Part of the process is to lightly blast the surface with a special media, this gives a grip for the coating and also allows it to embed into the babbitt material. Even if the surface of the coating is wiped off the DFL is still in the "pores" doing its job.

No bearing coating is supposed to be hard, like the babbit material on the bearing it's deliberately soft, as this is your last line of defence to avoid damaging the crank. The bearing surface is considered sacrificial and is designed to let fine dirt to embed into it, not the crank.

Lets assume that you assembled everything correctly, the short block turned freely, no bead blasting was performed anywhere. The machine shop removed the galley plugs and cleaned everything. You were meticulous in your cleaning and assembly. I assume the engine mounted oil cooler was cleaned and you said that there wasn't prior bearing failure.

That leaves us with the "trash" somewhere that wasn't cleaned and didn't get filtered via the oil tank filter. The things remaining are the oil tank, the S-hose, and the turbo scavenge pump and lines, which return oil to the tank unfiltered (irrespective of the factory "filter"). Were all of those cleaned or inspected?

But back to the original reason you're performing an autopsy. It had a knocking/tapping noise that you couldn't find. I remember watching your video and it sounded like it was from the #6 cylinder area. The bearing, although scratched from trash, doesn't appear bad enough to make a heavy knocking noise. (I've seen far worse on neglected, but otherwise quiet engines) What is the rod bearing clearance now, post mortem? How about the piston to wall clearance? Was there any scoring on the cylinder wall? On the piston skirt? Which pistons were installed? Anything obvious, like a piston installed upside down? Piston pin and bore spec'd out ok? Was the deck height within spec? Did you find anything wrong with the valve train? Rocker bushings were good on the noisy cylinder?

In addition to making sure there is no more contamination in the coolers or elsewhere. Get a new torque wrench. Every bearing that is not scratched by contamination appears to be torqued, twisted and warn all wrong. I over torqued head studs by not using the torque wrench correctly.....happens to the best of us.

Chris

There are many assumptions that can be made. There are only two facts though.

One is, the engine is damaged and needs to be repaired.

The other is, nothing will humble a man more than an angry wife or an engine.

Some advice to anyone who wishes to listen. Do not use those horrible piston ring compressor "POS" to install the pistons into the cylinders. As rings get thinner those things are difficult to use with any sort of confidence. Buy a proper installation sleeve. I think ARP sell these in many bore sizes. the pistons will slide into the cylinders will little force. You can then be sure you have not damaged or broken a ring. Nikasil coated liners require cast and or "softer" materials to be used for rings. This adds to the problem making a chance to break a ring very easy.

When assembling your engine always cover it when you are not working on it. Use a big trash bag. If most DIY's are building in their garage, what are the chances of some foreign object landing inside, unseen?

It comes down to good engine building habits. And those habits start before you even take the engine out of the car. Maybe I will post something later on how I would rebuild an engine if I was doing this at my house. God forbid that ever happens.

Sorry to see this.

My question... During your disassembly did you find what was causing the knock/tick? Yes, the bearings had some FOD go through them and are gouged. But I do not see anything indicative of an ill fitting part and movement.

Was crank tight in bearings?
Were rod bearings tight to crank?
Was intermediate shaft tight in bearings?
Etc...

Your measurements seem to show that everything was basically in spec. I would look closely to find the source of your noise. The cleaning process is pretty much self-evident.

My $0.02.

Neil,

Thanks again for all the advice. Trust me when I tell you I'm listening loud and clear to you, with just moving forward.

The exercise of trying to figure out what was wrong has been really helpful though. Just for example, the comment on the torque wrench was a good one I hadn't thought of.

Just want you to know I hear you loud and clear on just moving forward, and this engine has me MUCH MUCH less upset than if I had an angry wife on my hands.

Also I bagged my engine up every night during the rebuild (even have the dirty one bagged up in my garage right now).

This came up today on my amazon photos as today in 2016:

http://forums.pelicanparts.com/uploa...1561602702.jpg

1st - Yes engine mounted oil cooler was cleaned by pacific oil cooler.

2nd - No I didn't clean them, but I did plug all hoses and kept the oil filter on the tank during the time the engine was out. But it's certainly within reason to believe one of my plugs could have come off and I didn't notice for a couple days. So crap could have been in there or gotten in. I don't remember this happening, but I don't remember why I enter rooms sometimes so...

