crankshaft thrust washer clearance question.

[old52pan]

hey bro's.
I am assembling a lower end with std cases for a pan.1952 and 74" to be exact and noticed when I install the crank assembly in the right hand case the thrust washer will rub the main bushing face. Is this normal or am I going to have to start buying different thrust and spacer washers to shim out the bearing? Thanks for listening-Tim

[VintageTwin]

Does the thrust washer have a bevel on one side? I think the bevel side of the thrust washer goes towards the bushing face.

[old52pan]

VT, neither flywheel thrust washer has a bevel on them and they only install one way. Thanks-tim

[RUBONE]

That is what the thrust washer is designed to do, it rubs against the bushing. However, if the bearing clearance is too tight or the case line boring is not correct the crank will walk to one side or the other and cause one side to have pressure on it all the time. Not a good situation. The thrust washers should be roughly the same thickness and the crank should rest centered in the cases. It should not run to one side or the other when rotated. If it does there is a problem that needs to be found. The bearing spacers to not affect this as they are designed to ALWAYS be narrower than the width of the race when assembled. So if one side is rubbing all the time there is a bearing clearance or alignment problem, not thrust washers.
Robbie

[old52pan]

Robbie, excellent answer and I thank you for the response. make's complete sense-Tim

[old52pan]

one last question. I am told the thrust washers must be the same thickness on both sides.Yet I cannot find sets of two anywhere. the only ones I find are a complete set of 11 (one of each size) any ideas? thanks-Tim

[51Hog]

A page from the manual--

page116.jpg

[old52pan]

51hog, thanks for the eye opener. I read the manual and missed the word approximatly the same thickness.-Tim

[51Hog]

Any time--
I sometimes miss those key words also. LOL
Just finished assembling mine.
Went together without a hitch and is running well.

[mbskeam]

do you have a local shop near you that does old stuff?

on mine I bolted the cases together, then measured the ID from race to race
then the crank OD
then you figure the difference minus the end play you want, and divide in half
this way you can get the correct ones the first time

or borrow and big bag full from your local old engine builder......

[old52pan]

mbskeam -I just bought a set of 11 and hope they will arrive any day, what did you use the measure the flywheels themselves? All I have is digital calipers. thanks-tim