Big End Shells

[steige 1 1 Cars]

utter nonsense

 

stevie, i'll pop up and measure the crank and rod while you are away if you want, let her in doors know

Ok bud i'll let her know. What day is good for you?

[Mattsav 1]

We stock Plastiguage. Very useful stuff.

[ALEX 98 1 Cars]

What!

The picture's are bad, his thumb is covering the tab on one picture and the other is blurry, give me some credit.

I've seen bearing faces just as bad from running engines with no oil pressure probs. Besides the tabs might be bent in for other reasons. They might have been put in wrong in the first place.

"Gauging opinions is only of use if the opinions are correct"

I'ts hard to give an acurate opinion with a limited amount of information to work with. Even you've been wrong on the odd occasion Dave.

[Kev-G 1]

What!

The picture's are bad, his thumb is covering the tab on one picture and the other is blurry, give me some credit.

 

Your joking aren't you:

 

http://img.photobucket.com/albums/v512/steige/PICT2226.jpg

http://img.photobucket.com/albums/v512/steige/PICT2224.jpg

 

You need to get your eyes checked never mind your bearings....

[ALEX 98 1 Cars]

Your joking aren't you:

 

http://img.photobucket.com/albums/v512/steige/PICT2226.jpg

http://img.photobucket.com/albums/v512/steige/PICT2224.jpg

 

You need to get your eyes checked never mind your bearings....

 

Yes sorry I ment finger not thumb!

[PumaRacing 2]

What!

The picture's are bad, his thumb is covering the tab on one picture and the other is blurry, give me some credit.

I've seen bearing faces just as bad from running engines with no oil pressure probs. Besides the tabs might be bent in for other reasons. They might have been put in wrong in the first place.

"Gauging opinions is only of use if the opinions are correct"

I'ts hard to give an acurate opinion with a limited amount of information to work with. Even you've been wrong on the odd occasion Dave.

 

I'm sorry but you're giving someone advice that could literally cost him his engine. You said "Those bearings in the picture should go back in and give you no problems."

 

Any bearing that's spun must by very definition have its locating tangs destroyed in the process. You can see that clearly in the first picture even if it wasn't obvious from first principles that it must have happened. The pitting and scoring on the bearing faces is also clear. There is ample information to work with here on which to give the correct advice. If I give a customer the wrong advice I'd expect to have to pay to correct it. Do you still back your original advice with your wallet if the OP decides to refit those bearings?

[ALEX 98 1 Cars]

If anyone went to the trouble of removing crank bearings and even if there was any visible ware on them it would be common sense to replace them with new ones, Do you really think I was advising him to re-fit them?

You cant just look at a picture and assume the worst, thats what most garages do to try and rip you off, before you know it a garage would have sold you a new crank, conrods & bearings without reaching for the micrometers, and make it sound more convincing by sucking air through his teeth.

Has the bearing spun or has it just moved 90 degrees? I've seen a spun bearing before, there wasn't much bearing to look at. You can't see the back of the bearings or the bearing caps to say that it's been grinding away.

The difference between my opinion and yours is that your thinking worst case scenario and I'm thinking the opposite.

I gave an opinion based on a picture of some bearings and what can I say I'm an Optimist.

[Anthony 1,002]

Always better to err on the side of caution, but there's no doubt those bearing shells are not fit to be reused even on the tightest budget.

[DrSeuss 0]

Do Burton not sell it?

 

I'll certainly got some in the garage..

 

You get Red and Green (maybe more) for diff. clearances.

 

Just meant its only really sold through engine builders, not halfrauds.

 

I've used the red stuff to measure tolerances on a cam bearing cap. Dead handy.

[steige 1 1 Cars]

If anyone went to the trouble of removing crank bearings and even if there was any visible ware on them it would be common sense to replace them with new ones, Do you really think I was advising him to re-fit them?

You cant just look at a picture and assume the worst, thats what most garages do to try and rip you off, before you know it a garage would have sold you a new crank, conrods & bearings without reaching for the micrometers, and make it sound more convincing by sucking air through his teeth.

Has the bearing spun or has it just moved 90 degrees? I've seen a spun bearing before, there wasn't much bearing to look at. You can't see the back of the bearings or the bearing caps to say that it's been grinding away.

The difference between my opinion and yours is that your thinking worst case scenario and I'm thinking the opposite.

I gave an opinion based on a picture of some bearings and what can I say I'm an Optimist.

 

I think the bearings had just moved through 90 deg. There doesn't appear to be any damage to the back of the bearings or the caps. The tabs were bent over as well.

 

Despite what you said i would never have put those back in and i know feck all about engines.

 

I'm just hoping Jeram gives the crank the all clear when he has a look!

