gerryndennis

I couldn't find the post where the crank was spinning inside the bearing, just some supposition that it might be.

It's pretty obvious to me that it can't though. There's a step on the crank, the inner race of the front bearing seats against this, the prop driver sits against the other side and is clamped hard against it by the prop and prop.

Dave H

rv9-a

gerryndennis

You are correct. The front bearing is securely clamped and can not spin on the shaft no matter how bad the fit. When I saw it spinning the drive flange was off. Whether it is centered on the shaft is another story. It also puts to rest my theory on how the seal can come loose.

FWIW it was post 7 that I mentioned the crank spinning inside the bearing

thanks

gerryndennis

Hi rv9-a,

How's the drive collet on your engine? I had an engine where the the collet had worn and the drive washer sat too far back on it. Once the prop was tightened the drive washer rubbed on the front of the crankcase. Is there any possibility that your drive washer has moved back and is picking up the Bearing shield?

I solved my problem courtesy of some Rolls Royce aero engine shims behind the collet. Great when you have an aircraft engineer friend. Maybe you could find a washer to suit (the OD needs to be the same as the collet).

Other than that I'm back to the crankcase over pressure theory. I agree with Quicksport though, it's unlikely (still feasible though, even a shield can be blown out if there is enough airflow through the bearing).

It seems unlikely that you would have several bearing in a row that are faulty but it couldn't hurt to try a different brand as per Quick sport's recommendation.

Dave H

rv9-a

Dave

The back side of the drive flange is nice and shinny so I don't think it is rubbing on anything. The crankcase vent line was about 12" long as it has been since the plane/engine was new in early 2009. It always had plenty of oil dripping out of it. I did shorten it up to about 2" just in case.

What is really hard to understand is that the last bearing I put in had both seals on it. If CC pressure was the culprit it would have to blow thru both seals!

My local Fastenal store carries the front bearing, I am going to get one and try it and see what happens. The new crank is supposed to be here tomorrow.

thanks,

rv9-a

rv9-a

The new crank arrived today. It is not any better, as far as the fits go, than my old one. The new bearings just slide on.....no resistance at all. According to the "Complete Saito Notes" these should be a light to medium push fit.

I am thinking of using a small amount of Blue Loctite at least on the rear bearing.

Any other suggestions ? This is getting frustrating.

Rudolph Hart

Yes..reread some of the earlier posts and good luck.

rv9-a

the pope

The bearings I replaced on my 2 x 82s both were a reasonably tight fit , I put the crank in the freezer to get it on .( 1x was in an engine with about 50hrs and the other was after a dirt nap , not paying attention , not very bright ) . They certainly wouldn't just slide straight on with no effort . I know I mentioned rc bearings before but I would give their bearings a shot . Although they should be the same size one would think . Anyway good luck from the pope

1QwkSport2.5r

I use RC-Bearings exclusively. They fit superbly in the engines I've installed them. $12 a set beats the pants off $30 a set from Boca too.

Rudolph Hart

I don't think there is a price point for good engine parts and not familiar with where you go for that over there.If rv is going to our equivalent of bunnings then thats what you pay for.

Hobbsy

My Feedback: (102)

A little mis-info there Quick, the Boca's are $20.95 and free shipping.

Subtotal : $20.95
Order Discount : $0.00
Sales Tax : $0.00
Shipping : $0.00
Handling Charge : $0.00
Total : $20.95

Rudolph Hart

And i reckon they would be bloody good value for rv,then he can assemble the engine and hear it run sweet as.

1QwkSport2.5r

Sorry, I was generalizing. I shopped around and found Boca to be 2-3X the price of RC-B. (In this case) $9 is $9 these days, and if the only difference between one and the other is the retailer/source, I'll take the cheaper option. RCU members get 5% off too. No sense in paying more for the same thing. Moreover, the customer service is as-good or better at RC-B. Plus, Paul is a knowledgeable member of this forum that shares all sorts of information. I don't think Boca, although a forum sponsor, doesn't share info here on RCU? That's where I find the real value.

The bottom line is; RC-B was suggested as an alternative means to an end in relation to the original sources loose fitting bearings (in this case) even on a brand new crankshaft. The guy's engine is obviously not right and I just suggested another possible means to an end to help him get flying.

Just my overtaxed $.02

SrTelemaster150

I've always just used OEM Saito bearings.