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Another Rn + 20G, My 'build' Thread


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It could have been from a blocked oil passage, but I didn't notice any debris in the oil before it happened. I'll have a better idea when I take the engine apart fully.

BTW, are there anymore crank options for the 5 cylinder whiteblock other than the 77mm, 90mm and 93.2mm?

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I've had china rods (same as CXrods?) put in my b5234t5 back in 2010 but last week my engine (on stock 15G with a mild chiptunning) broke down.

It looks very simular to your bigend bearing fallure, see:

http://www.volvo850forum.nl/index.php?topic=70606.new;topicseen#new

Although in Dutch the photo's speak for themself...

Only cilinder 2 had the bigend bearing fail, rest was still as it should, there was no oil shortage when it happend...

Makes me wonder if this problem is related to these H-beam rods (not being 100%...?!)

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It could be a problem that the journals were not milled/honed to perfect circles. It is be hard to tell though, since the bearing failure was so catastrophic I can't get a read from them. I'll measure the big end rod journal when it is out, but it got so marred if it was out of round it would be hard to know if it was originally like that.

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In my case -rod bearing failure- the problem was I switched the Rod cap position 180°. It was clearly my mistake:(. The rods was unmarked and accidently mismatched them. You can't notice after that, they were even round, but in reality not, a few 0.001 difference and one is gone.

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Good god man, what bad news. Sorry to hear this.

In my case -rod bearing failure- the problem was I switched the Rod cap position 180°. It was clearly my mistake:(. The rods was unmarked and accidently mismatched them. You can't notice after that, they were even round, but in reality not, a few 0.001 difference and one is gone.

on my stock rods, it was impossible to get a cap 180 out ... and I am pretty confident that on the CX rods it was impossible as well (something with the dowels IIRC)

flame suit on. :)

Overall I consider the Glyco aftermarket bearings suspect ---> aftermarket meaning the Glycos not supplied to and resold by Volvo. I read around a while back and found information to support that Volvo and others require higher QC on the same parts and even perform their own random QC checks that the aftermarket equivelants are never exposed to or held to.

If you read around you will find people out there that skipped the dealer Glycos and ran aftermarket with similar results to yours (read the Porsche forums especially)

I know that the sputtered version is more expensive but that's just their nature --- they are significatly more expensive to make. That's my take anyways.

If they're coming from the aftermarket and not the dealer, then I personally am concerned with them.

As I understand it, the sputtered were OE from Volvo over in Europe, but on their -diesel- applications --- which makes perfect sense, as the sputters are suited to the higher compressive loads seen in a diesel. That being said, I personally don't see a whole lot of benefit in running a sputtered bearing unless you plan to knock/detonate on a regular basis or are running a diesel.

You've bent rods and made a lot of power. How did the standard bearings look afterwards?

Mine looked perfectly fine. Just sayin.

There's just no reason in my mind for your bearings to fail so catastrophically and in such short order on a crank journal that has run fine for so long and without issue other than replacement bearings that were out of spec ---- you were careful installing them, the crank was fine, the rod big end was almost certainly fine (mine measured up with no out of round), etc, etc, etc.

If you didn't protect the journals while honing with tape/etc then it IS certainly possible that the ball hone chipped and found it's way into the oilway on the journal. Also certainly possible that that nasty nasty slurry dripped down and found it's way into the oilway, although I would think that it would take a good amount to cause such rapid failure --- generally the slurry damage isn't localized to one bearing, as it comes down to poor or incorrect cleaning measures (brake cleaner) which leads to a contaminated oil supply.

Have you looked at the other bearings yet?

It is a shame that you didn't measure clearance. That would be nice data to have.

Now, a little disclaimer!

I'd like to make it clear that I have zero actual experience with these bearings and only have my own reading and digging to go on.

I wish any and all that have elected to run the Glycos acquired from the aftermarket nothing but the best of luck and success! :)

EDIT:

question.

You had to get one replacement set due to the ones you received being badly gouged. Are these the ones that failed? Was that the rod journal that suffered the bent rod?

Edited by mattwebb502
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The bearing that spun was neither on the rod that originally bent nor was it the replacement bearing for the gouged set.

With the CX rods, it is possible to put the rod caps on backwards (180 degrees out), but is fairly obvious when you do so by feeling the connection of the cap and rod. If it is misinstalled there is a noticeable lip between the cap and rod.

I did not tape up the rod journals before honing, but I did use foam cylinder cutouts and paper towels stuffed into the bottom of the bore. From my first oil change i didn't find any ferrous particles so I doubt that was the problem.

The stock bearings were in excellent shape, there wasn't a single contaminant trail longer than 90 degrees, and they all felt smooth.

Edited by Tightmopedman9
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I'd like to make it clear that I have zero actual experience with these bearings and only have my own reading and digging to go on.

I wish any and all that have elected to run the Glycos acquired from the aftermarket nothing but the best of luck and success! :)

I have installed glyco sputter bearings twice (before and after the previously described oil incident) and still running them now with CX conrods, never have had any problems with them.

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The bearing that spun was neither on the rod that originally bent nor was it the replacement bearing for the gouged set.

With the CX rods, it is possible to put the rod caps on backwards (180 degrees out), but is fairly obvious when you do so by feeling the connection of the cap and rod. If it is misinstalled there is a noticeable lip between the cap and rod.

Did it actually spin, or was it just ugly?

My CX rods were the same now that you jog my memory. They would fit backwards, but it was painfully obvious and would be _IMPOSSIBLE_ to torque down wrong unless you're brain dead. :)

Piet: It's very good to hear your luck with the bearings. I think others Glyco experiences line up with yours (Boxpin, IIRC?) Stories like TMM9's are "the pits" ... I only wish we could nail down a culprit in his case. We'll probably never know what went wrong or why. Fingers crossed that my testing the waters with King bearings turns out OK. So far, so good. They were a high quality product from what I could tell, but I'm really not an expert with a trained eye.

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When they are as discolored as mine, I would certainly not reuse them.
The discoloration indicates an extreme overheating of the material which has changed its metallurgic properties.
A significant loss in strength of the rods is very likely.

Edited by Piet
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Easiest way to tell if the bearing spun is by looking at the locating tabs on the back of the bearing.

Smashed flat (not protruding) means it spun at least 1 time. Protruding tab means it did not spin.

Rod

Locating tabs? What bearings are you using that have them?

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