Original Message
Min. Quench clearence/piston to head clearence?
By David - 05/01/2004 7:43:07 AM; IP 69.48.15.69
I am in need of some Hi Performance info.
I would like to & need to know what the
minimum/thightest quench clearence/piston to head clearence is that can be used on a '68 S code 390 FE. The motor will be lucky to see much over 6k RPM if 6k at all.
I am planning to run a min. of .020"
piston to head clearence in the quench/squish area. Just by changing the head gasket to a
.020" steel shim which would also bump my
CR to abt 11.7:1.
I am rebuilding & assembling the motor now.

I am going to be putting it on an engine dyno.
Depending on how it runs I may want to switch in the .020" shim gasket to get more power from the higher CR & tighter squish.
Below is a list of what other info I feel might be needed. If there is any more info need to help in answering my question please let me know. Thanks in advance.

stock steel rods

ROSS custom made forged pistons .030" over

Total Seal Gapless top rings

block is decked & pistons are @ 0 deck with
only the dome above deck

heads stock C8AE-H 390 GT (with 428cj valves)

Piston to valve clearence is not going to be a
problem. There is a ton of clearence there.

I have the chamber, valves, piston & exhaust port coated with a thermal coating By Swain Tech.

Built C6 trany & 3.25 rear gears.
This thread, so far...
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Collapse <b>Min. Quench clearence/piston to head clearence?</b>&nbsp;-- <font color=#0000ff>David, <i>05/01/2004</i></font>Min. Quench clearence/piston to head clearence? -- David, 05/01/2004
Collapse <a href=../ForumFE/reply.aspx?ID=21238&Reply=21235><img src=../images/reply.png width=30 height=10></a>&nbsp;<a href="#" id="anchor21238" onclick="return false;">You will need to run racing gas.</a>&nbsp;-- <font color=#0000ff>Dave Shoe, <i>05/01/2004</i></font><script type="text/javascript">
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 You will need to run racing gas. -- Dave Shoe, 05/01/2004
 RE: You will need to run racing gas. -- David, 05/02/2004
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