the piston each time the cylinder fires, THE ENGINES TORQUE CURVE INCREASES WITH THE NUMBER OF EFFECTIVE POWER STROKES PER SECOND, at very low speeds there’s not enough air velocity to mix the fuel correctly or produce a effective ram tuning effect but as the rpms increase the cylinders fill very efficiently until the rpms reach a point where the cylinders just don’t have the time necessary to flow enough air through the valves to fill the cylinders , remember a 5000rpm the intake valve out of 720 degs. in each cycle opens for about 250degs of effective flow even with a hot roller cam, now that’s only about 35% of the time and there’s 41.6 intake strokes per second , that’s only 1/60th of a second for air to flow into the cylinder Its your engines ability to fill the cylinders that increases your power and the more efficiently you do that the higher the rpm level you can accomplish that at the more power your engine makes, remember the formula for hp is (torque x rpm/ 5252=hp) so moving the torque curve higher in the rpm range increases hp but at some point the time available to fill the cylinders becomes so short that efficiency begins to drop off rapidly, the peak of efficiency is reached normally in the 4500rpm-5500rpm range, and as rpms increase its a race between more power strokes per minute trying to raise the power and the increasingly less effective percentage of cylinder filling dropping the power. Volumetric Efficiency The volumetric efficiency of a 4-stroke engine is the relationship between the quantity of intake air and the piston displacement. In other words, volumetric efficiency is the ratio between the charge that actually enters the cylinder and the amount that could enter under ideal conditions. Piston displacement is used since it is difficult to measure the amount of charge that would enter the cylinder under ideal conditions. An engine would have 100% volumetric efficiency if, at atmospheric pressure and normal temperature, an amount of air exactly equal to piston displacement could be drawn into the cylinder. This is not possible, except by supercharging, because the passages through which the air must flow offer a resistance, the force pushing the air into the cylinder is only atmospheric, and the air absorbs heat during the process. so, volumetric efficiency is determined by measuring (with an orifice or venturi type meter) the amount of air taken in by the engine, converting the amount to volume, and comparing this volume to the piston displacement. this increases until the torque peak then falls as the rpms increase. Here is a rough guide to match duration to port flow at different rpm level if you’ve been following along you’ll find that you’ll need intake ports about 2.3-2.9†sq inches in cross section, and between 12†and 21 “ long (DEPENDS ON WHERE THE ENGINE IS DESIGNED TO MAKE MAX HP) and cam timing in the 215@.050 to -240@.050 lift range, as the rpms or displacement increase either the port flow or the cams duration must increase or the engines cylinder fill efficiency rpm will drop! Now this is important, as the port flow efficiency goes up though the use of longer and larger intake ports the cam duration could remain the same or even be lower and you get more efficient cylinder filling as the rpms increase, that’s why high efficiency port designs like on the LS1 can use lower duration cams to flow similar total air flow