Hi, "Y-aaawwlll"
Asked a question to a member but as of yet, got no answr.
Spun a bearing on my '01 xj8. found a crank on ebay that mikes to the 10th to the original so its a good match for the other conn rods/bearings. HOWEVER...found a replacement conn rod/piston (don't need the piston) on ebay. the numbers on the rod/cap are different than the # on mine. Ouestion: Does it matter as long as I get the right bearings and/or do a plastigage on the fitting?
Also: I'll find out soon enuf, but can the piston come out the bottom or do I have to ****** the head off? Thanx, Guys. (Gals)
Gimme an old 350 and I can build it blindfolded. These cats are a "different breed"
Steve

PS: WATCH THAT OIL!!!!!!!
__________________
Buy and sell Cats.

 

Why did the bearing spin?

I don't have any experience with these engines, but I have never worked on one that it was possible to remove the crank without removing the heads and pistons through the top.

 

Why?
No light, no noise no nuthin. All of a sudden bearing noise. I assume the tolerances are so close that just a little lack of oil will score a bearing/journal. It never used oil but evidently ran low enuf to drain the sump turning a corner or whatever. I don't really kno. The way these engines are built it's even hard to identify the source of the noise. BUT.... there it was. ruined crank/conn rod. 1st journal. It seems to be rather common in these jags when they are oil starved.

 

Strange. Every time I've seen a bearing spin, there was some cause...like a missing oil gallery plug, wrong bearing shells, etc. You are very lucky if it was only 1 journal that was damaged. Was any major work done on the motor recently?

 

All very interesting, but why post in the X350 forum for cars dating from 2003 ? The X308 forum would be better, surely ?

 

He's lost. But we have to give him a break...his car came before GPS was offered!

 

Wrong.

 

Hi Steve, If you have already determined the correct replacement bearing size with a micrometer etc. why do you need to use a piece of Plastigage, what will it additionally tell you? what am I missing? Thanks Allan.

 

Hey, Allan.
The question is: The stamped numbers on my conn rod/cap are different than the one I've located on ebay. I haven't found out just what the numbers denote but in my limited knowledge of Jag, they mean something, perhaps the size of the race for the bearing. I mentioned plastigage in case I have to fit the ebay conn rod to my crank. I could use pop gauges and mike but i guess plastigage is a kinda "proof" crutch. I haven't quite fuiguered out all those color/size codes yet, but I will.
Thanx, Allan

 

Fraser, et al:

I may be reading it wrong, but I read "XJ ( X308 ) XJ8 / XJR 1997 - 2003" on the forum address. I figured my '01 XJ8 fit right about in the middle.

My apologies to the Regional Coordinator, John and anyone else I may have offended for being "lost" and my faux pas.

smagl

 

No worries- they moved your posting for you and they were just ribbing you anyway.

Let us know how it comes along.

 

I don't think I would assemble an engine without using plastigage. Many years ago an acquaintance did so and suffered a spun bearing due to an error in the shell.

 

Thanks Steve, i see now, makes good sense, I hadn't picked up the meaning from reading earlier. Thanks again. Allan

 

Hey, Guys,
Still no answer on the stamped numbers on the side of the conn rods. Do they matter?
Steve

 

No work. I think I let the oil get a little low. (STUPID!!!) My '98 never used a drop between changes. So I assumed........All of a sudden, slight rattle. sounded like an old lifter when they had them but got progressively louder. Tore it down and there it was. Only 1st 1/2 of the journal I "haint never seed nuthin like it".
Steve

 

But that should have been caught by the use of plastigage during the install checkout.

If the acquaintance didn't check the as-installed clearances, that is where he went wrong. As a matter of fact, I can't see how you would check "as-installed" clearances directly with micrometers. You can only measure and extrapolate.

 

It is probably explained in the engine assembly manual. They would be the journal diameter and hence you would need to calculate the required bearing shell for that journal.

But, that is a production line thing. For a custom build, you would use a inside micrometer in four positions to measure the diameter on the rod and calculate the required shell again.