1947 Farmall M Update - Machine Shop Woes

Ken Christopherson

Well-known Member
Well everyone... It seems I always pick the "basket cases" to work on. I'm beginning to feel the squeeze that this old M is putting on me. I have been sitting in limbo lately, doing small things like cleaning parts and priming the small pieces that I can... Nothing really "video worthy". But I figured since I don't have a press and a system to ream the wrist pin bushings, I might as well stop at the machine shop where the head and block are to see if they can tackle the job.

Here is what I have learned during today's visit:

1) The block is too big with the cylinder head studs in place to fit in their hot tank/rotisserie. They made a short attempt at removing the studs, but after turning on two decided to stop before they break one to see what I wanted to do. They informed me that they can get them out, but would have to bill me at an hourly rate of $85/hour, and some may break thereby needing more machine work. Otherwise I could take the block home and clean it up as best I can (still needing to install new cam bearings, since I already bought them). My dilemma is what to do. I don't have any oxy/acet setup to heat the studs but am sure if I did, they would most likely come right out.

2) The head looks real good EXCEPT... There are two very minor cracks - which they do not seem at all worried about. One in the surface leading from a coolant passage hole, and the other between two valve seats in combustion chamber 1. They are going to magnaflux/pressure test it after they get the new seats installed to see where we are at. They stated that they were not at all worried about it... I guess we will see where it goes from here. I know it is expensive to weld/repair cast (at least not from what I have heard), and cylinder heads for these M's aren't cheap either. Let's hope for the best on this.

3) Received the new bearings for the water pump today. Still waiting on seals, packing, and my gasket material. That will probably be the next video I do - Water Pump Rebuild.

4) I was going to purchase a governor rebuild kit (found one for about $85 with governor throttle rod), but I think I will wait to figure out what happens with the machine shop - wouldn't hurt to tear into my governor to see what is worn as well before spending the money on a kit.

5) On the connecting rod/wrist pin bushing press out/in & reaming.. My machine shop does not have a large enough ream, but I did find one local to me that can do the job. I'll be bringing the rods/bushings/wrist pins to them tomorrow afternoon.

I guess I am looking for opinions here on what to do. Do I just pick the block up, use oven cleaner & a pressure washer to get it as clean as I can and put the cam bearings in myself?
OR:
Do I have the machine shop remove the studs, hot tank, and install the cam bearings for me (potentially breaking some of the studs which may happen to me as well).

I'm beginning to feel the stubbornness of this old girl. Progress is probably going to slow significantly now.. Just gotta keep taking those baby steps.
 
If I was you I would take everything to one machine shop that can do the job. They sound like wannabees that work on nothing larger than Briggs and Strattons.
 
Maybe before you get in any deeper,you might want to give the trans/rear end, hydraulics a good look over. You probably don't want to have any more surprises.
 
I plan on going into the transmission after I get the motor back together. I might as well now that I'm this far into it. At minimum I know I need new brake bands, axle seals, and a pto seal. I've yet to do a tractor where those seals weren't leaking.
 
This shop is well established (30 years), is reputable, and I know many that have gone here with great experiences. Only issue is most of these friends are car guys. Not a whole lot of guys that restore tractors in the suburbs of Minneapolis. As far as the rods and bushings go he just doesn't have a reamer large enough.
 
I guess I just want to be sure that the block is extremely clean. If I'm putting all new bearings in it, I just want to introduce them to the best possible environment.
 
Completely understand, but its not some super hot rod 1000hp engine. Grab a few cans of engine gunk cleaner, or whatever degreaser you like, spray it in and out and blast it with the pressure washer. Havent found a machine shop yet that uses anything other than hot water to clean up blocks now, or find an older machine shop that has a vat to dip it in.
 
i think you better find a machine shop that has a decent hot tank, and capable for the job. an M block is not that big, and i dont know what the gain is to remove the studs. you need a cam bushing installer for the bushings, as not to many people have these . and you say they cant do the pin bushings either. and the head is to be magnafluxed after hot tanking, not after half the work is done to it.
 
I just pull all the galley plugs after stripping the block and pressure wash it well. Blow it off, oil it up, check over the nooks and crannies for more greasy spots, and rewash it until they are all gone. Before assembly, I spray everything out with brake cleaner and blow the galleys out with compressed air. I clean all the old gasket material off, wire wheel the block deck with a die grinder, etc, before washing the block. Local auto parts store has a cam bearing installer you can use for free if someone else doesn't have it at that time.

