Z1OwnersClub GB

hi, my z1r has been 1105 for a long time and always wanted to go bigger, but with the big blocks becoming harder to come by, i am thinking of going 1260 .
i know they use the original block so the block must be quite thin to get the larger liners in. but want to know if they are fragile ? can the liners move because of the thinner block ? and will they leak / seep from the bottom of the block to the crankcases ?, as that will also be thinner.
i am not expecting to go commuting on it, or have perfect trouble free riding, but i dont want to keep tearing it down to fix persistent leaks that i know i can never cure, or wish i had never gone down the road and waitted for a big block to come up for sale.
also was it worth doing regarding torque, and rwhp.
any help appreciated,

Buddy



Rob is the man you need to talk to rob1015 on here

Phil

The only issue when boring out the block is that you can break through the barrel casting to open air and get some minor oil seepage.
This does not have to be the case though if a liner bond is used.
I would also paint the block to protect any exposed liner material but Z1R's should be black anyway.
I also just happen to have a set of un-used Wiseco (los angeles liner co) 1200 liners doing nowt and i think also a bare block if needed.
These are a slightly smaller o'd and less risk of breaking out of the block.
You don't even have to go straight to 1200 either as the liners will take 1105 to start then 1135, then 1200.
There's no need to have any other oil leaks though if it's assembled correctly.
You will have to have the crankcase mouths bored to take the larger liner spigots as i'm sure you already know.

Jeff Saunders on here runs a 1973 Z1 at 1200cc with turbo.
Send a message and he may be able to advise how it was done.
From Mark