MTFCA Forum

J and M Machine

dykker5502 wrote: ↑
Fri Jan 16, 2026 5:04 am
Can't you get original blueprints from the Benson Ford arhives?

Yes: as we had to. Making the drums and gears to their exact dimensions and specifications.
You have to pay for them and we had to sign an agreement.

J and M Machine

If the rivets are loose I would recommend you check the plate for cracks as they crack between rivets.

J and M Machine

With the amount of dirty oil discoloration in the engine I doubt it came apart for a thorough rebuild. The connecting rod wasn't tinned as babbitt needs tin to fuse to as babbitt doesn't stick to steel. I would recommend you go through the engine methodically as i doubt anything has been done to it ...

J and M Machine

The piston being scored along with poor babbitting , Basically engine overheated or parts weren't sized accordingly. Babbitt of the rod wasn't tinned and it is lead based babbitt.

J and M Machine

You could show John Kohnke; Herm's son and he would know by the size of the mandrels.

J and M Machine

Kerry wrote: ↑
Thu Aug 07, 2025 7:05 pm
Ooops!! someone needs to pull the pistons on that block, split skirt is facing the thrust side of the bore and needs oil holes drilled for the wrist pins.Screenshot (227).png

Yup this is how it came to us. fresh re-rebuild.

J and M Machine

big2bird wrote: ↑
Fri Aug 08, 2025 2:18 pm
Just curious, have you guys EVER checked a block for cracks, and found NONE.

Yes it was a 1927 Model T Block.

J and M Machine

All Joking aside; hanging a crankshaft up and hitting it with a hammer is not a true test in relation of it being cracked or not . If I had that skill to know what a cracked part sounded like, the crack detection suppliers would be out of business. The reason for crack detection or "Magnalfux," bein...

J and M Machine

Hang 'em on a string and tap them with a hammer.............. Funny that you should say that. Standing in front of my magnaflux machine with the local T club present on tour of our facility, explaining what the magnaflux machine does. I asked the club members how they check their cranks prior to re...

J and M Machine

I would have the crankshaft in the OP cleaned, dye penetrant tested, and magnafluxed before I would put it into an engine. There's no need to have the crank "dye penetrant tested" if you are to have the crankshaft wet magnafluxed. Wet magnaflux as I have shown in bottom picture will work better tha...

J and M Machine

Shure-Mike: I have to wonder if the cranks got a bad reputation because People just slapped them into engines with bent pans, bad clearance etc. We have reused these crankshafts and they're still running today. We have the ability to crack detect and straighten and remachine them properly . Maybe th...

J and M Machine

Before pulling the motor, have a competent & knowlegable T mechanic like J & M look & confirm the problem. Its only fair to see if the original builder will warrant his work. Thanks for the vote of confidence. If we look at it ,you know what we're going to find Problem with a Model T is it all has ...

J and M Machine

Sounds like you'll have to pull the engine. and take the flywheel off and see what happened to the transmission.

If you 've changed the oil like you mention then this shouldn't of happened unless it had no oil in it or rebuilder didn't do it correctly.

J and M Machine

I'm new to model T's. The motor i bought came mounted on a small wooden cart. I recently overhauled a model A engine, which i had hanging on one of those water-inlet brackets that Snyders sells. Is it safe to hang this T motor with the hogshead and everything together? It seems like a lot of stress...

J and M Machine

Professor Fate wrote: ↑
Mon Mar 17, 2025 7:55 pm
Stitch it! Gotta be somebody local to you
that does it. My guy is in Milbury Massachusetts.

Frank Casey Died in 2023, so I guess you'll be coming to us.

J and M Machine

It can be repaired permanently by metal stitching if you ever decide to rebuild the engine.
Only problem is that may not be the only crack on the block.
Example shown is crack in similar location along with others due to ice damage.
https://jandm-machine.com/crack_repair.html

J and M Machine

If you know the car has been driven alot it would make sense to disassemble and inspect the transmission parts properly. With the red paint on the mag field , it's been apart before and that needs replacement. The drums especially reverse and to a lesser extent the low speed does crack . Along with ...

