Disaster Strikes; What went wrong?

[Rich76_911s]

I apologize in advance, but this is a long one. If you need more photo's, descriptions, etc. Just let me know.

So just a precursor to let you know what I built:
1987 930 engine built with

1. New Main and Rod bearings that were coated from turbokraft
2. Rods were measured and inspected on both the small and large end
3. New JE Pistons 7.5 compression ratio with New slip fit Nickies for 3.5L engine
4. Cams were reground to SC profile
5. rockers were refreshed
6. case was inspected and cleaned professionally
7. crank was magnafluxed and micropolished (I thoroughly cleaned it after the machine shop too)
8. New small gears on intermediate shaft (Big 0 gear was not touched)
9. New cam gears, but did not change idler arm gears
10. Heads were completely refreshed opening them up to 36mm along with the intake.
11. New Borg Warner S362 turbo.
12. CIS fuel head was sent out and refurbished and increase fuel flow
13. Adjustable WUR
14. ARP rod bolts and head studs were used.

That should give you a basic idea of where I started from.

The machine work was all performed by a very good machine shop.

I did break the engine in with 15 minutes at High RPM and changed the oil immediately after. Break in procedure was limited boost (0.2 Bar) and acceleration and deceleration in attempt to seat the ring.

It's been together almost 3 years, but I've driven it only about 500 miles since the rebuild. A ticking noise when the engine was warm really caused me to not drive the car much at all. I tried multiple times to adjust the valves to clear up the noise, but never could get rid of it.

A couple weeks ago I posted about diagnosing the ticking noise when the engine is warm. This noise has been going on since I rebuilt the engine. In an effort to diagnose what was wrong I began disassembling the engine.

Taking the engine apart I noticed:

There was some excessive oil in the cylinders, that I believe was due to excessive oil in my turbo compressor housing.

Excess oil in the compressor housing.


Excess oil in the number 4 cylinder


The bottom end though has some very troubling issues:

The intermediate shaft bearings look very beat up for 500 miles of driving:







Also the large thrust bearing had excessive wear for 500 miles:



The main bearings all had scratching (this is just a sample)



Rod Bearings were also FUBAR (this one #6 was by far the worst)



Also note the wear on #1 near the tab:



I did also have a broken oiling ring on the #1 cylinder shown here:




I'm still scratching my head as to what happened here. I was very thorough in my cleaning of the case, crank, etc. Brake cleaner and kim wipes out the wazzoo. THe machine shop checked all the clearances on the rods, crank, and case. I also checked the ones I could, and found everything to be within spec. Rods were tightened with ARP rod bolts checking stretch and torque.

Only major shrapnel in the case were some leftover 547 case sealant, and the broken oil ring. The oil ring basically broke one piece off, it didn't shatter into a bunch of pieces.

There was some sparkly bits in my oil changes, but I cut open the oil filters and never saw major metal in the filter.

Someone on the ticking thread suggested a problem with the gear on the crank that drives the intermediate shaft. If this gets loose when the engine warms would it cause these wear issues?

Don't know what's going on here and would love some internet help diagnosing what went wrong.

[Rich76_911s]

Also should point you towards a thread I did while I was building my engine on the wear I had on my bearings that came out of my engine when I first tore it down.

Bearing Shuffling Thread

[Catorce]

Wow, lots of bearing wear here. I see you coated the mains with Loctite 574, and while Wayne mentions to do this in his book, it is INCORRECT. You don't want to put the loctite on the mains because it will throw out the bearing clearance. It does add measurable thickness to the main area which can create slight ovality.

However, I don't believe this is your issue.

Did you measure the case halves bolted together for bore size? Did you plastiguage your bearing to crank clearance after building?

What machine shop did the case?

Lots of questions here.....

[Rich76_911s]

I did loctite the webs. I actually questioned whether to do it or not in my thread where I rebuilt the engine. I decided to go for it when I saw turbokraft do it here:

https://youtu.be/6MmSCxqnkZg?t=204

I do realize that there is some variance on doing it vs. not doing it. My machinsts actually agreed with you, not to put it on.

Yes I did plastigauge and the clearance was within spec. I have to find my notes on the build to get the exact number I had. I'll admit that I found the plastigauge a bit non-precise.

