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Thrust bearings. Guess which one faced the clutch.. I have never seen one of these before, is the scoring/gouging normal? Seems like it should be smooth wear. The friction face on the crank it pressed against was totally smooth.
That's definitely your source of metal debris. It seams to be getting more common place. Probably due to excessive stop and go traffic, or resting left foot on clutch while driving. High performance pressure plates with increased clamp load will also cause increased wear of the thrust bearing.
That's definitely your source of metal debris. It seams to be getting more common place. Probably due to excessive stop and go traffic, or resting left foot on clutch while driving. High performance pressure plates with increased clamp load will also cause increased wear of the thrust bearing.
What is the thrust bearing made of? Is it ferrous, or alloy?
What is the thrust bearing made of? Is it ferrous, or alloy?
Its a tri-metal bearing, it has a steel backing, and copper layer then a soft babbit layer. The steel is of course ferrous, the copper and babbit is not
If you Search , you'll find Thrust Bearing issues are mentioned but it seems unpredictable which engines suffer & who knows why?. Mine had perfect Thrust bearings at 90k miles but other items were worn.I speculate it may (like the IMSB) be influenced by manufacturing errrors/misalignment in addition to driver error(riding the clutch) and inadequate maintenance . Be sure to do all the appropriate end float measurements many times and very carefully when reassembling?
Originally Posted by Porschetech3
That's definitely your source of metal debris. It seams to be getting more common place. Probably due to excessive stop and go traffic, or resting left foot on clutch while driving. High performance pressure plates with increased clamp load will also cause increased wear of the thrust bearing.
Is this excessive/ abnormal wear? Does normal wear look like this? It's almost down to the oil channels. Why the smearing?
Originally Posted by Porschetech3
Its a tri-metal bearing, it has a steel backing, and copper layer then a soft babbit layer. The steel is of course ferrous, the copper and babbit is not
Ah thank you, did not know that. Maybe this thing is wearing, little pieces are coming off, and it is causing gouging in the oil pump and other areas making the marks and more debris? Not sure if it could have caused the damage in my scavenge pumps though?
From post #60, this is the only observable (2-4 mm's) piece of metal I have found in my engine. It has machine markings on one side and is course on the other. Non-ferrous. I can't find anywhere in the engine that has a piece like it missing from it. I haven't removed the valves yet though. Several spots in the engine have evidence some kind of debris went through them, the picture are further back in the thread. Oil pump, cam bearings, the plain bearing for the IMBS. The crank and rod bearings look great.
I emptied the oil filter housing four times, and the particles still returned after the oil was circulated so something was making them..... Maybe this thing flaked off during machining/assembly and has been bouncing around in the sump, scoring my #3 cylinder and getting chewed up sending smaller pieces through my engine?
Is this excessive/ abnormal wear? Does normal wear look like this? It's almost down to the oil channels. Why the smearing?
Ah thank you, did not know that. Maybe this thing is wearing, little pieces are coming off, and it is causing gouging in the oil pump and other areas making the marks and more debris? Not sure if it could have caused the damage in my scavenge pumps though?
From post #60, this is the only observable (2-4 mm's) piece of metal I have found in my engine. It has machine markings on one side and is course on the other. Non-ferrous. I can't find anywhere in the engine that has a piece like it missing from it. I haven't removed the valves yet though. Several spots in the engine have evidence some kind of debris went through them, the picture are further back in the thread. Oil pump, cam bearings, the plain bearing for the IMBS. The crank and rod bearings look great.
I emptied the oil filter housing four times, and the particles still returned after the oil was circulated so something was making them..... Maybe this thing flaked off during machining/assembly and has been bouncing around in the sump, scoring my #3 cylinder and getting chewed up sending smaller pieces through my engine?
I don't think that large piece of non-ferrous material is from your thrust bearing, it looks too large and I don't see chucks broken off the thrust bearing. Look around on the crankshaft carrier where the rods exit the carrier, look at the edges. There is minimal clearance here and since your thrust bearing is worn, it will allow the crankshaft assembly to move farther away from the clutch/flywheel trans side and due to very close clearance may have touched the edging of the aluminum carrier breaking off a small piece. Keep looking/investigating you will eventually find the place that piece came from.
The scratches in your oil pump and scavenge pump are the result of debris from the thrust bearing floating around suspended in the oil.Some debris from the thrust bearing can get sloshed back up into the head and and get sucked up by the scavenge pump before it gets caught by the oil filter.
Its a tri-metal bearing, it has a steel backing, and copper layer then a soft babbit layer. The steel is of course ferrous, the copper and babbit is not
Thanks Porschetech. Looks like it might be the root of leo's issue, but not mine (I'm hunting pure ferrous). One more thing off the list.
I think you need to get your B2 head checked for cracks also. Combustion chambers looked like they were steam cleaned. The "stains" may be from the coolant/water.
Anyone know if there is a reason my new head bolts have a head diameter about 1.5mm smaller than the originals? I like the larger size on the old ones, it seems like a larger area of distribution of the force across the head surface would be good. It is very noticable when you hold them side by side.
Hahahah, sarcasm, it hurts. They are the "OEM" version I got online for $8 vs $12 each, just wondering if they are also the "gouge your head" or "snap when you torque them" version .
Was out of town for two months, picking up my new oil squirters in two days and will start to reassemble the crank carrier with new Porsche bearings and ARP hardware. Anyone that has done it (crank carrier) before have any advice?
CLEAN solvent and air through oil holes (crank and carrier). Better to put it in a tank and pump solvent through the holes. ARP, not Porsche, torque spec for rods. Light coating of Loctite sleeve retainer for squirters, avoid coating holes. Installing IMSB probably easier now than in engine.
I coated my bearing shells with Molykote 321 - check Pelican forum if interested.
Measure your crank journals and check rod bushings. Replacing rod bushings is relatively cheap.
01-16-2018, 01:26 PM
They are the "OEM" version I got online for $8 vs $12 each, just wondering if they are also the "gouge your head" or "snap when you torque them" version .
