Early Knuck Engine Case Questions and rebuild info

[BTH14]

Hey guys,

I recently picked up a 40EL basket case along with some extra parts. Some of these extra parts are mixed matched engine cases. Trying to figure out what exactly I have, so I figured I'd post a couple questions.

1.) The cases on the assembled motor are long ribbed cases with the serial number 40EL88XX. The Vin boss is pretty thick with no signs of grinding down and the numbers look unaltered as well. The belly numbers match but they are only 2 digit numbers. "28" is stamped on both sides. Are this factory replacement cases?t This is currently the only explanation I can come up with.

2.) Also have a pair of short rib cases with 1937 casting dates and non matching belly numbers. Cases are in very good shape with no cracks or welds. Unfortunately the vin on the left case has been ground off, doesn't seem like a stolen part though because there is still part of the cast in the cylinder area. Is this also a replacement case of some sort? It has a full belly number. Fair prices for these cases?

3.) Last case is a right side 38 case with a weld repair near the front motor mount. What is a fair price for this?

4.) Lastly what is the average cost of complete knucklehead engine rebuild?

I realize that there is not a specific value for certain items, I'm just trying to find out what fair asking prices are. I'm just out of college, so funds are limited. Plan is to sell the extra parts to fund most of the restoration while doing as much as possible myself.

Thanks in advance for the help guys.

[Chris Haynes]

[QUOTE=BTH14;106461]Hey guys,

I recently picked up a 40EL basket case along with some extra parts. Some of these extra parts are mixed matched engine cases. Trying to figure out what exactly I have, so I figured I'd post a couple questions.

1.) The cases on the assembled motor are long ribbed cases with the serial number 40EL88XX. The Vin boss is pretty thick with no signs of grinding down and the numbers look unaltered as well. The belly numbers match but they are only 2 digit numbers. "28" is stamped on both sides. Are this factory replacement cases?t This is currently the only explanation I can come up with.
It certainly sounds like replacement cases.

2.) Also have a pair of short rib cases with 1937 casting dates and non matching belly numbers. Cases are in very good shape with no cracks or welds. Unfortunately the vin on the left case has been ground off, doesn't seem like a stolen part though because there is still part of the cast in the cylinder area. Is this also a replacement case of some sort? It has a full belly number. Fair prices for these cases?
It is an altered serial number and is illegal to own or posess.

3.) Last case is a right side 38 case with a weld repair near the front motor mount. What is a fair price for this? Without knowing if it is stolen or not it is hard to place a valve on something I can't see.

4.) Lastly what is the average cost of complete knucklehead engine rebuild?
My last Knuck rebuild cost $800.00 labor plus parts.

I realize that there is not a specific value for certain items, I'm just trying to find out what fair asking prices are. I'm just out of college, so funds are limited. Plan is to sell the extra parts to fund most of the restoration while doing as much as possible myself.

"A picture is worth a thousand words".

[BTH14]

Here are some pics of the 37 and 38 right side cases, the 37 is in nice shape, the 38 has the weld repair shown and also the unremoved casting mentioned previously. Any other thoughts on their value and why the 38 Case is like this?

weld on 38 Case



Extra material on 38 Case



37 Case



Another 37 Case Pic



Once again I appreciate any help guys.

[dommi7]

By extra casting are you referring to the oil baffles in the cylinder bore? Those are supposed to be there and unaltered until, I believe, 1941 when the oil control ring was introduced.
Shoot some pics that show the whole case half inside view and out. On the left side, show a closeup of the serial number.
Value for the parts is whatever you and a buyer agree upon. If you are in college, you can probably search the auction sites to get some idea. Title paperwork increases value as does authenticity (no alterations).
The full engine rebuild is a hugely variable number - it depends on what parts you may require. With no further knowledge, I can only say the cost is in the $$$$ range not $$$.
If you need case repair or extensive machining, the price goes up. If your parts are cherry and you only need a rebore and new pistons, the cost is pretty low.

[BTH14]

I didn't realize those were oil baffles, I thought all the knucks had an oil ring, this is still very much a learning process for me. The 37 case doesn't have them so I guess they were removed at some point.

[Chris Haynes]

The 1938 case may have a date casting code inside the flywheel area. It would be a letter and a number.

[T. Cotten]

Unfortunately the vin on the left case has been ground off, doesn't seem like a stolen part though because there is still part of the cast in the cylinder area. .

BTH14!

Stolen or not, if the VIN has been defaced, it has been felonized.

Sorry,

....Cotten

[BTH14]

I have full paperwork for the 40EL but these cases were in boxes of spare parts that have been sitting in a basement since the mid 70's.

Whats the proper thing to do with the ground down case? I certainly don't want anything to do with an illegal part.

[Chris Haynes]

Paperwork doesn't mean anything if the numbers have been altered.

[koanes]

It sounds like your 40 numbered cases are factory replacements. Most of the replacement cases I have seen had a matching 2 digit number on the bottom. 40 cases commonly cracked at the left case from the numberboss area around to the mating surface just above the front motor mount and were often replaced. As for your other cases they have value, l think the 37's would bring somewhere between 1000.00 and 2000.00 and the right case alone usually bring 400.00 to 1000.00 depending on overall condition. Don't be discouraged by the doomsayers, you have good and valuable parts that you can legally sell. Good luck with your project.

[BTH14]

Paperwork doesn't mean anything if the numbers have been altered.

The 40 Vin on the replacement cases hasn't been touched, The Boss is the correct thickness, numbers are good.


Kyle,

Thanks for the response, I'm just trying get to a ball park idea if these are decent parts.

[Jerry Wieland]

If the 40 number that is stamped on the replacement case is the first number there then it is 100% a legal case. Now I did not say it would be a hassle free case but provisions were in place to replace legal cases that got heavily damaged or destroyed - 40 and 41 were very prone to self destruction. The one problem that has reared it ugly head is that what was considered destroyed in 1950 might not be viewed as such today and if the person doing the stamping did not detroy the original case as he was required to do then it might still exist today and might be deemed fixable with its' story lost to time.

The bike would not be considered worthy of AMCA judging with that case but for most of us it could be a bike to fix up ride and be proud very of - naysayers be dammed.

I would though always be on the lookout for good 1940 cases or at least a leftside however

Jerry

[BTH14]

I'd like to restore the 40EL as close to original as possible but with the intent of being able to ride it often. Both my grandfather and father had a number of knucks when they were younger so the real purpose here is to basically carry on the tradition. Its not a big deal but I was under the impression the replacement cases are acceptable for judging as long as paperwork and numbers are in good order.

Once again I appreciate all the info guys

[T. Cotten]

BTH14!
Kyle is absolutely right, there is always someone willing to pay good money for a felonized case.

But they better not show it daylight in Illinois, (or most other States) lest it will be become the wrong kind of "History".

...Cotten

[Perry Ruiter]

1.) The cases on the assembled motor are long ribbed cases with the serial number 40EL88XX.

Anyone know what 1940 production was? 88xx seems an unusually high number to me ... Perry