grumpyvette

you did not state the LSA its ground on, that makes a huge differance but assuming a 112 LSA youll get about 438hp/470tq acording to my computers wild guess which is about perfect for your gearing to have lots of fun, don,t get hung up on what you might think is low hp, computers only see TRENDS not DYNO NUMBERS , that cam looks about ideal on the street,

(1)take the passangers side valve cover off amd rotate it 180 degrees so the top edge is now the lower edge and reinstall it with the pvc valve hook -up connection in the further forward position (2)while you have the valve cover off check to make sure the oil drain back holes in the rear of the cylinder head are clear and free flowing (3) if both things don,t fix it you have a restricted oil drain back, YES YOU NEED TO FIX IT! TEMP BAND-AID FIX SWAP TO HIGHER TALL VALVE COVERS, and INSTALL THE PCV valve CONNECTION about 2-3" back from the front of the valve cover OR DO WHAT MOST GUYS DO, use this type and hook the pvc to the center tube after weldini in a conection and yes before you say anything , yes your likely to need to weld these connections up (CUSTOM WORK) on TALL CENTER BOLT VALVE COVERS for an LT1 engine, and yes Im well aware that the brakets over the drivers side valve cover will also need to be cut and rewelded for greater clearance that hold the accessories on the drivers side valve cover area, (YES IT HAS BEEN DONE)

I was asked what other sites might have engine info? heres a few corvette/chevy sites that might give you needed info http://crossedflags.com/community/index.php http://vetteamerica.com/ http://www.corvetteforum.com/ http://www.chevytalk.org/threads/ubbthreads.php http://www.chevelles.com/ http://www.camaros.net/cgi-bin/forum/ultimatebb.cgi http://www.thirdgen.org/ http://www.crossfire.homeip.net:81/cftest/startdefault.asp http://web.camaross.com/forums/ http://www.corvetteactioncenter.com/

having done similar mods and having dynoed the results (HERES A SIMILAR DYNO RUN) I can tell you that the results will be a loss in low rpm torque, below 5000rpm where your engine spends 90% of its time and a loss in volumetric cylinder filling efficiency below 5000rpm and a slight gain in hp over about 5000rpm due to the shorter runner length lower restriction to the air flow, (stock the TPI flows about 190cfm) http://www.eecis.udel.edu/~davis/z28/winter01/dyno/dyno010511/webpage010511.html notice the loss of 60 ft lbs of torque and the gain of only 10 hp! look 1/2 way down the page at the chart now what would help would be porting just the upper 3 inches of the siamesed SLP runners and the PLENUM and useing an EDLEBROCK base with its bigger port size and straiter runners. look the stock TPI has runners 15" long with about 3 more inches of runner in the cylinder heads , for a total of 18" of runner length, with that length runner both the 3rd and 4th harmonic wave help fill the cylinder WITHIN the ENGINES RPM RANGE http://www.bgsoflex.com/cgi-bin/intakeln?length=18 BUT shorten the runner length to about 6" like you did by in effect extending the plenum volume down into the base of the intake bye making the runners for all intents just an extention of the plenum and you get this result http://www.bgsoflex.com/cgi-bin/intakeln?length=6 all the benefits of intake harmonics WELL ABOVE THE RPM RANGE OF THE ENGINE but look what just shortening the runners by 3" does http://www.bgsoflex.com/cgi-bin/intakeln?length=15 now Im not saying you won,t get a gain in high rpms, but your low and mid range will cancel most of the gains the HOLLEY STEALTH RAM has MUCH BETTER air flow (about 300cfm) and a cross sectional area that greatly improves the air flow at higher rpms and RUNNERS that are effectively about 11-12 inchs long measured from plenum roof to the back of the intake valve http://www.bgsoflex.com/cgi-bin/intakeln?length=11 http://www.bgsoflex.com/cgi-bin/intakeln?length=12

pparaska THE RPM LEVELS EFFECTIVE RANGE DROPS ABOUT 500-700RPM WHEN CHANGING FROM A 350 TO A 406 DISPLACEMENT THERES LITTLE CHANGE IN FLOW SWAPPING FROM THE 190CC-TO-195CC HEADS CERTAINLY NOT ENOUGHT TO WORRY ABOUT.