The case was bolted together and inspected by Verden Tool and Die in New Jersey. They did all the machine work on the engine. I highly doubt the error is theirs, but they are human. (I don't want to point fingers at anyone other than myself). They did give the case, crank, and rods a clean bill of health.

[cmcfaul]

broken oil ring....why?. Were the rings too tight? How do the cylinders look? Something circulated metal everywhere. Where did it come from? Cleaning of the coolers is in order to make sure there is none left. A oil analysis might help where it came from

Chris

[dannobee]

Rings usually break on Porsche's because of an installation problem. Not to say that's what happened in your case, but that's the most common reason.

It was originally torn down because of bearing issues? If the old bearings had trash pass, were the oil coolers replaced? Were the oil lines and thermostats thoroughly disassembled and cleaned or replaced? How about the hoses? Was the oil tank removed and cleaned? All of that nastiness is often a chore to remove, but it is what it is and needs to be removed, otherwise it goes right through the new engine.

[Walt Fricke]

1) Broken ring most likely happened on installation. Last one to go into the cylinder, and if the ring holder gets cocked a little, and just a tad more force/tap on the cylinder is used, might break? But that can't really be the source of the bearing wear - too big, fell into the sump and sat there harmlessly. Was that cylinder scored?

2) Agree bearing wear looks like dirty oil. The one place the oil filter doesn't catch anything is the oil tank - oil gets filtered before it goes in. This begs the question of what and how some bad stuff would get into the tank (which has a magnet in the drain plug, too).

3) What's the oil pump look like?

4) What did the shop do with the crank? Did they pull the oil plugs for a thorough cleaning? Agree shop reputation is good, and they know all about this stuff.

5) Wayne and some suggest that 574 on the main web seal surfaces helps keep those surfaces from fretting. I'd never seen that until his book came out. For a race motor I favor locating tubes around the case studs, like the #1 bearing has, or dowel pinning. The case sealant's principal purpose is as an oil seal. I don't seal these surfaces because Porsche didn't, but that isn't necessarily dispositive. But it can't cause a bunch of scratches. Some crap was hidden somewhere.

6) How does the turbo oil get back into the system? Does it go through the filter? Any chance crap could hide there during rebuild?

[Rich76_911s]

Originally Posted by cmcfaul

broken oil ring....why?. Were the rings too tight? How do the cylinders look? Something circulated metal everywhere. Where did it come from? Cleaning of the coolers is in order to make sure there is none left. A oil analysis might help where it came from

Chris

i

I assumed I made a mistake during installation that lead to the broken oil ring, as others have pointed out. Though I did not measure piston to wall clearance.

Yeah the big question for me is where did this metal come from, and why so much wear on the thrust bearing. I understand the contaminants and further damage they did to the bearings etc.

Good idea on the oil analysis. I've kept a little that has been in the case for just that purpose, but wasn't sure if it was worth it with all the bearing material already present in the oil.

Yes cleaning oil coolers etc will be in order.

[Rich76_911s]

Originally Posted by dannobee

Rings usually break on Porsche's because of an installation problem. Not to say that's what happened in your case, but that's the most common reason.

It was originally torn down because of bearing issues? If the old bearings had trash pass, were the oil coolers replaced? Were the oil lines and thermostats thoroughly disassembled and cleaned or replaced? How about the hoses? Was the oil tank removed and cleaned? All of that nastiness is often a chore to remove, but it is what it is and needs to be removed, otherwise it goes right through the new engine.

Original tear down was not due to bearing issues. I had bad leakdown numbers on the 6th cylinder, which drove the need to originally rebuild the engine. TUrned out to be a broken headstud on #6.

I did have the oil coolers cleaned initially, and did my best to clean out the rest of the oil system. I'll be doing a very very thorough job this time.

[Rich76_911s]

Originally Posted by Walt Fricke

1) Broken ring most likely happened on installation. Last one to go into the cylinder, and if the ring holder gets cocked a little, and just a tad more force/tap on the cylinder is used, might break? But that can't really be the source of the bearing wear - too big, fell into the sump and sat there harmlessly. Was that cylinder scored?

2) Agree bearing wear looks like dirty oil. The one place the oil filter doesn't catch anything is the oil tank - oil gets filtered before it goes in. This begs the question of what and how some bad stuff would get into the tank (which has a magnet in the drain plug, too).

3) What's the oil pump look like?

