what is that pink stuff (it looks pink to me) on the irons?

 

lint from my shop towel

 

it looked like metal shavings.

your wife wont be happy using her towels for wiping motor parts

 

That nasty bearing looks like oil starvation on initial start-up or bad / wrong assembly lube.
I used regular motor oil (from straight 30W to 20W50, all mineral), and I have never had bearings come out like that.

I've also had two motors with missing OPR's, and even as catastrophic as that sounds, the bearings don't come out as bad as that pic.

Reese, I don't suppose you know what was used for assembly of the motor?


-Ted

 

Steve, no bearings were replaced at that time.

Ted, the same assembly lube was used on this motor as was on my old 13B-RE... Baby Fresh scented Vasaline. FWIW, there have been ZERO issues with that motor, and it's been going for a few years now.

Not sure if I've mentioned this or not but it looks like I've got replacements for all four irons lined up. Now I just need to locate 3 really good housings (preferably REWs.) Bearings WILL be replaced this time (like I have a choice...)

 

Why do you guys think this is a startup oil starvation problem? Even a thin coat of oil on the bearings only during assembly will last for 30-45 seconds of running time (even if you don't prime the system first), and will be effective for as long as you want to turn the engine by starter. I'm sure the builder did this, though I can't know for sure, I just wonder what you guys see that I do not that tells you it is a startup issue?

 

Here is what it looks like when an engine runs low/out of oil all at once...rapid overheating of the iron/oil oring contact surface in a circular pattern, scorching, cracking, expansion. (These are not pics of any of reese's parts, these are from another bad core I recently tore down).

This is not what happened to reese's motor. His irons' wear had to have occured over a longer period of time, while lubrication was still present...just not enough of it. Also his wear pattern is more football shaped, and not the entire circular orbit of the oil control rings. IT couldnt have been a total lack of lubrication all at once, because there's no way that I know of for that to happen and form a football-shaped area of wear. It would have to be a circle.

 

kevin,
One of the main reason why I feel was caused by initial startup oil starvation was because of the long pickup tube. it takes significantly alot longer to prime the oil system (newly build engine) in a 20B than with a 13B. As a matter of fact, I could crank it for 2 mins and still not get oil pressure in a 20B (of course I eventually figure a trick to prime oil in the system within secs).

Actually, after thinking about the wear on the iron housing. I think what really made all these wear was from the bearings. When the rotor bearing became worn out per the pics provided, they tend to wobble during the power stroke. The excessive wear on both the O-rings and the iron surface suggest that this happened over time and eventually got worse where the O-ring was so worn out and begin leaking oil into the exhaust system. if it was an immediate rotor bearing failure, the first thing that usually goes would be stuck side seals and also hot spots on the surface of the iron housing. The pics have no indication of this but shows significant wear on housing, O-rings, and rotor bearings. There're really no way for the rotor bearing to wear out so fast other than the fact that it was either lack of lubrication on the rotor bearing during assembly and/or oil starvation during startup.

Knowing that the 20B takes significant amount of time to prime the oil system, I think initial startup oil starvation combine with lack of lubrication on the rotor bearing was what causes the failure since stationary gear bearing didn't show any signs of oil starvation (and they spin 3 times faster than the rotor bearing).

Whats your theory behind it?

 

You make a good point about the pickup steve, but I am giving the builder credit in my mind and assuming that it was not started until it saw pressure, regardless of the means used to prime the system. some just prelube the bearings and crank until they see 30psi, others prime during the build by pouring into the pickup tube and turning the pump, others prime by pouring into the oil filter pedestal. as long as one of those was used, I feel that sufficient oil was there...you won't get a pressure reading without plenty of oil, after all. But perhaps my entire assumption is wrong, and no pressure was observed before it started...I was not there.

I can tell you that the rotors absolutely did not touch the irons at all, I know what that wobble looks like, about 3/8" at the side of each tip will be ground off with marks to match on the iron...none of that here. So the engine was not run long with the rotor bearings being chewed up. If they had been running that way since the engine was first started, the e-shaft would look a lot worse than it does, too, IMO.

My theory is that the rotor bearings died at the end, when the engine was shut off and the car towed home. Reese said he saw low pressure, but still had some. Checked oil and was low. That means that the main bearings were still seeing oil, but there may not have been quite enough flow/pressure to supply the rotor bearings 100% which, if I am not mistaken, get supplied only after the main bearings. This could explain why the engine ran fine for a while until it smoked all the oil out due to the oil control sealing problems. I think the bearings being worn were the effect of running low on oil at the end because of previous wear on the irons, not the cause of the wear on the irons in the first place.

 

To me it's hard to believe all that damage was done over the "short" length of time the motor was breaking in.

I had a 13BT that lost it's OPR, and it took 4k miles for the motor to start smoking.
Even this motor didn't kill the bearings as bad as in those pics.
Granted this 13BT motor was babied for most of those miles, but I wouldn't think Reese would do an improper break-in.

There could've been "contamination" during assembly or in the Vaseline?
Just a few metal chips could easily kill the bearings like that.
I believe the motor was ported during the last rebuild?
It's very easy to overlook metal chip here and there, especially when cramming in all-nighters.
Metal chips sitting in a very bad spot in one of the oil passages?

Hey, which brings up an idea...did you inspect the oil pump to see if there is any damage on the gerotors?
If the oil pump internals are damaged, then it'll immediately put up a red flag on oil contamination...