J and M Machine

Like this. You just have to indicate it.

J and M Machine

Looking at the pictures , I can see that the triple gear itself is flaking and should of been changed out for a better example or new ones installed. Anytime you can see metal being removed from gear tooth itself it's setting itself up for this to happen. Most likely the low speed/reverse and drive ...

J and M Machine

Yes he in business and his name is John

J and M Machine

I'm looking for a replacement low speed drum and was looking for help in what to look for. Cracks across the band and across the ribs I've seen on videos but what about the outer surface condition? And what if it has been turned in the past? Thanks The low speed drums are the thinnest in the transm...

J and M Machine

Andre:
You will also need a "Magnaflux/crack detection" to identify the cracks .
Also you will need to pressure test it after the repair is complete to ensure there are no leaks.
https://www.jandm-machine.com/crack_repair.html

J and M Machine

Congratulations Rob and family!

Adjusting mag field, I know it was frustrating but free starts are worth the headache of setting it properly.
Amaze other Model Ter's . Pays dividends in doing it thoroughly.

There's a reason why we resurface the flywheel and mag field.

J and M Machine

Ok…. Now I’M frustrated! So which way do i go? Is there more to this story? Am i going with too much clearance at .004? I feel a revision of my table coming on….. lol. No offense to anyone else, but I'm going with what the machine shop said. It's a no brainer.... get your engine cleaned, radiator c...

J and M Machine

So you’re saying the piston can come from the manufacturer STD as 3.748 (-.002 ) and that the bore should be 3.752 (.004) or 3.753 (.005) or 3.754 (.006) …. Right? Table above has been updated!!!!! Again, I think it's preference for .004 vs. .005 vs. .006 so..... Maybe a better question is, "Has an...

J and M Machine

GEE, I hope this is the end of this thread ! ! ! Getting back to Tim's original question of this thread about the feasibility of stocking rebuilt short blocks: He said it best in his last thread; "What ever you do with it after it leaves, is on you, not me". Feasibility to stock Model T engines or ...

J and M Machine

Tim Foye: Please elaborate where we are libeling you? I am taking from your words on this forum that you have a small space to work in with a 30 amp service. Let's see the pictures that you can say we are your competitor ,what are you competing against? I don't know where you even begin to think we ...

J and M Machine

Admittedly, I have not watched many of your videos. Do you do your own boring, honing, babbitt, valve seats, etc.? No he doesn't: For a while he was our best source of work as we would do his engines over again after his customers paid him for a complete rebuild. We're not bashing him I am stating ...

J and M Machine

I too have seen late original drums with one bushing installed . However I've always installed two . Makes more sense to have two installed rather than only one with the amount of load on main shaft, two share the load. My high school drafting teacher told us; "Engineer may design it but takes a mac...

J and M Machine

George, Thank you for the input! As you say, maybe more folks with offer some further input. I have no history to offer as these came from a stash of parts of a friend who died awhile back. For now, these are just conversation pieces. It would be interesting to find out if they could machined to be...

J and M Machine

It's a 1926-27 engine; From the hazy pictures I can see the cylinders are rusty/rusted. Most likely a 75-100 dollar special as it will be cracked , brake drum maybe good but reverse and low could be bad along with drive plate. When they're rusty like this means that the cam could also be pitted and ...

J and M Machine

I don't know if they are still available, but years ago someone was making new narrow late '25 style brake drums with the extra bosses for the later lug shoes cast in, my '24 came to me with one. Update - looks like Lang's still sells it as a bare drum, you have to rivet it to your shaft. https://w...