thru the ports than the lower efficiency ports like the old fuelie heads could but at some point all ports reach max flow and an increase in the time the valves remain open at higher rpms increases the cylinder fill efficiency and that increases the engines ability to make torque at that rpm range if you pick a smaller runner or longer runner you should pick a cam with a shorter duration to match the resulting lower torque peak that will likely result Id like to point out something here! EXAMPLE (DYNO SHEET) LOOK CLOSELY AT THE TORQUE CURVE heres the combo SBC 407 · Block, 509, +30, Zero deck, Blanked water passages, Clearanced oil ways, Lifter valley vents, ARP main & head studs, Durabond cam & Clevite 77 main bearings. · Crank, Scat 4340 forged steel, 3.75â€, internal balance, Pioneer SFI balancer + ARP bolt. · Rods, Comp. Products 6.00†H beam bronze bushed + ARP bolts Clevite 77 bearings. · Pistons, SRP #4032 flat top, 5cc relief, Speed Pro plasma moly file fit rings. · Complete rotating assembly balanced. Including - Flywheel, Clutch, Balancer & Crank pulley. · Heads, AFR 210 Race Ready, 76cc, 2.080/1.600 valves, drilled for steam. FelPro #1014 gasket. · Cam, Comp. Cams ‘Magnum’ #12-450-8 (286HR) Hydraulic roller. 230/230 @ .050, .377 lift 110 LSA 106 ICL. · Pushrods, Howards Cams heavy wall 5/16†7.4†long. · Rockers, Pro Magnum roller, 1.6, 7/16†stud. · Lifters, Pro Magnum hydraulic roller. AFR Hydr-Rev kit. · Comp Cams Springs #950 + #740 retainers installed at 1.875†· AFR rev kit, AFR stud girdle. · Lube, Melling M99HVS pump, Canton 7qt 5 trap pan with inbuilt windage and scraper, Cooler, Accumulator, oil stat, remote filter. · Holley 800cfm #4780C, 1†spacer, Victor Jr single plane. · Static CR 10.32, Dynamic CR 7.9. · Quench 0.0415†(Gasket .039†+ .0025†down hole). · MSD Pro Billet Street Dizzy, MSD 6AL, MSD Blaster 2 coil, MSD 8,5mm leads. RPM BHP Torque 3800 367.3 507.7 3900 384.0 517.1 4000 395.1 518.8 4100 407.9 522.5 4200 418.9 523.8 4300 429.4 524.5 4400 439.6 524.7 4500 449.6 524.7 4600 462.1 527.6 4700 467.4 522.3 4800 476.6 521.5 4900 485.4 520.3 5000 489.2 513.9 5100 498.5 513.4 5200 496.0 501.0 5300 506.1 501.5 5400 508.4 494.5 5500 508.7 485.8 5600 505.6 474.2 5700 505.8 466.0 5800 505.8 458.0 5900 494.6 440.3 6000 491.9 430.6 Id like to point out something here to those of you who keep insisting that your required to run small ports sizes and dual plane intakes to make decent mid range torque look closely at what the combo uses Heads, AFR 210 Race Ready, 76cc, 2.080/1.600 valves, drilled for steam. FelPro #1014 gasket. · Cam, Comp. Cams ‘Magnum’ #12-450-8 (286HR) Hydraulic roller. 230/230 @ .050, .377 lift 110 LSA 106 ICL. Holley 800cfm #4780C, 1†spacer, Victor Jr single plane like IVE CONSTANTLY SAID, ITS THE CAM AND PROPERLY MATCHED COMPRESSION RATIO THAT HAS THE LARGEST EFFECT ON THE ENGINES TORQUE POTENTIAL, while its true that smaller ports can increase the volumetric efficiency at low rpms, they are not always required, and the tend to hurt the high rpm performance, you also don,t need a great deal of duration in the cam you pick,if the heads your useing flow decently, notice hes only running 230 @.050 lift LARGE ports matched to the correct compression ratio and cam can make very good torque. as always its the total combo OF PARTS and how the parts match the displacement and intended rpm range, NOT the result of a SINGLE PART choice!

