willysmjeeps.com

This post is a copy of a question one of our new members sent me in a private email that should be aired here so all members can benefit from the info exchange.

From Louc99:

Hello, my name is Lou - im new to the forum. I'm pretty sure my engine is in need of an overhaul due to low compressions ( mid 50s and low 60s). But before I start looking for an engine machine shop that I trust to do the work, I want to make sure I actually know what specific model of L-134 I have. I've obtained the engine block number on the passenger side of the block, and also the engine serial number just above the water pump. I wonder if you would be kind enough to look at these numbers and let me know what you believe is the model of engine, and the approximate year group that it was manufactured - hopefully from that I will be able to research the engine re-build specs before I contract to have it rebuilt.

Engine Ser # - MC86605
Block # - 841087-L-W-12A N1-CR-N2

I truly appreciate anything you can tell me about this engine - It is set up as a military engine with "fording" spark plugs, and wires and fording vent lines, etc etc. (I doubt that it has ever wondered into fording depth environments).
Again, thanks in advance. lou
Sent from my iPad.

Hello Lou,



You should have just posted this question on our technical board and you would have gotten 3 or 4 responses already. On our web site there are several references that answer this question. My photo album is the second album in member's albums and has a great sub-album devoted to the L134 and it's production history and changes. All the needed manuals are on our downloads page.



Some basics for the Willys L134 history are WWII casting 638632 used thru 1946/early 47. The 641087 entered production in 47 and occasionally during 47-48-49 Willys would throw a few hundred surplus 638632 casting from surplus sales back into the production line. The 641087 casting went thru several changes during it's production life. Four to be exact. The differences are clearly illustrated in my photo L-134 sub-album. Version 4 was actually an entirely new casting however someone forgot to have the engine mill add the new casting number thus we ended up with version 4 being the identical twin of the next casting in the L134 lineup, 804380. This switch happened during January thru March 1952. Your 641087 casting was used in all the Willys L134 chassis built from 1947 thru 1952 both civilian & military and their serial numbers are consecutive in military contracts.



So you should review my L134 sub-album and let us know exactly which version of 641087 you have and one of us will finish the answers to your questions.



Regards,

Wes K

PS. Here's the link to the post I created for this topic: http://www.willysmjeeps.com/v2/modules. ... ly&t=13582