Author Topic: Small block build question  (Read 2387 times)

Offline Rattler12

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Small block build question
« on: December 08, 2016, 03:37:36 PM »
I have an 85 305 I rebuilt 3 or so months back for my 37 that has fresh 64cc heads on it. I also have an 87 350 ready to be assembled that has fresh 76cc heads.  I bought Keith Black claimer pistons for the 350 that, according to them, will give me 8.8 to 8.9 CR with the 76 heads. The 64 heads on the 350 would be right at 10 to one. My question is will a 10:1 SB run OK w/o detonation on todays 93 octane premium?  I can ratchet down the advance and help prevent it but at the expense of negating some of the increased compression effects.......
83 C-10 shorty 454, 5spd, 3:73 posi

Offline 68post

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Re: Small block build question
« Reply #1 on: December 21, 2016, 09:55:05 AM »
If your 64cc heads are vortec and not dbl hump it is to your favor, and if your cam is a longer duration than stock that will also help you.

I would also bet that unless you've decked the block to zero, and calculated the gasket thickness, valve relief recess volume, crevice volume, and cc'd the combustion chambers, to have actual proof of the 10-1 estimated compression ratio - that it isn't actually up quite that high.

If your quench distance is .041" or less that is great, if it is greater you're much more likely to have detonation.

I'm assuming you have iron 64cc heads - if they're aluminum you're very likely fine.

Offline Rattler12

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Re: Small block build question
« Reply #2 on: December 22, 2016, 11:40:58 AM »
Thanks for the info... :)
83 C-10 shorty 454, 5spd, 3:73 posi