heres an old post that may help well heres a almost fool proof method if you don,t know what your looking for, because it removes to some extent bad info on the correct cam to buy (1) first carefully write a list on every other part in your engine,combo, your to include engine size(DISPLACEMENT) compression ratio cylinder heads port size valve sizes chamber sizes header size rod length engine bore/stroke intake type carb or EFI flow (CFM) intended rpm range trans stall speed rear gearing car weight intended useage does it need to pass emmission testing do you want hydrolic or solid lifters flat tappet or roller what is the max lift the clearances in your engine will support, what will the valve springs and rockers have for clearances whats the engines intended max RPM level (2) call six to seven DIFFERANT CAM MANUFACTURERS (MINIMUM) and read them the EXACT SAME INFO (3) write down the info they give you as to lift, durration at .050 lift , degrees of overlap at .050 lift and LSA (4) average the results and buy the cam thats as close to that average as possiable now as a general rule youll want to almost always want to choose the lower durration and widder LSA that matches the intended use range heres some guide lines OVERLAP trucks/good mileage towing 10-35 degs overlap daily driven low rpm performance 30-55degs overlap hot street performance 50-75 degs overlap oval track racing 70-95degs overlap dragster/comp eliminator engines 90-115 degs overlap rpm ranges/durration [image]http://www.babcox.com/editorial/ar/elements/30228b.gif[/image] short answer, 110 LSA if its a engine used mostly at high RPM, 112 LSA if its street driven (need more info,..look below) read these lessons (#1-8) http://www.newcovenant.com/speedcrafter/tech/camshaft/3.htm The LSA, or lobe separation angle, is ground into the cam and cannot be changed. It is the angle that separates the intake and exhaust lobe for a particular cylinder, and is measured in camshaft degrees. The intake lobe centerline is measured in crankshaft degrees. The #1 intake lobe centerline is usually between 100° to 110° ATDC and is what you use to degree the cam. The cam manufacturer will publish the specs for the cam based on a given intake lobe centerline. Comp Cams, for instance, produces a large number of cams with 110*° LSA ground 4° advanced, so they list the specs for the cam with a 106° intake lobe centerline. You can calculate the ILC by adding the intake opening angle in °BTDC, the intake closing angle in °ABDC, plus 180° for the distance from TDC to BDC. Divide by 2 and subtract the intake opening angle and you will have the ILC. For example a 12-430-8 Comp Cam lists IO at 34°BTDC, IC at 66° ATDC, so 34 + 66 + 180 = 280. 280/2 = 140. 140 - 34 = 106° ILC [image]http://www.newcovenant.com/speedcrafter/tech/camshaft/images/twolobe.gif[/image] Figure 3 is a picture of both an intake and an exhaust lobe of a camshaft, seen end-on. It shows the relationship between the lobes, shows the overlap area, and illustrates this next section. As stated in lesson 2, overlap has a great deal to do with overall engine performance. Small overlap makes low-end torque but less high-end power. Large overlap reduces low-end torque but increases high-end power. Overlap is determined by two other cam specifications, Duration and Lobe Center Angle. Duration is the time, measured in crankshaft degrees, that a valve is open. A duration of 204 degrees means that while the valve is open, the crankshaft rotates through 204 degrees. Duration is measured on two "standards," "advertised duration" and "duration at 0.050"." Advertised duration is measured from when the valve just starts to lift off its seat to when it just touches the seat again. This is measured in different ways by different manufacturers. Some measure when the valve lifter is raised 0.004", some at 0.006", and some at different points yet. So the industry agreed to another standard that was supposed to make it easier to compare cams. In this standard, the duration is measured between the point where the lifter is raised by 0.050", and the point where it is lowered again to 0.050". The 0.050" standard is great for side-by-side "catalog" comparisons between cams. But if you use engine prediction software on your computer, the software is much more accurate when you can feed it "advertised" duration numbers. Lobe Center Angle is the distance in degrees between the centers of the lobes on the camshaft. To increase duration, cam makers grind the lobes wider on the base circle of the cam. This makes the lobes overlap each other more, increasing overlap. More duration = more overlap. To increase overlap without changing duration, cam makers will grind the lobes closer together, making a smaller lobe center angle. Less lobe