F script

OK, what do I have here? I bought a trailer full of patrs almost 2 full jeeps in parts. Only one motor but the motor has an F-script head and a serial number on the block I can't identify. I'll try and attach some picts. The serial no. is on the boss on the upper pass. side of the block, #U56551. If it is a script motor it should have a gpw serial# right? The block cast no. is 638632 W5 AN-OR
Thanks for any info you guys can provide.
http://i71.photobucket.com/albums/i133/climbingrouven/My 2a page/serialno.jpg
http://i71.photobucket.com/albums/i133/climbingrouven/My 2a page/Fscripthead.jpg
http://i71.photobucket.com/albums/i133/climbingrouven/My 2a page/block.jpg
http://i71.photobucket.com/albums/i133/climbingrouven/My 2a page/blockcastingno-1.jpg
http://i71.photobucket.com/albums/i133/climbingrouven/My 2a page/blockcastingno.jpg

 

If ya don't find out here, try over at g503.com. Those guys are the WWII Jeep experts.

 

It looks like a GPW engine for sure. I can't help with the numbers, but Ron is right, the guys at g503 know their military stuff.

Jim

 

it is not a gpw or mb engine.
these engines have the
MB and GPW prefix followed by the S/N
stamped into the boss on the right front of the engine
behind the oil filler.
the expert on engines on the g503 is Dino.
if it was a gpw or mb engine
it would go like hot cakes on g503!!!
iowa

 

It looks to me to be a '46 wagon motor with a gpw head.
U= utility
T= truck
R= replacement
J3= CJ3a
J2= CJ2a
Did it have a manifold with a weird looking casting bracket?
638632 is the early block cast #'s
This is probably a chain drive motor but not for sure as they changed to a gear during the end of this casting #.
Gary

 

638632 is a Willys casting number for a chain drive engine . So although it could be a MB block or column shift 2A block the serial number says it's not. Looks like it's a very early Wagon engine. Is there a serial number on the water pump boss too?

 

lil willy
i saw you post on the G503.
very interesting.
iowa

 

Yes, I thought so too. I'm going to have to do some more searching and see if I can find any more numbers. I would be fantastic if it Was an MB block. Sell it and buy more parts for thr '48. The PO owner had it rebuit and never ran it. Even if its not a MB a spare rebuit engin is handy to have. I might pull the head off and sell just the head. Being GPW it might be worth somthing. I have an '46 head I could put back on it.

 

lil willy
you said that you had more parts.
the axles also are dated.
at least the block is wwii
it most be a wwii engine.
they show up in the darnest places
iowa

 

I only have the motor. All the other parts that I got are 2A& 3A for shure. I asked some more questions on g503, will see what other info I can gleen. Besides the serial no. what are the diffrences between a willys and a MB motor? Thanks lil'willy

 

On the bottom of the block under the oilpan is an assembly date. It's the only place that lists the year. That would confirm whether its WWll or not, Bill

 

Timing chain v/s timing gears. I think the timing cover. The cylinder head is definately different (improved) but interchangeable. Crank, cam, pistons, rods, oil pump, distributor are all interchangeable. The front plate that has the motor mounts on it is also different. Flywheel, starter are also different. If you got nit-picky you could go on all day.

 

The way to tell the difference between a GPW engine block and a 2A block is very simple.

1. 2A block; serial # is pressed into a flat portion above where the water pump is mounted. The other #'s are casting #'s.

2. GPW block; serial # is on the side under where the generator mounts.****There is no flat portion above where the water pump mounts. It is rounded off.****

To make it simple, if there is a flat area above where the water pump mounts, it's a 2A block. If that area is rounded off, it's a GPW block.

Also, you have a 2A head if there is a raised ridge that runs along where it bolts to the block. The GPW/MB heads are smooth with no ridges. (along with the script "F")