3rd - Onto the tapping noise.

1. I installed New JE Pistons in New Nickie Cylinders
2. I'll have to get some plastigauge and check the rod clearances now. Most of the bearings are not nearly as scratched as the #6
3. Cylinder walls look fantastic.
4. Piston Skirts also look good, but I'll take a closer look tomorrow as well.
5. I'll also check piston to wall clearance
6. The piston Pins were all new as well. I don't think the machine shop checked those though. Coming out of the engine they didn't look bad or have abnormal wear. I'll try and get a photo tomorrow.
7. Deck height was checked and I found it to be all good.
8. I've taken the 456 valve train out. I was surpised by some of the wear on the rocker shafts. The 5mm hex bolts were also very tight. I'll try and grab a decent photo of those tomorrow as well.

Thanks Jamie.

Crank wasn't tight in the bearings. Felt just right to be totally honest with you.

The rods all seemed good on the crank, but as dannobee mentioned maybe I should check the clearance now post mortem to see how they are.

Intermediate shaft also felt fine in its bearings, but it did have a noticable wear spot, and the thrust portion of the bearing on the outside of the case sure seems to have excessive wear. Almost like when combined with the wear on the thrust bearing for the crank it seems as though the crank and intermediate shaft were shifting back and forth too much or was too tight.

http://forums.pelicanparts.com/uploa...1561604640.JPG
http://forums.pelicanparts.com/uploa...1561604640.JPG

I have seen some intermediate shafts try to bind on the splines and not spin free. Neil mentioned this about oil pump alignment. Another way is to change how the shaft is clocked to the splines. I would also check the shaft on a V-block and make sure it is straight and not bent. Maybe the tick was the shaft rocking back and forth on the shaft and putting lateral pressure on the thrust bearing. You might see this in abnormal wear at some point on the aluminum layshaft gear.

possible tight links in a chain? Were they new chains? New or old sprockets? Chain lines good? Rubbing the case?

Loose wrist pins? pistons rocking/slapping?

Jamie brings up another question, how did the small end of the rod look? Was the bushing within spec?

The reason that I ask about upside down piston(s) is that the pin is offset to quiet down piston slap noise. It doesn't hurt anything if it's in upside down (it's an old stock eliminator drag racer trick, it'll actually make more power), but it'll have a noticeable rattle.

"DO you do the same to the IMS shaft bearing?"

Yes. With the pump and drive tube removed and the IMS sitting in each case half. Then assemble the case and check IMS end float.

930
 

Verdon Tools work has always been meticulous.They remove the plugs in the case and make their own threaded plug as a replacement.Your issue came from the oil tank.You have to be careful when changing the oil filter as there can be some dirt around it.Always spray some brakecleen around the base to remove any loose grit.Does not take much to spoil a fresh motor.The 993 filter housing is a nice way to ferry out any initial gremlins then install the factory cooler after initial runs.Fred

OK, just to simplify things... there seem to be lots of small issues with the motor. But most don't seem fatal...

1) Unusual wear on the IMS bearing. Seems to me that if it were tight, after about 10 rotations of the IMS shaft the bearings "makes" its own clearance by rubbing material down. Not optimal, but is what it is.

2) Main bearings have debris in them. Again, not optimal, but that debris likely landed there in the first 5 minutes of running. After that, it is what it is. Those bearings could have gone 50,000 miles like that, no?

The only really odd thing, is the weird wear on the thrust bearing, like the case was aligned way off. Or somehow the coating on the bearings was 5x thicker than normal...

The inner ims bearing looks like it was "pinched" when tightening the case. Same as dozens of pics on this site when people used glyco bearings in their rod ends and found out they were uneven thickness, etc...


Take your current worn thrust bearings, put them on the crank and IMS shaft, reassemble, retorque, and measure the endplay clearance...just to see what it is now.

Like I said before, my removed IMS bearing had lots of wear on the thrust surface...

The "new" IMS bearing fit, but had almost zero play...


Before you start putting in new parts, use the old ones and measure everything again. Until you find what was wrong it will continue to worry you...

