Quote:
Originally Posted by stu e  Hi All
I've been reading old posts about fitting composite head gaskets.
I understand if the heads are not skimmed by 26 thou you lose compression, can anyone tell me how that will effect the performance? My engine has composite gaskets fitted but did not have that much taken off the face, i was just wondering if they were skimmed if i'd notice any difference, or would it be a waste of time?
Regards Stu |
Bit of a "half educated" guess but you'll probably have lost round 10 BHP, maybe a bit more. whether you'd notice that is anyone's guess but tuning is all about small gains here or there adding up to something that is noticable.
If the heads are coming off for another reason that it might be worth having done otherwise its a fair amount of work for not that much BHP.
This is all JMHO, someone like V8 developments could give you a better idea. (They did a good job on mine).
To do the work properly you need to remove the heads, then do the following on least one piston:-
Put the piston on TDC using a clock gauge, not by guessing! You need to seal the piston to the bore with a smear of grease then bolt a piece of perspex to the head also sealed with grease then use a burette to measure the volume above the piston using white spirit poured in via a small hole in the perspex.
If your not a million miles from Bagshot you can borrow the stuff that you need or I could give yo a hand.
Regards,
P.S. 9.75-10:1 is around what you want, anymore and your going to be have to careful with mixture strength and ignition, not to mention the octane rating of the fuel itself!
Pete