R.O.C.K Restoration Project

Guess I'll start looking for a new block.

Do you think the head will be OK?

I will begin tearing it apart tomorrow and will post my findings.
 
rockfarmer":2x87rkvm said:
Do you think the head will be OK?
The only way I know to check for sure is to have it magnifluxed. You could also get an opinion on repairing the block from a good machine shop. I've read that welding a freeze damaged cracked block has been done in non stressed areas on some other tractor engines like SA and A. Never had any experience with this type repair.
 
rockfarmer":370hzb5s said:
Do you think the head will be OK?
Look at the casting dates on the head and the block, if they are way different then the head may have been replaced when the freeze happened. With the block and the front bolster both being repaired I wouldn't think those were the only 2 places it froze and busted but I could be wrong.
 
staninlowerAL":3o8epykk said:
. . . I've not found a "fix" so far. Any ideas?
This is one situation where Chipmaker's comment from earlier might apply:

Chipmaker":3o8epykk said:
. . . Fix what leaks and needs fixing, don't worry about what don't need fixing . . .
If the engine is running fine, decent compression and not burning a bunch of oil, it might be best left alone. I wouldn't do major mechanical work on a defective block but there really is no point in discarding a functional engine if the problem is no more than cosmetic.

People don't generally expect a perfect stock restoration on a tractor (or anything else) that is donated to charity to be auctioned or raffled. If you spend more on the restoration than the auction/raffle yields, the charity would have been better served by giving them the money!
 
Fix it too nice....you won't want to part with it.
Get it clean and running good.
No warranty expressed or implied.
A good running decent Cub around my area runs around $1800- 2500. Your areas average value is going to be a factor in what it is worth.....

Restored see higher prices than easy to sell.
 
rockfarmer":2f2jl390 said:
Guess I'll start looking for a new block.
One other possibility that you could discuss with the machine shop is to drill and pin the crack. This involves drilling and driving brass pins into the holes so that the pins overlap. Since the engine runs at atmospheric pressure this process works well if it can be done. Some breaks do not lend itself to this type repair.
 
Using a hand crank, with the exhaust manifold removed, I got the following compression numbers:

Cylinder 1 2 3 4
Dry - 55 45 65 45
Wet- 90 50 95 65

Test method
1. Remove spark plug.
2. Connect compression tube with tight fit.
3. Hand crank as fast as possible for 5-6 revolutions.
4. Record number as dry value.
5. Relieve pressure.
6. Repeat 1-5 with one tablespoon of 10W-30 and record as wet value(s).
 
I repeated the wet test on #2 cylinder,

# 2 Cylinder wet compression test.jpg
..after I noticed a small puddle of oil on the floor. Traced it to #2 exhaust port. I presume the exhaust valve was open while adding oil or too much was added.

There was a slight improvement, from 50 to 60 psi, but based on what I have read, the numbers are still too low... aren't they?

This is the first time I have run a compression test on an engine, maybe I'm not doing it correctly, or, it just needs new rings.

Anyway, It is probably going on a road trip to Thrall, TX tomorrow. Machine shop. Let them evaluate it.
 
Chipmaker":1e4vazh5 said:
rockfarmer":1e4vazh5 said:
Do you think the head will be OK?
Look at the casting dates on the head and the block, if they are way different then the head may have been replaced when the freeze happened. With the block and the front bolster both being repaired I wouldn't think those were the only 2 places it froze and busted but I could be wrong.

I don't see any other repairs or cracks, yet. The head casting is 1-14-C
 
Hi,
You could look at the engine serial number, you probably know where it is, to the rear of the carburetor, stamped in the engine block. And look at the block part number and casting date, below the carb. The whole engine could have been replaced, or just the head.

In your pic above, it looks like the high speed limit bolt, on the governor is screwed down all the way, it probably needs to be backed out so the throttle can open.
Also, the stop on the throttle arm is not in line with the end of the bolt, unless it is just the pic making it look that way. Something probably needs fixing there. Maybe the arm needs to go on the shaft farther.

I would oil the shaft and arm while it is easy to get to, so it turns easily, they commonly get tight there from no oil.

Below is a pic from TM Tractor, of how they should fit, and the bolt usually has to be about in this position, if it is the original length bolt. :)
 

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  • Cub gov 8.jpg
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Here's the page from ENG 1 REV 20 12-75 detailing the head applications:head.jpg Looks like Engine SN 312589 and below used head PN 251 221 R1 and Engine SN 312590 as well as Number series LOBOY used head PN 355 691 R2. Part of the increased HP change.
 
Engine serial number is 80322
Block ID 251341 R2
6-10-S
Exhaust valve - 251 261 R1

Wiped with acetone
49 Cub Block wiped.jpg
Look original?
Piston 49 Cub.jpg

I noticed a small crack at #4 and #3 cylinder where the head bolt and triangular shaped coolant port meet, which, coincidentally is located next to the JB Weld we found.

I think we should probably replace this one. Never know, I might be the highest bidder :D
 
Glen":3cd519m9 said:
Hi,

S is the code for 1949, so the block was made on June 10, 1949. Maybe you already knew that. :)



So, Glen, based on your information, in keeping as close to the "original" theme as possible, we need to replace the block with an S code.

Well, a few days ago, we were offered a free block with an S on it by one of our members. I'm not going to mention his name without permission first, but he lives in the great state of Alabama :hattip:

Also, we just received a brand new;
49 Grill.jpg
Sure does make the rest of Rocky (our tractor) look bad!

Thanks Chipmaker!
 
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