J and M Machine

We try and keep them as big as possible. At least 3/32"
Problem is after 100 years and bad machine shops most often nothing left.
BTW: since everyone else is advertising now on the forum:
https://www.jandm-machine.com/grinding.html

J and M Machine

J and M: Are the current replacement shafts made the same size the length of the shaft or like the ones mentioned in the manual. Probably the same size length wise and then ream the gear bushing to fit? Thanks Hello John: Yes approximately the same ,you just have to be aware that the portion that p...

J and M Machine

Check the size of the holes after you push them out .
We have seen replacement pins that are oversize and will crack the flywheel when trying to reinstall.!

J and M Machine

Check the drive plates carefully as we have seen alot through the years that the iron of the plate is crumbling around rivets and forms a crack between them. May not be the rivets that failed it could be the plate itself. I was not able to see your images but wanted to point this out as well. As wit...

J and M Machine

Nv Bob wrote: ↑
Sun Nov 19, 2023 10:50 pm
Best way seal a cracked block still good but had water left in it and cracked between rad and s/n
I've used block seal in the past any other ideas
Thanks in advance

You mean a permanent repair like metal stitching? Yes we can do it. Without the silly putty.

J and M Machine

I would recommend you check the other two drums along with triple gears while you're there as you may be replacing more than just one drum.!

J and M Machine

Refurbishing the engine for my '13. By matching heavier pistons with lighter connecting rods, weights vary 9/10 of an ounce, 1/2 oz., and 3/10 oz. over the lightest pairing. I suppose it's possible to have them weigh up equal, how necessary is that ? What do experienced T engine rebuilders consider...

J and M Machine

I am thinking about Lock N Stitch as a repair method on a cracked water jacket. This is for a Buick Model 14, not a Model T, so replacement or risking any futher damage in the repair method is not really an option. I am thinking that the planning is every bit as important as the actual drilling and...

J and M Machine

I've had issues with the new generation gasket material not holding torque. You shouldn't have to retorque but once. Unfortunately this is what the head gaskets are today. Same with Model A and V8 gaskets. Must be retorqued after 5 minutes of running time as they will loosen up. We tell our custome...

J and M Machine

Quote " However, upon checking the head, it appears to be out by .004", (on a freshly re-decked head), making the gasketed surface concave. So, what did it? The .004" out-of-flat," It could of been machined that way, if you just installed the head and already blew a gasket then I would speak with th...

J and M Machine

Mr.Man: Looking at the condition of your drums I would suggest disassembly and inspection for cracks! You have it apart and only takes a little more time to have them off and on the table. There's a high probability that the reverse is cracked with the brake drum wear as the reverse drum is usually ...

J and M Machine

Hello Pierre: I have never seen this before. most likely you're victim of bad parts."Bushings" The triple gear pins have to be perfect to fit the new bushings , If there is any wear as they always wear on one side. They need to be replaced from just overheating them alone. If you'd like to contact u...

J and M Machine

JTT3 wrote: ↑
Tue Mar 14, 2023 2:51 pm
So now does anyone in South Carolina or Georgia have a pan straightening table that repairs pans? Trying to help a member that lives in South Carolina close to the boarder of Ga around Augusta. Best John

Have you tried "Gator Gould"?
gatorsts@frontiernet.net

J and M Machine

'Quote" If I sandwich the flywheel between two transmission shafts, bolt them together, and put the works on the balancer, will that be good enough, or is there likely to be too much runout in the shafts. Yes You can get away with this to get it close but right way is to have it dynamically spun on ...

J and M Machine

As with anything pushing 100 years old.
Really doesn't matter year it matters of it's condition.
Main thing is to have them crack checked; both block and crank.
Just because people in this forum rave about the EE crank, they crack just like any other.

J and M Machine

"Are you saying the drum lugs tend to be undersized on the Evans drums? Might explain why 3 are missing on my example!" An Affirmative Yes: Most frustrating thing for us rebuilding engines is when the parts don't fit or fail. As I mentioned these were the reason we started to make them the right way.