4) What did the shop do with the crank? Did they pull the oil plugs for a thorough cleaning? Agree shop reputation is good, and they know all about this stuff.

5) Wayne and some suggest that 574 on the main web seal surfaces helps keep those surfaces from fretting. I'd never seen that until his book came out. For a race motor I favor locating tubes around the case studs, like the #1 bearing has, or dowel pinning. The case sealant's principal purpose is as an oil seal. I don't seal these surfaces because Porsche didn't, but that isn't necessarily dispositive. But it can't cause a bunch of scratches. Some crap was hidden somewhere.

6) How does the turbo oil get back into the system? Does it go through the filter? Any chance crap could hide there during rebuild?

1. I think you're most likely correct in that I did something wrong installing and breaking the oil ring. Possible to be something else, but odds are stacked against me there.

2. Yeah never had anything major on the drain plug on the tank. Your 6th question in regards to the oil from the turbo, it gets dumped into the oil tank, not into the filter.

3. The oil pump on intial teardown looked perfectly fine. I'll dig deeper into it tonight and see if I can get a clearer idea of its current condition.

4. Verden cleaned the crankshaft, but the notes do not indicate pulling any plugs. They did magnaflux and micropolish. I cleaned it thoroughly after them. They are great guys and deserve the reputation they have.

5. Yeah I agree with your analysis. Could excess sealant cause these scratches? I did have excess hardened sealant at the oil pump screen.

[Walt Fricke]

Any history from before you first rebuilt the motor?

I assume the bearings at that time looked normal for whatever hours/miles were on them? A bit hard to imagine that crap from a previous disaster sequestered itself in the engine oil cooler or the tank, and then snuck out after the rebuild. You'd think it would have made the bearings the first time look bad.

I take it the guys on the Turbo forum don't have any ideas as to how being a turbo might account for all this?

[Walt Fricke]

I think the worst that excess 574 sealant might do is clog a hole somewhere, restricting or blocking oil flow. It is normal for a little sealant to be extruded on the inside of the case. It eventually either hardens or gets washed off. Sometimes you see a bit of orange in the oil strainer for the pump. But it would have to get past the oil filter to hurt anything. The only way I can see that happening would be if the filter were in bypass mode due to being clogged, which probably would be from some other disaster that would have been noticed.

Plus the oil pump would macerate it, and I don't think that stuff could be hard enough to make all those scratches.

[Catorce]

Originally Posted by Walt Fricke

I think the worst that excess 574 sealant might do is clog a hole somewhere, restricting or blocking oil flow. It is normal for a little sealant to be extruded on the inside of the case. It eventually either hardens or gets washed off. Sometimes you see a bit of orange in the oil strainer for the pump. But it would have to get past the oil filter to hurt anything. The only way I can see that happening would be if the filter were in bypass mode due to being clogged, which probably would be from some other disaster that would have been noticed.

I have had extensive conversations with William Knight about this, and the sealant issue represents a problem for clearance reasons.

Since I make the aftermarket cases as well, I have an in depth knowledge of what the measurements actually should be as well.

So if you bolt the case together, then measure the bore, your bore should be 65.000-65.019mm. That is the tolerance.

If you disassemble the case then bolt it up with sealant on the mains, you will absolutely, 100% change the bore dimension and make it an oval. Perhaps the number is very small, or even hard to measure, but adding ANYTHING to that case parting surface at the mains changes the dimensions.

If you are saying to yourself right now, "doesn't all the sealant get squeezed out?" My question to you is, what is the point of having it then.

Also, it is difficult to impossible to apply the sealant in a consistent manner, so your numbers on bore may vary by main. You might not be able to measure this with your $50 harbor freight bore gauge, but I can absolutely measure this with the Renishaw Probe that's on my $265,000 Haas Mill.

Again, it probably is not a factor in this build, but it's not the right way to do it either. JFYI for next time.

[dannobee]

A couple of points.

Were both thrust bearing surfaces worn on the same side? Or were they mirror images, with the other side worn on the other bearing? Way back when, the guy who showed me how to assemble cases would put everything together but leave the bolts loose, then, before torquing the through bolts, would pry the crank back and forth to "set" the case. His end play check was always perfect.

