Crankshaft end play. I think this is to much. What do you think.

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N8053H

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I spoke with Scott just a few mins ago. He said it will not effect anything for the play is in one direction. When turning the crank in the direction it runs the crank has the correct gap or is aligned. It's when turning it backwards I get the play. But when turning the direction of travel or the way it would turn when running the crank is at a correct alignment. He said it has something to do with the snap ring. Some engine will have this end play and some will not. But it only pulls one direction when running. Quote from Scott.
I trust what he is telling me. I do like this engine. She runs better every time I run her. I noticed this when getting her ready for the end of the year Condition inspection.

Tony
 

Pops

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When Scott lived in NW Ohio, I used to go to the Humble Bird fly-in at the airport where he was based. I have met and talked to him several times and he seems like a very nice person and knows what he is talking about and sells good products. I would trust his engines over the engine with the pretty red parts.

Dan
 

N8053H

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I wanted Scott building my engine just for the reasons you mention Pops. When I called him and ask him to build me an engine, he said it would be close to one year before I had it back in my hands. I told him not a problem. I wanted an engine I could count on. I feel Scott gave me just that. I have over 100 hrs on it now and she runs better with every flight.

Tony

P.S. I wish Scott was still in the midwest and not Arizona.
 

ekimneirbo

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I spoke with Scott just a few mins ago. He said it will not effect anything for the play is in one direction. When turning the crank in the direction it runs the crank has the correct gap or is aligned. It's when turning it backwards I get the play. But when turning the direction of travel or the way it would turn when running the crank is at a correct alignment. He said it has something to do with the snap ring. Some engine will have this end play and some will not. But it only pulls one direction when running. Quote from Scott.
I trust what he is telling me. I do like this engine. She runs better every time I run her. I noticed this when getting her ready for the end of the year Condition inspection.

Tony
While Scott may have enough experience to tell you the play won't be a problem, I can't agree with his statement that the play is only
in one direction....because of the engine rotation. Endplay by its very definition has to be in two directions.. When a prop is spinning,
even though it's only turning in one direction, it speeds up and slows down....so does the crankshaft. While these changes in rotational
speed happen at a speed imperceptible to the human eye, they do happen.Maybe it won't ever cause a problem for you, but from the
information available I have to say I'm skeptical of the explanation.
As an old time machinist I know that excess play doesn't just happen....there has to be a reason.,and that reason should be found
during assembly and dealt with. Proper build procedures should produce similar results each time. Just saying that "some engines
will have it and some won't" doesn't inspire confidence from my perspective.
 

Tuneturkey

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My full case 1/2 VW uses a full thrust bearing at the cutoff location of the crank, bearing #2 position (#1 being on flywheel end) with a round plate bolted to the cut of end of the crank. Only one shim in place between the thrust bearing and the rod bearing throw, provides .006 mm gap. In the above posts, I read that there should be no less the 3 shims. Shaft rotation still feels tight, but rotates easily by hand. Should I shave the face of the thrust bearing so that 2 additional shims can be inserted?
 

GeorgeG

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You want 3 shims. They act as an 'end play' bearing and you need them, so you have enough spaces to enable oil to get between them. Each one spins at a slightly different rate, to reduce friction between the bearing thrust flange (which is locked stationary in the case) and whatever is bolted onto the end of the crank (and spinning).
And you can measure end play with a feeler gauge. Bolt some kind of arm or bracket on the case that reaches over the end of the crank. Make something out of angle iron or something. Measure the clearance between the end of the crank and your 'fixture', push or pull the crank, measure again. The difference is your end play.
 
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