I have the transmission and engine all rebuilt and am ready to mate the two together. Can anyone tell me how I go about gaping the Magnets to the field coils? I see in one manual I have to insure the gap is between .025 and .040. Do I have to check each coil on each magnet or what? Do I have to bolt the tranny all down to check them? I'm a little confused and don't have a mentor to help me out. Any help would be much appreciated. Thanks, Rand
Check out these videos. It's worth the time to watch from the beginning, there are initial and interim checking methods that will save you a lot of effort. Once you have your tail shaft running true it makes everything easier, and while you're at the point you are it's the time to do it. Don't be in a rush with a set schedule; if you don't take the time to do it correctly now you'll regret it in the future when you have to do it over.... On the engine I just did I wast tempted a few times to say 'good enough' but did not. I redid some things a few times, but it did all come together in the end.
Thanks a bunch Gary. I'll watch it and try and do it right. I have always been in a hurry my whole life so I'll really work on taking my time here. Rand
Hope trueing and balancing the Transmission was also part of the rebuild.
It wasn't but I'm now going to take it apart and do the balancing as I can see it is of the utmost importance. Thanks, Rand
Be assured that the end play is most forward make a wood wedge and tap it down between the block and the front pulley to keep the shaft tight forward. There are proper shims available to slide down between the coils and the block. It is a slow fiddley job take your time. I spent a couple of evenings to complete mine. Mine now starts and runs good on the mag. With excessive end play in the crank shaft will cause the gap to be too wide and can cause sputtering and back firing decelerating.
Its not a high speed aircraft engine, its a low speed four cylinder in line engine that is inherently unbalanced. The moment of inertia of a disc is 1/2 x mass x radius squared. Ford only balanced the flywheel. On the other drums, mass is small and radius about half that of the flywheel, thus balancing them is of little value.
Balancing is not of utmost importance. Having sufficient clearance in the bushings is of utmost importance. You do need to check each magnet pole at each coil position and you do need to cinch the flywheel to the crankshaft each time you check it. Once you have done it with the transmission nose down, then you need to check it in the horizontal position. There should be almost no axial play in the crankshaft if the engine has been properly rebabbited and fitted.
Ted, thanks for the input. I'm new at this stuff as this is my first T and I'm still trying to comprehend everyone's suggestions. Can you please elaborate on the cinch part. I'm not getting that.....Thanks very much for your help.
David, Thanks for your input as well. I'm not sure what you are exactly saying. Are you implying that there will be some play in the engine and using a wedge will pull the play toward the front of the engine? If that is the case, what do I do with the play, if there is any? Thanks, Rand
Here is another question regarding the coils and mags. I had the engine re-babbited and the rest of the machine work as well by Idaho Antique Engine in Idaho Falls. From what I know Bud does super good work and is very conscientious in his craft. Bud went ahead and installed the pistons in each hole so I can't rotate the engine very easily. It's making checking the distance in the mags and coils very difficult. What do I do here? Pull out the pistons?
Ted, balancing can make a BIG difference depending on how un-balanced the transmission components are. Also, make sure the transmission shaft is true.....many are bent which places more stress on the crank shaft. I have my own static balance equipment and have balanced my transmission and those for numerous friends. Also have a lath to check transmission components for run out. I know what a difference it can make....I have walked the walk. You are wrong in thinking that "Balancing them is of little value". I have found that most flywheels that were balanced by Ford still required re-balancing.
I second what Les says. In the end, its what you want and expect from a Model T. In earlier years I did no balancing, then I tried static balancing, but only the rods and triple gears (total weight) and flywheel with magnets (on knife edges), nothing with the drums or crank. Now I have all the drums, flywheel and crank dynamically balanced (first individually, then as a unit the way they will attach in the car) and the triple gears and rods static balanced. (both ends of the rods) It doesn't cost much and the difference is remarkable. EG I have a 12 roadster that vibrated between low and high shifts. First, I thought it was clutch chatter so I changed the clutch, no help. I tried a number of things including changing the drums, still no help. I finally bit the bullet and took the crank rods flywheel and trans parts to a fellow in Oakland. He found the crank was 22 grams out of balance. He said that at modern rpms the crank would have come apart. This is a factory crank that had not be fooled with. He balanced all parts as described above and the vibration is gone.
For me, if I had a closed car, which is noisy anyway, I'd definitely get the items balanced.
Rand, We have a Chapter of the MTFCA in Utah. We have a page on Facebook. We have taken the whole State of Utah into our Chapter and have regional directors in all parts of the state. Our President, Doug Jenkins's did a seminar on Magneto's and it was great. He has restored a 1926 Tudor. I would ask him these questions or one of our outstanding members; many have been Model T mechanics their whole life. You are not the only one in Utah with T's. There are at least one or more for every town in Utah. Welcome to our affliction.I have sent you a PM.
Rand there will be some end play if not now there will be some later. If the end play is not brought forward then as time and wear proceeds the magnets may strike the coils. End play is inherent it will always be there it just has to be managed. There was available at one time a brass spacer that fitted between the front pulley and the block to correct excessive end play. That is where I suggest you place the wedge to force the crankshaft most forward. As far as a tight engine is concerned, my method of assembly is to turn the engine after each component is installed and torqued to check for any binding. When all parts are fitted there should be little or no binding and the engine should turn over relatively easily. Each bearing should be torqued and turned and should turn freely each piston should be inserted in each respective cylinder and there should be no binding. When all is fitted the engine should turn with little effort.
Rand, by cinch,I mean full tightened down.
New piston rings in honed cylinders means a lot of friction until it has been run just a little.. I put the fan belt pulley in place and turned the engine with the regular starting crank while checking everything during assembly. It was hard to crank it at first, but as soon as it had been started the first time, hand cranking became much easier. When a babbitt bearing is adjusted a bit tight it may also be needed to pull the T with another car for the first start, but when it has been run in for some slow miles it'll be just as easy to start as before.