compression

[darkon]

hey all my car is running a 1mm head gasket and has flat-top semi skirt pistons in it. the compression is 8.7. iv been rackin ma brain thinkin of a way to raise the compression so i was just wondering if there was any cheap, easy way to do it n give it a little extra edge.
thanx all

[PLACEBO]

run a smaller head gasket... http://www.ae86drivingclub.com.au/forums/emoticons/laugh.gif

[slide86]

TRD have gaskets at several different sizes
0.5mm and 0.8mm are ones i can think of at the moment. they will bump the comp up a bit. while the head is off, you can have it faced. that will help a bit.

[darkon]

faced? could you explain this to me please? never heard of "facing"

[slide86]

the surface of the head that goes onto the block is flat.

if you get this surface machined and have a very small amount taken off, this will make the combustion chamber smaller.

smaller area with same amount of air = higher compression.

there is a limit to what a machine shop will remove. you dont want to take to much off, otherwise the head is no good and un repairable.

[mattysshop]

i took 20 thou off my head, and 10 thou off the block.. (the head needed to be straightened first though.. with a bit of post work.. came up very very well..

[ae86trueno]

As for cheaply, there are 2 lots of pistons cheaply available

The ACL 100KW ($200 a set) and the Toyota 100KW (about $400 a set) (see below)

http://img210.imageshack.us/img210/8740/pistons6ga.png

The Toyota Pistons are raised further then the ACL,
I am running new Toyota pistons in my engine, which also might have a ceramic top coat similar to the forged pistons (see below), as well as a 0.5mm TRD head gasket, The combustion chamber has also been cleaned up and 10 thou off the head and block to get a good clean mating surface. The engine does not ping with set up on 98 octane fuel, but does on 95/92 so its probably close to the limit.

http://img239.imageshack.us/img239/6493/newpiston1qu.jpg

Ben.