mult68

iTrader: (1)

Using the compression calculators on the net...Im getting about 10.4:1 with 68cc heads....and 9.7:1 with 74cc heads. Im a bit confused about deck height and head gasket thickness/bore...I just left it at 0.015 deck height, 4.166 head gasket bore, 0.039 thickness (is this correct?) Which cc heads would be best for my engine...and will the 10.4:1 be ok with pump gas?

350 block bored .30" over
3.75" stroke crank
Manley Flat Top pistons (Pin Height: 1.560" Weight: 482g Compression Ratio w/64cc heads: 11.0:1 Dome Volume: -3.5cc)
AFR Emissions legal aluminum heads
SuperRam intake
LPE 219 cam (219/219 5.25" w/1.5 rockers, .560" with 1.6 rockers, 112 c/l)

So what do you think

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1992 Teal Camaro RS
T-Tops
305 TBI V8
Open air element
3" Flowmaster Exhaust System w/Quad Tips
Aiwa CD/Mp3 player
10 Disc CD Changer
Rockford Fosgate Speakers
SLP Headers Coming
Dynomax High Flow Cats Coming
More to come.

BuckeyeROC

Awesome combo! Of course I'd say that. I have around 10.1 compression with 58cc AFR 190's and flat top Speed-Pro forged pistons. I use 92-94 octane gas and haven't had any problems yet, but it's only been 2 months since I've had the new engine. I don't expect to have any problems. I like this combo b/c the car still acts like stock, except it idles at 750 rpm instead of 550. But when you get on the gas, you definitely feel it.

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89 IROC-SuperRammed 355 w/ AFR 190's and LPE 219/219 cam-http://www.geocities.com/buckeyeroc

[This message has been edited by BuckeyeROC (edited November 28, 2001).]

AlkyIROC

My calculations show your current 64cc engine with 10.89 compression ratio. With 68cc heads I get 10.42 and with 74cc I get 9.79 so your understanding of deck height and gasket thickness is correct.

Today's EFI systems can get away with higher compression than the older carb systems due to better fuel management and engine monitoring. Typically 10:1 is about the highest you want to go with 92 pump gas however the higher in altitude you live, the higher the compression can be. I don't know how high you are in Texas but lets say your current engine was in Denver. It could probably survive on 89 octane with no problems. If you took it to LA, 92 octane may not be enough to keep it from pinging.

For a street engine, the 74cc heads with large valves are probably your best choice. You could easily use 92 octane with no fear of detonation. The valves could be unshrouded and get better flow also.

Those cam specs look out of whack. 219 duration with .525 lift??

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Follow my racing progress on Stephen's racing page
and check out the race car

87 IROC-Z SuperPro ET Bracket Race Car
461 naturally aspirated Big Block

Best ET on a time slip: 11.447 altitude corrected to 10.99
Best MPH on a time slip: 119.42 altitude corrected to 124.86
Altitude corrected rear wheel HP: 493
Best 60 foot: 1.586

Racing at 3500 feet elevation with a typical race day over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley

[This message has been edited by Stephen 87 IROC (edited November 28, 2001).]

mult68

iTrader: (1)

Well everything sounds good....74cc heads would be best bet.....do you think I will notice a difference in power by going with the higher compression 68cc heads? Is it worth the risk of not being able to use pump gas safely to find out? As for the cam...i messed up...heh..i actually put 5.25" lift with 1.5 rockers...obviously thats wrong...its .525"....but also the 219/219 duration is at .050".....the post totally messed up my spacing I had.

mult68

iTrader: (1)

by the way BuckeyeROC....the engine looks good...but dont you think its kinda dangerous working on your car in just shorts and sandles? especially when pulling the engine...heh...."Hey watch the......ouch...nevermind"

BuckeyeROC

Thanks for the compliment. I'm not in any of the pics, those are my friends. They did most of the work while I helped where I could. Don't you think they should have put some clothes on? It's not like there were a bunch of hot chicks around to help us.

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89 IROC-SuperRammed 355 w/ AFR 190's and LPE 219/219 cam-http://www.geocities.com/buckeyeroc