Civi crank in GPW

1941 - 1945, MB, GPW modifications, sugestions, and ideas, official MWO's and unofficial WWII field mods NO EBAY or COMMERCIAL SALES.
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Ron Geddes
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Post by Ron Geddes » Tue Apr 17, 2007 9:25 pm

HI---- I have cj2a shaft in my MB with timing gears if you go to my older post I have listed what is required to change to the latter shaft if I knew how to repost the info I would have. The f/head shaft is the same.
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JeeperFIN
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Re: Civi crank in GPW

Post by JeeperFIN » Fri Feb 24, 2017 12:05 am

Those who are using F-head crank in MB/GPW block, Did you machine the oil hole for the timing gear?

Joe Gopan
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Re: Civi crank in GPW

Post by Joe Gopan » Fri Feb 24, 2017 3:28 am

One can outsmart one's self by endorsing or attempting these little "fixes". I do have an NOS GPW Crankshaft in a NOS "F-Head" block and the crankshaft gear does seal the front oil hole on the chain drive crank shaft.
As for CJ-2A Crankshafts making for smoother running Jeep Engine, WWII mechanics and drivers would comment on the GPW having a smoother running engine-there was a difference.
One major detail to note when swapping crankshaft types is that the oil galley plugs inside the crank case do not interfere with the counterweights of the crank shaft.
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JeeperFIN
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Re: Civi crank in GPW

Post by JeeperFIN » Fri Feb 24, 2017 9:05 pm

Just wondering will the oil filter passage lubricate the chain... Or do i have to machine the hole to the crank....

Marty, SoCal
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Re: Civi crank in GPW

Post by Marty, SoCal » Sun Feb 26, 2017 6:34 am

For a little extra chain oiling, I drilled a small oiling hole in the front block pipe plug, and a corresponding hole in the front plate on my friend's chain drive MB block with a gear drive crank. Here's how I did it.

While the engine is apart, take a timing plate gasket and use it to get the location for the hole in the front plate:
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Then use the gasket to mark the location on the plate to drill it for the squirter.

I used a new pipe plug and drilled a .040" hole in the center of it to act as a squirter. The hole is the same size as the jet on a gear drive engine.

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Here's the oil hole that needs to be drilled to match a chain drive crank:
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Here is the pipe plug inside the block that will get hit by the counterweighted crank, you must fit a flush plug here. The person who assembled the engine previously to me left the stock plug in and it was hitting!

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This shows the counterweight easily clears the pipe plug now. No other mods were needed inside the block
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Hope this helps!
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