Aluminium flakes in the oil filter?

Here's the deal. This year we are seeing some very fine aluminium shavings in our oil filter every pass, not a huge amount but enough to make me look for the source. After some inspection I think its coming from the big end of the rods to crank cheeks, is this normal? When we pull the pan all the rods are pushed against their rear crank cheek, I dont know if thats normal either.


We are running a different crank this year, trying to solve our thrust bearing problem, but the side clearance is the same for the rods. We are running different rod bearings, they are a bit narrower if that makes any differance.

Other than this pesky aluminium problem the motor is running great, thrust bearing is still doin good, hell I even smoked the tires out past the 330' last weekend, (that was a first).

 

thrust bearing Prob.

If you can, can I get some idea what was going on with your thrust brg? I have been fighting a thrust. brg.problem all year. Thanks Don donimus333@yahoo.com

 

Maximus,.....are you running a clutchflight ????

 

This is a powerglide car.

Don Onimus, Im sending a PM.

 

So you're convinced the stuff in your filter is coming off the sides of the rods?
How much side clearance do you run? Check this with the rod bearings installed and without the bearings, if it changes your brgs aren't releived enough for the radius in the crank.

We get small aluminum looking like material in our filters also. But its babbit from the main bearings that has been "rolled" off the edges. Seems to be related to high RPM.

I've had thrust brg grief and mine have been solved by:
1-make sure there is enough crank endplay when the motor is on the motor stand 8-10 thou
2-after the motor has all the stuff on it (ie, bellhousing, tranny, etc) make sure it still has enough endplay
3-make sure the flywheel is balanced correctly

 

The rod bearings are definently not rubbing in the raidius, we do see the mains roll off some babbit sometimes like you said, but not enough to make this amount of material in the filter. We have .070 side clearance per pair, just as our last crank had.

Im not positive its coming from the rods, but we are seeing some skuffing on the big ends.

 

Thrust bearing

Don what bearing are u running I ran all v bearings and had trouble with transfering metal on the thrust. I put a m series thrust in and had no more problem. Just lettig u know Kevin Newburgh

 

What stroke crank? check to see if the crank counter weight is hitting the radius on the rod on the small end. I had to set my rods up in the mill and cut a small half moon out of the rod on the side that had the crank counter weight. That also takes all the side clearance out, when the weight hits the rod and pushes it over. You may have good clearance when the piston is up the cylinder, but at the bottom you will lose your side clearance. I'm not sure i explained this very well, but i tried.

 

Its a 4.500 stroke on a 2.200 pin.

I think I know what you are talking about, I'm pretty sure its not doing it but I sure will take a closer look.

 

Hmmm, good point, I've had this also but had forgot about it.

I've had it where we releived the block with ample clearance, but when the alum. oil pan was bolted on there wasn't enough. It cleared on the motorstand but not at high RPM and therefore the rod bolt heads "relieved" the pan themselves.

 

I looked over my motor pretty well just now, the counterweights are not hitting the small end, no (self clearancing) of parts.

Im positive now that its all coming from the crank side of the big ends, all the rods have skuffing on them, caps too. I know its not really hurting anything but I'm still wondering why this new crank is machining on my rods....?

Has anyone else had this happen?

 

I haven't had it but did hear of this problem with the machinist not truing the stone and grinding a tapering the journals.
Steve

 

If this is a new engine...Think you will find its coming off the piston on the pressure side because of the rotation of the engine loading the skirt..don't worry its normal first start up.... it should clear up.

Mark

 

Check for sharp edges at the bottom of the sleeves shaving the piston skirt.
Check for sharp edges on the lifters shaving the lifter bores.
Both of these would sprinkle all over the crank and rods.

 

I did check all the lifter bores and they look fine, I havent had the pistons out to look at the skirts in a while though.