I've never used any kind of sealer on the back side of bearings, on main webbing, or anyplace else inside of the engine. As a matter of fact, we all used brake cleaner and isopropyl alcohol, after a very thorough cleaning with dishwashing soap and blowing out with filtered compressed air. Our stuff was spotless inside. Dunno how others do it, but I've done it that way for 30 years. In modern nascar engines, our rod bearing clearances were down to 0.0007-0.0010", so anything else in there would probably cause them to spin on the dyno.

Sealant didn't cause the scratches. Could have been something in the coolers from before. Or leftover in the oil tank. Or carbon from the turbo drain. The way that the oiling works on a 911/930 is that anything in the oil tank gets sucked up into the inlet of the pressure side of the oil pump through the S-hose, unfiltered. I hate that. The better way would be to put a 993 oil filter console on it, then put the coolers on the pressure side with an adapter. Leave the scavenge side for keeping the sump dry. That way any oil that is going into the engine would be filtered 100% of the time, and oil going to the coolers would always be filtered unless opened on cold bypass by some bozo revving the engine when cold. But to each their own.

[Mark Henry]

That's a lot of trash, it didn't come from the ring.
Looks almost like a pocket of glass blasting bead got missed in a galley.

I'd take the pump apart, if it came from the tank the inner housing pressure side would be just as badly scored.

[Rich76_911s]

Originally Posted by Walt Fricke

Any history from before you first rebuilt the motor?

I assume the bearings at that time looked normal for whatever hours/miles were on them? A bit hard to imagine that crap from a previous disaster sequestered itself in the engine oil cooler or the tank, and then snuck out after the rebuild. You'd think it would have made the bearings the first time look bad.

I take it the guys on the Turbo forum don't have any ideas as to how being a turbo might account for all this?

When I first disassembled the engine the bearings look great on the TOP, but the bottom side that is up against the crankcase had some odd wear. So I do think whatever caused my current problems was due to a mistake in the rebuild process somewhere.

I just wish I had some indication where this and the ticking noise came from. Worst thing would be to build it up again and still have the problem remain.

Top of OLD bearing:


Backside of OLD bearing:

[Rich76_911s]

Originally Posted by Catorce

I have had extensive conversations with William Knight about this, and the sealant issue represents a problem for clearance reasons.

Since I make the aftermarket cases as well, I have an in depth knowledge of what the measurements actually should be as well.

So if you bolt the case together, then measure the bore, your bore should be 65.000-65.019mm. That is the tolerance.

If you disassemble the case then bolt it up with sealant on the mains, you will absolutely, 100% change the bore dimension and make it an oval. Perhaps the number is very small, or even hard to measure, but adding ANYTHING to that case parting surface at the mains changes the dimensions.

If you are saying to yourself right now, "doesn't all the sealant get squeezed out?" My question to you is, what is the point of having it then.

Also, it is difficult to impossible to apply the sealant in a consistent manner, so your numbers on bore may vary by main. You might not be able to measure this with your $50 harbor freight bore gauge, but I can absolutely measure this with the Renishaw Probe that's on my $265,000 Haas Mill.

Again, it probably is not a factor in this build, but it's not the right way to do it either. JFYI for next time.

Yup, sorry if I came across sounding as though I doubted you. Not at all the case.

[bpu699]

So sort that happened to you...

Random thought...

The wear on the thrust bearing and ims suggests your case halves weren’t sling or set perfectly...

To be honest, I don’t think Porsche cases are machined perfectly.

When I took my virgin case apart, my ims bearing had wear on the mirror side flanges. So, from the factory, the ims bearing wasn’t sitting exactly right. The wear was significant. Yet, the thrust bearing flanges were just fine. Motor was fine ran well...

It looks like you had stuff inside your crank if the main bearings are shot...

The ims bearings sold now, in my humble opinion, are crap. The new ones I bought measured thinner than the ones I took out. Had to buy the Porsche item.

What brand were your main bearings? Glyco?

You also coated the bearings, as did I. The coating won’t absorb debris like the original ones do. It’s not designed to do that. So even small amounts of debris will scratch the bearing...

[Neil Harvey]

Some advice that may clear your mind.

At this stage with so much damage and what appears to be a lot of unchecked fitments, I would approach this, this way.

Start again. Is there any point in asking what happened when it appears a lot was un checked and assumed.