Ok I get lots of questions on how to build a good street engine and how to find and match the correct parts, now Im going to be refering to your average hot street combos built on a budget with easily available parts. first the math (1)youll be limited to about 1.2 hp per cid on engine size (2) YOULL BE LIMITER to about 6400rpm with HYDROLIC flat tappet cams and about 7500rpm with SOLID LIFTER flat tappet cams (3)piston speeds that exceed 4000fpm usually lead to trouble (4)dynamic compression ratios of over about 8.3:1-8.5:1 with aluminum heads or about 7.8:1-8:1 with iron heads can cause detonation problems, but keep in mind only the dynamic compression matters not the static, because the engine only sees the dynamic cpr.try to get your dynamic compression as high as you can while still getting a cam wild enought to easily reach the rpm levels you need to to make good hp. (5) theres little to no possiable benefit to useing a cam that makes power above 6000rpm if your transmission ALWAYS shifts at 5300rpm and your geared so that youll be running 130mph before getting in high gear http://cochise.uia.net/pkelley2/ (5)the formula for matching POTENTIAL HP to INTAKE PORT FLOW is (.257 x port flow at max cam lift x 8(3 of CYLINDERs)= POTENTIAL hp (6) look closely at the duration used for each MATCHING rpm range. ALSO KEEP IN MIND THE DCR AND OVERLAP MUST MATCH 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 but all engines will need the correct matching dcr for those overlap figures to correctly scavage the cylinders in the rpm ranges that apply to each engines use range OK now lets follow the rules and build an engine suitable for the average street strip car and lets set the goals at pushing a 3400 lb car to 12.5 seconds in the 1/4 mile with a 3.08 rear gear, and TH350 (JUST TO SCREW THINGS UP BECAUSE USEING A 4.11 RATIO MAKES THINGS TO EASY) 26.5" tires and an auto transmission to simulate an average late 70s car. well the first thing we are going to need to know is how much hp /tq will we need useing this quick guide http://users.erols.com/srweiss/calchpm.htm http://www.prestage.com/carmath/calc_ETMPH.asp http://users.erols.com/srweiss/calcrpm.htm we find that we need about 375 rear wheel hp or 469 flywheel hp to easily run very low 12s those 3.08 rear gears and 26.5" tires we will only be spinning about 4900rpm in the lights so well need an engine with lots of mid range tq, the 469 flywheel hp says we will require heads that flow at least about 230-240 cfm at about .48-.499 lift if we figure that we must build a hydrolic cammed torque monster that has very high intake port speeds for good volumetric efficiency in the mid rpm ranges to get the tq curve correct for those crappy 3.08 rear gears, the cam rpm chart shows we will need a cam in the 230@.050 duration range with about a 50-75 degree overlap and we need about 390-406 cid mimimum to get 469hp, REMEMBER WE ARE ONLY SPINNING 4900rpm in the lights so an engine that makes most of its hp at far higher rpms is a waste, that combined with the low rpm range would make a 383-406 the first choices here. http://www.prestage.com/carmath/calc_gears.asp]http://www.prestage.com/carmath/calc_gears.asp so what we wind up with is a 406 with a 10.5:1 static compression, a comp cams #12-246-3 cam with 190cc AFR heads as the smallest port heads that flow enough air at that low duration http://users.erols.com/srweiss/calchpaf.htm http://www.compcams.com/information/search/CamDetails.asp?PartNumber=12-246-3 http://www.compcams.com/information/search/CamDetails.asp?PartNumber=12-246-3 open headers 1 5/8" full length,at the track, an 850 carb and a dual plane intake. a 3000rpm stall speed, shifts at about 5500rpm now theres other combos and ways of getting there but you get the idea about how the parts should all be working towards the goal and within the restrictions , drop a cam like the crane cams #114681 and your hp goes up but above the rpm range that you ideally need it in altho the results are still good, a 3.73-4.11 rear gear would make the change to the solid lifter crane cam a far better choice

