Crankshaft bearing fretting in cases?

[Nessism]

I spent some time this last weekend bolting together the crankcase on my 1000S (number 2). This is the engine that had the 1176 cc kit installed but is now being put back to stock. Of concern is one of the center crank bearings has what looks like fretting inside the crankcase bore and on the OD of the bearing; a pin keeps the bearings from spinning in the cases but it looks like there was some relative movement between the two parts. With the crank just laying in the upper crankcase half that one bearing seemed like it wasn?t as tightly held as the other bearings - although this is obviously not the best way to judge fit between these parts. Now that the cases are bolted together I?m starting to wonder if I should have used some loctite on the OD of the bearing to help hold securely? Have any of you guys ever seen a problem like this before and if so, do you think there is reason for concern? I?m not too keen on opening the crankcase again but now is the time if I screwed up.

 

[blowerbike]

here is what we have.
even a severe use stock engine will bounce the main bearing races somewhat.
it is a given that when you build a hot rod engine that you need to install H/D studs in the lower case halves.
this stops the crank from bouncing in the main saddles as the extra horsepower/compression tries to push the case halves apart.
what i do..yes me.
i put a little red loctite in the saddle areas when assembling to take up any loose clearance issues in the main saddles on a roller bearing engine.
the ping marks in question won't really hurt anything in a street engine but always look for cracks in the casting around the main saddles.

 

[Nessism]

Okay, thanks for the info Terry. Makes sense. Wish I'd done the loctite thing now but don't think I'll break it apart since this engine won't get hammered overly hard.

 

[Nessism]

This situation was nagging at me so I decided to pull down the engine and add some loctite to the bearing saddles in the cases. A two hour job turned into a four hour job when two case screw holes stripped out while buttoning up the engine, and then two more holes on the sump cover (yes, I have a torque wrench, two of them actually). At any rate, the job is done and have some photos to show what the marks look like.