J and M Machine

I picked this up in Hershey this year. It's not marked Ford anywhere. Just the part number and the date. I'm thinking J&M, but they usually have their name in the casting, don't they? Also, wondering why it was removed. It shows almost no wear or damage, I have not checked the balance yet. Anyone k...

J and M Machine

DRY MAGNAFLUX is useless on a 3 Dimensional part. Ring test is also useless. Only way to know for sure is to clean the crank that there is no dirt or rust on it and have it wet magnafluxed. Doesn't matter if it's an ABCD EE crank they all will crack and there's only one way to find out. When we had ...

J and M Machine

Would it be a good idea first to see how the issue raised in this thread is resolved? [/quote] Yes, Because for people out of the country like this person, your calls will most likely fall on deaf ears. We're in USA and it's hard enough for us to get any updates on cranks for our customers never mi...

J and M Machine

I would listen to what Mr.Jelf Says as just cleaning it isn't doing the transmission justice.
The drums may be cracked along with magnets and the triple gears may be toast along with the pins.
What you may not see will hurt you and the engine.

J and M Machine

It's unfortunate that you didn't get what you've paid for. However the crank could be straightened but I would wait to hear back from Lang's, Have you tried directly contacting former owner of SCAT? Tom Lieb <tlieb@ScatEnterprises.com> IMG_3211.JPG Problem with straightening your crank is they may h...

J and M Machine

[quote="Steve Jelf" I believe machining the face of the whole assembly is overkill. Using shims I get a variation among the plates of less than .005". I call that good enough. For the people that want the best for their Model T, it's not overkill. We resurface both flywheel and the mag field so that...

J and M Machine

We typically stop at .030" under.
Don't forget to have the crankshaft crack inspected with wet mag "magnaflux"
Also make the shop aware they have to touch off the crank flange surface.

J and M Machine

One to ask questions to is the snowmobile man Brian Moriarity
https://www.nhsnocar.com/

J and M Machine

don't forget to purchase a lint screen for the new bands and Clean it often.

J and M Machine

I found a report online about inserting cylinder liners and installing hardened valve seats https://www.modeltcentral.com/Model-T-Ford-Engine-Specifications.html. I think that matches what you wrote. According to my engine shop friend, it is common for us to use a top flanged cylinder liner as in t...

J and M Machine

We've seen more of the earlier beaver tail version of the Model A crack than the later style rounded style crank.
As with any crank you can say one is better than another, the only test worth doing is to have it wet magnafluxed.

J and M Machine

Hello Brett:
Just sent you an email with his contact information.

J and M Machine

Cost to resurface the Mag fields is $100 dollars plus shipping.
Thanks

J and M Machine

Quote" First and foremost, there is crankshaft end play, about 0.03" worth. When the engine is shifted, the crank and transmission audibly move back and fourth. This is the only play I can detect, however. Secondly, when the crank is in its most forward position, the magnet clamps slightly grind on ...

J and M Machine

resurfacing mag fields

J and M Machine

We offer this service of resurfacing mag fields.
No more struggling with uneven air gaps get it right the first time.
Contact us by phone 508-460-0733 or email sales@jandm-machine.com

J and M Machine

Bryant wrote: ↑
Sun Apr 10, 2022 4:59 pm
So are there any suppliers of new gears/shafts that are riveted to the drums/drive plate? Or only used ones?

Yes we make new drums and gears that are fully machined to each other so you don't have to install new drums on old gears.
http://www.jandm-machine.com/custom_works.html

J and M Machine

Has anyone tried to re-rivet their transmission drums? Has anyone tried to tighten up loose transmission drum rivets ? Does anyone know what tool was used to rivet drums? Is there a source for replacement riveted gears/shafts for drums? My driving plate rivets are just slightly loose. Not scary/cra...

J and M Machine

Of the articles/ posts that I've read it seems that most common issues is a bock cracks on the water outlet side of the motor (driver side) from mostly freezing it seems. Are there other known weak spots on this block that happen for other reasons such as vibration or tension? On all the picture I ...

