ULH Flathead flywheel thrust washer thickness

[Pete Engelman]

Does anyone know what the OEM flywheel thrust washer thickness was in a ULH engine? A shovel is 0.055'' then you can get 0.060'' I have machined 0.065'' TW's for this flathead 80 and still have 0.023'' rod set side play. The recess for the thrust washers was worn as was the inner shoulder that the thrust washer centers over was also worn down due to a previous loose thrust washer. Having to use shorter early pan rollers (shorter than BT flathead crank pin rollers) I would like to tighten up the side play to give myself a little comfort factor. I'm concerned that if the rods walk over, the crank pin cages could move out the side of the rod and possibly bind. I think I may have to machine thicker thrust washers to compensate for with all of this play or would a new set of Truett & Osbourne flywheels be a better option.
Thanks
Pete::::::::;;;;;;;

[Steve Slocombe]

Dear Pete, Palmer says 372-36 thrust washer is 0.055" thick. The correct pre-1940 304-15 and 305-15 crank pin rollers are still available. Take the crank pin nuts torque up to 150 pounds feet and I'd be OK if the rod end float was under 20 thousandths.

[Pete Engelman]

Thank you Steve.
I am using the OEM crank pin nuts, they fit the best. I bought new Jim's crank pin nuts and they won't even start on the threads. I have another new set that are loose on the threads as well, thus the lower torque on the OEM nuts. The severe wear causes me concern about the flywheels in general. The flywheels had so much slop they wore the inside of the cases where the primary cover bolt bosses protrude and wore the bottom of the left case. I installed 0.065'' thrust washers which added up are 0.020'' thicker than standard and still have 0.023'' rod float when 0.055' stock thrust washers would have put the rod float within tolerance of the book between 0.012'' and 0.014'' something is haywire with these flywheels. I will try 150 ft/lbs and if that doesn't rectify the problem I may machine thrust washers to provide 0.013'' float. I think this engine was on the verge of exploding before it was shut down in 1960. One more thought, I wonder if this crank pin had been changed at some point with something inferior? I am taking for granted that this is the OEM crank pin. The new replacement stepped crank pins are 0.030'' longer so this assembly has 0035'' rod float.
Thank you for your assistance.
Pete::::::::::;;;;;;

[Carl Olsen]

Why don't you use a new set of T&O wheels and get rid of that scrap iron and do it the right way, plus they come with a later pin that you can easily torque to 200 ft. lbs.
If you are this far into the motor, do it right so you don't have to do it over.

[Steve Slocombe]

Good advice Carl and I've never had problems with Truett & Osborn flywheels, but I also like original parts and have an economical streak. I think all the older Harley engine clearance specs are on the tight side and meant for a 1000 mile engine break-in period which no-one will do today. When you see the rod end float on some engines, still running, I would be relaxed about building a rebuilt engine outside the tight Harley specification.

[Pete Engelman]

Thanks you guys I was leaning that way as well, this engine was COMPLETELY worn out as you can see in my earlier posts. I will try and tighten the crank pin nuts a little further like Steve mentioned and if that doesn't help I think I'll run a new set of fly wheels by the owner. I think this may be the wrong crank pin for a ULH creating this huge rod side play.
Pete::::::::;;;;;;;;

[sswaney]

image000001.jpg

Here's an option if you can fnd someone with the correct setup.
Careful to not remove more that neccessary.

[T. Cotten]

Sorry I gotta ask, Pete,...

But did you lapp your tapers,

Even if only for inspection?

http://virtualindian.org/10techfly.htm

...Cotten

[duffeycycles]

If this scares you don't do a Twinkie motor.I think crankpins from aftermarket companies like Eastern are wider between flywheels to make sure there is enough clearance.

[exeric]

This an Acedemic question: How do you match the crank pin angle to the bore angle in the flywheels? Achieving a tapered, molecular fit for a pin to a bore is quite a challenge even with the best sine configuration, and how do you know the crank pin center line is perfect to the center lines of the pinion, and drive shaft bores in the wheels? . . . Not to mention how to match the starting location of the tapers to achieve the right clearance? I'm only asking because I have always wondered how Harley-Davidson, and Indian did it on a production basis, and how accurate were they in the real world. As Tom stated, lapping the pin to the bore has been the only option that has been successful for me as I have had reproduction pins that were not tapered correctly. I'm not questioning the aftermarket industry as much as the challenge of making inter-changeable parts that can span so many years of application to used, and worn out parts.

[Pete Engelman]

Thank you guys.
I am using the OEM stepped crank pin and the tapers look good. I did not lap them for fear of having to use this replacement crank pin which has terrible side play. That grinder for working the taper is a pretty ballsy move. I am pretty conservative. I have lapped other crank pins when replacing them but with the OEM I thought it should match up pretty good with the flywheel taper. I am going to spend some more time, use a little more torque and see what I come up with. I will let you know what the final result turns up to be.
I really appreciate the input and advice.
Pete::::;;;;;;;;