Bearing Failure

DCarr511 · Post by **DCarr511** » Sat Jun 11, 2005 11:42 pm

Scott Smith wrote:Dcarr,
Do you have screens in the valley?
Screens in the valley + HV pump = empty pan.

No it doesnt. No restrictors either. Sold flat tappet cam.

The Oil system consisted of a Moroso 21043 pan w/ full length kick out and solid windage tray.
M77HV pump
Oberg Oil Filter -10 lines supply and return
I plan on going with a stock pump and getting rid of the Oberg and most likely going to a stock canistor type filter.

Does anyone know of an online diagram of the oil system on a production BBC ?

Duane

bsfc9 · Post by **bsfc9** » Sun Jun 12, 2005 9:23 am

Thanks Carl for the input. It seems the same (brand) bearings we are seeing trouble with have been run in the past with no problems what-so-ever. Our checking procedures(valve train fully assembled) are the same. Checking fully assembled valve trains with a primed lubrication system is a great idea. We have been thinking there are some bad(soft) bearings out there. I hate to blame it on the bearings but our combos are proven reliable and this has come "out of the blue". And like I said, not just us but others have (confidentially) reported to us similar problems. The only other thing that I noticed is the cam journals on our most recent failure seemed to have a rougher surface finish that what one would expect. I would imagine a cam journal should have the same requirements as a crank journal.
Sorry, DCarr511 for butting in on your post.

CNC BLOCKS · Post by **CNC BLOCKS** » Sun Jun 12, 2005 9:53 am

bsfc9

We reacently had to line bore the cam tunnel for another engine shop as they went from a flat tappet cast cam to a billet 8620 cam core and ran it 5 minutes on the dyno and spun numbers 3 and 4 cam bearing and they were using ACL bearings which are Aluninum as they went to the durabond bearings which are a babbit bearing and ran it last week on the dyno and things were fine, And he also mentioned that the journals on the cam looked rough.

We have always used the ACL with no problems.

bill jones · Post by **bill jones** » Sun Jun 12, 2005 12:12 pm

-I always check and straighten camshafts as one of the very first things I do.
-Then as the very last details before I install the cam is I double check the cam for straightness, straighten it if I can find ANY measurable runout, then I set the cam in the lathe and I hand polish the journals and on roller cams I also polish the lobes and the base circles before I wash it and install.