center angle = more overlap. Overlap and duration are the two big factors in cam design. More overlap moves the power band up in the engine's RPM range. Longer duration keeps the valves open longer, so more air/fuel or exhaust can flow at higher speeds. It works out that increasing the duration of the camshaft by 10 degrees moves the engine's power band up by about 500 rpm. A smaller lobe separation increases overlap, so a smaller lobe separation angle causes the engine's torque to peak early in the power band. Torque builds rapidly, peaks out, then falls off quickly. More lobe separation causes torque to build more slowly and peak later, but it is spread more evenly over the power band. So a larger lobe separation angle creates a flatter torque curve. So you can see how a cam maker can tailor the camshaft specs to produce a particular power band in an engine-- Short duration with a wide separation angle might be best for towing, producing a strong, smooth low-end torque curve. Long duration with a short separation angle might be suited for high-rpm drag racing, with a high-end, sharp torque peak. Moderate duration with wide separation angle might be best suited for an all-around street performance engine, producing a longer, smoother torque band that can still breathe well at higher RPM. Remember, there's always a compromise made in this process. One last item to consider is the lobe centerline. The lobe centerline is the angle of the lobe's center peak, measured in crankshaft degrees when the piston is at Top Dead Center (TDC). In general (but not always), when a cam is installed "straight up," the intake lobe centerline and the lobe separation angle are the same. The lobe centerline can be altered when the camshaft is installed, by advancing or retarding the camshaft's position in relation to the crankshaft. Advancing the camshaft by 4 degrees will move the power band about 200 RPM lower in the RPM band. Retarding the cam by 4 degrees will likewise move the power band 200 RPM higher in the RPM band. This allows you to fine-tune the engine's performance according to your needs. personally I try to stay close to 110 degrees on most carb engines and 112 degrees on EFI engines because I value a wider torque curve more than a few hp only close to peak rpm if cams are a mystery please take the time to read these, it will get you a good start http://www.newcovenant.com/speedcrafter/tech/camshaft/1.htm (read LESSONs 1-8) http://www.rpmoutlet.com/camfac.htm http://www.symuli.com/vw/camp1.html http://www.symuli.com/vw/camp2.html http://www.wighat.com/fcr3/confusion.htm http://www.cranecams.com/instructions/valvetrain/camfail.htm http://www.idavette.net/hib/camcon.htm http://www.cranecams.com/master/adjustvt.htm http://www.centuryperformance.com/valveadjustment.htm http://www.totalengineairflow.com/tech/valvelashing.htm http://www.chevytalk.com/tech/engine/Cam_Selection.html http://www.chevytalk.com/tech/101/Cam_Theory.html http://www.babcox.com/editorial/ar/ar119736.htm http://www.mercurycapri.com/technical/engine/cam/vtg.html http://www.n2performance.com/lecture1.shtml http://home.wxs.nl/~meine119/tech/camqa.html BTW CRANE AND CROWER HAVE GIVEN EXCELLENT SERVICE AND PRODUCT QUALITY OVER THE YEARS

you want turbo info? this will get you started http://www.turbofast.com.au/javacalc.html http://www.racetep.com/size.html http://www.airflowresearch.com/ (articles)-(1000 HP 383 ci AFR 210 cc ) http://www.turbomustangs.com/turbotech/main.htm http://www.montygwilliams.com/ http://www.rbracing-rsr.com/compression.htm http://www.turbofast.com.au/TFcompB.html http://www.grapeaperacing.com/GrapeApeRacing/tech/turbochargers.pdf http://www.turbocharged.com/main.htm

there seems to be a HUGE mis-understanding about port size and how it potentially effects your engines torque range, port size should be thought of more as a restriction to reaching necessary flow than a benefit to making a significant torque curve PROVIDED your matching the total engine component list to the intended rpm range and expected hp peaks the engine will be expected to produce and run at! its not port size but the ports cross sectional area and length matched to the other components like the engines displacement,compression, cam timing and bore/stroke ratio PLUS the exhaust systems designed scavage effiecincy range at any give RPM level has a major effect on results, the size of the ports in your cylinder heads are one of the least> THATS RIGHT I SAID THE LEAST important of the factors that determine where in the rpm range your engine builds its best power, while its true that smaller port cross sectional areas due cause the airflow speeds to increase,its also very true that the runner length and cross sectional area of the intake used, the compression