Thread: 327 rebuild

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Originally Posted by ecreek

if I build for 10:1 will the engine ping on unleaded gas? also, how much can I shave the heads b4 taking away too much head strength? btw, thank you all for the info. I really appreciate your time and expertise. Ron

Looks to me like you just have an old 327 that you will freshen up a little bit and use for a daily driver. Nothing earth-shattering, just a motor.

None of the early iron heads will make any kind of power compared to the heads available to us today, so it really does not matter which heads you use, they're all junk. I might opt for the 882's simply because of the low static compression ratio they produce. As Lynn said, you'd be just over 8:1 static compression ratio. You never know what fuels will be available in the near future, so don't paint yourself into a corner with a high-compression ratio motor and then not be able to buy fuel for it tomorrow. There is nothing wrong with an 8:1 daily driver, but you will have to run a stock camshaft with it. Any hot-rod cam you bolt into the motor will want and need more than 8:1 static compression ratio.

Here's a tutorial I wrote for the wiki on another site. It explains the relationship between static compression ratio and the intake valve closing point @0.050" tappet lift. Cams must be matched to your combination. You cannot just reach out into thin air and grab any cam that you think looks good to you. You must build for it.
http://www.crankshaftcoalition.com/w..._compatibility

To answer your question about what static compression ratio to use with pump gas, generally use up to 9.5:1 with iron heads and up to 10.5:1 with aluminum heads. You can, however, use up to 15.0:1 static compression ratio with E85 fuel. Problem is that you have to use such a radical cam to support that SCR that usage on the street is very limited.

Use a cam something like this....
Crane Cams 114102 2010 Hydraulic Flat Tappet Camshaft and Lifter Kit Chevy 262-400 V8 57-87 RPM Range: 500-4000, Duration @.050": 184/194, Lift: 0.
I'm not saying you should use a Crane cam, I'm just showing you the cam timing you need to use with a low-compression motor. Use this cam timing to aid your search for the brand of cam you want. Be very careful about the quality of flat tappet lifters. There is some junk circulating out there, but if you buy a quality name brand like Crane or one of the other major cam makers like Iskenderian, Crower, CompCams, Lunati, etc., etc. and you buy their lifters with the cam, you should be OK. Alternately, toddle on down to your local Chevrolet dealer and belly up to the parts counter. Order a bone-stock cam and lifters for a 1980 Camaro 350 LM1/Z28. Those motors had an 8.2:1 static compression ratio and the cam designed for them will work well in your 8:1 motor. Again, buy cam and lifters together, from the same supplier.

Here's a tutorial that I wrote concerning using a flat tappet camshaft with the crankcase oils that are generally available off-the-shelf today. You must exercise extreme caution with them.
http://www.crankshaftcoalition.com/w...ips_and_tricks
Sidestep the nightmare of a flat tappet cam by moving up to a hydraulic roller cam or solid roller cam. You can get into a Howards cam and lifter retro-fit combo for about 600 bucks, that eliminates all the mumbo-jumbo in the tips and tricks article.

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