Skimming My Head

[R.G_205 0]

hi guys,

 

i got a rolland garros and im doing a top end rebuild on it ported and pollished

but if i get the head decked to the max ( i have about 3 more heads so no worrys if the head gasket goes or some thing )

will i need a thicker head gasket?

but if does need a thicker gasket all the work of decking it would be undone no????

or if you can find a thread where this has been raised would be helpfull as i cant find one?

and im thinking about buying a ti motor sport 4-2-1 manifould are they any good ?

 

any comments will be helpfull

 

thanks Roddy

[R.G_205 0]

any help?

[trogboy 17]

Hey Roddy.

 

Taking off a lot starts to change the shape and reduce the thickness of the squish area which can have negative effects, which may or may not be offset by the increased compression. Taking off say 1mm shouldn't see any issues with contact between the valves and pistons so you don't 'need' a thicker gasket from that point of view.

 

I am just trying to think, but I can't think of anyone that has aggressively decked their head - maybe they do and don't talk about it, or maybe their is a good reason for it. From memory you can take a fair bit of meat off before you risk cutting into a waterway.

 

I have a TU24 head that I skimmed 1.19mm from to reduce the size of the combustion chambers to the point that I could use it with a stock TU3 bottom end and maintain a CR of 9.6. I decided to use a vernier pulley to set the timing as removing material from the head and shortening the distance between the cam and crank sprockets retards the cam slightly - maybe not enough to notice but I didn't want to run the risk.

 

Ad

[R.G_205 0]

right so you wouldn't advise decking it all the way as it may suffer from abit of pre ignition?

so go down a fair amount to up the compression slightly, just not mental

 

thanks for the help to ads