Re: ZL1 3946052 spotted today at Pomona Swap Meet
 

Got the engine back from the machine shop and there are no date codes on it. There is a series of numbers opposite the casting number but I don't see any way they could be a date code. I will post them tomorrow. If any one is interested in this engine please let me know, otherwise it will be going on EBay soon(probably tomorrow) . The heads pressure tested good. The block is also crack free. The crank is STD/STD.


Jason

Re: ZL1 3946052 spotted today at Pomona Swap Meet
 

Jason;
The way you describe your engine, I think you have a service only - 4.440 bore block, not a ZL-1.These large bore blocks can't be resleeved to a 4.250 bore. Sorry for the bad news.
Ron

Re: ZL1 3946052 spotted today at Pomona Swap Meet
 

According to the machine shop it can.


Jason

Re: ZL1 3946052 spotted today at Pomona Swap Meet
 

You better talk to the machine shop again. Even if they could find sleeves to fit they would be too thick to cool properly. It doesn't take much to have over heating problems with a big block.
Ron

Re: ZL1 3946052 spotted today at Pomona Swap Meet
 

Jason, I dont think this is a feasable swap to use a 4.250 sleeve where a 4.440 sleeve is used...Remember the OD on the sleeve vs. yours. Your Block should be the 4.250 version. https://www.yenko.net/ubbthreads/imag...mlins/grin.gif https://www.yenko.net/ubbthreads/imag...lins/beers.gif

Re: ZL1 3946052 spotted today at Pomona Swap Meet
 

That is just what the machine shop told me. If it were me I'd run it this way anyway.


Jason

Re: ZL1 3946052 spotted today at Pomona Swap Meet
 

This will be my last post on this. Here is where Ill ask the who's who of this BOARD as well as any others in the know: Sleeve size : does the 4.250 sleeve have a different OD than any larger displacement sleeve to be used here, 4.440 or 4.500 & larger? I am guessing now, but if a larger sleeve is installed, would the aluminum core have to be machined to accept that larger OD if this is the case? https://www.yenko.net/ubbthreads/imag...s/confused.gif [the last time I saw this engine setup at Pomona, it was assembled as such in your attatchment above. I never saw the sleeves being different with the heads bolted on.] https://www.yenko.net/ubbthreads/imag...lins/beers.gif

Re: ZL1 3946052 spotted today at Pomona Swap Meet
 

rpoz11
You are correct, sleeve od's are different. The blocks were the same when they were casted, but as you mentioned the aluminum cores were bored out alot bigger for the 4.440 application. The 4.250 ZL-1 could only be bored saftly to 4.300. Chevrolet made these blocks from 1969 to 1972. Hope this helps.
Ron https://www.yenko.net/ubbthreads/imag...ns/scholar.gif