grumpyvette

get a aug 1998 copy of (VETTE) magazine theres an article with instructions on how a guy installed a fuel injected big block in a C-4 vette without cutting the hood, if your going to spend close to $10,000 or more to make a C4 vette fast you may as well do it so youve got something spectacular when your done

http://www.thirdgen.org/carbswap this should help btw its not all that difficult to do and you won,t have near the problems with gauges reading that you think, and your sensor problems with the larger cam will be far easier to deal with, but your mileage will suffer. btw think salvage yard, most of the small parts can be found there cheaply, but personally Id sellect a new carb compatible fuel pump and a super vic intake and a 750 cfm vacume secondary holley or demon carb, the super vic intake will also produce better power over a wider rpm range than the miniram, BUT BE AWARE THAT HOOD CLEARANCE MAY BE A PROBLEM, MEASURE CAREFULLY, YOULL SURELY NEED A DROP BASE AIR CLEANER, AT A MINIMUM, THERES A TOTAL OF 9.5" BETWEEN THE BLOCK RAILS AND LOWER HOOD SURFACE http://store.summitracing.com/partdetail.asp?autofilter=1&part=JET%2D700225&N=700+318244+115&autoview=sku http://store.summitracing.com/partdetail.asp?autofilter=1&part=HLY%2D0%2D9015%2D1&N=700+115&autoview=sku http://store.summitracing.com/partdetail.asp?part=EDL%2D2925&N=700+304736+4294903502+115&autoview=sku

the answer depends 0n factors like the cam,compression ratio, heads and intake youll use, generally the 3.90 ratio would be my choice on a well built street strip combo example build the 400 with 10.5" cpr similar to this and youll get good results with a 3.90:1 rear gear ratio with a manual trans or useing a 4000rpm stall converter 385 Cu.In. 10.5:1 cpr GM 4 Bolt "010" Block 4.04 Forged SRP pistons -16cc Eagle Cast 3.75" Crank Crower 6.0" 4340 I beam rods Crower Billet Steel ROLLER Cam 254/257 @ .050 .712 lift w/ 1.6 rockers 108* LSA installed at 104* Jesel Shaft Rockers 1.6:1 PSI Springs 230# closed, 620# open Super Victor Intake ported to match heads, Fel-Pro 1209 Wilson Manifolds 1.5" carb spacer Holley HP950 Carb, 79-81 jets, .055 air bleeds all the way around MSD Pro-Billet Distributor Custom Stepped headers 1.75 - 1 7/8 - 2" Iron Eagle Platinum 230cc Heads CNC'd by M2 Racing 320cfm @ .700 333 cfm @ .800 66cc chambers 42* total timing 110 octane on dyno will run 91 on street It's a custom billet steel ROLLER cam. Youll need to order one 282/286 adv 254/257 @ .050 .445 lift @ lobe .712 lift w/ 1.6:1 rockers 108* LSA 104* ICL Solid Roller 450tq 580hp http://i5.photobucket.com/albums/y197/stevemc1979/finaldyno.jpg http://i5.photobucket.com/albums/y197/stevemc1979/finaldynonumbers1.jpg http://i5.photobucket.com/albums/y197/stevemc1979/finaldynonumbers1.jpg http://i5.photobucket.com/albums/y197/stevemc1979/finaldynonumbers2.jpg http://www.crower.com/misc/contact.shtml

this will get you started in the correct dirrection,(KNOWING WHAT YOUR TALKING ABOUT) BUT READ CAREFULLY,YOU NEED TO FULLY UNDERSTAND HOW THE COMPONENTS EFFECT THE RESULTS http://victorylibrary.com/mopar/header-tech-c.htm http://www.newcovenant.com/speedcrafter/tech/camshaft/1.htm http://www.isourcecenter.com/results.php?&q=calculat%20header%20primary%20length http://www.isourcecenter.com/results.php?&q=calculat%20header%20primary%20length http://www.e21motorsports.com/kendanielson/header%20design%20article.htm http://www.pontiacracing.net/js_header_length1.htm http://www.newcovenant.com/speedcrafter/calculators/runnerarea.htm http://www.newcovenant.com/speedcrafter/calculators/intake.htm http://www.burnsstainless.com/TechArticles/Theory/theory.html http://www.btinternet.com/~mezporting/exhaust_length.html http://www.stahlheaders.com/Lit_measurement_1.htm http://www.uucmotorwerks.com/html_product/sue462/backpressuretorquemyth.htm http://www.mustang50magazine.com/techarticles/4328/ http://www.grapeaperacing.com/tech/