-Ted

 

I havent taken the pump off yet, no. I was just worried about getting the big stuff apart while he was here. I will of course worry about the rest once we get some useable replacement parts here. I have plenty of oil pumps regardless so I will check at that time. IT felt tight and smooth to me, though.

 

Has anybody tried plasma coated chrome to fill in the wear, then resurfacing?
Or any other thick coating?

The ceramic coating is usually less than .001" and cannot fill the wear grooves. This would allow the irons to keep stock thickness and be reused.

There seems to be some discussion of chrome not sticking to cast iron when electoplated, but the plasma might be better.

 

Did you guys replace the rotor bearings, the stationary gear bearings, and the oil control rings on the last build? Or just reused the old ones?

 

either very minor oil starvation or extremely dilluted oil with fuel.

a front cover o-ring blowout might not hurt a 13b all that much but a 20B requires a bit more lubrication. what did the seal look like in the front cover?

 

after some though, IMO of course, the added oil seal wear is from the side seal wear grooves which is likely just due to years of abuse on the irons. i have never seen oil seal retainers that worn before either but really, so long as they are still in one piece they will hold oil into the rotor so i don't think that is the main cause of failure but really for how easy it is to get good oil seal retainers they should have been replaced regardless(the worn housing issues should have been addressed also).

this engine has a lubrication issue not due to that wear but for some other reason which you will need to find, either a restriction in the oil cooler, blown out front cover o-ring, worn oil pump or clogged oil filter/oil passages.

 

I talked with JHB today.
They say that they can coat the side housing up to .050" with cermet to restore the factory thckness after surface grinding.
This might save the irons.
http://www.jhbperformance.com/

 

how much to coat all irons?

 

i don't think he can afford to have them cermet coated though, i suppose that would be a last resort.

 

Karack is right about not being able to afford it right now. Considering that I just paid to have it rebuilt within the last two months, it's bad enough having to pay for another rebuild kit, much less having to buy replacement irons, housings, etc. I'd almost be better off just buying another motor; however, I wouldn't know much about it's condition.

As for the parts used in the rebuild, I simply went with the list of suggested parts given to me by the builder.

I'll try to check on the oil cooler lines etc for blockage although I'm thinking there's nothing wrong there since there were no issues whatsoever with those things prior to the rebuild.

For ceramic coating, IF the prices stay the same as a 13BT, I'm looking at roughly 1500 for the irons and then another 1000 to 1200 for the housings. Sigh...

We'll see what happens. I think I'm switching builders, though. This was a first time 20B build for the original one. I'm just not sure what to do. If I had known this was going to happen, I'd have just left well enough alone and not torn the motor down. It was running fine beforehand. I just figured that while I had the money I'd go ahead and freshen it up.

I'll update you as I can.

 

Hiya Reese.. sorry to see the engine down

One thing I havent seen anyone mention.. Well only in passing....


Contamination of the engine and housings before assembly.

I have seen a couple.. umm people... With a bead blaster.. like the Harbor Freight one soo many of us have.. Glass Bead thier parts. Like the intake. And the outside of the rotor housings.. And the Oil pan.....

The problem is.. the soft aluminum will hold the glass bead particles in teh aluminum even though it is blown clean etc. When the engine gets hot, and or the specific part gets hot.. the glass beads come free and proceed to move through whatever is downstream and score the hell out of it.
I have seen a few fresh motors last only a few hundred to few thousand miles because they were not properly cleaned after being glass beaded.

The solution I have seen, and used, is an old dishwasher. Put the parts in it, crank it so it gets really hot.. and use some jet dry in it. That will heat the manifold and or housings enough to cause the beads to break free, and be washed away.

Just another idea on what it could have been.. Still makes me quite sad to see it like that.

I hope it ends up getting resolved without much wallet pain Reese..

 

I noticed that as well when I tried bead blasting several years ago. This is why I now only soda blast my parts, or simply clean them in a solvent tank and pressurewash with water then blow dry. The soda is finer and easier to wash away, and even if some of it remains, it is too fine to do any damage.

 

Thanks for the kind words, Scott! As for the cleaning, we only used Purple Power. No blasting with any type of media, so that rules that out.

Kevin, I promise I'm working on getting this moving. I hate that my stuff is just taking up space at your house. f you need it moved, let me know and I'll try to arrange something.

Reese

 

Yeah I was sorta beginning to wonder.

 

Just a quick question, did someone measure the clearances on the eccentric shaft? That kind of bearing damage has to be either massive oil starvation, foreign debris, or a slightly crooked eccentric shaft or improperly balanced rotating assembly. On the rebuild might he have accidentally used a different series rotor or something or an improper counter weight? I have only seen bearing damage like that once but that was caused by high rpm oil starvation and a completely spun bearing. But that guy slept on a mattress of cash at night and just rebuilt it.

Just food for thought.

IMO, the damage on those irons wasn't caused by whatever killed the bearings. I think you are right in assuming that wear was already there, but that is some pretty extensive iron wear. How many miles do you think the motor had on it before the first teardown?

 

Reese,

I sent you a pm and got no response. I need a decision on what we are doing with these parts. If it's going to be a while before you decide and/or can pay for replacements/repairs, that's fine. I do need for the parts to leave, though, if that is the case. I wouldn't say anything about it, but it's been a while now and I could use the space with new work coming in. IF you want to put it back together in the next week or 2, that is fine, the stuff can stay here in the meantime.