The Stovebolt Site Forums The Shop Area The HiPo Shop Wet sleeve 235?

Since the 261 engines are getting scarce and E$$$$$PENSIVE, has anyone thought about making a 235 into a Rube Goldberg "261"? I've just discovered a flanged sleeve intended for a small displacement Cummins Diesel engine with a 95MM bore size. That converts to an inch measurement bore size of 3.740- - - -just .010" shy of the 261's 3 3/4" bore. I'm pretty sure that sleeve could be opened up by any machine shop with a Sunnen CK-10 power hone to equal a standard bore 261. The sleeves aren't all that expensive- - - -$34.00 from an Ebay seller, with free shipping. Yes, I ordered one! I'm going to see if I can bore out a junk 235 block that I'm scavenging some usable parts from, to see if it's feasible to install the sleeve. The small flange on top will get a counterbore so the cylinder head will hold it down, and there will be a press fit at the bottom to prevent coolant leakage into the crankcase in case I "hit water" before the boring job is finished.

www.ebay.com/itm/388651586061

www.ebay.com/itm/232095741821?

There's another sneaky trick I remember from my round track racing days. We used to bore all the way through the cylinder walls on the Ford Pinto overhead cam 4 cylinder engines, and install a 4" bore Chevy 350 piston and sleeve. Then we would pour the bottom 3/4" of the water jacket full of epoxy to seal off any potential coolant leaks. I don't see a reason a stovebolt couldn't get the same treatment, since a lot of them have been running around with that much (or more) crud built up at the bottom of the water jacket! A 3 3/4" bore"235" combined with my big block Chevy V8 connecting rod and a 4" stroke- - - - -equals 265 cubic inches!

Jerry

Probably just me but I think I'd prefer the first option rather than the second. The press fit at the bottom sounds better. Good luck. Are there any less expensive pistons that would work in this?

It's not an either/or option- - - -it's both the press fit and the epoxy layer. By using a custom length big block Chevy connecting rod, a 4" stroke, and either a 292 Ford or a 265 Chevy piston, the "261" can gain a few cubic inches in the process, and use commonly available, less expensive parts than the conventional 261 bits and pieces.
Jerry

The Honda guys are making open deck engines no longer open deck by filling the block with sugar up to the level below the deck of how thick they want the epoxy to be, then pouring epoxy up to deck level, and of course carving out coolant holes to match the head gasket. Then they're going insane with boost and RPM, and the epoxy is standing up to it. So it seems perfectly reasonable to do the same with a layer of it in the bottom of a stovebolt to keep the sleeves leak free.

I wonder if anyone ever tried that with the GMC fuel pincher diesel engine. It's open deck, and prone to fail head gaskets because of that.

Those little Pinto OHC 4 cylinder engines were turning 9500-10K RPM in the "Outlaw Mini" dirt track classes- - - - -they sounded like a whizzed-off bumblebee!
Jerry

The sleeve arrived in yesterday's mail, and it looks pretty promising. It has a wall thickness of just about 1/16", which would require the 235 cylinder to be bored out approximately 3/8" to install it. I'm not sure if that would leave any of the original cylinder walls intact, but I've been successful with similar modifications on engines that get a lot more abuse than the average stovebolt engine. For the cost of one sleeve and a little machining time on an otherwise junk block, it's definitely worth a try. The Ebay vendor's ad says "more than 10 available" so the sleeve is not some kind of exotic, expensive part that's going to disappear any time soon!
Jerry