Forget what you did or didn't do. Rebuild the engine, and this time check everything, measure everything and make sure everything is clean. Take your time and do it in stages, making sure you cover everything. Don't rush to send out parts to the machine shop. Do one part at a time. You are learning as you go. If you don't know, ask.

Once the engine if completely rebuilt and you have left nothing unchecked, then focus on the car, oil tank, oil lines etc.

Disassemble the whole engine including all of the subassemblies. The damage shown on the Rod shells will probably show up inside the oil pump as well. That may be trash.

Pull everything apart, including the heads. Start again, and this time clean every oil galley, port, anything that oil flows through it or around it.

This time measure everything including the main housing bore. Start with the case. make sure all bores are in spec, have it crack checked, surfaces checked and lapped if necessary, and thoroughly cleaned. Remove the 3 galley plugs and flush the case galleys. This includes the squirters.

Now is not the time for short cuts. After exhausting all inspection, cleaning and measuring of the case, now look at the crank. I'm sure it will need some repair. Galleys plugs will need to be removed and after any repairs, flushed. First check it has not cracked, then have it straight checked, then if its ok, it probably will need to be repaired. Here you have a choice, cut the journals undersize or have it repaired back to std.

The 1st motion shaft needs to be checked now as well. Have it crack checked, make sure its straight and has no run out. Remove the plug and flush out the internal galley.

Now look at the oil pump and coupler shaft. If the pump is junk, buy a new one and check it before you install. If the pump can be repaired, have the gears crack checked, shafts checked for straight and the clearance all checked.

When case work has been completed, buy the main bearings and the inter bearing shells. Lay the pump into the case along with the 1st motion shaft and bolt down the pump. Make sure the coupler shaft is free to move back and forth on the splines. If not, reposition the pump until it does. This removes any misalignment of the shaft and allows it to run parallel in its bearing shells.

Now do the main bearing ID measurements and establish your clearances. Now is the time to check the crank thrust clearance. You can now test the 1st motion shaft thrust as well.

Then the rods need to be checked and once checked and ok, fit the bearing shells and go through their clearance check. When completed, you can go ahead and assemble the bottom end knowing everything has been checked and recorded.

DO NOT put any glue on the bearing supports. I have no idea why anyone would suggest to do this. I guess they have not thought it through and figured out why you would not.

It seems if there is a machined surface it needs to be covered in glue, knee deep. I have seen engines assembled on this forum where there was so much glue squeezed out. Tubes worth. It squeezes out on the inside as well. Have faith that a couple of microns of glue will seal if you make sure the surfaces are prepped correctly.

Go slow and look forwards not backwards.

[Rich76_911s]

Originally Posted by dannobee

A couple of points.

Were both thrust bearing surfaces worn on the same side? Or were they mirror images, with the other side worn on the other bearing? Way back when, the guy who showed me how to assemble cases would put everything together but leave the bolts loose, then, before torquing the through bolts, would pry the crank back and forth to "set" the case. His end play check was always perfect.

I've never used any kind of sealer on the back side of bearings, on main webbing, or anyplace else inside of the engine. As a matter of fact, we all used brake cleaner and isopropyl alcohol, after a very thorough cleaning with dishwashing soap and blowing out with filtered compressed air. Our stuff was spotless inside. Dunno how others do it, but I've done it that way for 30 years. In modern nascar engines, our rod bearing clearances were down to 0.0007-0.0010", so anything else in there would probably cause them to spin on the dyno.

Sealant didn't cause the scratches. Could have been something in the coolers from before. Or leftover in the oil tank. Or carbon from the turbo drain. The way that the oiling works on a 911/930 is that anything in the oil tank gets sucked up into the inlet of the pressure side of the oil pump through the S-hose, unfiltered. I hate that. The better way would be to put a 993 oil filter console on it, then put the coolers on the pressure side with an adapter. Leave the scavenge side for keeping the sump dry. That way any oil that is going into the engine would be filtered 100% of the time, and oil going to the coolers would always be filtered unless opened on cold bypass by some bozo revving the engine when cold. But to each their own.

So went out and took a look at the thrust bearings.

The 123 side had most of the wear at the top of the bearing, the 456 side has wear all the way around.

123 (top of the engine is to the left of the frame)


456


I seriously looked into doing the 993 oil filter conversion for just the reason you pointed out, just seemed to escalate in complexity fast.