Don Terrill’s Speed-Talk

Barry_R wrote: ↑Tue Feb 06, 2018 12:45 pm Its not oil pump cavitation - its bearing cavitation - similar name but a different deal.

No signs of heat or smearing on the surface - it had lube, but something pulled the material away from the bearing.

Yep, and typically more clearance aggravates it!

Id send the bearings back to the manufacturer and see what they had to say about it.

exhaustgases wrote: ↑Thu Feb 08, 2018 6:46 am What are the clearances? What is the oil viscosity? What rpm range? What kind of load? How many miles or hours on the bearings?

Exactly, I get called in to warranty issues and there is no information on the engine
Except low oil pressure or some other vague issue.

bentvalves wrote: ↑Wed Feb 07, 2018 7:57 pm Id send the bearings back to the manufacturer and see what they had to say about it.

One of those has already commented here.

Clearances were 0.050 -0.055mm. Oil used during the life of the engine was 20w 50 later changed for 15w40. Engine only done 20,000 road km. Around 2000km short distance sprint and hill climb events. Oil Temps on road around 80*c . Pushed hard maybe hit 120*c but very rarely. Usually my highs are 110*c.
Max rpm 7200.
oil pressure 65psi+ hot above 3500rpm.
Main bearings are clevite bi metal.
Rod are federal mogal bi metal.
Thrust are oem and look like new.
I know these are not race bearings but I really didn't expect such damage so soon.

bentvalves wrote: ↑Wed Feb 07, 2018 7:57 pm Id send the bearings back to the manufacturer and see what they had to say about it.

Agree...sure looks like a bearing plating issue.

It’s a manufactured part...things go wrong.

exhaustgases wrote: ↑Fri Feb 09, 2018 9:00 pm I like the metric system, but when it comes to the small sizes, I know the English fractional better, .05mm = .00196, and .055mm = .00216.
So what is the journal diameter?

50.8mm

integrale Evo wrote: ↑Tue Feb 13, 2018 5:36 pm

exhaustgases wrote: ↑Fri Feb 09, 2018 9:00 pm I like the metric system, but when it comes to the small sizes, I know the English fractional better, .05mm = .00196, and .055mm = .00216.
So what is the journal diameter?

50.8mm

I bought some king tri metal Integrale bearings meant for rods without oil holes for the rebuild. Have u had the Integrale apart? How did yours look? Brand of bearing?

AC sports wrote: ↑Wed Feb 14, 2018 11:42 am

integrale Evo wrote: ↑Tue Feb 13, 2018 5:36 pm

exhaustgases wrote: ↑Fri Feb 09, 2018 9:00 pm I like the metric system, but when it comes to the small sizes, I know the English fractional better, .05mm = .00196, and .055mm = .00216.
So what is the journal diameter?

50.8mm

I bought some king tri metal Integrale bearings meant for rods without oil holes for the rebuild. Have u had the Integrale apart? How did yours look? Brand of bearing?

I've had one or two apart yes, but they aren't in particularly good order when they come to me. I don't know who made the original bearings, they had Fiat and CL (inside a diamond) on them, I also don't know why the earlier models like yours had holes in the bearings and the later ones didn't.

The ones with holes like mine didn't have oil squirters in the block pointing up under the piston like yours. My current rods have 2 holes in them that point up. My new rods don't need them either. They get splash lubrication. Tried and tested I hear.
Your right about the oem bearings. These were changed by myself a while back. I always thought CL was clevite & made for fiat/lancia but prob wrong.

Just asking : what’s the reasoning behind asking the question about the battery charger ?

I'm guessing some sort of electrolysis?
But it definitely looks like water damage now I'm examining it under magnification.

Why are you still looking at the bearings when it's the crank that's [DELETE THIS POST].

I think I would be keeping the piston cooling jet holes, if the stock motor had them then certainly a modified or hard driven one will.

integrale Evo wrote: ↑Fri Feb 16, 2018 11:09 am I think I would be keeping the piston cooling jet holes, if the stock motor had them then certainly a modified or hard driven one will.

In a turbo application like yours I'd definitely keep them. Mine is na and they are not really needed. My pistons won't see the temps yours will. Splash and mist are adequate to lube in an na tc. I know of many na powered tcs that run flat out on ovals, full throttle in top gear for extended periods and never had pin oiling issues.
The squirters were needed when Lancia redesigned the 2l tc block for turbo in order to cool the pistons from below. At least that's what logic tells me. I know they kept that set up in their gpA wrc cars too.....I'd sure like to see what they did with the S4 though. Completely different engine I know...but still wonderfully engineered as they all were.