Advice on stroker build with cracked cylinder
I've had a cracked cylinder in a 440. After a new sleeve was put in, as a test we lightly skim-bored the new cylinder surface with a (same KeyWay) cylinder bore.
After that it became obvious the bore hadn't touched the area where the original crack was. The sleeve had conformed itself slightly to the old cylinder shape. (I have pics of this somewhere but need to put them on my site)
Given that experience, and you're saying you will race the engine anyway, I would say do a 'partial or half fill' with concrete in the block to limit any further distortions and have an ease of mind.
Then you didn't use a .125 wall sleeve.
One thing I always do is look at all the sleeves available. I didn't just order the sleeve that the book called for.
I can't remember the part number that was called out for a 340 (I used to but I'm older now and that's what they make charts and catalogues for) but, if I was doing a sleeve for your engine and you were going to go .040 over, (so a finished bore size of 4.080-4.081ish depending on what you need for piston to wall clearance) I'd look at the chart of available sleeve sizes and look for a sleeve the correct length (or longer as it's easy to top cut the sleeve and if it's way too long put it in the lathe and part it off first...it ain't that hard) and with a bore size of 4.100ish.
But you say...I'm only going to be 4.08ish finished. Yup you are. But the sleeves are .030-0.035 UNDER nominal bore size.
That means, once the sleeve is pressed in (you only need .001-.0015 press on a sleeve that diameter and if you leave a .100 wide ledge at the bottom for the sleeve to seat on it will never ever move) you will have a bore diameter of roughly 4.068-4.070ish and that's PLENTY of material to hone out. You don't even have to bore it.
When you are done, your sleeve will have about a .125 wall or a bit more and the damn thing is made of better material than the block.
Some of the fastest guys in the country were sleeving all 8 holes back in the day before you could get harder aftermarket blocks, especially they Chevy guys because the stock Chevy block is soft as butter compared to the Chrysler.
That is the brief rundown of how to correctly select a sleeve. It ain't that hard.
Put a sleeve in that hoopty and get on with it. I've sleeved blocks that have been blown alcohol, stuff that's been in the low 7's naturally aspirated and everything in between.
Think about it...every single aluminum block out there has 8 sleeves in it.