read. it will help, first thing to do is buy these FIVE books, it will be the best money you ever spent, read them, and you will be miles ahead of the average guy. HOW TO BUILD THE SMALL BLOCK CHEVEROLET by LARRY ATHERTON&LARRY SCHREIB . HOW TO BUILD MAX PERFORMANCE CHEVY SMALL BLOCKS ON A BUDGET by DAVID VIZARD . JOHN LINGENFELTER on modifying small-block chevy engines how to build & modify CHEVROLET small-block V-8 CAMSHAFTS & VALVTRAINS BY DAVID VIZARD SMOKEY YUNICK,S POWER SECRETS http://www.sa-motorsports.com/blockdiy/blkdiy.htm http://www.hardblok.com/info.html http://www.findarticles.com/cf_0/m1...Bchamber+design http://www.speedomotive.com/building%20tips.htm http://www.se-r.net/engine/block_prep.html http://racerhelp.com/article_racing-10.html

Id highly advise useing CRANE or CROWER cams as first choices BECAUSE they work with you, and stand behind their produces , better than some other co. Ive dealt with. I won,t name the guys Ive had problems with but they are not CRANE CROWER ULTARDYNE LUNATI ERSON ISKI summit cams are very similar to MELLING http://www.melling.com/production1.htm

http://www.iskycams.com/ART/techinfo/ncrank1.pdf heres that chart look at a cam spec card EXAMPLE http://dab7.cranecams.com/SpecCard/DisplayCatalogCard.asp?PN=114681&B1=Display+Card compare the piston position to the valve opening point, youll notice the piston is already on its way upward compressing at least in theory the cylinders volume, now think about this!...... if the piston does not start compressing ANYTHING on a 383 for example with its 3.75" stroke untill the piston is lets say 3.2" from TDC your effective stroke is 3.2" x 4.03" for an EFFECTIVE displacement of 326.5 cid, your trading MORE effective cylinder filling at higher rpms for slightly lower effective displacement knowing that because the formula for hp is (tq x rpm/5252=hp) that even though the tq drops the hp goes up! EXAMPLE look lets say you had 400 ft lbs at 1500rpm with a very mild cam and the hot cam had exactly the same tq per ci of displacement at 5000rpm 383/400 X326.5=340ft lbs 400 x 1500/5252=114hp 340 x 5000/5252=323hp why does that matter? READ THIS http://www.69mustang.com/hp_torque.htm http://victorylibrary.com/mopar/cam-tech-c.htm

