I have an original flathead motor from a 40 that has sleeves and is std bore. (cyls bad) I was told that an old trick was to take out the sleeves, hone the cyls and use oversize pistons anyone ever head of this and if so anyone know what size pistons to use ? thanks
If your flatty has sleeves, it's that way for a reason. Maybe cracks, maybe just worn. You can't "take out" the sleeves. Most of your big diesels have replaceable sleeves, but not gas engines. When an engine is sleeved, the cylinder is bored out, then the sleeve is PRESSED in. After that, the cylinder is bored and honed back to standard dimensions. So, depending on how bad the cylinder is worn, you may be able to get the block boredand honed again with no problems. .030" is the norm. Something else you'll want to check, flatheads sometimes have a problem with cracks in the cylinders. I've seen quite a few crack out of the valve seat, up, over, and down the cylinder wall.
If I recall correctly, there were flatheads produced with sleeves that were not repairs. I can't remember which engines, probably around the time Mercs went to a 239, but those Fords are the ones that the sleeves could be knocked out of for a larger bore. Bruce Lancaster, where are you on this one?
The late 221's used "tin can" sleeves from the factory. And yes, you can knock them out and put in an oversize piston, though I think it's kind of an odd-ball size and possibly hard to find now a days.
One of my early '50s Hot Rod magazines mentions knocking out the factory sleeves, honing the bores, and using .082 oversize pistons that were available in '51, but are probably extinct today.
Obviously....I couldnt resist that! Ford built one block for the 221 & 239 from 39 to sometime during WW2. The Ford got sleeved, unsleeved was for Mercs, some industrial and some war stuff. The 43 1/2 ton I have was sleeved and was a WW2 purchase for the B&M RR. Repair/replacement sleeves are also available at Joblot.
Actually there are two series of blocks in EACH displacement--the 239's of this period have incredibly thick cylinder walls, much thicker than the 221's. These 99 series blocks seem to be the thickest flatheads by far. These blocks used to be the standard fuel dragster block. The period is roughly '39-41 or so. Both series were produced with and without sleeves in assembly production. Production sleeves were thin sheet with a lip at the top. Ford also sold rebuilder type thick cast sleeves for engimes with serious problems. Production sleeves when worn were to be removed by simply crushing them inward, then new ones put in for a quick, cheap rebuild with no machinist needed. There used to be pistons available for the oddball oversize you got by removing the sleeve, but you can also just bore a little more and use standard 239 pistons in a 221 block. Some of the step remains, but it is above standard top ring. This is cheap, as there are pistons available at places like Joblot, but there are practically no standard bore engines anymore! I've got the press kit for installing the origianl sleeves if you want to just change out sleeves. The sleeves should be miked first--they are pretty hard, and it is not unusual to find them reuseable.
Bruce, Thanks for the info, I will pass it on to my machine shop. Mike Duffy Kingston, NY 31 Av8 roadster
Good information. I've got a '40 flathead sitting around that is sleeved also, but maybe they are replacement sleeves because the engine rebuilders tag is marked as standard bore.
the motor in my roadster has all 8 bores sleeved, So I have always thought that is was a factory job, as it has had a ford factory rebuild during its lifetime. However this is an 8BA series motor. I got this motor out of a boat, so not sure what it originally came from.
I haven't checked their catalog or anything but I'd bet Egge Machine can make pistons to fit the sleeveless bore if it's one they don't already make.
Don’t feel bad, it’s only 15 years old, - the record is held by someone else, - for bringing up a 17 year old thread........ and it was actually @KenC who brought it back............it is a quite interesting thread though !
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