J and M Machine

Thanks for quick reply and answer to my wishful thinking question. I am dong a refresh of my engine and going to replace magnets with dist. ignition. Don't want to mess with trans, as car did drive ok before this engine work. I hope I am not being short sighted in leaving trans as is. I appreciate ...

J and M Machine

rebuilding a 1913 ,1915 and a 1925. Model T Hobby is alive and well around us.

J and M Machine

Hey Bob! I had reached out to Ora this morning and am awaiting his reply. I kind of get the impression that he has gotten away from doing T stuff anymore and is concentrating solely on the Model A’s. I bet your mentor had one of these jigs…. He had some cool stuff in that garage! We're located in M...

J and M Machine

I've heard tell of making a jig from a 26-27 block and hogshead bolted together. I aim to give it ago. That wouldn't work by just bolting them together. The fourth main alignment tool that locates the pan and hogs head to the assembly. If you tried to straighten pan off the engine you don't have an...

J and M Machine

There is more than one thread to refer to. After my father received a pace-maker, I looked into it. Searching the internet brought up Boston Scientific's safety matrix, a very informative matrix of what his pace-maker could and could not handle. At the time, I posted the information, it's source, a...

J and M Machine

Someone will have a drawing, and I'll bet there is no surface finish call out that equates to modern measurement systems (if any at all). In reality, a 32Ra or 16Ra finish is fine. 16 being a bit of overkill. With the correct tool and surface speed, lathe turning is absolutely fine if you know what...

J and M Machine

Looking for recommendations of a machine shop that can work on transmission drums in the Portland Oregon area. Thanks Tom Make sure they can clean and crack inspect them first. ! The picture enclosed is the reason we started making new drums and hubs as what was is available wasn't to our standard ...

J and M Machine

What would be the best rod to use for welding a small crack in an engine block base? Earlier I was told mild steel, but I forget the number. Recently, I was told stainless steel. Now a guy wants to use nickel that is a lot more expense. I hope that it's not his first welding job on cast iron? Main ...

J and M Machine

I just bought a set of pistons and it says 2 to 3 tho clearance, it seems tight to me ,what do you think for new pistons? MEL It depends on condition of the block: We thermal clean the engines so they get the heat transfer. We set our cylinders to their recommended 3 thousandths clearance and have ...

J and M Machine

1915 and a 1921 being rebuilt:100 plus years and counting, coming back to life.

J and M Machine

Hello Rob:
It may of been Ron Patterson that rebuilt the coils as he used to live in MA.
i would tell your friend in Fort Dodge to look for Model T club out there.

J and M Machine

Speedytinc, Thanks for your suggestions but it is not necessary for us to perform a hardness test on our drums as we know the iron is quality checked before leaving the foundry and we know the WEAKEST of ductile cast iron is as strong as the STRONGEST available gray cast iron which Henry didn’t even...

J and M Machine

J&M Machine makes their own drums. I've got them in my car. They have new gears pressed on them as well not old gears pressed on a new drum. The drums I saw had used gears. Do you happen to know the hardness condition of these new drums? How do they compare to Henery's? Would like to know if I need...

J and M Machine

This is what the engine looks like. We just completed.

J and M Machine

Yes it is a good idea to balance when done properly.! The three pictures show how far out a Model T flywheel can be. This example is a 1914 that we balanced. Being off a total of 1010 grams or 2.2 pounds. Definitely car would of shook at any RPM. Best advice is to have it balanced along with weight ...

J and M Machine

That's an interesting place for the block to crack. I believe that's something we can fix. If the block doesn't have a sleeve in that cylinder now it would need to be sleeved. Which we can do. I have enclosed two pictures of a 1912 Model T block that someone tried to repair with JB weld and our meta...

J and M Machine

Bruce- applying Glyptal to the inside of you engine and hogs head is completely un-necessary and will yield no measurable increase in performance. Use your commons sense, why go through all the trouble of making sure that every last bit of petroleum residue has been removed from the interior of you...