perhaps I failed to explain the answer well enough. you MUST KEEP THE CORRECT QUENCH DISTANCE (.037-.042) REGAURDLESS OF STATIC COMPRESSION RATIO ONCE YOU GO ABOVE ABOUT 9:1 STATIC COMPRESSION,OR YOU ENGINE CAN RUN INTO DETONATION PROBLEMS THE ENGINE ONLY SEES DYNAMIC COMPRESSION NOT STATIC COMPRESSION that will depend on the cam your useing, look at these diagrams and keep in mind that the piston compresses NOTHING untill both valves are closed you don,t need to lower your STATIC COMPRESSION , what you need to do is lower your DYNAMIC COMPRESSION RATIO, a cam with a wider LSA or a cam with slightly greater duration or both will do that for you[/b]]here read this http://www.mercurycapri.com/technical/engine/cam/lca.html http://www.mercurycapri.com/technical/engine/cam/lca.html http://ourworld.compuserve.com/homepages/axelg/cams.htm'>http://ourworld.compuserve.com/homepages/axelg/cams.htm http://ourworld.compuserve.com/homepages/axelg/cams http://tru-442.tripod.com/camselect.htm http://tru-442.tripod.com/camselect.htm http://victorylibrary.com/mopar/cam-tech-c.htm http://victorylibrary.com/mopar/cam-tech-c.htm read this info http://www.newcovenant.com/speedcrafter/tech/camshaft/1.htm http://www.newcovenant.com/speedcrafter/tech/camshaft/1.htm >lessons 1-8 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 but all engines will need the correct matching dcr for those overlap figures to correctly scavage the cylinders in the rpm ranges that apply to each engines use range.<BR> DCR and overlap are related but not directly related. However, both must be correct for the best performance. Overlap, which is determined by the advertised duration and the lobe separation angle (LSA), has a profound effect on idle characteristics and high speed scavaging. I believe it was Ed Iskenderian that said we don't have a 4 stroke-4 cycle engine, we have a 4 stroke-5 cycle engine, with overlap being the 5th cycle. It is that important. Use the list posted to help select the proper overlap. BTW, I include bracket cars in the "oval track racing 70-95degs overlap" catagory. DCR is affected by the same advertised duration and LSA that overlap is. However, another cam factor enters into the equation, the installed "intake lobe centerline." This is how far the intake lobe centerline is offset from the LSA. If they are the same, then the cam is said to be installed "straight up" (say a 108º LSA cam installed with the intake lobe centerline at 108º ATDC). If they are different, then the cam is said to be advanced or retarded. Advancing or retarding the cam changes the cam timing in relation to the crankshaft. Nothing on the cam changes, just the relationship of the cam to the crankshaft. Getting back to DCR, advancing the cam causes the intake valve to close earlier than it would if the cam were straight up. When this happens, the piston is lower in the cylinder at intake valve closing increasing the sweep of the piston in the cylinder causing the DCR to be higher. Retarding the cam decreases the DCR for the same reason, namely the piston is now higher in the cylinder at intake closing since the intake valve closes later. Changing overlap requires either changing the advertised duration or the LSA or both (both are ground into the cam and cannot be changed once the cam is made). Tightening up the LSA (say from 110 to 108º) without changing the adv dur increases the overlap. If the same amount of cam advance is maintained (say 4º), the DCR will increase. If the intake lobe center is maintained in the same location (say 106º, which is 4º advanced for a 110º LSA and 2º for a 108º cam), the DCR will not change (changing duration while maintaing the same LSA has a similar effect). So you could have a number of cams with a varity of different LSAs, durations, and overlap values yet all could have the same DCR. Overlap and DCR are related but, as I said above, not directly related. first look at this simplifyied example<the V-8 is near the bottom of the page the A pushrod engine diagram http://www.howstuffworks.com/camshaft2.htm http://www.howstuffworks.com/camshaft2.htm now in that example if you carefully watch the valves they have no overlap as one closes before the other opens but in the real world the exhaust valve is still open altho closeing when the intake valve starts to open, here read this http://www.newcovenant.com/speedcrafter/tech/camshaft/2.htm http://www.newcovenant.com/speedcrafter/tech/camshaft/2.htm http://www.newcovenant.com/speedcrafter/tech/camshaft/3.htm" http://www.newcovenant.com/speedcrafter/tech/camshaft/3.htm http://www.newcovenant.com/speedcrafter/tech/camshaft/4.htm http://www.newcovenant.com/speedcrafter/tech/camshaft/4.htm now notice in the diagram below how the exhaust valve is still closeing as the intake is opening , this allows the fast moveing exhaust gases that have alread left the cylinder to DRAG the intake chager into the cylinder by negitive pressure (SUCKING THE INTAKE CHARGE INTO THE CYLINDER AS IT TRIES TO FOLLOW THE EXHAUST OUT THE EXHAUST PORT)<BR> now the closer or tighter spaced the valve angles are (LSA)like 104-108 the more the valves timeing that they are both open <B>OVERLAPS</B> and the greater the amount of suction from intake port caused bye that fast exiting exhaust gas can occure but keep in mind that the piston starts back up and as it compresses the fuel/air mix in the cylinder the mixture can,t compress untill both the valves are closed, if the intake remains open to long the intake port has a bunch of the cylinders volume pushed back into the intake port causeing a reversion pressure wave, if the exhaust stays open to long excess fuel air mix flows through the cylinder and follows the exhaust into the headers. not only does the cylinders displacement and cam timeing have an effect here but also the rpm level that the engine is spinning at, that one big reason that "hot racing style cams have that lope sound at idle" the low rpm cylinder mixture is poor because the valve timeing is very efficient at lets say 5000rpm- 7000rpm due to longer durration that allows the cylinders to effectively fill in the 1/42nd-1/58th of a second the cylinders have available to fill at those rpm levels but its allowing much of the fuel/air mix to push back into the intake ports at low rpms where the mixture has time to reveres direction as the piston starts back up at low rpms<p in your case changing to a slightly higher duration cam will cure your high dynamic compression for EXAMPLE SWAPPING TO A CAM LIKE THE CRANE 114681 http://dab7.cranecams.com/SpecCard/DisplayCatalogCard.asp?PN=114681&B1=Display+Card drops the DYNAMIC COMPRESSION DOWN TO ABOUT 8.1:1 well under detenation range with 92 octane gas