i think you might find this of interest (FROM EDELBROCK, THEY MAKE INTAKES AND CARBS) CFM Rules... CFM and Carburetors: Carburetors are rated by CFM (cubic feet per minute) capacity. 4V carburetors are rated at 1.5 inches (Hg) of pressure drop (manifold vacuum) and 2V carburetors at 3 inches (Hg). Rule: For maximum performance, select a carburetor that is rated higher than the engine CFM requirement. Use 110% to 130% higher on single-plane manifolds . Example: If the engine needs 590 CFM, select a carburetor rated in the range of 650 to 770 CFM for a single-plane manifold. A 750 would be right. An 850 probably would cause driveability problems at lower RPM. A 1050 probably would cause actual loss of HP below 4500 RPM. For dual-plane manifolds use 120% to 150 % higher. CFM and Manifolds: Manifolds must be sized to match the application. Because manifolds are made for specific engines, select manifolds based on the RPM range. CFM and Camshafts: With the proper carburetor and manifold it is possible to select a cam that loses 5% to15% of the potential HP. These losses come from the wrong lift and duration which try to create air flow that does not match the air flow characteristics of the carburetor, manifold, head and exhaust so volumetric efficiency is reduced. An increase in camshaft lobe duration of 10 degrees will move the HP peak up 500 RPM but watch out, it may lose too much HP at lower RPM. CFM and Cylinder Heads: Usually, cylinder heads are the limiting component in the whole air flow chain. That is why installing only a large carburetor or a long cam in a stock engine does not work. When it is not possible to replace the cylinder heads because of cost, a better matching carburetor, manifold, cam and exhaust can increase HP of most stock engines by 10 to 15 points. To break 100% Volumetric Efficiency, however, better cylinder heads or OEM “HO” level engines are usually needed. CFM and Exhaust: An engine must exhaust burned gases before it can intake the next fresh charge. Cast iron, log style manifolds hamper the exhaust process. Tube style exhaust systems are preferred. But headers are often too big; especially for Performer and Performer RPM levels. Improving an engine’s Volumetric Efficiency depends on high exhaust gas velocity to scavenge the cylinder but this will not happen if the exhaust valve dumps into a big header pipe. On the newer computer controlled vehicles it is also important to ensure that all emissions control devices, and especially the O2 sensor, still work as intended. CFM and Engine Control: Spark timing must be matched to Volumetric Efficiency because VE indicates the quantity of charge in each cylinder on each stroke of the engine. Different engine families require distinctly different spark advance profiles. And even engines of equal CID but different CR require their own unique spark advance profiles. Rule: Expect 0.1% to 0.5% loss in Torque for each 1 degree error in spark timing advanced or retarded from best timing. Also, detonation will occur with spark advanced only 3 degrees to 5 degrees over best timing and detonation will cause 1% to 10% torque loss, immediately, and engine damage if allowed to persist. " then read this CAREFULLY " http://www.chevyhiperformance.com/techarticles/148_0403_seven_holley_carbs_test/ http://www.edelbrock.com/automotive/math.html

http://forums.hybridz.org/attachment.php?attachmentid=1181&d=1156555303 looks like classic (OOPS it went lean and detonation/heat did the piston in)

OK lets discuss it! I build enought engines to know what works both on the street and the track, where am I wrong?? most chevy V8 engines make max power with a fuel air ratio between 12.6:1 and 12.9:1 fuel air ratios most chevy V8 engine can be designed to make thier best power in an rpm range where the piston speeds are between 4000fpm and 4500fpm at aproximately 12:1-12.5:1 cpr with 110 octane fuel as long as the heads and cam and exhaust scavaging can fill the cylinders at that rpm range with little restriction., and that ,with little intake flow restriction, is important,add a RESTRICTOR plate or a smaller carb,and increasing the plenum volume and static compression, or a carb spacer and changing the cam timing, can compensate, to some extent dynamic cpr needs to be between about 8:1-9:1 if youll use current street fuel,and vacume readings in the plenum at max throttle should be less than 1.5 inchs of vacume . dual plane intakes generally can effectively use larger carb flow rates than single plane intakes, but again the combo used has some flexability, in what will work intake design and port cross section , exhaust scavaging,cpr,head flow , displacement,effect your results, but theres a great deal of wiggle room in the carb size that CAN be used

