So my build has hit a screeching halt. I "got the call" from the machinist today that my '46 59a block has a crack in the lifter valley. From what I've gathered via the HAMB its .... the death crack. A few phone calls later I've located a possible replacement but I'd like to research it as much as I can before I go check it out. The story as it stands is it came out of a '40 military vehicle with +/-37,000 miles on itand the engine was stuck apparently, but it was due to mice when he pulled a head to check. Note that I'm saying vehicle because I'm not sure if it was a jeep or a truck or what, but from passed experience of where the engine is, I would assume it to be out of a truck as he has quite a few.... Anyway I wanted to know if it is a 40 can it still accept the late merc crank, be bored out to 3-5/16", and have the valves enlarged? I've already began ordering parts for what was to be my 59ab. Any tips on ID'ing a block in the field (literally)?
If actually 1940 vintage sides of block will have bulges leading down to 2 freeze plugs on each pan rail. If '41 up, common wartime, intake manifold surface of block will have a raised-looking platform for manifold that looks just about like the manifold gasket. Both generations can be sorted by the center vertical row of water holes on the decks...lower 2 holes are trapezoidal on 221, 239 has lower trapezoid but next hole is round. Merc crank direcly fits all 24 stud except 1938, 221's can generally go to 3 3/16 bu 5/16 is probably out of reach.
Awesome! Thanks Bruce. I was hoping you would chime in. I've read through quite a few of the other posts and this is the definitive answer I was looking for. Here's to hoping its a 239!
Also always check for the '46-8 "59" on bell of ANY 24 stud vehicle, as that was essentiallyu the universal replacement and MANY earlier vehicles now have one. And post a picture of your crcked areas for commentary...as the supply of good blocks dwindles, "lethal" is a moving target.
Oldsboy, Just for suture reference jeeps had not happened yet in '40. Once they did all were bangers, never built a V-8 jeep.
I'll be heading to the machine shop next Friday so I'll snap some photos as I'm out of town currently. I'm definitely hanging onto the block though as it was beyond good in all other aspects, so I'll post and see what everyone thinks. Good point on the 59 on the bell. The place I'm going is about 3 acres of miscellaneous flatheads strewn about. Unfortunately they aren't all covered and out of the weather. So I'll see if I can find a usable one... Thanks for the heads up. Before I posted the thread I did a search and couldn't pin point a v8 jeep either. Good to know.
I am going to get this wrong but Ford, Willys and kaiser all put in offerings to the military around the beginning of the war. Willys won the contract. I actually had a ford jeep for awhile back in the '70s. I don't think that many were built and I probably let a real winner get away from me.
there were three Ford jeep types...a prototype (N motor) submitted for the Army request for what became the Jeep, a somewhat different low production Ford N based one built very early in the war before the final jeep was standardized, and then the GPW, which was the Wiilys design built entirely by Ford (almost half of WWII jeeps) because Willys was too small to handle the demand. All were fourbangers, 2 with Ford N motors, the last with Willys design motor.
sorry to hear about your block, I had the same thing happen to mine. looks like you're getting some good info though!
Well I made it to the machinist today and snapped a few shots of the crack. Bruce - Not sure if you have seen anything like this before but the machinist has been around fatheads for awhile and he even said he'd never seen anything like this before either.... What can't be seen is that the crack continues into the lifter bore and up into the guide bore as well... The good news is though I found a replacement, even though its not a 59ab. I ended up going with an 8ba. The military block my friend had was a 40 for sure with 3-1/16 bore.
If that is the full extent of the crack, it could be pinned to seal up the water jacket. It looks like there is enough room to get in there with lock & stitch or equivalent as long as the shop has the proper tools for confined areas. There are hundreds if not thousands of engines working out there with pins in them to seal up cracks. It's real common on industrial engines and old tractors and such. Not so much on blocks that are easy to replace.
That is a strange place for a crack; I'd assume it froze? But I'd expect there to be other cracks down low near the pan rail if it froze hard? Were there others? You're lucky to have such a thorough shop!
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