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Airwreckc
Eric Cumming
RTP, North Carolina
(248 posts)

Registered:
05/28/2020 10:10AM

Main British Car:
1972 MGB-GT (working on a Sebring project) Buick 300-4 V8

Crankshaft "gouge"
Posted by: Airwreckc
Date: December 02, 2022 05:19PM

Hi all,

After a lot of searching, I found a 350 crank recently. Upon initial inspection, it appeared to be pretty clean and apparently recently ground 10 thousands under. I started to clean it up and begin a polishing process and then noticed a small gouge near one of the oil galleys. I'm not sure if going to the next size under will eliminate it, so wondering if it's something that could normally be lived with. Of course, I'll have the crank checked for cracks, but otherwise, what do people do with these sorts of things? Too bad it's not on the mains, since those have a lot of grinding to be done...
IMG_4497.jpg



Edited 1 time(s). Last edit at 12/02/2022 05:20PM by Airwreckc.


mgb260
Jim Nichols
Sequim,WA
(2463 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Re: Crankshaft "gouge"
Posted by: mgb260
Date: December 03, 2022 01:42PM

Looks like it needs to be welded up and then have rod journals turned down .020 under.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6469 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Crankshaft "gouge"
Posted by: BlownMGB-V8
Date: December 03, 2022 02:06PM

Since it isn't on the thrust side of the journal you can probably get by with just cleaning it up a little and having the crank ground. There may be a small chance it could pick up whatever dirt or grit might come through but for the most part it will just fill up with oil and not cause a problem. Generally speaking you want a smooth continuous surface but imperfections below that surface aren't going to touch the bearing.

Jim
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Airwreckc
Eric Cumming
RTP, North Carolina
(248 posts)

Registered:
05/28/2020 10:10AM

Main British Car:
1972 MGB-GT (working on a Sebring project) Buick 300-4 V8

Re: Crankshaft "gouge"
Posted by: Airwreckc
Date: December 03, 2022 02:18PM

Jim and Jim,

Thanks for the feedback, as always.


DiDueColpi
Fred Key
West coast - Canada
(1365 posts)

Registered:
05/14/2010 03:06AM

Main British Car:
I really thought that I'd be an action figure by now!

authors avatar
Re: Crankshaft "gouge"
Posted by: DiDueColpi
Date: December 05, 2022 02:08PM

Take it to a good machinist and get it properly ground and you'll be fine.
It looks like the previous grind ignored the fillets all together, which can lead to cracking.
Get the fillets rolled and then grind the crank. Go find sleeping beauty and live happily ever after.

Live like you mean it
Fred


Airwreckc
Eric Cumming
RTP, North Carolina
(248 posts)

Registered:
05/28/2020 10:10AM

Main British Car:
1972 MGB-GT (working on a Sebring project) Buick 300-4 V8

Re: Crankshaft "gouge"
Posted by: Airwreckc
Date: December 05, 2022 02:39PM

Fred, ha--I already have Sleeping Beauty ;)

Thanks for pointing out the lack of fillets--missed that myself.

Eric


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