ratio and the cam timing and the design of the header primary tubes are at least two to three times as important simply because they control the airflow thru the cylinder to a much greater extent, and the engines stroke and total displacement are extremely important, changing JUST the displacement and cam timeing has a HUGE EFFECT on WHEN and HOW the airflow in the ports gets its vacuum signal and how the port responds to that change in pressure. you can build a torque monster engine with large ports in the cylinder heads, quiet easily if the other factors are carefully matched notice that the 180cc AFR heads which are known for torque production have basically the SAME cross sectional area as the TRICKFLOW 195 cc heads and that the differance between the AFR 180cc haeds and the 210cc heads is only approximatly a 6% increase in size so the true air flow thru a 210cc head will be only approximately 6% slower on the same engine.........swap to a 383 from a 350 which is approximately 8% larger and you quickly see where the smaller heads can become more of a restriction than a benefit to the combo! know I know from experiance building engines for years that a rought guide to matching hp to the intended engine port flow requirements can be guessed at fairly closely useing these formulas below, play with them then measure the port cross sectional area in your engine at its narrow point, and don,t forget the cam lift your restricted too and the valves curtain areas in the combustion chambers "Fortunately for our purposes, these complex calculations can be broken down into a very simple formula that is useful for us as speed crafters. Intake Runner Area = Cylinder Volume X Peak Torque RPM 88200 This formula takes into account the best theoretical speed that air can move down the runners, to give the best volumetric efficiency. Peak Torque occurs in an engine at the RPM where the engine is enjoying its highest volumetric efficiency. " below youll find some things to read/play with http://www.n2performance.com/lectures/airflow.pdf http://www.rbracing-rsr.com/runnertorquecalc.html heres a chart FROM THE BOOK,HOW TO BUILD BIG-INCH CHEVY SMALL BLOCKS with some comon cross sectional port sizes (measured at the smallest part of the ports) ...........................sq inches........port cc edelbrock performer rpm ....1.43.............170 vortec......................1.66.............170 tfs195......................1.93.............195 afr 180.....................1.93.............180 afr 195.....................1.98.............195 afr 210.....................2.05.............210 dart pro 200................2.06.............200 dart pro 215................2.14.............215 brodix track 1 .............2.30.............221 dart pro 1 230..............2.40.............230 edelbrock 23 high port .....2.53.............238 edelbrock 18 deg............2.71.............266 tfs 18 deg..................2.80.............250 Potential HP based on Airflow (Hot Rod, Jun '99, p74): Airflow at 28" of water x 0.257 x number of cylinders = potential HP or required airflow based on HP: HP / 0.257 / cylinders = required airflow NO!ITS NOT FOOLPROOF! BUT ITS A VERY GOOD TOOL! what tends to make me crazy is guys that insist on running vortec or similar small port heads and a dual plane intake for max low rpm torque, when I or someone elsae builds thier engine,who then come back and want thier 383-421 sbc to run the big hp/tq numbers and pull hard at 6000rpm and above where those small ports are far past there effective air flow limits Ive built some KILLER engines useing the 215cc and 230cc IRON EAGLE heads and SIMILAR larger port heads that made great torque in the low and mid ranges, a dual plane intake,with long runners and a 600cfm-750cfm carb helps, as does a cam thats designed for the midrange torque, and full length headers , with 1 5/8" primairies,its NOT the port size in the cylinder heads ALONE that determines the results! its the COMPLETE MATCHED COMBO and the thought that was put into makeing the components match the intended power curve, and matching the cars rear gear and stall speed to that power curve, sure you might be running slightly higher average rpms, to get the best power ,but youll be making a whole lot more power at the rear wheels too! if you want to get good mileage and decent torque and limit yourself to 1500rpm-3500rpm the small port vortec type heads work great on a 350,thats what G.M. spent the money researching the design to do! ,they are after all TRUCK HEADS! but increase the displacement to 383 or more and spin the engine to 6500rpm and they become a huge restriction! while a larger head can give up very little if anything down low in the rpm range but pull far bigger numbers on the hp/tq up higher in the