[C_W 3 1 Cars]

The bearings are not too small and in fact bigger than many/most other engines of similar capacity. The reason the big ends fail is because they are lead/copper, very hard and not tolerant of poor lubrication. Fine for well maintained race engines but not the right choice for road ones. In conditions of marginal lubrication they pick up against the crank and spin where an aluminium or white metal bearing would embed the debris and carry on quite happily. That's why Peugeot abandoned the lead/copper bearings for later engines and why I use softer ones in all mine.

 

Maybe this might be why mine is lasting so long (touch wood!)?? I bought my Mi16 engine with 110,000miles on it and replaced the bottom end bearings - it's now done over 180k and still seems fine despite around 50 trackdays but the oils been changed almost as many times each time oil pressure is built up without the plugs in. Warmed up gently every time and it seems to be able to sit out on a track all day.

[steige 1 1 Cars]

Just an update to this old thread. I have had the crank measured with a micrometer and it appears to be fine with no ovalling. I have since polished the crank and it now looks good with a mirror type finish. Below are some before and after pics. Although they are not great quality.

 

Before

http://img.photobucket.com/albums/v512/steige/PICT2395.jpg

 

After

http://img.photobucket.com/albums/v512/steige/PICT2400.jpg

 

Hopefully the new baffled sump+oil pump baffle and group "A" spring will prevent any future occurance of the problem.

 

Baffled sump

http://img.photobucket.com/albums/v512/steige/PICT2399.jpg

 

Oil pump baffle

http://img.photobucket.com/albums/v512/steige/PICT2398.jpg

Edited January 31, 2006 by steige

[tom_m 0]

are there trap doors in your baffles to let the oil back to the pump?

[C_W 3 1 Cars]

are there trap doors in your baffles to let the oil back to the pump?

 

With 2 simple baffles like that in the sump I don't think there is any need for trap doors. I think those baffles need to be higher IMO.

[steige 1 1 Cars]

are there trap doors in your baffles to let the oil back to the pump?

There are no trap doors in the baffles but there are gaps about 10mm at the bottom to let the oil back to the pump.

 

Not sure about the height of the baffles. But I only ever track drive the car round knockhill and I have never suffered any oil surge on my old engine and that is totally standard.

[veloce200 3]

I had a lucky escape with my 8v when the oil pump sprocket sheared off (i think the chain came off and took it with it). This was at 6700 rpm at Lydden. The power disappeared instantly. Bearings were shot with material all over the crank. At the time I lived in a terrace so a full engine rebuild on the road was out. Budgets were low so I chanced my arm and cleaned up the crank and put new shells in. Been fine for two years of sprints and about 8000 road miles. Would I do it again though - NO! It's a false economy I think and I was just very lucky. I always think it's about to let go ever since!

 

Like CW though I've always warmed engines slowly and I think this does make a difference to longevity.

[petert 585]

There are no trap doors in the baffles but there are gaps about 10mm at the bottom to let the oil back to the pump.

 

I still think it's hard to beat the full XU10 setup for a wet sump. By the time you payed someone to gin around modifying a 1.9L sump, you could have fitted all the factory parts. Have you heard of an S16 or a GTi6 spinning a shell?

[Mandic 0]

That's why Peugeot abandoned the lead/copper bearings for later engines and why I use softer ones in all mine.

 

When did Pug start to put in softer bearings? with S16? And are todays aftermarket (Payen for one) bearings softer and should be used w/o problem?

 

What about those competition (Grp.A) bearings some sale? They are harder ones and should be avoid for road and occasional track use?

 

Thanks

 

Ziga

[petert 585]

When did Pug start to put in softer bearings? with S16?

 

Yes, XU10J4 rod bearings are soft, although exactly the same size and tang position as XU9J4 rod bearings. So mix and match at will.

[ALEX 98 1 Cars]

By looking at the shells I would imagine you crank is fine too.

 

 

Just an update to this old thread. I have had the crank measured with a micrometer and it appears to be fine with no ovalling.

 

 

Good news then.

See it pays to be a little optimistic now and then! .

[fiji bob 0]

when i was buying bits for an mi bottom end i was given the choice of either aluminium or "boy racer" lead/copper bearings so you should be able to get either easily enough

[Martin@PRD 0]

New and the old original bearing out of 108,000 MI16

 

Note this was NO 1 bearing (flywheel side)

 

Crank was checked and there was no damage coursed

 

http://img.photobucket.com/albums/v728/tomoprd/100_6703.jpg

[steige 1 1 Cars]

New and the old original bearing out of 108,000 MI16

 

Note this was NO 1 bearing (flywheel side)

 

Crank was checked and there was no damage coursed

 

http://img.photobucket.com/albums/v728/tomoprd/100_6703.jpg

Holy Sh*t the damage on mine looks tame compared to that. Its re-assuring to see though!