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.
User avatar
Ron Geddes
G-First Lieutenant
G-First Lieutenant
Posts: 692
Joined: Mon Dec 30, 2002 9:14 pm
Location: Australia [Melbourne]

Post by Ron Geddes » Tue Apr 17, 2007 10:25 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.
RON

JeeperFIN
G-Sergeant Major
G-Sergeant Major
Posts: 174
Joined: Tue Feb 02, 2010 6:12 am
Location: Finland

Re: Civi crank in GPW

Post by JeeperFIN » Fri Feb 24, 2017 2:05 am

Those who are using F-head crank in MB/GPW block, Did you machine the oil hole for the timing gear?
https://www.facebook.com/pages/2nd-Armo ... 1736259059
Chevrolet G506 -42, Willys MB -44, GMC CCKW 353 -44, Ben Hur -42

Ben Dover
Gee Addict
Posts: 42005
Joined: Sun Mar 02, 2008 2:37 pm
Location: Proving Ground

Re: Civi crank in GPW

Post by Ben Dover » Fri Feb 24, 2017 5:28 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.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO

JeeperFIN
G-Sergeant Major
G-Sergeant Major
Posts: 174
Joined: Tue Feb 02, 2010 6:12 am
Location: Finland

Re: Civi crank in GPW

Post by JeeperFIN » Fri Feb 24, 2017 11:05 pm

Just wondering will the oil filter passage lubricate the chain... Or do i have to machine the hole to the crank....
https://www.facebook.com/pages/2nd-Armo ... 1736259059
Chevrolet G506 -42, Willys MB -44, GMC CCKW 353 -44, Ben Hur -42

Marty, SoCal
G-Lieutenant General
G-Lieutenant General
Posts: 5842
Joined: Thu Mar 09, 2006 12:34 pm

Re: Civi crank in GPW

Post by Marty, SoCal » Sun Feb 26, 2017 8:34 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:
Image

Image

Image

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.

Image

Image

Image

Image

Here's the oil hole that needs to be drilled to match a chain drive crank:
Image

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!

Image

This shows the counterweight easily clears the pipe plug now. No other mods were needed inside the block
Image

Hope this helps!
43 Ford GPW 92098
53 Dunbar Kapple M100
Sold: 61 CJ-5, 41 T207 WC-1 Dodge closed cab pickup
MVPA #8266
USMC Tanker (1811, 1812), 85-93
ASE Automotive Master tech, former Chrysler-Jeep Level 4 Mastertech, CA state EA smog license

Post Reply

Return to “MB GPW Modifications”

Who is online

Users browsing this forum: No registered users and 7 guests