Engine work on Clausing 8520 possible ?

[Piggiron]

Bought a new (to me) original side-by-side yesterday, a 1946 Jeep cj2a.
It still has the OEM 4-134 L head engine and the valve seats haven't been replaced with hardened ones in order to use unleaded gasoline.
I've been Google searching to try and figure out if milling the block for the new valve seats is possible on my mill before removal and disassembly.

[chips and more]

Great find! I did the hard seats thing in one jeep engine a VERY LONG TIME AGO. No mill, just made a Z bracket kinda thing and a boring bar that fit the valve guide and hole in the Z bracket and fitted with a double ended tool bit ground to hard seat size. Used a hand drill motor. Sorry, can't recall the press fit tolerance that I used?

[TerryWerm]

THAT. IS. COOL!

Just boring for the valve seats should be doable on the 8520 without too much fuss. That head, though not large, is still a fair bit of weight and could potentially cause some stability issues if not careful on that mill. You will probably have to set up the head on the table twice - not enough X travel to do all eight in one set up.

Personally, I would take it to my guy here in town that does automotive machining. Great work, fast turnaround, and reasonably priced, plus the new seats would be installed and valves ground and installed already. That way I could get right down to reassembling the engine in a couple of days, but that's just me.

If you were going to try to plane the head, well, that would be a different story. I believe you would run into rigidity issues in that case, and a shortage of X travel distance, so the 8520 would be out in that case.

Whatever you choose to do, have fun!

[chips and more]

I could be wrong but are we talking about a flat head engine? And mounting that engine "block" on the clausing mill is challenging.

[TerryWerm]

Oh crap! I never thought about it, but he did say it was an L head engine, or flat head, not valve in head. Putting that whole block on the 8520 table would definitely be too big and too heavy. I don't think it would even fit between the table and the spindle if the table was all the way down.

[Piggiron]

Yep, valves in the block.
Figured it would be tight, if possible.
Little 143 cid 4 banger, total engine weight little over 300 lbs. Head off and stripped down, block alone guessing closer to 200 lbs or so.
60 HP and about 105 ft/lbs of torque in a low (6.48:1) compression engine designed to run on 62 octane uncracked gas.
I saw on a video that the original engine test ran it for 100 hours straight at max rpm and it kept on running. No wonder the GI's nicknamed it the Go Devil engine.

[chips and more]

My first car was a 1942 Ford GPW Jeep with a model A body all morphed together. The engine was kinda OK. It would spin rod bearings, fuel pump failures, carb problems, wore out timing chains yearly, exhaust manifold cracking and more. I remember adding a Waren overdrive to the transfer case. It helped a lot on reducing engine RPM's. But then that overdrive had its own problem and would freeze up, geez. But I learned a lot from that jeep. Yeah, what kinda soap works best on greasy hands LOL.