sidexside comparison std. vs. 1075cc

while doing a 1075cc overbore on some std.j model cylinders i snapped a couple shots to show the difference in cylinder wall thickness as it has come up a few times in the past.







leon

Looks like my 903 bores after installing a 1015 kit. Got a 1015 block and am wondering it it can be bored to 1105. Don't look like it.
Steve

steve,
here is a page from the wiseco catalog.




it looks as though they believe 1105 cc to be the last overbore on your 1015 cyl.

leon

you should see 750 turbo cylinders after 810 overbore.

DFIGPZ wrote: you should see 750 turbo cylinders after 810 overbore.

I assume you are referring to them being thin. That's why I didn't want to bore my 750 to 810. Makes me nervous.

My 1015 in my 903 block did seem to run hot. I got my 1015 block and it was like normal. I'd have to get the sleeves bored for the 1105 but I think bigger sleeves is a better idea. That means opening the case more to accept them. I ran the 1015/903 block for years with a oil cooler. The 1105 will be mandatory. :dry:
Steve

That really shows the diff ....... my 700cc bore did about the same to my 650....... can see why they did away with the 720 and 740 kit although I'm sure some of it was to reduce inventory too.

It doesn't make sense to me going less than 50cc. If I do decide to go bigger it will be 1105 or I will stay with the 100cc overbore. In my case the 750 crank was a good idea at the time but I didn't know the stroke was shorter.That was in the 80's and not much was known about the Z2 750. I think I would get more ponies with a 903 crank and hotter cams.
Steve

swest wrote: It doesn't make sense to me going less than 50cc. If I do decide to go bigger it will be 1105 or I will stay with the 100cc overbore. In my case the 750 crank was a good idea at the time but I didn't know the stroke was shorter.That was in the 80's and not much was known about the Z2 750. I think I would get more ponies with a 903 crank and hotter cams.
Steve

Only go 1105cc as a last resort on a worn 1075cc liners.
1105 leaves the liner spigot very thin and is prone to cracking and also excess oil usage.
Don't ruin a good set of 1015 liners going 1105.
you won't really see a worthwhile difference over 1075.