what pistion should i use z900 z1000j head 8-1 com

i hope some one can help..new motor kawasaki z1000 1976 73mm wiseco pistion with z1000 j head.the motor has been cc'ed ond only has 8-1 comp. .what piston do i need to run this going into a race bike

73 mm is 1105, i think they only made those pistons in 10.25 to 1 your compression is low due to the j head swap. you can get custom pistons made, deck it to bring it back up, or use a kz head. thats the only things i can think of.

thats a turbo comp

stock is about 8.7 - 1

race can start at 10 and go though 13 to 1

You could check with ape to see if they stock an 1105 kit for j-series motor,they don't list one on the website but Im sure they don't list every combination they can get.
Or you could just call mr turbo and get it over with! :woohoo:

i have z1000 with 1105-73mm pistons,and have fitted a z1000j head,the comp has gone to 8-1.i have seen this done before,i am at a loss as to what pistons i can get to up the comp.i have tipped $$$ into the head as it is to go on my race bike and i dont want to not use it..can any one help with info ,cheers

You're going to need J model pistons with a spacer under your block. Make sure you measure your deck height and leave plenty of "squish". It is also very important to check valve to piston clearance if you're using a race only cam.

I installed a J-head with stage 1 porting on my 1260 KZ bottom end using this combination and it was the biggest improvement I ever made to my bracket bike. A real kick in the pants.

I would give APE a call. They have everything you need.

More info here

just go turbo lol, internally your done, stock j cams are great for boost

MTC Wiesco or any piston manufurer make pistons for using a KZ bottom end with a J cylinder head. The wrist pin hole is moved to allow for the extra KZ rod length. Call the manufacturer of choice.

don

There is no off the shelf piston for this application. Besy way is to run a J piston and a .040" spacer.

73mm is not available. 72 and 74 are.

If the OPs block is a KZ1000 with the oem sleeves bored to 73mm, it is a poor choice for a race motor. Put some bigger sleeves in it and run 74 or 75 mm J pistons.

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