i see alot of people say not to use a thinner head gasket to bump up compression a little. people say because it bends valves. can someone explain this. whats the difference between using higher compression pistons or using a head gasket. either, or is just decreasing the height of your compression area. i think the only reason people bend valves ,is because they forget to take into account the thinner head gasket. and tune as if it were a lower compression.

anyone who can shed some light on this please feel free.

 

Valve-to-piston clearance issues .. same goes for milling the head. If you're using high compresson pistons especially, you have to clay the motor to ensure the valves will not hit the pistons .. anything that brings the piston and valves closer together should be clayed.

 

another reason to not run them is because if your surfaces are not completely flat then the headgasket wont seal properly = lose power. milling, decking, & thinner head gaskets will put some slack on the T-belt. if you do all 3 too much mayb cause the T-belt to jump teeth = bent valves = owner

 

so nobody really has an answer to this?? ive seen so many posts here saying "dont use a thinner head gasket, just get pistons" well come on people back it up with some info. why would u spend 5 times more for the same end result??

 

i think an issue that is often overlooked is cam timing.

If you mill or use a thinner head gasket then you are changing the cam timing


A little bit you arent going to notice much power, but extreme cases cam gears are needed to correct the off set cam timing.

 

anytime you change the distance between the cam centerline and the crankcenterline [ie: crank centerline] i believe you change cam timing.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 99b18 &raquo;</TD></TR><TR><TD CLASS="quote">so nobody really has an answer to this?? ive seen so many posts here saying "dont use a thinner head gasket, just get pistons" well come on people back it up with some info. why would u spend 5 times more for the same end result?? </TD></TR></TABLE>

going from a stock 3 layer to a 2 layer will change your CR by about 0.2. you will see [on a dyno] very minial gains if any and feel next to nothing on a butt dyno. when people change pistons they usually increase their CR by around 1.0, you will not gain that much with a thinner headgasket. going for a thinner headgasket is usually to up the already high CR to alittle higher to complement the rest of the engine [cams, pistons, stroke, head, etc].

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gutted &raquo;</TD></TR><TR><TD CLASS="quote">anytime you change the distance between the cam centerline and the crankcenterline [ie: crank centerline] i believe you change cam timing.

going from a stock 3 layer to a 2 layer will change your CR by about 0.2. you will see [on a dyno] very minial gains if any and feel next to nothing on a butt dyno. when people change pistons they usually increase their CR by around 1.0, you will not gain that much with a thinner headgasket. going for a thinner headgasket is usually to up the already high CR to alittle higher to complement the rest of the engine [cams, pistons, stroke, head, etc].</TD></TR></TABLE>

this is what i was planning on. i ordered a set of 11.5/1 pistons. and i have a head gasket that will up that to about 12/1. i dont think ill have any probs with this. ill be having it professionally tuned.

 

i've done 1 layer headgaskets on at least 10 motors. just be sure to use some copper spray adhesive from the auto parts store, and torque the head bolts 5 more ft/lbs. i've never had problems. only time i ever had a problem is the first time i did it, and didn't know about using the spray adhesive. just remember that and you're money.

 

if you plan on running a 1 layer better make sure your head & deck are pretty damn close to flat...so you dont run into sealing problems

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mike K &raquo;</TD></TR><TR><TD CLASS="quote">i've done 1 layer headgaskets on at least 10 motors. just be sure to use some copper spray adhesive from the auto parts store, and torque the head bolts 5 more ft/lbs. i've never had problems. only time i ever had a problem is the first time i did it, and didn't know about using the spray adhesive. just remember that and you're money.</TD></TR></TABLE>

did u change anything with your cam timing?? this is my main concern. i dont want to be bending any valves.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by redlineintegra &raquo;</TD></TR><TR><TD CLASS="quote">Valve-to-piston clearance issues .. same goes for milling the head. If you're using high compresson pistons especially, you have to clay the motor to ensure the valves will not hit the pistons .. anything that brings the piston and valves closer together should be clayed.</TD></TR></TABLE>

What is "claying the motor"??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lingerbw &raquo;</TD></TR><TR><TD CLASS="quote">

What is "claying the motor"??</TD></TR></TABLE>

http://www.c-speedracing.com/h...y.php

 

i didnt do anything with cam timing until i got to the dyno.

once you're on the dyno, you go from there. i just did the headgasket for an additional .2 or .3 on my compression ratio.

 

did u find u had less advance on your timing then a normal engine would. once u were done your tuning??