quicker240 you sound fine! the largest percentage of time in building a good combo is in the RESEARCH BEFORE your sellect the parts, youll use and in the care and precision durring the clearancing and installation of those parts. just keep in mind the basics largest displacement you can easily afford a decent well tuned engine combo will make between 1.1 and about 1.3 hp PER CUBIC INCH OF DISPLACEMENT, I.E. a 350 that makes 1.25 hp per cu inch makes about 438hp, boost the displacement to 396 with a 3.875" stroker crank and you can reasonably expect to make about 495hp from a similar build great flowing cylinder heads if you can,t get the airflow in and out of the cylinders youll never reach your full potential, heads that flow at least 240cfm at .500 lift are almost mandatory for a good performance engine build, and the closer you can get to about 270-300 cfm at max cam lift the more potential power you can make PROVIDED the rest of the engine build can take advantage of that flow, but match the port cross section to the intended displacement and rpm range cam timing matching the intended rpm range and compression ratio. heres a few links that might help http://www.crossedflags.com/modules.php?name=Forums&file=viewtopic&t=21567 http://www.crossedflags.com/modules.php?name=Forums&file=viewtopic&t=21724 http://www.crossedflags.com/modules.php?name=Forums&file=viewtopic&t=21138 http://www.chevytalk.org/threads/showflat.php/Cat/0/Number/1137028/an/0/page/0#Post1137028 http://www.chevytalk.org/threads/showflat.php/Cat/0/Number/1527608/an/0/page/0#Post1527608 http://www.chevytalk.org/threads/showflat.php?Cat=0&Board=UBB64&Number=292257&fpart=1&PHPSESSID=57a75c70424b5a4c3f355dd48aa6a38d http://www.chevytalk.org/threads/showflat.php?Cat=0&Board=UBB64&Number=320707&fpart=1&PHPSESSID=57a75c70424b5a4c3f355dd48aa6a38d http://www.chevytalk.org/threads/showflat.php?Cat=0&Board=UBB64&Number=704273&fpart=1&PHPSESSID=57a75c70424b5a4c3f355dd48aa6a38d http://www.chevytalk.org/threads/showflat.php?Cat=0&Board=UBB64&Number=1178626&fpart=1&PHPSESSID=57a75c70424b5a4c3f355dd48aa6a38d http://www.chevytalk.org/threads/showflat.php?Cat=0&Board=UBB64&Number=229372&fpart=1&PHPSESSID=57a75c70424b5a4c3f355dd48aa6a38d and remember about the drive train ,and matching the engines most effective rpm band

are you in a mad rush to just add performance parts,or do you have a long term , well thought thru plan/goal and a list of matched components that will get you there? steve, one of the neigbors kids whose about 20 years old came by today with a mopar (duster) he just purchased, it was running poorly and he had purchased it from some other local guy who never was able to get it running correctly. steves already talking about getting a tunnel ram intake and nitrous and a new cam, (he has no idea what heads, compression ratio, or cam is in the current engine, what his rear gear ratio is or the transmissions stall speed) or for that matter even what displacement engine he had, he was told it was a 340 magnum, but a extensive check of casting numbers makes me think its a 318. (heads,#2843675 ) anyway the point I tried to make was that he should at a minimum find out EXACTLY WHAT HE HAS CURRENTLY BEFORE STARTING TO BUY PARTS AND PLAN MODS to his new pride and joy. but being 20 years old and having a reasonably good paying job and few bills since he lives at home, hes hard to reason with, he thinks a tunnelram and nitrous will make for a killer combo.......so I wished him luck, and told him to stop bye once he found it was unlikely to work and wanted to get it running correctly. now most of us started out in this hobby with more enthuseasum than skill or money (I know I did) but unless you are willing to do some research on what will and has worked in the past your doomed to spend far more time and money getting a car running correctly than you can imagine, and while IM sure a tunnel ram sticking out thru the hood will be impressive looking , Id bet my last dollar I could get better results from the money spent, with a carefully matched set of components and a well thought thru plan of attack, (starting with a careful inventory of current parts) rather than just slapping a tunnel ram on an engine with an unknown combo. point is guys, you need to know both what your starting with and where youll like to wind up! and in some cases stepping back and thinking things thru is going to save you alot of agravation, theres little sence in slapping parts on a 318, when a well built, 340,360,383-440 could be swapped into the car yeah its a mopar, but I see the same thought process going on with us chevy guys at times its not always a good idea to just start adding parts as you can afford them,to what ever engine came in the car... your results may be far better if you build a seperate engine/ drive train, or rear suspension and swap it in once its completed to your exact specs, larger heads, increased, displacement, larger cams etc, may or may not be compatible with stock components if installed in a hit or miss random installion order to reaching your goal

