What happened to Isabella's Engine?

[wmadoty]

I think the thing you referenced as possibly a breather element is the oil cooler. In the picture of the block showing the broken bold, it looks like there are metal fragments in the oil passages for the cooler.

I would suspect the oil pump as the culprit for this failure, but the upper end looks pretty good, and when oil pumps start failing you will usually see a lot of wear around the the cam bearings and lobes since they are so far from the pump. That does not seem to be the case here.

 

[Denver_FJR]

The suspense is killing me!

I expected to see the filter clogged with a fine coating of metallic particles, forcing it to run in "bypass mode". Instead, it appears something internal cratered rather quickly. Maybe the particles traveled through the system, eventually clogging the oil passages, with the crank bearing being the first to succumb.

 

[Fred W]

Well, if we are going to play guessing games, I would speculate that when our man pants gets the cases split he'll find that the bottom end bearing for that cylinder's rod is roached and there will be no apparent reason for the failure. That's kind of how these type of things usually come out in the end.

 

[Redfish Hunter]

I am thinking that Fred W is correct (I get so damned tired of saying that!) and there will be obvious signs of damage but not obvious root cause. The metal particles in the filter are most likely a result of the failed rod bearing rather than the cause.

In any case, I cannot heap enough praise on hppants for taking this task and for the stellar reporting job he is doing. This job requires room for the work, room for the storage, and time not spent with family. Add to that the inconvenience of having to box and ship these parts to whichever forum member needs them, and hppants is really going out of his way.

If this forum has done nothing else it sure has introduced me to some wonderful folks. I will never forget that it was Patriot who organized our very first ride together. The three of us and Mvette as well all met for breakfast and a day ride. It seems another lifetime ago.

 

[ionbeam]

...also, and be reminded of the burnt exhaust valve on that same engine...I remember some questioning whether a crushed header 80% closed would do that...but then that was the cylinder in question...

If it is a spun crank bearing, it all goes back to a lubrication failure. All these other issues may be contributing, but that has to be the bottom line.

Plane bearings like on the rods and crank depend on a film of oil to carry the load. Modern plane bearings are made to be tolerant of dirt particles by allowing them to be embedded into the bearing. They are also 'self healing' to a point should they ever bottom out.

If you go back to the bad old days in the 80's when emission controls were grafted onto engines that were not intended for emissions some bad things would happen. Engines were set to run very lean (in place of efficient) which created hot running engines with hot spots in the combustion chamber which led to knocking and detonation. Each time a cylinder experienced an uncontrolled flame front (ping/knock/detonation) the piston experienced a sledge hammer blow which was transferred to the rod bearing on the crank and also shocked the crank. Under these conditions the hammering could thin the oil film on the plane bearings creating damage. The rods and pistons themselves could also be damaged. It was not unusual for the mid displacement engines to develop 'rod knock' or 'crank knock' upon first start-up due to knock/detonation pressure pulses in the combustion chamber.

Patriot mentions that his header was dented and had significant narrowing. [speculation] At higher RPMs only, the exhaust might create pressure pulses and would not shed heat from the header the way it should. The pressure pulses would hammer on the rod & crank bearings as mild knock/detonation might. It could be that the #3 cylinder lost a long war of attrition as it got beat up by back pressure from the exhaust.[/speculation]

But, what about the small balancing passage that couples Cyl #2 & Cyl #3 together in the header? Wouldn't that have help alleviate the pressure pulses that some idiot speculated about? I dunno. It sure is suspicious that the cylinder that had the occluded pipe also had burned valves and then a spun bearing. I guess someone could put that header on their engine and see if it kills their valves and rod bearings

BTW, Patriot where is that dented header these days?

 

[Chiefblueman]

As Johnd mentioned, prolonged idling could be a culprit here combined with a crushed header which can create heat in the cylinder and lead to mild detonation. I became acquainted with a renowned engine builder (automotive) quite a few years back. He told me one of the worst things you can do to an engine is idle it for prolonged periods of time and operate it at too low an rpm because the oilpressure is low and plain bearings rely on pressure to create a wedge of oil to prevent metal to metal contact. Putting the engine under load at very low rpm can defeat the wedge. Bearing clearance is crucial to keeping pressure up and forming that wedge. Prolonged idling/lugging can open up those clearances, then at higher rpm and higher pressure oil blows through, inviting metallic contact which can seize and spin a bearing.

 

[John d]

...also, and be reminded of the burnt exhaust valve on that same engine...I remember some questioning whether a crushed header 80% closed would do that...but then that was the cylinder in question...