7cc valve reliefs 59.2 cc heads if your blocks not decked youll have close to a .025 below deck piston figure on a .018-.022 head gasket to get the quench correct, that gives you a 11.0-11.2 static compression the cam drops this to about 8.5-8.7 dcr the computer makes its WILD GUESS AT 444hp/466tq BTW YOULL MOST LIKELY NEED A TOUCH OF OCTANE BOOSTER, with that dcr, if you go thicker on the head gasket to drop compression slightly your very likely to INCREASE the ENGINES chances of DETONATING as the slight drop in compression will NOT offset the loss in effective quench. in a light weight (Z) that should be good for close to 11.6 et @ 115mph http://www.gnttype.org/techarea/misc/octanebooster.html SCE Gaskets, Inc. makes a .021 copper gaskets NO THEY ARE NOT ALWAYS LISTED BUT THEY ARE NORMALLY SOMETHING YOU CAN SPECIAL ORDER http://www.babcox.com/editorial/ar/eb70228.htm

get the G.M. crate engine and add a good cam and intake suggestions, (im assumeing its a flat tappet hydrolic cam engine) performer RPM air gap intake http://www.crower.com/misc/cam_spec/cam_finder.php?part_num=00230&x=45&y=11 http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=1234&prmenbr=361 cam works well in that engine with either auto or manual trans

well I see you took my advise and asked DOUG FLYNN, BTW for those that don,t get around much the answer is the HOLLEY 20 degree heads use stock 23 degree valve train parts

ask your question here http://www.chevytalk.org/threads/postlist.php?Cat=&Board=UBB12 DOUG FLYNN who runs this forum,is one of HOLLEYS engineers and has access to all info you need

I bet if you kick the timing up to about 38 degrees all in by 3000rpm and jet the carb to about 13:1 youll pull much better #s check the valve lash/ preload adjustment is correct,and make sure the cam is indexed correctly It sounds like either the cam timing,ignition timing and carb fuel/air mix are not correct or mabe even all of them or out of spec. a restricted exhaust will also kill hp really fast so check that also!

heres a simple way to get close to the correct length BUY ONE OF THESE http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=3567&prmenbr=361 after making sure the valve springs are correctly installed you drop the checker in place on the rocker stud and install your adjustable pushrod adjust the length to fit and measure the resulting length if its within twenty thousands of the stock length its fine for most applications, if its more than 30 thousands long or short get the closest length set available [color:"red"] btw, if your one of the people that still does not own an adjustable push rod! you can easily make your own by cutting a stock pushrod in 1/2 (2 pieces), removeing 1 inch from the total length an then with about 2 " of a 4 inch section of 3/16 or 1/4" thread rod installed and (in one section epoxy it in place leaving about 2" sticking out thread two nuts onto the thread rod and slip on the other end of the cut pushrod,(no epoxy) use the two nuts to adjust to stock length and let the epoxy harded in the one section[/color] now you can easily measure and order custom push rods useing the pushrod checker and adjustable push rod as tools AND YEAH IT ONLY WORKS WITH THE CYLINDER HEADS ON AND THE INTAKE REMOVED BECAUSE THE HOLE IN THE CYLINDER HEAD that GUIDEs THE PUSH ROD WON,T ALLOW THE NUTS ON THE ADJUSTABLE PUSHROD TO PASS THRU, UNLESS YOU PLACE THE CUT ABOUT 1" from the UPPER END OF THE ADJUSTABLE TEST PUSHROD [color:"red"] BUT I prefer to place the adjusting nuts centered as I like to watch for all clearances with the intake manifold removed while manually checking as I turn the engine over by hand durring assembly, and at that point, while checking all the clearances, I use test springs which apply very little load on the push rod[/color] http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=3272&prmenbr=361 HERES OTHER TOOLS YOU MIGHT NEED SOMETHING TO READ http://www.compcams.com/information/Products/Pushrods/ CCA-7705 5.800 in. to 9.800 in. adjustment range, Master pushrod length checker 4 piece kit ... $78.69 here