a carbs function is to efficiently blend atomised fuel droplets into the air entering the engine in a totally controlled and adjustable manor, while the size of the venuries and the pressure drop across the bores effects the results ,the DESIGN of the carb more than the bore size or flow rate will effect the power curve. yes its true that a fixed displacement engine can only use a set flow at a given rpm, and a 350 is well served with a 600-650cfm carb, but a slightly larger or smaller 450cfm-750 cfm of the correct design will produce very similar power and throttle responce once correctly tuned. its carb design and tune levels more than just rated flow rates you don,t DETUNE a large carb, you adjust it so it gets the correct mix and ratio of fuel at the correct time, changes like swapping booster styles, jets and power valves ,accellerator pumps, jets and linkage cams, ETC. can be used to match the engines requirements

youll be almost correct in thinking that "the whole "port velocity" thing go out the window when useing a turbo?" as it becomes far less critical to the low rpm throttle responce and the larger ports help the upper rpm power curve, but youll need to match the cam timing, compression and turbo size/type to the application to take full advantage of the larger ports,higher flow rates and potentially higher lift cam youll use but Id also point out that with the cost youll be looking at in a well built turbo engine build, your fooling yourself if you think the 305 with its smaller bore that shrouds those valves,and the weaker block will be a good investment, and the stock 305 block may not even allow you to have the necessary clearance for the 2.02 inch valves in the bore at full lift) or will save you money youll be FAR better off useing a well designed aftermarket block with 4 bolt main caps and a thicker web on those main caps and thicker decks and cylinder walls....a stock 305 block is designed to handle about 350-400 hp MAXIMUM and with those heads and a correctly tunned turbo your obviously looking for more than that! Id strongly suggest a minimum of a 383 displacement and ALL FORGED COMPONENTS in an AFTERMARKET 4" or 4.125" block with 4 bolt main caps, since youll need a NEW FORGED 4340 crank, ID suggest a 3.75-3.875" stroke, as the costs will be similar to the same basic crank in the 3.5" stroke version the 350 has (look closely at the MAX rated hp of even the 350 production block) http://www.sallee-chevrolet.com/frame.html?/Engine_Blocks/gm.html now look at a good block,(cylinder walls and decks are easily twice as thick) http://www.dartheads.com/sbclittlem.aspx http://www.dartheads.com/manager/uploads/tech%20-%20Little%20M%20Iron%20Small%20Block.pdf

