What has happened to these shells?

[alfa145]

Hello, firstly it's good to find a forum regarding engine oil/issues.

I have recently rebuilt an engine for use in my track car, all was going well until the oil cooler broke, it dropped the oil and ran dry - 6 litres of oil pumped straight onto the road in about 1.5 seconds... killed the ignition, hit the clutch, but all too late, it sounded rough.
I got the car recovered, I immediately stripped the sump to check, not much but there was some sludge in the bottom, thought I'd better check the shells, here they are:

The rebuilt engine has done about 80 miles of running in before the oil cooler incident. The crank was fine before the rebuild, so a polish and standard sized shells were used. The mains look a lot better, though still some wear so all will be replaced. Luckily the crank has escaped without damage.

What concerns me though is the wear pattern going horizontally in the picture. I *think* I know what has caused this, but would like to hear anyone else's thoughts first.

The engine is from a Lancia Integrale/Fiat Coupe 2.0 16v turbo, 4 cylinder.

 

[Yuk]

Originally Posted By: alfa145

The engine is from a Lancia Integrale/Fiat Coupe 2.0 16v turbo, 4 cylinder.




Off topic, but reading Lancia Integrale made me all giddy remembering 'Miki' Biasion and Markku Alen flying down the special stages. Is your car the Lancia?

 

[alfa145]

Neither - my car is an Alfa 145 - I realise this model wasn't sold outside of Europe. Standard it was a 2.0 Twin Spark engine, but I fitted the Fiat Coupe/Lancia engine. It is quick, for a wrong wheel drive car(!), but it has fantastic handling with lift off oversteer making it very controllable.
I would love the Lancia, but they are too expensive for even a toy/weekend car, I grew up watching them dominate the rally scene, so I have to make do with Fiat's incarnation of the fantastic Lampredi engine.

Alfa 145: http://www.alfa145.co.uk/photos/car/fk_side.jpg

 

[Yuk]

Sorry for not saying this sooner (got distracted by Lancias), but WELCOME to the forum. I can't help you, but sure someone will pipe up.

 

[mechtech2]

Shells must = bearings.
I hope your spanner worked well when you took it apart!
But I'm not getting a picture or any link for the original post.

 

[Pablo]

There is something about those pics or the server hosting that wants to invade my PC.....

 

[XS650]

Originally Posted By: Pablo
There is something about those pics or the server hosting that wants to invade my PC.....

Did you notice that it's an HTTPS site?

 

[Eddie]

Your refering to the closly spaced lines that look like chatter marks? Possibly do to crankcase flexing? The marks seem to be more pronounced at the case ends. My unexpert guess. Ed H.

 

[kokopelli]

The center one looks BAD, like maybe it was torqued too tight.

 

[DmanWho]

Originally Posted By: Pablo
There is something about those pics or the server hosting that wants to invade my PC.....

Me too. Is this because of a cookie?

 

[pev223]

I would like to offer some advice but outside of some failed bearings there isn't much to go on.

The fact that you only had 80 miles on the engine and already had some sludge in the oil pan is interesting. That seems like an awful lot of damage for 1.5 seconds without oil. My guess is you had lubrication issues prior to losing the oil cooler.

Are you running an oil temp. guage? Also, you may want to consider synthetic oil to reduce the sludge.

 

[alfa145]

Firstly - sorry for the link, I used the https instead of http protocol, and the https certificate isn't setup correctly yet on my server. The pic will work, I promise nothing is trying to invade your PC's, any pop ups you get in IE/Mozilla will be referring to the domain name mismatch on the certificate. No cookies should be being set, the link is direct to an image (jpeg) and is not a dynamic type link. I can't edit the post to change the URL to the pic unfortunately.

Shells=bearings. The pics are the big end (con rod) shells.
They were torqued correctly, then angle tightened - they are stretch bolts, these were renewed when I built it.

