Let's Tear down an Engine

[Deleted]

I recently purchased a complete L-134 off of Craigslist, the block is junk but has many usefull parts. My dad was an avid gun collector and would say as he was inspecting an old Winchester Lever action, "If It Could Only Talk", well for the most part it can, so can a Jeep engine, so lets see what this one has to say! ;D. This thread will work better with comments and input by YOU the Viewer, lets all learn sompthing.

The engine



Typicall 134, or is it!, Notice the welded cracks, that appeared to be leaking, The distributor is froze in the block, and "It ran Great when removed 20 years ago",,,,,,,,,,,I bet not!



Haines Garage will find this block Interesting, Here are the casting numbers on the side, Anyone Know what they mean?




More to come later.

Lee

[Deleted]

The block has the s/n on the water pump boss, but also has the pad behind the oil filter bracket.



Here is a shot of the thermostat hsg, NO Tstat, but hey it ran great when removed



The water outlet in the head, notice the cast rib in the bottom of the opening,,,,,,,it is a tan color,,,this is a sign of overheating, I have seen this before. Note the broken bolts for the T Stat hsg., do they ever all come out ?



Here is a tip, always remove the temp gage adapter before the head is removed, this offers more leverage for a stubborn adapter



Lots of crap in the hole



Here is the head, I have highlighted the words with soapstone, all typical



Lee

[Deleted]

Lee...do you think the old serial number has been ground off of the boss behind the oil filter? I know there are replacement war time engines out there that were blank, too. They should have some sort of stamping on the opposite side, above the valve cover plate.

But the boss looks like it was milled after the fact. I once had a GPW replacement block, clean boss, and I don't think it had any of those evident milling marks. I'm not sure if I have pictures of that engine any more.

Those numbers on the bottom will code it for you, though. But...I don't know how to read them. I'm sure you do, though!

[Haines Garage]

What a Fantastic Thread!!
Those #s look familiar to an engine I own
Can't wait to see where this conversation goes

[Deleted]

Hmmmmmmmmm, I have done NO research, that responsibility belongs to you Will-is enthousiast's, HEY, Im the guy getting dirty pointing things out ...............So, the casting# 641087 tells us it's a post war block. Moose, a WW2 block does not have a number pad behind the water pump, IMHO I do not think there ever was a number on the side pad on this block. Also a WW2 block casting # is ???032 I believe..................The head is stuck to the block extra bad.

Lee

[Deleted]

I wasn't aware of that casting ever having the side oval serial number pad. Interesting. I was going to say late war buy back block.

SN on head surface is?? Gear drive I assume?

[Deleted]

I've got a buddy, locally, with a '42 GPW. He's got a GPW head, but a post war block. The boss behind the oil filter is there, but it is about the size of a quarter...not the oval shape of the wartime blocks.

And Leo...I ran out to my GPW and looked behind the water pump. I'll be darned...there is a flat spot, but nowhere near as big as the CJ's.

Its been a great week for Bo...I've learned a few things! ;D

[Deleted]

Dec 3, 2013 22:30:52 GMT -5 @fbill said:

I wasn't aware of that casting ever having the side oval serial number pad. Interesting. I was going to say late war buy back block.

SN on head surface is?? Gear drive I assume?

Bill, I would side with you on this, gear drive yes, and very interesting, I have 2 other blocks I need to check casting # on them and see if they have the 032 or 087. I may e-mail wes K on this.

Lee

[Deleted]

The S/N behind the water pump is J144786, so a true 2A block, a little digging has told me some 641087 blocks had a pad behind the oil filter, This I did not know. The buy back blocks would have a casting number of 638632 and be chain driven cams, hopefully the macineing date is stamped on the oil pan web near the rear main cap, this will date the block. I will get the engine on the stand this weekend. Very cold here today, zero degrees right now .

Lee

[Haines Garage]

Here is the numbers stamped on the water pump boss on mine.



My grind marks on the oval look similar to yours.

I am going to check for the build date stamp.

This has been a long arguement on my chain Drive 134.

In no way trying to pirate this thread.

Markings are very interesting to talk about....

Should you like your very own board to do so...say when

Please continue on the tear down...It is FUN!!