BTW FOR THOSE OF YOU WHO DON,T KNOW WHAT WE ARE TALKING ABOUT! ok after looking into this for several years heres what Ive found <b> ITS NOT AN EXACT SCIENCE but..YOU CAN GET CLOSE ON YOUR EDUCATED ESTIMATES and YES IM LEAVING A BUNCH OF STUFF LIKE FLAME FRONTS,IGNITION TIMEING,PRESSURE PEAKS, ROD LENGTH,ETC> out of this discussion</b> (1) volumetric efficiency filling the cylinders and the resulting pressure pulse pushing the piston down into the cylinder, if graphed follows the engines torque curve graph extremely closely, or put another way the efficiency of the cylinders filling and scavaging increases with the rpm level untill a point where theres just not enough <b>TIME to effectively fill the cylinders,</b once that rpm level is reached the TORQUE peaks and altho the total HP may continue to climb for awhile because the NUMBER OF LESS EFFICIENT power stroke increases per second the effectiveness of each individual power stroke effectively falls in power as the cylinder filling time and cylinder burn time gets lower (2) the pressure produced in the cylinder that depends on the cam timing and RPM level exserts pressure for only about 20-24 degrees of the 720 degrees in the 4-stroke engines repeating cycle and the EFFECTIVE cam timing (VALVES FLOWING AIR)filling the cylinders is limited to about 250 degrees with even a hot cam (less with a stock cam) (3) displacement and cam timeing plus compression ratio and rod to stroke ratio have an effect on where and when in the intake stroke the max flow rate happends in the port. (4) now lets look at port size and engine displacement, lets say you have a 350 chevy with a cam that effective flow is in the 230 degree range, (that would be about a 250 degree cam) look here, we see the average 250 degree cam is most efficient at about 5200rpm so taking a 350 displacement/8= 43.75cid per cylinder, at a max piston speed of 4000 fpm .at 5200 rpm thats 43.3 intake strokes per second, at the probable max engine speed of 6857 rpm thats 57 intake strokes a second thats 1899cid of air at 5200rpm and potential 2493 cid of air at 6857 rpm but remember the valves only effectively open 230 degrees or 32% of the time so the port needs to potentially flow between 5935cid and 7790 cid of air per second, thats between 5935cid and 7790cid flowing past the valve through a port, the calculator say a 2.6sq inch port is the correct size at that displacement and rpm level, now 5935 cid of air flowing past a port 2.6 sq inchs in size is moving at 190cfps (cubic feet per second), at 6875 its moveing at 325 cfps but theres not enough time to fill the cylinders <b>so as a crude guide your looking too find a port size that keeps the air flow velocity at between 190fps and 325 fps</b> now lets look at my 383, its about 10% larger so its quite logical to figure the engines port speeds will be 10% higher with same ports or youll need a port <b> that flows 10% more, NOT a 10% BIGGER PORT</b> at that cam timeing and torque peak. Now in your application with a 190fps-325fps air flow as a target plug your own engines info using the same math and see what port size you get, example lets say we want to build a 468bbc (468 bbc have a 4 "stroke so we have a 6000rpm max (STOCK)engine speed that,s 58.5cid x 8 cylinder displacement ,and with that cam timing about a 4000rpm torque peak, that,s 6088cid per second and 211 cfpm at 4000rpm and 317cfpm at 6000rpm , that suggests 2.66 sq inches-4.0 sq inches at 6000rpm for that 468 bbc http://www.rbracing-rsr.com/runnertorquecalc.html if youll look and compare youll see why the 468 engines tend to run better in the mid range rpms with oval port heads http://www.newcovenant.com/speedcrafter/calculators/runnerarea.htm <b>so the bottom line here is your looking for a port that flows about 2.0 sq inchs and 210cfm at 5000rpm and 2.68 sq inches 270cfm at 6857rpm average the two and youll be looking for a port of about 2.3-2.6 square inchs that flows between about 250cfm-270cfm at your cams peak lift because remember the port cant flow enough due to time restrictions at the peak rpm range</b> BTW thats most closely matched by a 195cc AFR head below 5500rpm and ABOUT 235@.050 lift duration and a 210cc head above 5500rpm and 240@.050 lift duration on a 400cid engine the short answer here is that its NOT PORT VOLUME ,ITS THE AVERAGE PORT CROSS SECIONAL AREA your looking for! a #1205 gasket size port is about correct for hot street and a 1206 port is about correct for an engine thats mostly used on the track look at it this way a 195cc port thats a #1205 size cross section tends to flow about the same and have the same average air flow speeds as a 210cc port thats also a #1205 cross section. these about 16.38 CCs in a cubic inch, a port that measures about 2.5 sq inches like a #1205 port needs to be only about .67" longer to remain at the same cross sectional average, raiseing the port floor and roof and changing the entrance angles can easily account for a great percentage of that volume