rpm range simply because its still able to flow the necessary voluum of air the engine needs, G.M. knows that! but they also know that 90% plus of the time EMISSIONS and GAS MILEAGE and smooth just off idle low rpm torque is where most engines are used, so they build to fit MOST users expectations http://www.rbracing-rsr.com/runnertorquecalc.html play with the calculator,, notice the vortec heads 1.66 are would peak the torque at about 3100rpm on a 383, while a dart 215 cc with its 2.14 port only moves it up to about 3950 rpm AND THATS ASSUMING the larger port head has a matching larger intake runner the whole way to the carb venturies, if you stuck the same intake and other mathing components on BOTH cylinder heads the differance in rpm ranges would be more likely to be in the 300rpm range EXAMPLE http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33615&item=7965364790&rd=1 BTW notice the 215cc heads and the strong torque curve????? its fairly obvious from the dyno chart this combo is UNDER CAMMED to make good low rpm tq at the sacrifice of potential top rpm power, power/tq starts to fall off at about 3700rpm,while thats a good idea in a street engine, you could pick up some mid and top rpm power by swapping to a slightly wilder durration cam PROVIDED THE REST OF YOUR COMBO, like the trans stall speed and rear gear allow it just some info a 10.3:1 cpr 383 with 215cc alunminum heads if its matched to a 3000rpm stall converter and 3.73-4.56 rear gears makes a really nice power curve with a cam similar to the CRANE 114681 or lunati voodoo 60104 or for that matter most cams with a 235-245 intake duration and about a .510 or greater lift on a 110-112 LSA swapping to a cam like that would boost power significantly (40-50hp)_but also make it less street driver friendly in that it would require the drivetrain changes above ans sound like a race engine at idle and would be unlikely to pass emmission testing "Is there any problems with an “under cammed “ engine? " no! not if low and mid range torque and NOT peak horsepower is the goal.....but Id like to point out again that the 215cc ports size makes very good low an mid range rpm torque if the compression and cam used are designed for very good low an mid range rpm torque, the comon crap you always hear about port size being very critical to low rpm torque is just that ( mostly CRAP), its just not as important as displacement, compression or cam timing to the results and small cross section ports restrict high rpm power far more than large ports hurt low rpm torque IF THE OTHER COMPONENTS in the combo are DESIGNED to produce mid range tq/power EXAMPLE heres a 427 sbc with 227cc port heads, that does not seem to be losing a great deal of low rpm torque do to its large ports

http://purplesagetradingpost.com/sumner/techinfo/350%20chevy%20engine.html you might want to look at this for ideas on a much cheaper engine build up keep in mind its the heads,cam and displacement that are the major keys to power, and ANYONE thinking about building thier first engine really should get these books and read them before going any further, it will help a good deal, while only the basic info is presented it still makes for a good knowledge base, and referance DO YOURSELF A HUGE FAVOR buy these books, FIRST it will be the best money you ever spent, read them, and you will be miles ahead of the average guy. youll save thousands of dollars and thousands of hours once youve got a good basic understanding of what your trying to do! http://www.amazon.com/exec/obidos/tg/det...F8&v=glance http://www.amazon.com/exec/obidos/tg/det...nce&s=books HOW TO BUILD THE SMALL BLOCK CHEVEROLET by LARRY ATHERTON&LARRY SCHREIB http://www.amazon.com/exec/obidos/tg/det...2699400-6836852 . HOW TO BUILD MAX PERFORMANCE CHEVY SMALL BLOCKS ON A BUDGET by DAVID VIZARD . JOHN LINGENFELTER on modifying small-block chevy engines

most STOCK PRODUCTION FIRST GEN.sbc corvette oil pans fall in the 6.5"-7.5" depth range I own 3 corvettes currently and all three fall in that range and all the oil pans from my former vettes also fall in that range on all my current corvettes the sump can easily be extended to within 3" of the front edge at the full sump depth with zero clearance problems as the front 2" is only close to the (K) frame

http://store.summitracing.com/default.asp?Ntt=ls1+intake&Ntk=KeywordSearch&DDS=1&searchinresults=false&N=0&target=egnsearch.asp&x=44&y=14 EDL-7118 $699

can you post pictures and specs?? prices,general info? if its a good deal I may be able to let a few thousand guys on the five performance sites I moderate know about it for you

