Strange sound from rebuilt engine...
03-01-2013 | 10:47 PM
#286
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Burning Brakes
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I honestly don't know how 'worn' they were. I just recall getting them back from Steve, looking at the new one's and noticing a big difference.
03-01-2013 | 10:57 PM
#287
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Burning Brakes
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From: SF Bay Area, CA
This has been an interesting thread, and with much of my engine in pieces it does raise some concerns as I start the rebuild process.
I would be concerned at finding bearings that were between 1.4 and 1.6mm thick. Generally the tollerance we are looking for here is in the 100's if not 1000's of a mm. I have measured all of my rod bearings and they measure between 1.479 and 1.482mm. With 2 bearings at 1.4mm you are going to have massive clearance which could quite easily show up as knock. The only way to measure these is with a micrometer, a vernier caliper is not accurate enough for measuring clearances.
Measuring clearance with plastigauge is really the only option if you are not splitting the case, as it is impossible to put a micrometer in to measure the rod journal.
If the old rod bearings were as damaged as you say I would be concerned that there may be damage to the crank as well. How out of round were the rods?
As for the metal pieces, Is it possible you broke a ring on install? It could explain a bunch of things (Oil on Piston, Low compression etc)
Good Luck...
I would be concerned at finding bearings that were between 1.4 and 1.6mm thick. Generally the tollerance we are looking for here is in the 100's if not 1000's of a mm. I have measured all of my rod bearings and they measure between 1.479 and 1.482mm. With 2 bearings at 1.4mm you are going to have massive clearance which could quite easily show up as knock. The only way to measure these is with a micrometer, a vernier caliper is not accurate enough for measuring clearances.
Measuring clearance with plastigauge is really the only option if you are not splitting the case, as it is impossible to put a micrometer in to measure the rod journal.
If the old rod bearings were as damaged as you say I would be concerned that there may be damage to the crank as well. How out of round were the rods?
As for the metal pieces, Is it possible you broke a ring on install? It could explain a bunch of things (Oil on Piston, Low compression etc)
Good Luck...
My best guess now is there was not enough pressure to adequately pump up the lifters and that is where the noise is coming from.
03-01-2013 | 11:02 PM
#288
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Burning Brakes
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Can you shoot me some pics of the rod bearings? I'd like to see the inside surface of each one and it would helpful if I knew which cylinder was which.
The case needs to be split and EVERYTHING cleaned out very very thoroughly along with the oil tank, lines, thermostat, cooler, and all oil passages in the cam housings and case. The galley plugs should be removed and all passages scrubbed out and flushed.
The crankshaft also needs its oiling plugs removed and then ultrasonically cleaned.
The case needs to be split and EVERYTHING cleaned out very very thoroughly along with the oil tank, lines, thermostat, cooler, and all oil passages in the cam housings and case. The galley plugs should be removed and all passages scrubbed out and flushed.
The crankshaft also needs its oiling plugs removed and then ultrasonically cleaned.
Agree totally on all the cleaning.
03-01-2013 | 11:16 PM
#289
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Burning Brakes
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Update on Dis-assembly:
Got down to 1-2-3 cylinders today. Pics below. I did not find anything unusual other than confirming oil in combustion chamber. We can rule out oil seepage from the valve train (at least on this side). Both exhaust and intake valves were dry. The oil is getting past the rings perhaps because they have not seated. There was no obstruction on the oil pathway between case and chain housing. Chain housing interior looks normal.
The camshaft looks ok to my unexperienced eye. The only thing that COULD be off is the wear pattern. One side of each lobe seems a little shinier than the other. I really don't know if this is normal or not - take a look at the pics.
Pistons, cylinders are next to come off.
Got down to 1-2-3 cylinders today. Pics below. I did not find anything unusual other than confirming oil in combustion chamber. We can rule out oil seepage from the valve train (at least on this side). Both exhaust and intake valves were dry. The oil is getting past the rings perhaps because they have not seated. There was no obstruction on the oil pathway between case and chain housing. Chain housing interior looks normal.
The camshaft looks ok to my unexperienced eye. The only thing that COULD be off is the wear pattern. One side of each lobe seems a little shinier than the other. I really don't know if this is normal or not - take a look at the pics.
