Since this is my first post, I wanted to introduce myself. I live in Chattanooga, TN and am an Engineer. I have been playing with cars for almost 40 years now. My latest project is something I have been wanting to do for a long time. I am putting a V8 flathead in a Ford 9N tractor. I found a 9N with a cracked block that I bought for s**** value. It has one almost new rear tire and the other is pretty nice. I intend to buy a conversion kit from Awesome Henry as soon as the dust clears on the engine. I obtained an 8BA flathead from a '50 truck and tore it down. It was cracked between a valve and cylinder. I wasn't too worried as I read that this is common. The engine had been left outside as a casualty of late model drivetrain in the '50 truck. It had water on one side worse than the other, but some on both sides. The cylinder with a crack also had pitting so I ***umed that it would have to be sleeved. Long story short, the block has 6 cracks by valves and would have to go .125 over (plus 1 sleeve). I will save this block for posterity, but he found me a better block for about what all that machine work would cost and it finished only .030 over. Roberts Machine Shop here in town is doing my work. They have a stellar reputation and so far I see why. They have been great to work with. We are almost to the re***embly stage. They will install the crank and cam and adjust the valves and I will finish ***embling from there. My question is this: They were a little wary of the original nylon cam gear (no damage, just old) so I ordered a new aluminum one. They do not come with the lower gear as a set. Is it necessary to replace the crank gear also? I don't want to cheap out on this, but it seems to me that since it was nylon on steel that the crank gear probably does not wear much. I cannot find any definitive answer on the Internet. I have been lurking for while and this forum seems to have a lot of knowledge. Your thoughts on new vs: used crank gears with a new cam gear in a flathead? Thank you!
The original gear wasn't nylon, it was a woven/impregnated/fiber based material. I think it's a lot like phenolic. But anyway, it is perfectly fine to reuse the original crank gear. Commonly done with no problems.
you're still better off with the aluminum 'commercial/industrial' cam gear; The only thing to 'check' is to match the new gear to the old one(making sure its an 8BA gear, as the 59 gear had the teeth slanted the other way ; the late gear set pushes the cam towards the 'front' of the motor, while the early set pushes it towards the 'rear' of the motor.
"6 cracks by the valves" and pitting? If I were you, I'd spend some time trying to find a better block. The cracks you "don't have to worry about" are the ones between the water holes and headbolt holes. There are still some good blocks out there; you will be ahead both time, money, and future relability-wise to find a better block. Sleevin' usually ain't cheap.
I did find a better block. I hate to junk this one though. Someday it may be a "good" block. Thank you for all your comments. I will stay with the crank gear I have. When I finish this thing I will post some pics.
I just had a cylinder in an 8BA sleeved. It ran $160.00 if I remember correctly. Sure wouldn't want to do 8 of them.
^^^ This is what I would have said nearly word for word. Scary actually. The only way to tell if you need to replace the crank gear is to give it a good look, your machinist should be able to do that for you if he is worth his salt. but you should be fine with it like alchemy said.
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