"Originally Posted by Pyro Carb tune is also very important. Most people just throw on a carb and expect it to work. There are a bunch of things to tweek on a Holley to make it run right. Front and rear jets, power valve, accelerator pump squirters and cams, and vacuum secondary springs to name the most common. That 600 may just run better because it just happens to have a tune on it that complements your engine combo. " Ive got to agree..I can,t even tell you all the times when I had guys tell me a carb was too large or small, when simple tuning tricks made a HUGE improvement in both the responce and power curve almost reguardless of the CFM rateings, its usually NOT the CFM rateing , its how well the carbs set up, jetted,and adjusted, in fact Ive had many cases of exceptionally good results useing DUAL QUADS, with two 600 cfm carbs on most 400-500 cubic inch displacement engines, correctly set up. its not at all uncomon to get an extra 10-15 hp off a good dual quad set-up over a single carb and they sound better and run smoother when correctly adjusted. yes, I usually sellect a single holley or demon 750cfm carb on a 350-383-396 sbc. but on big blocks in the 454 plus range duals are a very valid option, 8 small venturies can be fine tuned to run a more precise fuel air curve than 4 large venturies in most cases, but IT does take some experiance/knowledge/skill keep in mind the intake used, the port size, runner length, cross section and the plenum volume, the headers used, the transmission and rear gear ratio, plus factors like displacement compression and cam timing ALL effect your results and required tune. its USUALLY simple things like the wrong float levels, wrong fuel pressure, metering rods or jets, perhaps a bad power valve, or badly adjusted accellerator pump. http://www.bob2000.com/carb.htm http://www.goldrush.com/~rhuish/temp_data/carbtune.html http://www.jason.fletcher.net/tech/carbtuning/carbtuning.htm http://edelbrock.com/automotive/eps_intro.html http://www.mortec.com/carbtip1.htm http://www.centuryperformance.com/vacuum.asp

Keep in mind the object is to make the least expencesive changes do the greatest good, here! well the first change ID MAKE is to swap to this cam, and it sure would help if you pocket ported those current heads, adding an X or H pipe to the exhaust would help also ERSON E113123 http://go.mrgasket.com/pdf/Chevrolet.pdf WHY? well your seriously over cammed for the application, and the heads can,t flow nearly enought air in the rpm range that the cam wants or is designed to produce max power in and the heads have a flow range that fades before reaching the cams power curve , so you loose low rpm power due to the cam durration and high rpm power due to restricted flow potential of the heads. yes IM only too aware what your software dyno predicts, but having been down this same path more times than I can count, I can tell you youll see results that will move the car better and increase power in your USEABLE rpm band, which due to the heads potential flow is all well below 6000rpm, while your cams designed to reach 7000rpm plus the ERSON much more closely matches the heads potential flow curve as does your dual plane intake

V80Z lets start from the basics and both see where we stand and what can be done fairly cheaply to reach your goal, I NEED to know ALL the details on your engine youve listed some of the info but please repost it ALL HERE displacement compression ratio compression test readings vacume readings CAM (part # and lift/durration/LCA) heads (casting #, valve size)flow numbers if you have them spring bind height max spring clearance max piston to valve clearance intake used headers used size of exhaust pipes carb size piston type/ part # jet size fuel pressure rockers used (ratio/type) head gasket thickness rear gear ratio tire dia transmission used converter stall speed any port work ignition?? any and ALL other vaguely or potentialy useful info

go for it! it sounds like an easy swap that should be fun

Ive been married 37 years now! I figgure IM DUE for SAINTHOOD! Ive never even hit her once even thou shes truely deserved it a few times...just count to about 500 slowly when she gets FEMALE CRAZY STUPID before doing or saying anything youll REGRET LATER and youll be fine! when my wife gets crazy I just ask her to tell me how the argument went later and go out in the garage to tinker with the vettes, it makes her nuts but its better than fighting... just remember she sees everything from a differant perspective and requires CONSTANT reassurance you still love her..even when you think shes nuts/insane...try to see things from her perspective, remember, on rare occasions she could be correct! and your HOBBY NEVER COMES ahead of the wife and kids

if the question, is will it opperate or drive with the lower octane and retarded ignition timing to avoid detonation,? the answer is YEAH! it will run, but youll be very noticably down in power if the engine is set up to run correctly on the higher octane fuel and more ignition advance

I got 60%

it will (work) with the correct length drive shaft even if the nylon collar is used but Ill point out that nylon sleeve can and do occasionaly break and fall off. if that happends the shaft can slide back and forth (side to side) and put higher loads on the pump, this also tends to screw op the timing consistancy make sure the oil pump drive shaft has some vertical clearance (.040-.060 is about correct)when the distributor is fully seated prefered http://store.summitracing.com/partdetail.asp?part=MEL%2DIS%2D55E&N=700+115&autoview=sku notice the STEPPED DIA. thats to prevent the middle of the shaft rubbing on the block near the crank bearing area,non stepped dia shafts DO tend to rub ESPECIALLY on the 400 blocks