Ross
 
A reamer is not precise enough for those parts. They should be honed for one to three ten- thousands clearance. Find another shop & get it done right.
 
So far you have gone the extra mile and haven't cut corners. Why start now? It might cost you a few bucks but I would pay them to remove the studs and hot tank it properly. On a tractor that you are trying to do a quality restore on I wouldn't dick around with oven cleaner and a pressure washer.
 
Here are my thoughts.

1. Do not remove the head studs! Even with heat you will will likely twist off several and then have to try and get the broken part out of the block, it is not worth it just to get the block to fit in the hot tank. Take the block to the car wash yourself and spray it down with oven cleaner, let it set several minutes and then wash it off and repeat as necessary.

2. If your machine shop wants to ream the rod bushings, I would be leery of even having that machine shop do any work for me! :shock: Those bushings need to be HONED. A proper machine shop will have a machine to do this.

3. Unless you have a cam bearing installation tool, you will not be able to properly install the new bearings, better have the machine shop do that.
 
Your block did not look that bad to begin with and those blocks are not big on having nooks and crannies. The hot tank will loosen tough crud but you'll end up washing it anyway to get it clean. The oiling system is simple enough that with some rifle brushes, brake cleaner and some diligence you can get them sparkling clean.

Degreaser then pressure wash then go at with scrub brushes and bucket of hot soapy water and you'll be good to go.

A crack between two seats is not great but without seeing it in person it's impossible to judge. If your going with both intake and exhaust seats then it will likely be ok. You may go and buy 10 head cores and every one has some small cracks.

I agree that the pin holes will need to be honed to size vs. reamed but you probably meant that in your typing.

Unless some of the studs are damaged or if there were signs of head gasket leakage due to warping I would leave the studs alone. If you were planning to replace them anyway that's one thing. Gripping tools are likely to marks that are stress risers. My 2 bits.
 
First, let me apologize in my typing. I want to clear things up:

1) The head has been magnafluxed already. They identified the small cracks, and once all new valve seats are installed they will pressure test the head to see how it checks out (not magnaflux again, as I stated previously). Hopefully everything checks out ok. He did not seem at all worried about it.
2) I think that seeing the feedback here, I will likely pick the block up and clean it myself. I am pretty meticulous, and the parts I have cleaned already have come out sparkling, so I am confident I can do a great job on the block.
3) The wrist pin bushings I was told would need to be reamed and/or finish honed to size. I found a shop local that has no issue doing this, and have no issue having it done properly.
4) I had no plans to remove the studs, but seeing as it seemed necessary to get it into his hot tank, I thought it would be an option. Seeing as I am going to tackle the clean up myself, I will leave them in place.

Hopefully this cleared up some issues I may have miscommunicated.
 
Kirk, I posted a follow up message above, but just to quickly clarify - I think I may have confused a couple of terms. You are correct. The bushings will need to be honed to fit the new wrist pins.

I have no issue cleaning the block myself, and would rather not remove the studs. I think this is what I will do.

The cam bearing tool might be tricky. I have watched some do it online themselves with a homemade tool (threaded rod and washers), but I may have them pull the bearings prior to me picking it up and then drop it off again for reinstallation.
 
Change machine shops, that block is smaller than many 6 cylinder engines and tanking it should be normal. Jim
 
I installed new cam bearings ONCE in an engine before I bought the right cam bearing installation tool, I was VERY careful and it was not easy, but I got it done. With the proper tool, installing the cam bearings is a BREEZE!!
 
I agree 100%.

Places I deal with can handle a 14 liter Cummins block, they would be embarrassed if you thought they couldn't handle a little "M" block.

Oh, for gosh sakes!
 
I think that the issue is the fact that they have a rotisserie-style tank. They put the block in a jig, and the jig rotates the block around via the main journals (from what he was explaining to me). With the studs in the block, the entire rotating assembly does not clear the hood/shield components of the tank/washer. (At least that is what I have gathered). It's not the length of the block or height of the block that is the problem, it is the height + the added height of the studs as it rotates around the stationary assembly within the washer.

I think that I will just pick the block up from him and clean it myself. I am pretty meticulous, so I have faith that I will be able to get this thing sparkling clean. A few cans of brake cleaner, a few assorted brushes, some hot soapy Dawn dish soap + water, and a pressure washer and I'm sure I will get it good and clean.
 