If you used glyco bearings, my limited experience showed that they had waaay more clearance than the Porsche bearings. Measure the glyco bearing against the Porsche bearing, its about .0005 thinner, adding an extra .001 clearance when both are installed...

If your rod clearance was too great, that could be your clicking sound you heard...

How do the valve guides look? Any loose valves? What about the rockers and their shafts?

FWIW, IMO that ticking sound did not sound like it was coming from deep in the motor.

And the turbo itself and the turbocharger sump.

Danno - VWs, with their flat piston crowns and no valve reliefs, had offset wrist pins, with an arrow on the crown which you pointed at the flywheel. Since the crowns were flat, following the arrows produced anti-slap. Hot rodders (Formula Vee) immediately reversed the orientation, and gained a tiny bit of HP. At one point Chevrolet did this on V8s, but their piston crowns weren't the same rightside up as opposed to upside down, so to speak. So they produced right and left side pistons. Eventually they tired of the inventory issue this created, and went back to centering the wrist pin.

Porsche has never had right vs left side pistons. At least not in the air cooled cars we have. But, to my amazement, I found that some models did have wrist pin offset. So one side has anti-slap, and the other makes a bit more power.

Chris Seven once offered his considerable automotive engineering expertise in explaining why this isn't a crazy thing to do. So it must not be, but I still don't understand it - you'd think the loss of noise (from being centered to being offset) on one side would be cancelled out by the noise gain from the other.

You could have aftermarket pistons made about however you want - the offsets aren't all that large. I pondered this when having some pistons made, but decided not to - it's a good idea to have seven made, so you have a spare. But if he ordered them, or had the documentation, it should be easy to verify - or if he hasthe pistons loose and handy.

Agreed. They're JE's, so who knows where they're putting the pin. If it's straight up, then no harm, no foul. If it's offset, one way is quiet, one way is noisy.

The offset pin changes the dwell time of the piston, parking the piston near TDC a tad bit longer, allowing cylinder pressure to increase (installed in the "power" direction). It's more beneficial on 2 valve heads and lousy combustion chamber design. On a 4 valve head with a pent roof chamber, it makes less difference because the flame front is so short and far less ignition timing is needed. On the intake side, the dwell time gives the benefit of better timing the intake stroke with the breathing of a 2 valve head. On a 2 valve head, it takes a bit of time for the air to start flowing. Low lift numbers are nowhere near as good as 4 valve heads, where decent airflow starts much sooner. You could also change the rod ratio to better match the head. And obviously, the cam also plays a big part in this. With the 2 valve head, as the cylinder goes through overlap, the exhaust backpressure could pollute the intake charge because of the poor low lift flow. If you just added more overlap to the cam, the BSFC goes to crap because of reversion and the engine becomes more "peaky." These effects are obviously for all out race engines. On street engines the noise is one of the main issues. FWIW. YMMV

A common number for the amount of offset is 0.050".

The way you get the noise is the piston rocking because of the cylinder pressure. If the piston hasn't rocked yet, the combustion event exaggerates the rock and the associated noise. If the pin is offset and the rock has already occurred, that noise is minimized.

I see a valve relief in the piston picture. That suggests each piston will only work in one orientation. Anti slap might make sense in a Turbo, but the better breathing of the opposite offset on a forced induction engine doesn't make sense to me.

My VW 1600 and 1775 race motors were so loud you couldn't hear piston slap if you tried.

I think the source of the noise has yet to be identified.

Exactly on pinpointing his noise. Although none of us like the look of the bearings or their thrust surfaces, it's not the source of his noise.

Hey guys. My apologies on not getting back in groove with responding to these questions. Just had a busy day today.

Yes I did use JE pistons in LN cylinders, and I did have valve reliefs cut in the pistons, and I did double check my photos from the build and they were all orientated with the large valve relief at the top.

Interesting discussion on the offset pin though.

I do have some markings on the case where the chain goes through the case on the way to the chain housing. There were some on it when I took it apart time #1, and I found an OK photo from the first time that I'm going to compare with the current setup. I did use new chain gears on the intermediate shaft and the main cam gear. I did not alter the idler arm gears.

I'll get back to the rest of the questions asap.

Thanks again for all the help!