#1 bearing mishap

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Bill Romano
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#1 bearing mishap

#1 Post by Bill Romano »

Despite all the good advice in Secrets and having done an engine before I screwed up the installation of the crank into my C case!

I was just testing the clearance (yes, I did all the measurements and calculations and all looked fine) by placing the crank where it belongs and snugging the acorn nuts down to make sure everything was OK. Maybe I was overzealous in "cranking" the nuts down but I was quickly aware that the crank was stuck. Releasing the nuts and separating the halves I took the #1 bearing off. It was a bit reluctant. On close examination I'd obviously not place it over the dowel pin. It now had a clear dowel head impression on the back of the bearing and the dowel pin is firmly stuck in the left case half.

So I tried it again with the dowel pin properly aligned. I reassembled and I can turn the crank although it's a bit tight. I'm of the opinion that I deformed the bearing a bit but when the thing gets going it'll either wear away whatever high spot I created or cause the bearing to reform since the crank will be exerting a bit of force. What think you? Should I find a new set of bearings (1st under)? Does anyone have a pristine #1 first under C bearing available? Name your number. I'm pretty sure I'll not find one but am of the opinion that the engine will survive this mishap but let me know if your experience would make me regret that idea.

While searching my inventory I did come across a virgin A/B standard set still in original Porsche vacuum pack. I did cut out the #1 bearing to see if it could be used but it's on spec as a standard. If anyone needs this set, it can be purchased. Stoddard wants $400 plus so make a reasonable offer.
Bill Romano

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Vic Skirmants
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Re: #1 bearing mishap

#2 Post by Vic Skirmants »

Don't run it as-is. Use a bearing scraper to trim down the dome. And be more careful!
Take a marker and put a line on the bearing thrust surface where it lines up with the dowel pin and mark the case at the same location. Place the bearing by itself into the case half and scribe a light line on both sides where it meets the case half. The C dowel pins were a tighter fit in the case than the earlier ones. And they are longer, so should not be used in an earlier engine.

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David Jones
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Re: #1 bearing mishap

#3 Post by David Jones »

Bill, just for the hell of it I looked up bearing scrapers on Amazon and I guess this is as good as it gets.
https://www.amazon.com/GEDORE-8777350-T ... B076WRDK5X
If I had known I would live this long I would have pushed the envelope a little harder.
Cymru am byth
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Steve Hatfield
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Re: #1 bearing mishap

#4 Post by Steve Hatfield »

Check Stoddard on line catalog. I was surprised seeing a selection of nr. 1 mains available for less then a whole set. Scroll down under Bearings.
Steve Hatfield
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Bill Romano
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Re: #1 bearing mishap

#5 Post by Bill Romano »

Thanks all. And Steve, I'll be darned, Stoddard had a 1st under #1 bearing. I had looked earlier and didn't get a hit with either the Porsche or NLA part number. Looking under just "bearings" produced. A bit pricey but I'll be more comfortable with an unabused bearing. Thanks for suggestion on a bearing scraper and for finding one on line. Sounds like fun but will go with a new one.

On an earlier B engine that was 1st under and 1st over I bought a set of bearings from Harry Pellow. The set measured up a tad thick and on consultation with Harry he suggested sanding the steel backings. I spent hours doing that and did finally achieve a usable fit. The engine ran but a caller spotted the engine number on the VIN DB and despite my advising him that the engine number was bogus and impressed on a ground off area he insisted on buying it so I have no idea about engine life or on the road performance. Attempts to contact the buyer to find out how it went have been unsuccessful. The engine number was *KD*0600625* and I know that's not a legitimate number. Anyone seen it lately?
Bill Romano

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Steve Hatfield
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Re: #1 bearing mishap

#6 Post by Steve Hatfield »

Bill,
Happy to help. If it’s any consolation, I committed the very same misalignment error a few years ago but didn't consider Vic’s suggestion. That’s how I discovered Stoddard’s selection.
Hope it all works out. The good news is, bet you won’t make the same mistake twice.
Steve Hatfield
Fort Walton Beach, FL
'63 S90 Sunroof Coupe
'06 997S Coupe

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Greg Bryan
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Re: #1 bearing mishap

#7 Post by Greg Bryan »

Bill - you can also try AA Performance Parts in California. They probably sell more main bearings than anyone else for the 616 motor, and may sell you the #1 Bearing only.
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Richard Shilling
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Re: #1 bearing mishap

#8 Post by Richard Shilling »

When you re-install get a soft pencil and mark the location of the hole for the dowel pin on the front of the bearing. Install the bearing into the case and mark the outside of the bearing with a line to the edge of the case. When you install everything that makes it easy to line up the bearing with the dowel pin.
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Vic Skirmants
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Re: #1 bearing mishap

#9 Post by Vic Skirmants »

Richard; check my post, #2. Dejavu.

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Steve Hatfield
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Re: #1 bearing mishap

#10 Post by Steve Hatfield »

Richard and Vic,
One important last step to your procedure, ‘then pray..,’
Steve Hatfield
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Dick Weiss
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Re: #1 bearing mishap

#11 Post by Dick Weiss »

Bill,

Definitely follow Vic's advice, but it's possible the bearing shell might not be distorted enough for reuse
and just trim the pin hole's surroundings. If it's slightly outaround, it can be re-rounded, but if the crank
can be turned by hand easily (w/oil added to the journal?) after the case stud-nuts are torqued, it should
be OK for use.

However, I looked in my archives for a -0,25 #1-M/bearing, but I must've used it on another job.
Otherwise, I only have 1-set of -0,25s (for another rebuild), several sets of -0,50s, and even a set of -0,75s.
All OEM; not steel-backed.

Dick

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Ron LaDow
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Re: #1 bearing mishap

#12 Post by Ron LaDow »

My oops, years ago:
I opted to drill though with a diameter such that the 'bulge' was drilled out and there were no raised edges. The choice was based on an assumption that 'feather edges' from scraping were possibly of more concern than the loss of the 18mm loss of surface area.
The engine got probably 60K miles before it was sold, and there were certainly no oil pressure issues.
Ron LaDow
www.precisionmatters.biz

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Harlan Halsey
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Re: #1 bearing mishap

#13 Post by Harlan Halsey »

To Vic's instructions I might add that after scraping, you can get the bearing coated by H M Elliot Co and end up better than new.

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Vic Skirmants
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Re: #1 bearing mishap

#14 Post by Vic Skirmants »

Dick Weiss; you have to learn to be patient when hitting the "submit'" button. You have two duplicates here, and THREE on another topic.

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Wes Bender
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Re: #1 bearing mishap

#15 Post by Wes Bender »

Possibly been tricked by the recent slow forum response issue....
Some days it's just not worth chewing through the restraints.....

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