"The better your welder is, the better your welds will be. Buy as much welder as you can afford. " GOOD ADVICE tig http://www.htpweld.com/ stick http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=91888 mig http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=43550 http://www.millerwelds.com/ lincoln http://store.weldersplus.com/liweeq.html?gclid=CNn74rKX0YYCFSccVAodigYo7w general http://store.cyberweld.com/miltigwel.html http://www.weilerwelding.com/shopsite_sc/store/html/welderTIG.html http://www.weldingmart.com/lincoln.htm

GOOD CYLINDER HEADS will make or break your combos power potential, yeah we all have a strong tendency to look for "BARGINS","DEALS" and to rush to get results, and optomistically expect "fairly good" to be GOOD enought, trust me here! the heads you buy will totally make or restrict your power potential, the differance between some $500-$800 heads and $1300- $1500 heads can easily be 70-80 hp OR MORE! PRICE is NOT directly related to QUALITY or POWER POTENTIAL , but you do tend to get what you pay for, I.E. the better heads do cost more and crap goes for alot less! theres few other things that will SCREW up an engines power potential faster than restrictive heads or not matching the cam,compression ratio and drivetrain/gearing to the head flow rates, in the rpm range you want to make http://www.dartheads.com/manager/uploads/Tech%20-%20215%20IRON%20SBC.pdf http://www.sdpc2000.com/search.asp?searchterm=25534431&doquery=1 http://www.brodix.com/Top%20End%20Combos.html http://www.jegs.com/webapp/wcs/stores/servlet/CategoryDisplay?storeId=10001&catalogId=10002&catalogIdentifier=Jegs_Direct&categoryId=27305&parentCategoryId=10187 power.http://www.trickflow.com/product/chevycylinderheads/rseries_sbchevy/pr_r_sbchevy.asp

some tools are just so darn useful in some applications... http://store.cyberweld.com/spec375cut.html not quite as good as SEX ...for bring a grin to your face... but alot more helpful when removing an ENGINE from a DONOR car WRECK ,when you don,t give a crap about the condition of fenders/supports/ETC. remember to keep a CO2 fire extinguisher handy, support all transmission,and engine parts, linkage, lines, don,t forget to check all the clutch, fuel ,ignition,and coolant lines are disconnected, and only cut thru the minimum nesessay, the object is to quickly/easily remove the engine, NOT to destroy parts someone else may need, even if you intend to scrap the remainder of the car

it SOUNDS like the damper and timing tab may not reflect the TRUE TDC http://www.fourwheeler.com/howto/67578/

"Am I under carbed for this cam " NO! a 750 cfm carb can supply a 600 hp/406 sbc engine easily with the correct tunning but you might want to install a open center spacer under the carb to increse plenum volume, but thats NOT your problem, It may be the floats are set to low, the fuel pressures not set correctly,the jettings wrong,or you may have accellerator pump shot problems, the carb may not be the problem at all, it may be the ignition, or the ignitions advance curve. or even the cams installewd a few degrees off or lifter lash clearances are wrong or even a clearance issue in the engine

I don,t know why, the basic formula/guide to expected hp from FLOW numbers is .257 x max flow x #of cylinders= expected max hp so those 270 cfm flow #s relate to a 555 hp expected so those 282 cfm flow #s relate to a 579 hp expected thats for a N/A engine, add a supercharger or nitrous and the power goes up significantly BTW heres a very good big block head thats about 850hp of flow http://www.sonnysracing.com/products/heads/sarbrodix390marine.html'>http://www.sonnysracing.com/products/heads/sarbrodix390marine.html heres a very good set http://www.hekimianracing.com/heads.html#Pro1BBCHeads 184 Series BBC 12deg 470cc Spread Port Flow Numbers Lift .200" .300" .400" .500" .600" .700" .800" .900" Intake 159.6 238.6 314.5 384.2 431 457.8 482.6 496.6 over a 1000hp n/a Exh 137.4 181.8 226.3 274.9 297.9 306.4 310.5 320.2 heres two totally differant set of bbc heads http://www.sonnysracing.com/products/heads/pb1802bigduke.html'>http://www.sonnysracing.com/products/heads/pb1802bigduke.html http://www.sonnysracing.com/ flow exceeds