No. 2 shell has taken the worst hit - this is the cylinder that was not firing after the build, so idle was very rough = low and uneven oil pressure. I wonder if this is what really wore them, and made the lines wear across the shells not down the length. It was run for quite a while trying to figure the cause of the misfire (wiring issue, injector was not firing), so I guess there was no bang forcing down on piston no 2, so lubrification would have been worse around the bearings in no 2?

It was assembled with engine assembly lube, and run in on semi synth 10w40 - this is the recommended viscosity for the engine according to manufacturer specs.

 

[Shannow]

The horizontal markings look like a phenomenon that I've seen on 22" turbine bearings...also seen them on street engines.

The ripples could not be seen, nor felt. Bearings were burnished during manufacture. Once run, the high spots polished, and showed marked shiny/dull lines. Still could not feel nor measure them.

On my big bearings, they were machining marks, and it looks like there was some maybe repeatable roller bearing issue happening while they (the 22") bearings are machined.

I don't know how your bearings are made, but I doubt that they are finish machined.

My guess is that the bi metal (tri-metal?) bearings are manufactured as a sheet, guillotined to size, then rolled to ellipses (to provide the spring into the rods). Compressing the inner surface could well set up ripples on the inside face, as the material has to be displaced somewhere, it can only go out.

Drag your finger nail around thee very edge, on a 45 degree angle. I'd be interested if you can feel a serration effect.

#2, IMHO looks suss...first thought is that there was something in the oil port in the crank. There's what looks like abrasive wear in the centre of the bearing where the oil feed is. Maybe ran enough cycles to break down, and smear the adjacent metal before escaping.

Could also be insufficient radial clearance, possibly from the shell sitting proud of the cap for some reason. Look at the "part line" between the insert and the rod cap adjacent to the locating tang. Looks to be a gap, but I think it's probably the insert shrinking after the damage and a cool down.

 

[alfa145]

Thanks Shannow,

The shells/bearings/caps are made by Federal Mogul, the website for states they are tri metal, aluminium plated.
Regarding #2, in the pic the bearing isn't seated quite correctly in the cap - it was when I removed the cap, but before the photo I removed all bearings to check the back for marks/wear - all backs are clean, so they are not moving in the caps, I just didn't put it back home properly for the photo.

 

[mechtech2]

I am getting a pop up to install some crud.
No thanks!

 

[Pablo]

Originally Posted By: XS650
Originally Posted By: Pablo
There is something about those pics or the server hosting that wants to invade my PC.....

Did you notice that it's an HTTPS site?


I didn't bother getting that deep. But I just now screened for viruses, etc and nothing nasty was detected so I manually allowed a mismatch.

The second bearing looks galled. Too hot, too fast, lack of lubricant, or maybe a lubricant/clearance missmatch....maybe I missed it, but what were the clearances set up for on this crank/bearing interface?

 

[alfa145]

I'll just clarify again why you receive a pop up when your browser requests the image from my server:

I accidentally entered https:// instead of http:// when linking to the image. It resides on my webserver, there is nothing malicious residing there. Try reading the pop up, it is not installing anything, it is not asking you to install anything - it is simply alerting you to the fact that the SSL certificate has a common name of localhost and not my domain name of acarter.co.uk.

I have made a request to a moderator to edit the url linking to the picture to remove the s from https, as I cannot edit the post. Hopefully this will remove any future doubt.


Now, back to the issue in hand. Pablo, what do you mean clearances set up for the crank/bearing interface?
The crank had a polish, and standard thickness shells were used.

 

[Pablo]

Quote:
Pablo, what do you mean clearances set up for the crank/bearing interface?


Did you plastigage it? What is recommended? What does the book say on this engine?

 

[kokopelli]

Too small of a clearance/gap is what I meant by "torqued too tight." You can torque them down to spec, but still have too-tight of a clearance. You should've (hopefully) received some PlastiGage with your Bearing kit.