FAQ |
Members List |
Social Groups |
Calendar |
Search |
Today's Posts |
#1
|
||||
|
||||
Cometic .120" head gasket
Any one run the .120" thick cometic? What would be an appropriate application for this gasket? Turbo/supercharged engine? Looks like it would drop my compression down a full point and save me the trouble of prepping new heads for a blower. Pricey but still cheaper than new heads or pistons. Thanks.
.
__________________
1967 Firebird ragtop, 464, Weiand 8-71, ported 6H heads, Hyd roller, 4L80E, paddle shifter, Moser 9", Cal-Tracs, Vintage Air, Corbeau seats, 13"/12" disk brakes, Hydraboost, electric cutouts and M&H drag radials. |
#2
|
|||
|
|||
They can get the compression down in a semi-inexpensive way. It's still best to have a chamber and piston form the "combustion space". I've only used the .120s to make a small chamber head pump gas friendly.
-Rob WWW.ICTCengines.com |
#3
|
|||
|
|||
I would think perhaps only for blown applications.
Using thick head gaskets as a means to drop compression is not a terribly good idea, as it will decrease the squish in the cylinder, which in turn will decrease the amout of turbulence in the cylinder immediately prior to spark plug firing. The more violently the air/fuel mixture is compressed (by means of squish), the better it will burn, which in turn will help to decrease the tendency to detonate. This is why it is beneficial to "zero deck" a block, as you are then bringing the piston up to the deck at TDC, effectively minimizing the distance between the piston and head, and maximizing squish. I have heard of many instances where engines with CR reduced by such methods as thick head gaskets have actually shown WORSE detonation, than engines with higher CR but with less piston-to-head clearances. |
#4
|
||||
|
||||
I ended up having to use .074 cometics in mine because I had P/V clearnance problems. With the 1016's clearance was only .030 on the exhaust. I lost a good bit of compression but I can run a more radical lift cam. I always thought of thicker head gaskets being a band aid. There is a better way to drop compression.
|
#5
|
||||
|
||||
From a practical standpoint- that much additional head gasket thickness might require head-to-intake spacers of about .080" thickness, unless you can buy gaskets about .110" thick.
|
Reply |
|
|