Pistons, cylinders are next to come off.
03-02-2013 | 01:34 AM
#290
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Was that oil on the piston there when you pulled the heads?
Steve, you asking to look at the old bearings or the new ones? Maybe it does not matter - both sets - he will need to check those bearings anyways.
Steve, you asking to look at the old bearings or the new ones? Maybe it does not matter - both sets - he will need to check those bearings anyways.
03-02-2013 | 01:38 AM
#291
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You can't measure rod bearings unless they are installed in the rods with bolts torqued up to spec. You need an inside mic. Alternately plastigaging them during assembly will verify acceptable clearances.
03-02-2013 | 01:40 AM
#292
Drifting
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.The case needs to be split and EVERYTHING cleaned out very very thoroughly along with the oil tank, lines, thermostat, cooler, and all oil passages in the cam housings and case. The galley plugs should be removed and all passages scrubbed out and flushed.
The crankshaft also needs its oiling plugs removed and then ultrasonically cleaned.
The crankshaft also needs its oiling plugs removed and then ultrasonically cleaned.
03-02-2013 | 12:34 PM
#293
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From: Calgary...Under my car... :)
The measurements on the bearings were the old ones. Back then there was no knock at all. The bearings in there now are new and there is a sound, but the sound is originating between the cam tower and the cylinders. I wouldn't call it a knock but that is subjective. There could be a broken ring - don't know yet.
My best guess now is there was not enough pressure to adequately pump up the lifters and that is where the noise is coming from.
My best guess now is there was not enough pressure to adequately pump up the lifters and that is where the noise is coming from.
Cleaning is going to be a long process, but needs to be slow and very exacting.
Oil Lines can be cleaned with a wire fish and rag soaked in oil
Oil Cleaner to American Cooler ~$120 http://www.americancooler.us/
Case hot tanked, galley plugs and squirters cleaned - Ollies ~$300 http://www.olliesmachine.com/
Cam Towers Cleaned - Ollies ~$90
Oil Tank ultrasonic clean or wash/flush at lease 6 times (When I cleaned mine I poured out the cleaning solution through a coffee filter to check for particles. I had none in the any round of cleaning but I kept going, still found nothing though)
Thermostat can be taken apart (regulator etc)
Be careful removing the oil tank as the filler hose (Convoluted hose) is easy to break.
That's all that comes to mind for the moment.
03-02-2013 | 02:02 PM
#294
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Burning Brakes
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Yes. I also boroscoped these prior to disassemby and saw the oil there.
03-02-2013 | 02:08 PM
#295
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Burning Brakes
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I would suspect that the knock is from the lifters. However that still doesn't explain all the particles in the oil filter etc.
Cleaning is going to be a long process, but needs to be slow and very exacting.
Oil Lines can be cleaned with a wire fish and rag soaked in oil
Oil Cleaner to American Cooler ~$120 http://www.americancooler.us/
Case hot tanked, galley plugs and squirters cleaned - Ollies ~$300 http://www.olliesmachine.com/
Cam Towers Cleaned - Ollies ~$90
Oil Tank ultrasonic clean or wash/flush at lease 6 times (When I cleaned mine I poured out the cleaning solution through a coffee filter to check for particles. I had none in the any round of cleaning but I kept going, still found nothing though)
Thermostat can be taken apart (regulator etc)
Be careful removing the oil tank as the filler hose (Convoluted hose) is easy to break.
That's all that comes to mind for the moment.
Cleaning is going to be a long process, but needs to be slow and very exacting.
Oil Lines can be cleaned with a wire fish and rag soaked in oil
Oil Cleaner to American Cooler ~$120 http://www.americancooler.us/
Case hot tanked, galley plugs and squirters cleaned - Ollies ~$300 http://www.olliesmachine.com/
Cam Towers Cleaned - Ollies ~$90
Oil Tank ultrasonic clean or wash/flush at lease 6 times (When I cleaned mine I poured out the cleaning solution through a coffee filter to check for particles. I had none in the any round of cleaning but I kept going, still found nothing though)
Thermostat can be taken apart (regulator etc)
Be careful removing the oil tank as the filler hose (Convoluted hose) is easy to break.
