I figured I would show one of the projects I had worked on a little while ago. We basically made a 1954 239 Y block into a 283 cubic inch stroker. We did this by boring the block .125 over which utilizes the same bore as the 256 Merc. and I believe the 272 Y block. Memories a little short right now. I searched long and far for a useable and affordable 312 crankshaft which everyone seemed to have but nobody seemed to want to part with or wanted way too much money for, and one person had one that needed the snout welded up to be useable. Finally found one and had the mains ground down to a standard 239 main bearing size. I also ended up having to get 312 rods. The pistons I bought for a 256 mercury, but the tops of the pistons had to be milled down for the proper compression height, and the bottoms of the pistons had to be milled for crankshaft counterweight clearance. Dummied up we found out we had to cut the counterweights down in a lathe because we still didn't have enough clearance. The heads are one of the last sets my father ported and polished.
Here are some more pictures. I didn't want to overload all in one post. The paint used inside the oil pan and cylinder heads is just Rustoleum Rusty Metal Primer, and it holds up very well to heat and oil.
Their was a bit of a learning curve on this particular build, luckily this 239 block had the same cam bearing bore dimensions as the 272 and later blocks. I also had a hellacious time degreeing the cam in as the timing set and books that I had, had no information as to putting I think it's 13 pins between the marks on the 2 gears. I think the first time I degreed it the cam was installed at something like a 150 degree intake centerline which was way off. This was my first Y block rebuild I have ever done. I think we figured it was going to have about 250-280hp as the camshaft was very mild, basically it was an RV cam that a guy had from forever ago.
Sadly no news on it. Their was a bit of misunderstanding because of too many people involved we parted ways. It happens and if anything bad happened to it, I'm sure I would have heard about it. It was probably one of the most expensive builds I've ever done. Parts and time were a big factor on that one.
What is the advantage of using the 239 over the more common 292 Y block? Y block's have a great sound............
Cool to see someone using the earliest yblock parts in a build. I see more than a couple parts being used there. I know what your talking about when you degree a yblock cam in. Worked a couple days on mine before I got it. The problem in the end was me. Once I figured it out it was no problem. FWIW its 12 pins between the marks. Good luck, keep us posted.
Their was no advantage, it was what he pulled out of his 1954 pickup truck, and he wanted to use as many of the original parts as he could. Price wise he would have been better off getting a 272, 292 or even doing a 351W. The 351W would have been the cheapest way to go. Price was what ended up sending us our separate ways.
Yeah the 12 pins is what got me. I was a little angry at the timing set company that they didn't have instructions on how to install the set. It was my first Y block build and that info would have been nice to have, I can just imagine someone new to Y Blocks aligning the marks like on a small block Ford or Chevy in chassis and putting everything back together just to have it not run.
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