your very unlikely to have any problems WITH A PROPERLY INSTALLED AND CLEARANCED SILENT STYLE GEAR DRIVE, and they do last almost forever without getting slack or allowing your timeing to change. NOW THEY CAN CAUSE A KNOCK SENSOR IN AN efi ENGINE TO RETARD THE TIMEING , SO IF YOUR USEING efi WITH A KNOCK SENSOR A CHAIN DRIVE MIGHT BE THE BETTER CHOICE. (btw im useing a gear drive on my efi engine with no problems) SMOKEY YUNICK of STOCKCAR FAME USED GEAR DRIVES and found valve train stability was much better over 6000 rpm, in fact in his book "POWER SECRETS" he says "I SEE NO REASON TO EVER USE A CHAIN DRIVE TO DRIVE THE CAMSHAFT IN A RACING ENGINE!" THEN GOES ON TO SAY SOMETHING LIKE "watching a chain drive useing high speed photography its amazing that they every last five minutes" (PAGE 90) btw that old MYTH ABOUT GEAR DRIVES CAUSEING VALVE TRAIN HARMONICS IS JUST THAT..A MYTH, TRY AND FIND ANYONE WITH DYNO PRINTOUT PROOF< RUMORS, FRIENDS THAT SAY THEY HAVE SEEN PROOF, YES, FACTS ...WELL IN 33 YEARS OF LOOKING IVE NEVER SEEN ANY!!! (theres SEVERAL THOUSANDTHS CLEARANCE BETWEEN THE GEARS PLUS KEEP IN MIND THAT THERES 16 VALVE SPRINGS WITH AN AVERAGE OF ABOUT 200LBS OF FORCE each!! HOLDING THE CAM IN PLACE, THATS WELL OVER A TON OF FORCE, ON THE CAM, SOME ON THE UP AND SOME ON THE DOWN CAM LOBES THAT TEND TO PREVENT HARMONICS BUT theres nothing wrong with a good CLOYES TRUE ROLLER CHAIN DRIVE, PROVIDED YOU REALISE THAT YOULL NEED TO INSTALL A NEW CHAIN ABOUT EVERY 50,000 miles if you intend to keep the valve timeing exact.

just some info guys http://www.vtr.org/maintain/gasoline-octane.html http://www.gnttype.org/techarea/misc/octanebooster.html http://www.team.net/sol/tech/octane_b.html http://www.turbofast.com.au/racefuel8.html http://members.optushome.com.au/cacklingpipes/technicalarticle10.htm http://www.diabolicalperformance.com/hotrodoctane.html http://www.turbofast.com.au/racefuel6.html http://www.zhome.com/ZCMnL/PICS/detonation/detonation.html

http://temp.corvetteforum.net/c4/ld85//front_holley_stealhram.jpg http://temp.corvetteforum.net/c4/ld85//c-4_stealth_ram_plenum.jpg http://temp.corvetteforum.net/c4/ld85//corvette_hood_close.jpg http://temp.corvetteforum.net/c4/ld85//otherangle.jpg http://forums.corvetteforum.com/zerothread?id=491809