I wouldn't hesitate if it were only a few bucks, but let's just say I were to only replace the studs. That is a minimum $200 deal by the time I get all 16. Then add in shop labor of $85/hour to remove them. Add more shop labor if one or more break, that is machining time.. Before you know it I might be at $500+ before I even get the block in the tank to be cleaned. I know I haven't been cutting corners, and that is not what I am trying to do - but I do think that I can do a really great job cleaning it on my own (and not having to replace studs/machine broken ones out/etc. would be a huge plus). I'm just thinking that with my meticulous attitude, and from what others have said, I could probably do a real nice job cleaning it on my own.
 
Ken I know you have had plenty of input already but I will jump in and add another. I have seen your work and I agree with those who said do it yourself. You do a great job of cleaning parts and if it were my block I would have no problem having you clean it up. The cam bushings aren't that hard to do either, I've done many, new cam bushings will be the cheapest part of the overhaul. The only advantage of removing the head studs will be to clean the block deck but can be done without removing studs. You are doing a great job on this old tractor!! I am confident it will run great when you are done. Mark
 
Hmmmm. Ask if you can stand in their shop and try to remove the bolts yourself. Should not cost you anything to stand there and give it a try. Seems like alot of work to take it home and try and take it back. Forget that. If you break some off, eh, pay them to drill them out and re thread as necessary. I don't know man, have not cut corners yet.
 
I would pick up my stuff, pay for work done, and choose another shop.

The head studs do not need to come out unless you are planning on decking the block, after the issue with getting them to reseal, I would not pull them unless needed. I do like to get a block boiled out and get the cam bearings replaced, it just makes for a cleaner assembly.
 
I would think that soaking the studs in PB blaster for a day should result in them coming out. But I wouldn't do it. I agree with others, do the car wash or pressure washer routine with soap. That's cheap and easy and its very sufficient.
Anything that happens to be left behind, well...that's what they make oil filters for.
 
You need to pick up the block and do otherwise with it. Yup just get one of those siphon spray guns and drop the line in a gallon of Stoddard solvent. It will spray it on as you blow air. Will soak things cleaner than you can get with oven cleaner.
The wrist pin bushings can be fit fairly easily. I have fit them with a hone and by feel as they go in. I do my king pins that way also. Cam bearings can be pulled in with a good washer and a bolt. Or by the plug to fit and pull it in with them on a bolt. I would just take a plate and cut to fit the hole in the block with a ledge. For a pull on center. Big thing with cam bearings is to make sure theoil holes line up right.
 
I think that is what I'll be doing. I'm going to tackle the block cleaning myself. Found another shop locally that can handle the wrist pin bushings. This afternoon I'm going to call around to local auto shops to see if they have the cam bearing tool. I've already got the bearings so it's just a matter of getting them out and back in. Oil hole orientation is definitely a big part of it.
 
I thought about asking them that, but from looking at what several others have said (and knowing my meticulous nature), I don't have a problem cleaning the block on my own.
 
Mark, thanks for the input. That's one of the great parts about this forum. Lots of good people willing to give you good, honest advice. I am going to tackle the block cleaning myself and see if there are any local auto shops that I can rent the cam bearing tool from. I've watched many videos on YouTube and it just looks too simple to pay someone to do. If I've gotten this far on my own, the bearings should be of no issue. The wrist pin bushings are another story I think. I'll be bringing them to another shop today. This shop also does flywheel/pressure plate resurfacing. I'll probably drop mine off with them as well. (If you all remember the light surface cracks it had). Stay tuned....
 
(quoted from post at 12:01:17 04/05/16) ... (If you all remember the light surface cracks it had). Stay tuned....

Those light surface cracks are called crazing. It's generally nothing to worry about.
 
The MAIN reason for removing the studs would be to have the block surfaced "decked" to become perfectly flat. ( like milling the head to become flat) There is a certain amount of (warp) allowed form side to side, and front to back. They can check it with a straightedge to determine if it needs to be machined.
This would create a perfect block to head mating surface for the head gasket. The issue would be once the block has been "surfaced" (milled) the recesses the liners go into will need to be milled as well. One to the proper depth, two perfectly round with perfectly square edges for the liner to seal at the top where it meets the block ( once installed). A good experienced machinist who is familiar with this important configuration of block to liner protrusion & fit, can make one better than new. An inexperienced machinist will ruin block after block trying to get it just right. The issue being you can take metal off, but it gets expensive to weld it back up to re-machine it back to original specs. The other issue you would have a very hard time checking his work. Liner slap would not be evident until after quite a few hard working hours, by then it gets pretty expensive.
 

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