Quote:
Originally Posted by Rev. Buzz
Thank You Gentlemen Especially Frank
What would it take to put 3.5 L heads on a 3.8 L ?
I have heard that this would raise compression to around 9.5 - 9.75. That would be wonderful if possible !
Also how difficult is it to change out the cams ?
Hopefully this doesn't envolve removing the heads.
Thank You Gentlemen !
Sincerely
Rev. Buzz
|
To address the matter of CR only, the heads from the 3.5 engine would give a ratio of 9:1 - 9.1:1. The change in total chamber volume is on the order of 6 cc; ~60 cc to 54 cc.
Compression ratio aside, five head bolts in each head are in a slightly different location in the block,
and, they are ~2 degrees inclined from the normal. There is also the matter of differences in chain tensioners and tensioner rails, steering pump mountings, alternator mountings, and air injection provisions.
If cams were to be exchanged, ones from other aluminum block engines do exchange directly, without head removal, provided that the head bolts that pass thru the cam stands come out cleanly.
A complete 4.2L M116 engine may well be the most satisfactory approach. All ancillaries, including exhaust manifolds, attach directly. Only the intake system (air guide & air/fuel meter, WUR), oil pan, and oil filter from the 3.8 would be reused.