J and M Machine

I do agree that the hard seats are a more reliable seat material... but are overkill for the valve temperatures seen by a relatively low output engine equipped with quality stainless steel exhaust valves. The real cause of valve seat recession is carbon steel exhaust valves operating near their fus...

J and M Machine

There are cracks to be avoided and cracks of little consequence. The J & M photos show both. The cracked web in the drum makes that drum a throw away. The small one around the rivet is of little consequence. It goes to the inside of the drum hub, and was most likely created in the riveting process ...

J and M Machine

Jerry- my experience has been that you almost always see the valve chamber crack in the 26-27 blocks and not the earlier ones. Anyone? It depends on how hot the engine got as the valve seat cracks towards the exhaust manifold not towards the cylinder. It happens on all of them and not just a partic...

J and M Machine

I disagree: The reason being is that if you are going to drive the vehicle on a regular basis then you should install them. The other factor to take into consideration is the new valve is harder against the stock cast iron block surface and will pound the stock seat out. If you're going to rebuild t...

J and M Machine

. . . You'll never win an argument on the internet as some expert . . . will know more than all of us combined. :lol: So true ! So often contradictory opinions seem to prevent posts from actually providing good answers to the questions posed. As for re-surfacing heads and blocks, my question is whe...

J and M Machine

OK We have a spray at work that checks welds for cracks. This spray is also used in engine construction. Surely it is enough to examine the drums with it ?! Do you have the one side where the drums are cheaper than Snyders? Would you drum and statically balance the starter wreath? greetz patrick Th...

J and M Machine

You're right regarding surfacing the block to make it flat as you don't have to remove much. Just enough to enable the surface flat. The cylinder head it doesn't make sense to remove that much better off to get a Z head or change pistons. Model A guys think they can do the same thing. The heads aren...

J and M Machine

Wow Walden tools in Australia? Who would of thought? Allan: here's a link if you haven't already seen it. http://alloy-artifacts.org/walden-worcester.html We drive by the factory often as it was on the main road leading into city of Worcester. http://progress-is-fine.blogspot.com/2018/03/vanished-to...

J and M Machine

Here's a perfect example of the flywheel being Way off. This is a 1914 we did . It was off @ 134 grams almost 5 ounces per inch of the diameter of the flywheel. Looking at it the total amount off was 1010 grams/ 2.2 pounds in total unbalance. Combined weight of unbalance of the magnets and flywheel ...

J and M Machine

...there's no way to keep weight of the magnets even. [/size] Is there anything wrong with picking magnets that are all within a few grams and grinding a little off the ends of the heavier ones to equalize them before you charge and install them? Hello MrJelf: There's nothing wrong with that. HOWEV...

J and M Machine

For people in the know - should the crank and flywheel be balanced separately and then balanced again as an assembly or just balance the assembly only? balance.jpg As Dan mentioned the parts have to be balanced separately and don't forget to weigh the triple gears as most often they are off. As see...

J and M Machine

Bruce: You can have a look at these pictures as this was shipped to us from Calgary Canada and went both ways without damage.

J and M Machine

If you are to proceed to do a valve job: Once you remove cam,inpect the cam lobes for wear and pitting. If the lobes aren't pitted it can be reground to touring or stock lift. The valve guides will need to be checked for wear if valves have never been replaced then you'll need to ream the valve guid...

J and M Machine

It's an early Chevy block. One I have shown above is a 1927 that has distributor on side, Rusty one shown has it mounted in front so that one is very early.

J and M Machine

As a suggestion it may be better to sell them crack inspected and not ground.
Leave it up to the customer to get the crank reground.

J and M Machine

Quote "Has anyone real first hand experience of finding an original Ford crank that has shown no cracks after magnafluxing. " Yes we have. We had a customer a while back go to Langs to see what they had for cranks and Lang's Allowed him to choose the ones he wanted as he only needed one but brought ...

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