<VV> Combustion Chamber Modification

JVHRoberts@aol.com JVHRoberts@aol.com
Sun, 21 Mar 2004 10:30:08 EST


9:1 should be totally in the range of what is possible. 
However, you will need to do a few things first:
1. Make SURE the heads are well deflashed.
2. Mill the step out of the heads, to maximize squish.
3. Do the fly cut on the pistons, in the area NOT in the squish zone to 
achieve 9:1. 
Regular gas should be no sweat. However, do consider mid grade, with slightly 
advanced timing. In my experience with Corvairs and other engines, increasing 
timing advance to take the most advantage of higher octane fuel almost 
completely offsets the added fuel cost by improving mileage, and in return you get a 
bit more power and a bit cooler running engine. 

John


In a message dated 3/21/2004 10:23:11 AM Eastern Standard Time, 
Mikeamauro@aol.com writes:
The Greenbrier's 110 is out for a major rebuild.  The time is ripe to 
reconfigure the heads to reduce engine tendency to knock and ping.  My 
version of the 
Technical Manual is 1986; while it has some good info on this topic, there 
must be more current information out there.  I also have Bob Helt's latest 
book 
(presently out on loan)...is there anything there?  My goal is to end up with 
9:1 compression ration, but burn regular or mid-grade fuel (87-89 octane); is 
this a pie- in-the-sky dream?  The vehicle is already equipped with Safeguard 
knock control system.  Also, what is the chamber CC for a 110 @ 9:1?  Any 
info 
available would be appreciated.
Thanks,
Mike Mauro
64 Greenbrier, PG & A/C
(plus too many other Corvairs for my own good) 
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