I got EMAILED asking how and why swaping gear ratios works and why if your using the same engine does it even matter? well, thats a reasonable question if your not up on the basics of how it works so Ill try and explain it in basic terms first you need to under stand that the rear gear ratio and the transmission work as a combined team to provide the transfer of rotary force from the engine to the pavement. first you need to understand that horsepower is simply a mathematical way to express the RATE at which TORQUE is available and applied and torque is basically the force in the cylinders thats trannsfered to the crankshaft thru the connecting rods and the leverage in the cranks throw TIMES the NUMBER of POWER STROKES PER SECOND and that the current design of auto engines make thier best power over a narrow rpm range, usually in the 4000-6000rpm range, below that rpm range theres just not quite as effective of cylinder filling and torque is still building, since theres less power strokes per second theres less total torque,and above the engines power band,efficiency falls off rapidly after the 4000rpm-6000rpm zone,(depends on components used) so the KEY is both KEEPING the engine IN that effective torque production range and having the most power strokes applied to the pavement thru the drive train. example a 3.07 rear gear allows the engine to spin 3.07 times in direct drive or top gear in a NON-OVERDRIVE type trans but in first gear,which could have a 2.52 first gear ratio like a TH 350 http://www.oldengine.org/unfaq/leadfoot/trans.htm we see it has a 2.52 too 1 ratio in first gear with that 3.07 rear gear we effectively have a 7.74 :1 ratio so if the tires turn over once the engine has spun over and applied approximately 7.75 times in low gear,swap to a 4.11 rear and youve just increased the number of power strokes applied to 10.35 timesor 34% more torque avalible at the rear wheels, from the same engine the down side is that the engine runs above its effective rpm range at a lower top speed and gets less efficient mileage http://users.erols.com/dmapes/GEARCLC.HTM http://users.erols.com/srweiss/calcmph.htm below is a closely related post/thread we have all heard it, " you need massive low rpm tq" "you need a screaming high rpm hp peak" well heres some info, More in-depth description: http://www.revsearch.com/dynamometer/torque_vs_horsepower.html http://www.dynacam.com/Product/Torque_vs__Horsepower/torque_vs__horsepower.html http://vettenet.org/torquehp.html http://auto.howstuffworks.com/horsepower4.htm http://homepage.mac.com/dgiessel/engine/hpvstq.html first thing to keep in mind is that theres no such "thing" as horsepower, horsepower is a mathmatical formula for the RATE at which TORQUE can be applied the formula for hp is (tq x rpm/5252=hp example 450 ft lbs of torque at 3000rpm=257hp 450 ft lbs of torque at 6000rpm=514hp because the torque at the higher rpm useing gearing can be applied faster here read this http://www.69mustang.com/hp_torque.htm http://www.ubermensch.org/Cars/Technical/hp-tq/ http://vette.ohioracing.com/hp.html where most guys go wrong is in not correctly matching the cars stall speed and gearing to the cars tq curve, if you mod the engine for increased high rpm performance but fail to also match the stall speed and gearing to that higher rpm tq curve much of the potential improvement is wasted. example in the close to stock engine above, the engine should be geared to stay in the 3500rpm-5000rpm range for max acceleration (lower in the rpm range if mileage is a big factor) in the moded engine above the rpm range moved to 4000rpm-6500rpm requireing differant rear gears and slightly higher stall speeds to gain max acceleration in the same car, you should readily see that a trans that shifts at 5000rpm will work in the first example but would waste most of the power curve in the second example,where shifting at 6500rpm under full power acelleration would make more sence. a 3.08 rear gear and 700r4 trans matches the first example well but it would take a swap to a 3.73-4.11 gear to allow the engine in the second example to keep its most effective power band matching that second power curve well. links youll need to figure out correct rear gear ratios http://www.miata.net/garage/tirecalc.html http://www.wallaceracing.com/reargear.htm http://users.erols.com/srweiss/calcmph.htm http://users.erols.com/srweiss/calcrpm.htm http://users.erols.com/srweiss/calcrgr.htm http://www.prestage.com/Car+Math/Ge...io/default.aspx http://www.geocities.com/z28esser/speed.html http://server3003.freeyellow.com/gparts/speedo.htm http://www.pontiacracing.net/trannyratios.htm http://www.tciauto.com/tech_info/gear_ratios.htm

http://www.team.net/sol/tech/octane_b.html http://www.gnttype.org/techarea/misc/octanebooster.html http://www.elektro.com/~audi/audi/toluene.html http://www.turbofast.com.au/racefuel8.html http://www.sdsefi.com/techocta.htm this should help