Later d17 saved from fence row

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   M & W were 7.5 to 1 compression with a 4 1/8" bore. Don't get confused here. It was two things: bore and compression. Raising a 4 inch bore from 7.25 to 7.5 to 1 compression would indeed be a minimal increase in HP.  WD45's can use D-17 pistons and sleeves and just like M & W's give the crankshaft a real workout if it is a plowing/discing tractor. Just the compression increase on a WD45 to 7.25 to 1 would yield 5 to 7 HP I think at 1400 RPM. I'd have to check my engine specs book at home, I'm going from memory.

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DrAllis Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 12 Sep 2009 Points: 22650	Post Options Post Reply Quote DrAllis Report Post Thanks(1) Quote Reply Posted: 05 Feb 2026 at 9:57am
	M & W were 7.5 to 1 compression with a 4 1/8" bore. Don't get confused here. It was two things: bore and compression. Raising a 4 inch bore from 7.25 to 7.5 to 1 compression would indeed be a minimal increase in HP. WD45's can use D-17 pistons and sleeves and just like M & W's give the crankshaft a real workout if it is a plowing/discing tractor. Just the compression increase on a WD45 to 7.25 to 1 would yield 5 to 7 HP I think at 1400 RPM. I'd have to check my engine specs book at home, I'm going from memory.

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55allis Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 30 Jun 2020 Location: Griswold Iowa Points: 1291	Post Options Post Reply Quote 55allis Report Post Thanks(0) Quote Reply Posted: 1 hour 28 minutes ago at 11:57pm
	Got a Reliance kit a couple days ago and now ready to get the block from machine shop (he’s still trying to get me to do the secondary sleeves). He got new cam bearings and got the block maniflex and it checked out okay. What should the oil pressure be being rebuilt? Looking at new gauges and there are a lot of options!! Notice the new pistons have a note to run on a dyno within minutes of first starting it, does that have to be done or is there another trick that’s better?
	1955 AC WD45 diesel with D262 repower, 1949 AC WD, 1963 A-C D17 series 3, several Allis garden tractors