camshaft

1941 - 1945, MB, GPW Technical questions and discussions, regarding anything related to the WWII jeep.
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chucks_toy
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camshaft

Post by chucks_toy » Thu Jul 20, 2017 8:23 pm

Can you use a camshaft from a late cj2a engine in a Willys mb engine? Also what is the difference between a Mb oil pump and a late cj2a oil pump? Got a machine shop trying to put a late cj2a camshaft in a willys mb engine. Will this work?
C Strickland


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Re: camshaft

Post by artificer » Fri Jul 21, 2017 12:47 am

I can possibly get toasted on this....but if we are learning, is that important?
Camshaft & distributor drive gear [interchangeable between MB & later models] must be compatible.
John GIBBINS Member Institute of Automotive Mechanical Engineers [Ret], ASE Master Medium/Heavy Truck & Auto Technician USA -2002 Licensed Motor Mech NSW MVIC 49593 Current 2015
TO DIAGNOSE, TROUBLESHOOT OR FAULT FIND ANY AUTO SYSTEM....
Understand how system parts interact with one another. GOOD parts can then be established & the NOT GOOD problem/s part/s isolated for repair or replacement.

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Ron Geddes
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Re: camshaft

Post by Ron Geddes » Fri Jul 21, 2017 2:03 am

Hi ---- Unless you change to gear drive cam & cranky you would not be able to use the cam shaft it has a different way the gear is attached to the shaft. If you do a search I did a post a few years back on how to do it using a latter shaft. Ron

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Re: camshaft

Post by pkozak1 » Fri Jul 21, 2017 5:00 am

Doesn't the Cj gear driven camshaft spin opposite of the MB chain drive camshaft?

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Re: camshaft

Post by Wolfman » Fri Jul 21, 2017 5:23 am

Technically, yes, but it won't be simple.
The main issues will not be with the cam but how it is held in the block. The cam itself will fit.
To begin, the early cam is chain driven. The later cam is gear driven. The two cams rotate in the opposite direction.
The oil pump is the same. The oil pump gear is not. Because of the difference in cam rotation, the teeth on the oil pump drive and driven gear are slanted in the opposite direction. Teeth angle difference in the gear teeth make oil pump and distributor rotate the same direction on each engine. The distributor will interchange.
Here is the main issues.
The chain drive cam is held in by a spring and plunger in the front of the cam that pushes against a pin in the timing chain cover.
The gear drive cam is held in by an oval shaped plate with two ears that have bolt holes and bolts that screw into the front of the engine block.
The chain sprocket and cam gear will not interchange between the two type cams.
The front engine plate on the chain drive engine has a round hole for a brass thrust washer.
The gear drive front engine plate has an oval hole for the oval shaped cam retaining plate with ears. The block on the chain drive block does not have the threaded bolt holes for the oval retaining plate bolts.
The gear drive cam front engine plate and timing chain cover is also taller than the chain cam engine plate and cover. The gear drive cam gear is larger in diameter so these two pieces have to be taller.
With the gear drive cam, you would have to replace the cam gear, crank gear, front engine plate, timing gear cover, oil pump ( or at least the pump gear ) and figure out how to retain the cam in the block. No bolt holes.
I have put a chain drive cam in a gear drive block. That's another story. I have never put a gear drive cam in a chain drive block. But It is possible if you want to bad enough.
Personally, I would replace the chain drive cam. Unless you have a pile of extra parts lying around and love a challenge.
Mike Wolford
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Sean Collins
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Re: camshaft

Post by Sean Collins » Fri Jul 21, 2017 8:08 am

chucks_toy wrote:
Thu Jul 20, 2017 8:23 pm
Can you use a camshaft from a late cj2a engine in a Willys mb engine? .... Got a machine shop trying to put a late cj2a camshaft in a willys mb engine. Will this work?
Not without non-trivial modifications to the block: accurately drill & tap 3 holes in front of the block (2 for cam retainer plate, 1 for gear squirt oiler), and weld a piece of metal on block casting.

Image

Then you have to swap all related parts: camshaft, gears, oil pump or gear, front engine plate & timing cover (or modify chain plate & cover).
 

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Re: camshaft

Post by Sean Collins » Fri Jul 21, 2017 8:11 am

Wolfman wrote:
Fri Jul 21, 2017 5:23 am
,,, The gear drive cam front engine plate and timing chain cover is also taller than the chain cam engine plate and cover. ...
Correction, they are same height. It's the front of the block casting that is taller (to cover the larger cam retainer hole and provide enough meat to drill & tap the upper cam retainer bolt hole without break-out).

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Ron Geddes
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Re: camshaft

Post by Ron Geddes » Fri Jul 21, 2017 8:32 pm

I have changed two MB engines to gear drive as I mentioned in a post a few back I posted a how to make it possible you can use the timing cover as it is the same just minus the peg
RON"

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Re: camshaft

Post by chucks_toy » Mon Jul 24, 2017 3:25 am

Thanks to everyone that has come forth with information on this subject.
C Strickland


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