[Deleted]

Dec 6, 2013 19:15:19 GMT -5 Haines Garage said:

Here is the numbers stamped on the water pump boss on mine.



My grind marks on the oval look similar to yours.

I am going to check for the build date stamp.

This has been a long arguement on my chain Drive 134.

In no way trying to pirate this thread.

Markings are very interesting to talk about....

Should you like your very own board to do so...say when

Please continue on the tear down...It is FUN!!

WOW!, that's an early one, your casting number is 638632, right?. Another interesting thing is at what point did they quit stamping CJ2A#####, just use the J#####, I find these numbers very interesting, And Haines your not in any way pirating, that's what this thread is all about, I would like to see the numbers of other members engines, carry on ;D.

Lee

[Haines Garage]

I will create a board for Jeep numbers, if this is of interest to our members

[athawk11]

Great informative thread. Nicely done!

I find the identical cracks in the heads to be very interesting.

The engine numbers are always fun to see. We all seem to like to discover the history of the engines.

Here are a few of mine...


This one is strange. This is a GPW engine in a 3A. I'm pretty sure this is a WWII surplus engine. The serial numbers were generally wiped clean on these. Not sure why this looks like this. This engine also has the oval pad behind the oil filter, but there is no number on it at all...





This is the engine in Whitey, a pretty early 3A. Notice the different fonts used for the '3'...




This is the engine in a 1946 2A, # 44017. It's a pretty early engine, but I'm not sure it's original to this Willys. It only has the 'J' . No CJ2A in front of the number...



I have one more engine I picked up before the PO planned to take it to the scrap yard. I can make out most of the digits, but I can't get a good photo right now. 3J 8010x If there is a last number, I can't see it.

Anyway, thought I would add to the discussion.

Tim

[Deleted]

Tim, thank you for your input, several things come to mind.

GPW engines are in a league of there own, and are of great intrest to me as well. WW2 engines did not have anything stamped behind the water pump (typically), the s/n was stamped on the oval pad behind the oil filter canister.

I wonder if 3 before the J notes a 3A engine? (3JXXXXX) anyone know?.

We may have discovered something already, HG's engine,CJ2A 28123, Tims early 2A, J45343, being 18,000 apart, did the change happen between them?, and we know HG's is a 638632 casting and chain driven, Tim is yours?, I bet it is a 641087 casting and gear driven. And I would speculate the CJ2A was dropped as they went to gear drive and then just used the J prefix.

Haines I really think we need an engine numbers board as you suggested, may take a little time to fill with knowledge but a very interesting topic.

Tim if indeed your J45xxx block has a casting number of 641087, look and see if it has the oval pad behind the oil filter.

[athawk11]

Okay, Engine J45343 is casting 641087, a gear drive, and does have the oval boss behind the filter.

Yes, 3 before J does denote a 3A engine. As the years progress, the stampings become more specific to the vehicle they were going to end up in. For example, a 'T' in the engine serial # means it was destined to be installed in a truck.

Tim

[Haines Garage]

Sir Leemeister, you wish is my command...Love it!

[Deleted]

Tim, "Excellent info", so at this point we will assume that the CJ2A prefix ended with the 638632, then the next series 641087, they started the J prefix and if you have a CJ2A prefix it is most likely a c/d engine. Not bad detective work for novice enthusiasts .

So at this point detectives we need to figure out when the oval pad on the side of the early 641087 castings disappeared, I have an early MC block (m38) that is a 641087 and it does not have the pad.

Also if you have a block with a "U" prefix I believe that was a wagon engine or Utility.

All great info, Lee

[Haines Garage]

Sir Leemeister, I am going to create a whole board for this information...
And Guess what...I am putting you in charge!!!

Might even be a promotion in the ranks here at the IFFC

[Haines Garage]

Here are my Block casting #s

[Deleted]

Well,,,,,Thank you I guess,,,,,Cool!, may be a while before it gets going, we went Christmas shopping tonight and coming home I picked up the mail, and my new M-38 reference guide by Ryan Miller was in the box, lots of engine info in there, ssssssppoooky. I plan on educating myself a little prior to the persuit of this board. I would also like to add, a camera gets mighty F'ing greasy while photographing an engine tear down ;D. I did get the engine on the stand today, but have issues,,,,,dist. is frozen to the block, the head absolutely refuses to let go of the block, and have found some disappointment number wise. I did learn something today, if anyone tells you the rods and pistons will not come out the bottom they are full of s$%t, I did it!, details will be posted tomorrow.