That's all that comes to mind for the moment.
03-02-2013 | 02:17 PM
#296
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Burning Brakes
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From: SF Bay Area, CA
Just curious to see if the rod journal measurement and bearing id were measured prior to assembly to verify clearance.
You can't measure rod bearings unless they are installed in the rods with bolts torqued up to spec. You need an inside mic. Alternately plastigaging them during assembly will verify acceptable clearances.
You can't measure rod bearings unless they are installed in the rods with bolts torqued up to spec. You need an inside mic. Alternately plastigaging them during assembly will verify acceptable clearances.
03-02-2013 | 02:20 PM
#297
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I think the big issue for Pete is to find the source of the particles in the oil - once that is found, then he can assess if that caused the noise, or it was an independent issue.
The complete cleaning that Steve is talking requires splitting the case of course, and that will involve a lot more work and expense, but with those metal bits in the filter, you have to be careful not to have anymore in the oiling system.
Years ago, when I attended Bruces engine rebuilding class, there was a guy with a 964 who was on his second engine rebuild - the first one was from the PO because of a bearing failure (rod I think), it resulted in metal going into the oil system, the current owner bought the car, and the engine was failing shortly afterwards. the PO did not clean well, and the particles got into the engine, and now he was taking it all apart to fix it again - and cleaning all the lines/etc. Bruce at that time suggested he toss the oil cooler, its too hard to clean right... but technology has moved on since then.
Cheers,
Mike
The complete cleaning that Steve is talking requires splitting the case of course, and that will involve a lot more work and expense, but with those metal bits in the filter, you have to be careful not to have anymore in the oiling system.
Years ago, when I attended Bruces engine rebuilding class, there was a guy with a 964 who was on his second engine rebuild - the first one was from the PO because of a bearing failure (rod I think), it resulted in metal going into the oil system, the current owner bought the car, and the engine was failing shortly afterwards. the PO did not clean well, and the particles got into the engine, and now he was taking it all apart to fix it again - and cleaning all the lines/etc. Bruce at that time suggested he toss the oil cooler, its too hard to clean right... but technology has moved on since then.
Cheers,
Mike
03-02-2013 | 02:26 PM
#298
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Measuring accurately down to the accuracy required is actually a bit of an art form, especially using bore gauges, etc. It also depends a lot on the quality of the tools, temperatures, and picking the right spot to measure. That is why I also like, for amateurs like us, to use a shot and then Plastigague since its a last confirmation and its hard to screw up (possible but harder... ).
Of course, I assembled the rods onto the crankshaft before putting the case back together...... and also Plastiguaged those, and used a stretch gauge for the rod bolts since there was room.
Cheers,
Mike
03-02-2013 | 02:33 PM
#299
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Burning Brakes
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From: SF Bay Area, CA
If the crank is out, the shop that you will send the crank out to get cleaned can do that for you, they should have good tools. I did that, also used my own micrometer (you need a fairly big one given size of the crank), and then used Plastigauge on both the mains and rod bearings. If the measurements all line up, you are good to go.
Measuring accurately down to the accuracy required is actually a bit of an art form, especially using bore gauges, etc. It also depends a lot on the quality of the tools, temperatures, and picking the right spot to measure. That is why I also like, for amateurs like us, to use a shot and then Plastigague since its a last confirmation and its hard to screw up (possible but harder... ).
Of course, I assembled the rods onto the crankshaft before putting the case back together...... and also Plastiguaged those, and used a stretch gauge for the rod bolts since there was room.
Cheers,
Mike
Measuring accurately down to the accuracy required is actually a bit of an art form, especially using bore gauges, etc. It also depends a lot on the quality of the tools, temperatures, and picking the right spot to measure. That is why I also like, for amateurs like us, to use a shot and then Plastigague since its a last confirmation and its hard to screw up (possible but harder... ).
Of course, I assembled the rods onto the crankshaft before putting the case back together...... and also Plastiguaged those, and used a stretch gauge for the rod bolts since there was room.
Cheers,
Mike
03-02-2013 | 02:53 PM
#300
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Burning Brakes
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I think the big issue for Pete is to find the source of the particles in the oil - once that is found, then he can assess if that caused the noise, or it was an independent issue.