will a 16v 4age big or small port head fit on a 20v bottem end

 

beacuse ive been told by a few people that it can, and some it carn't

i'd like someone to let me know the correct answer

 

cheers

if thenobbler sees this, he should be able to tell you how possible, and how much work is needed to fit a 16v head to a 20v block. his old twincam was running this setup.

The blocks are identical, I've even dummied up a 4AC head on one. You'll make an interference motor for sure, but the compression will be up there. If its a smallport head there won't be an oil drain port on the block though.

so big port is a better for 20v bottem end

If its a smallport head there won't be an oil drain port on the block though.

 

Smallports have the oil drain. Bigports don't. 20V and smallport blocks are identical along with the crank, both are the 7 rib block.

also identical to the ae92 onwards GZE

ahhh so i'll need a small port head wwith a silvertop block

is there any problems with the pistons

The number of ribs, bearings, crank, rods are much the same. But there is no provision for an external oil drain like a 100kw block. The 20v head had a new design for the oil drain and didn't require an external drain to stop the head filling with oil. You'll have an interference motor with any 16V head on the 20V block. Also the keyway on the crank is a few degree's out of whack. You'll need adjustable timing gears to get it spot on.

 

also identical to the ae92 onwards GZE