if you do truely have a static 11"1 cpr your DYNAMIC cpr WITH THE HOT CAM will be about 8.5:1 which may cause problems if you get less than 93 octane gas on hot days even with aluminum heads.(UNLESS YOU INSTALL IT RETARDED ABOUT 6 DEGREES)and even then its close to the limit, swapping to a CRANE #109831 installed 4 degrees retarded will get you down around 8:1 where youll run just fine on 92 octane PLUS my computer makes its wild guess at 394hp/450 tq peak with the hot cam and 415hp/470 tq peak with the crane cam but the crane cam requires a 2500 stall converter or a manual transmission http://dab7.cranecams.com/SpecCard/DisplayCatalogCard.asp?PN=109831&B1=Display+Card same cam but for early block http://dab7.cranecams.com/SpecCard/DisplayCatalogCard.asp?PN=119831&B1=Display+Card but as always CALL AND TALK TO CRANE BEFORE PURCHASING THE CAM and ask LOTS OF QUESTIONS

yes you can drive constant flow injectors on the street but they tend to foul plugs at low rpms so they run less than ideally for long periods at idle I wrote two pages on how to convert constant flow stack injectors to EFI which is what you need to do if you intend to drive on the street.(THEN THE SITE WENT DOWN AND I LOST IT ALL) heres what EFI stack injectors look like http://www.hilborninjection.com/product.asp?Id=52&CatId=37 you can convert an old constant flow system for under $1500-$1700 to efi, btw thats what I finally did after tuning the constant flow system and finally finding the only real answer that worked was to set the idle or hold the gas petal at 1500 rpm to keep the plugs clean

no but windows rattled, dogs howled, car alarms went off,the local police followed me alot and SUNOCO OIL STOCK prices went UP! and my wallet got THINNER

PERSONALLY I think youll be better off makeing a list of each and every part you want to use and every bit of machine work and getting the parts assembled and either doing the engine build yourself of haveing a QUALITY local ENGINE BUILDER do the work. yes its likely to cost you about $1000 or slightly more,than the mail-order rebuilt engine but the resulting engine will not be a nearly stock rebuild that some guy put together in 4 hours useing mostly rebuilt/reconditioned chevy parts which is what Ive see from most of the low price rebuilders. the simple fact that you should specify 6" rods,(posibly a stroker crank)slightly higher than stock compression hyper or forged pistons, a ballanced rotateing assembly, a high volume oil pump and windage screen with a baffled oil pan, pocket ported heads and ALL arp fasteners will MAKE A HUGE DIFFERANCE in the quality of your finished engine and in the long run cost LESS than rebuilding a cheap engine and being forced to throw away many of the parts yes I know its not what you want to hear! if you want a nearly stock 350, chevy sells them for about $1500 WITH A WARRANTY http://www.sdpc2000.com/cart.asp?action=prod_detail&catid=128&pid=110 if your looking for something a little better http://www.sdpc2000.com/cart.asp?action=prod_detail&catid=128&pid=105 or something that kicks butt http://www.sdpc2000.com/cart.asp?action=prod_detail&catid=120&pid=464

Z-Dreamer PLEASE don,t get the IDEA Im trying to kill your plans,I ran METANOL in a 13.7:1 cpr 496 injected BBC engine for several months but converted the car back to use 115 octane racing gas after I got tired of all the little (B.S.) details that you must watch and corrosion problems, all Im trying to do is get you to know ahead of time what your getting in to. youll have a great car either way,(METHANOL or GAS) but you better think everything over before decideing. BTW my car ran quicker (10.25 @ 133mph on gas compared to 10.30 @ 134mph on methanol but SURE sounded neater and had slightly more power on METHANOL, but the CORROSION was way too expensive. I used a constant flow injection like this (CROWER sold them back then , KINSLER sells them now) and it cost me almost $800 back in the 80s (not counting the basic system)to do the conversion,and it was wasted money as far as I was concerned, true with more tuneing the METHANOL would have been faster but I got totally PI$$ed off with all the corrosion problems, the only neat thing was watching the injector stacks frost up on very cold mornings as the METHANOL super cooled the ALUMINUM and the engine was a real P.I.T.A. to fire without an ether/starter fluid boost on cold days