Hello, I'm looking for advise here. I am resurrecting a '23 Touring that has been sitting for over 30 years and new to the hobby. This fall I repainted the body and this winter concentrating on the mechanic's.
Are there some "static" inspections/tests I could perform that would help know if the magneto may work?
I also pulled the head to inspect the cylinders (which look pretty clean), I did find a bad valve keeper-see photo.
I also pulled the hogs head to clean, paint , replace o-rings and bands. I did notice the first two drums seem a little loose meaning I can wiggle them a bit I don't think that would be a healthy thing...
So basically I'm trying to find any issues that would cause me to stop and pull the engine. My hope is I may be able to catch and repair issues like the valve keeper I found and hopefully have a decent runner.
I also spoke with my machine shop and to inspect my head and surface it is about $125-150 so thinking I should put the money in a Z or P head.
Thanks for any advise.
Link to magneto output test method
The valves appear to be the two piece type and general recommendation is to replace them.
Others can comment on the trans drums.
Google is a friend. Search for the terms you are inquiring about but add MTFCA at the end of the string
Yes thank you for the reply. I have seen that magneto test however that requires the motor to be running. I was looking for a static test that would give me the hope it will work or know there is an issue... I did measure from the post to ground and read almost 2 ohms. I'm guessing that is better then a direct short to ground but I have not been able to find any measurements without motor running.
To test the magneto, you need to spin the engine. A heavy duty drill with an adapter in place of the hand crank will do it.
2 Ohms sounds about right for the MAG coil, however, it does not mean that it will work. Not sure how you would use a drill to turn the crank, it would have to be fairly powerful and you would certainly need to remove the plugs to lessen the effort needed to turn the crank.
Realistically you can measure output while hand cranking. You just need an analog volt meter and a light bulb #1156 across the circuit to load it enough so the results can be believed. Again remove the spark plugs to make it crank easily.
The valves look like the original two piece style. They should be replaced, the heads come off and end up ruining the engine sometimes.
Here's a photo of a original two piece valve (right) that has had the carbon cleaned off so that you can see the outline where the stem is pressed into the valve head.
(Message edited by royce on January 15, 2017)
Ok, good tip on the valves. I didn't know there was such a thing. So I will need to replace and figure out if I need an oversized stem or not. Any thoughts on the lifters? I can measure the lift on each lobe and if lift is good stay with the solid lifters but if lobes are worn upgrade to adjustable.
You can test the magnets for sufficient magnetism by checking if each magnet will hold a 2 pound weight, a T piston is ideal. Test each magnet, I just messed up and didn't test each one and sure enough a couple need recharging.....
Take out those two piece valves, they will fail. I don't know if it's modern gas or that we drive faster than when they were new, but fail they do...
You need to be able to put the transmission in neutral which would mean you need to install the hogs head, or you can jack up one or both rear wheels. With the head off, you should be able to get the crankshaft turning fast enough to get a spark. If you put an analog AC voltmeter from the output post of the magneto to ground, you should get a reading if you spin fast and the magneto is good.
Concerning the engine, inspect the cylinder walls. Are they smooth like polished glass? Are they all scored up? A few small scores won't be a problem but much scoring would cause a loss of compression and burning of oil. Turn the crankshaft so that two pistons are at the top and try rocking them back and forth side to side. They should not move more than a few thousandths at most.
Concerning the head. Try a straight edge such as the edge of a framing square on it and look for unevenness. If it is straight, use it as is. I wouldn't install a high compression head on an old engine. It is harder on all the parts to use high compression. A high compression head would be good on a rebuilt engine.
There are other things to check too. Look at the rod bearings underneath the engine. They should have good babbit and properly adjusted. When you remove the rod caps you can also mike the crankshaft to see if it is out of round or excessive taper.
Concerning the transmission drums, it is better to be on the loose side than too tight. The bushings tend to bind onto the flywheel pins and spin the bushings loose in the gears if too tight.
It's better to try to start the engine before disassembly and check the compression first before you remove the head so that you can get a better test of the condition of the engine. But the above tests will tell you whether you should button it up and try to start it or remove it and rebuild. If you do remove the engine and transmission you should rebuild or replace everything which needs work including replacing the magneto ring.
If you don't already have them, purchase these three booklets. Engine, Transmission, Electrical system. You can get them from the club and they will give you step by step instructions on how to repair all these parts.
As you say, take out the plugs.
How would you hook that up to the crank? It's big, but how powerful is it really? Maybe 1/2 HP?
Hand crank out, ratchet in, rod from drill in, pin in, spin. I don't know how much power it has, but it's enough to turn me if a bit catches.
So far the cylinders look smooth I really don't see any scoring but still need to wiggle pistons. I did do a compression test when I purchased and was able to hand crack 40 psi in each cylinder.
All the rods seem good really don't wobble around at all.
40 psi at hand crank speed is OK. I'd agree that a framing square or other good straight edge will tell you if the head is flat or needs surfacing. If flat, I'd stay with that head until you have some miles on the car and can decide if a change is needed.
Replacing the valves (highly recommended) almost necessitates pulling the engine as it's not very likely that you will be able to get proper valve lash adjustment with the new valves and original non-adjustable lifters. Lifters could be changed in the car but would require removing the valves, holding the old lifters up with clothes pins, removing the cam, inserting the new lifters (again held up by clothes pins) and then replacing the cam. By the time you get done getting under out and up and back under way too many times you might be better off just pulling the motor. It's a lot easier to deal with on a stand or bench than leaning over the fenders. Also easier to ream the guides if needed and grind/fit the new valves with it out of the car.
David, When you re-install the head, pay attention to the head gasket. On both ends of the head gasket, there is a kidney shaped opening in the gasket for coolant circulation, and one of those openings is larger than the other. The larger opening goes to the back of the engine. Don't ask me how I know that .... I think someone told me.