Lee

[Deleted]

Okay, back to "The Meat and Potato's", the manifolds were hanging on by a thread, I do not know why if replacing a stud why one would not get the correct length,?



The center nut was very rusty and undersized so I split it with a cold chisel.



I think the "Critters" have wintered in there a few years ;D


Care full inspection of the manifold shows none of the dreaded cracks, looks as if I have lucked out there.




Here is a shot of the flywheel timing marks, if you are assembling an engine make sure you get the flywheel properly positioned and not 180 degrees off.



The bottom end exposed, no surprises.



After care full cleaning of the oil pan web, I was disappointed that I did not find any machining dates stamped, Damn, this would have added to our detective work.




Lee

[Deleted]

After removing a rod cap, I took a photo of a rod bearing shell, you can see the .020 stamping this tells us the rod journals have been reground .020 UNDERSIZED, and requires a .020 OVER SIZED bearing.



With all the rod caps removed you can see the journals, no suprises here, a little scuffing and wear, I would guess this engine did not have the greatest oil pressure.



Here is a bearing shell, it's not wore through the "Tin", a good sign.



Here I am performing an inspection of the journal, My dear old friend "Bob" taught me this many years ago, if you drag your thumbnail across the journal, and it catches at any point, the crankshaft will need to be ground, His rule of thumb ;D, works for me!,,,,,,, and yes it did not pass the rule of thumb test .



Lee

[Deleted]

Here is the front cover, what will we find there ?



Well, it's gear drive, note the oil spray nozzle.


The cover is very clean, note the spring on the oil seal, it's on the wet side of the seal.



Here I am removing the rear main bearing cap, I am sharing a little trick for doing this.



The main bearings look to be in very good shape, note the rope type seal, and the dowel in the bearing.




Lee

[Deleted]

The Main bearings were also .020 over sized, I also found .010 stamped on the crankshaft, so this crank has been resurfaced two times, very common on a 70 yo engine, the good news is there is plenty of "Meat" for another resurfacing, providing the crank has no cracks.

Here is a shot of the flywheel dowels, Note they are the tapered type, later engines have straight dowels, you will need to know this if your replacing a crankshaft, so you have the proper dowels to match the crank, and flywheel, or if your installing a later crank in an early engine you will need to modify the flywheel.



Here is the spacer behind the front cover, do not forget to install this on an overhaul, I did once,,,,,,,,,that's how we learn ;D


I have never seen this fiber spacer before that I recall, it was on the shaft to keep the metal spacer from cocking on assembly.


Here is a picture of a new bearing I will use for example, Note the 10 86 .040, this is a clue,,,,,,,,,,,the bearings in this engine were not date coded like this one, this surprised me as most are, so if your tearing down an engine inspect the bearing shells closely for a date code, it may be a clue to when the engine was last rebuilt......This bearing was made the tenth month of 1986 and is .040 over sized. this is an example of how an engine talks to us ;D



Here are the four rod Assembly's, I had to remove them from the bottom as the head will not come off the block, and yes they will come out the bottom with the crank removed from the block.



Note the rod in the photo, it's #2 as stamped, on a GoDevil 134 and a Hurricane 134 the rod numbers face the camshaft on assembly, common on most engines.



A Little more on rods, a 134 rod is offset to the crankshaft, as you can see in the photo, so rod one and three are the same, and two and four are the same, do not mix them up, again the rod number faces the camshaft.



Lee

[Deleted]

I am telling you guys, these engines talk , below is the photo Sir Haines posted earlier of his block, note the "A" after the S/N


The "A" means the engine was factory shipped with .010 oversized main and rod bearings or a .010 undersized crankshaft main and rod journals , another way too look at this is for what ever reason the crank was not standard, most likely a mistake was made in it's first grind so rather than waste it they went .010 undersize and saved it, a cost saving measure. I found this info in several service manuals, so no secret.

Lee