Help with J head swap

I am getting ready to put a J model head on my KZ1000A4. I have the head already (thanks Cary). I will be tearing down and replacing the springs and valve seals. It will also be blasted and painted. What will I need to buy to get it on the bike? I know I need a cam chain tower. Will I need different cam sprockets than what the J cams come with? I have 10.5-1 compression pistons. I know the J head will drop compression. What will I need to do to keep my compression up. Doesn't have to be 10.5-1 but needs to at least be stock or better. Any other advice would be great.

If you are going to do pistons too, use J pistons with a spacer and the comp ratio, etc is taken care of.

If not, you can mill the head to get compression back, but then you will have piston to valve issues. You may have to cut piston valve pockets which are a different angle.

Jay

the j head will drop it to 8.5-1 wont it? add a turbo!:evil: :evil:

I'm doing the same with my MKII and What Jay says is apparantly the simplest from what I've heard. J pistons with spacer. The J pistons will be flycut for the valves too whereas the KZ pistons the valve angles are slightly different....

I've heard about a wiseco piston kit that is 1076 for just such a conversion, but Jay would probably know more about this than myself...

Yes. If you want to go 1075cc, the Wiseco K1076 piston kit and a spacer and you've got it.

Jay

I already have the 10.5-1 Yoshimura pistons that I have been running in my MKII. Can I still use these pistons? It should make the compression close to stock right?

Would I be better off using the whole top end from a J (head, cylinders and pistons)? I have them all available in the back yard (again, thanks Cary). What is the piston spacer you guys are talking about?

Not a piston spacer but a cylinder block spacer to raise the block and head up as the rods in the earlier 1000's are a little longer.
It's considered bad form to smack the cylinder head or valves with the pistons

Is the spacer something that APE sells or is it just an extra few head gaskets?

Spacers kzzone.com/blocks.html

You can not use the J model/GPZ block on a KZ case.

Jay

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Jay beat me by three minutes (I type slow)

Post edited by: steell, at: 2006/11/23 17:03

Cool. So to keep the highest compression but still clear the valves what size spacer do I need? Also how does it work with gaskets? Is it the regular head gasket under the spacer and special gasket on top?