I picked up a different 3rd main cap. This cap will improve the thrust clearance on the crankshaft quite a bit. I had nearly 0.037" with the old cap and this newer cap will reduce it to under 0.010". Not the best but much better. The cap needs to be fitted to the crank. Here is what I'm doing. Correct me if I'm wrong.
First I started with thick shims and then reduced them until some contact was made between the crank and the cap.
Then with a sharpy pen I blacked the babbit on the cap.
Torqued the cap in place and rotated the crank a few times. Then the high points would wear the sharpy ink off.
When I started there were bigger rub points and I cut them down with a babbit knife. Got to a point where almost no contact was being made, but plastic gauge showed too much clearance. I then reduced the shims by one, from 0.017" to 0.015" and started over. Is this method OK? Mike
I would say that you are headed in the right direction.
Agree you are on the right track. One suggestion, when you get close, use Timesaver.
Or use plastigauge and set for 0.0015 inch clearance with the shim stack.
Be sure your crank flange isn't "dished"
After an hour or so of work the cap looks like this. I figure to continue until there is nearly full contact, then adjust for 0.0015". Mike
Looking good, done this for lots of guys, it works. I have even done it in the car. The alternative is to spend a grand and a bunch of time on new bearings. For some guys here that is the only acceptable solution for them and that's fine. Everyone has their take on things. I will say that model T's by their very nature respond quite well to repair methods that would be considered unconventional and even crude by today's standards. Just ask the guys who drove T's home a hundred miles with a piece of leather belt for a rod bearing. It's one of the reasons these cars were such a success at a time when most people had never worked on a car.
Erik, you are the voice of common sense and reason. Mike, beautiful work. Wish me and my scrapers were with you. Also, I would like to post some OT pictures of a steam engine gathering going on as we speak. Two of my former engines are in it. Can't reduce pic size with this phone.Could some kind person resize my pic and post? Only have one so far.Also,anyone near winamac, Indiana I can get you an invite. Tomorrow the big day. Depressed I can't be there.
Well... I've been continuing with scrapping the bearing and I think I have good contact and the clearance (with plastic gauge) is between 0.0015 and 0.002". The crankshaft moves rather easily with the three mains torqued in place. My question is how stiff should the crank be in the bearings? I know this is a difficult question to answer in words, so I made a 1 foot arm that fits on the crank flange and used a scale to measure rotational torque. I need about 2-3 foot pounds to move the crank. Although there seems to be a spot where it is a little more, maybe 4-5. Would this indicate that there is still a high spot? And should I try to work this out, or will the engine work this out once it is run for a while?
The engine will certainly work this out soon when you start running. Sometimes you may have to pull start a car after adjusting the bearings - but a few miles in a slow tempo will usually work this out. Just let it have plenty of oil and water and test crank it afterwards - it should loosen up fast and be much easier to crank.
Ford ran in their new engines with an electric motor in the factory and many restorers do that too. You may set the proper play with a 1" wide strip from a newspaper as a go / no go gauge.
Did you check to see if your crankshaft is straight? If the rotation is hanging up in one spot you should check it. Remove one bearing cap at a time and check the journal with a dial indicator.