If it is a spun crank bearing, it all goes back to a lubrication failure. All these other issues may be contributing, but that has to be the bottom line.

Plane bearings like on the rods and crank depend on a film of oil to carry the load. Modern plane bearings are made to be tolerant of dirt particles by allowing them to be embedded into the bearing. They are also 'self healing' to a point should they ever bottom out.

If you go back to the bad old days in the 80's when emission controls were grafted onto engines that were not intended for emissions some bad things would happen. Engines were set to run very lean (in place of efficient) which created hot running engines with hot spots in the combustion chamber which led to knocking and detonation. Each time a cylinder experienced an uncontrolled flame front (ping/knock/detonation) the piston experienced a sledge hammer blow which was transferred to the rod bearing on the crank and also shocked the crank. Under these conditions the hammering could thin the oil film on the plane bearings creating damage. The rods and pistons themselves could also be damaged. It was not unusual for the mid displacement engines to develop 'rod knock' or 'crank knock' upon first start-up due to knock/detonation pressure pulses in the combustion chamber.

Patriot mentions that his header was dented and had significant narrowing. [speculation] At higher RPMs only, the exhaust might create pressure pulses and would not shed heat from the header the way it should. The pressure pulses would hammer on the rod & crank bearings as mild knock/detonation might. It could be that the #3 cylinder lost a long war of attrition as it got beat up by back pressure from the exhaust.[/speculation]

But, what about the small balancing passage that couples Cyl #2 & Cyl #3 together in the header? Wouldn't that have help alleviate the pressure pulses that some idiot speculated about? I dunno. It sure is suspicious that the cylinder that had the occluded pipe also had burned valves and then a spun bearing. I guess someone could put that header on their engine and see if it kills their valves and rod bearings

BTW, Patriot where is that dented header these days?

The original post says the crushed pipe was on cylinder 4 and the failed rod bearing was on cylinder 3.

I really don't think the two are related but will accept that number 4 pipe would have experienced higher pressure, thus higher heat in that pipe. The high pressure and heat in the exhaust pipe backed up to the valve, burning it out. That's my guess on that.

 

[gixxerjasen]

BTW, Patriot where is that dented header these days?

Ooooh, good point.

 

[Patriot]

If this forum has done nothing else it sure has introduced me to some wonderful folks. I will never forget that it was Patriot who organized our very first ride together. The three of us and Mvette as well all met for breakfast and a day ride. It seems another lifetime ago.

such an idealist...

Patriot mentions that his header was dented and had significant narrowing. [speculation] At higher RPMs only, the exhaust might create pressure pulses and would not shed heat from the header the
BTW, Patriot where is that dented header these days?

#4 header pipe had some damage too, but not as much

if someone searches my "content" for threads started...all the history of the engine is there with "real time" information including the valve repair and lotsa pics of the header

it was disposed of by Aaron Graves after fixing the head...I replaced it with an ebay $100 used '03 header in pristine condition. I can't complain about anything really. All engines grenaded in my garage or the last one, 1 mile away and it then got me home.

The nightmare (some have experienced) is an unfixable bike 750miles from home having to face a $600 U-haul bill.

As Johnd mentioned, prolonged idling could be a culprit here combined with a crushed header which can create heat in the cylinder and lead to mild detonation. I became acquainted with a renowned engine builder (automotive) quite a few years back. He told me one of the worst things you can do to an engine is idle it for prolonged periods of time and operate it at too low an rpm because the oilpressure is low and plain bearings rely on pressure to create a wedge of oil to prevent metal to metal contact. Putting the engine under load at very low rpm can defeat the wedge. Bearing clearance is crucial to keeping pressure up and forming that wedge. Prolonged idling/lugging can open up those clearances, then at higher rpm and higher pressure oil blows through, inviting metallic contact which can seize and spin a bearing.

don't the piston end of the rods have needle bearings ???

I'm out of town on the hotel PC; pics and such are at home

BTW, Patriot where is that dented header these days?

Ooooh, good point.

either Aaron Graves junkyard or I'm sure he disposed of it by now

 

[NickBrewer]

One thing that can be very useful in determining the health of an engine (before it blows up) is Oil Analysis. I periodically have the oil checked in my various vehicles just to find out what is going on before a failure occurs.

This is the company I use and their website explains what can be analyzed from an oil sample: https://www.titanlab.com/

You can purchase their oil analysis kits from here: https://www.pegasusautoracing.com/productselection.asp?Product=5090

 

[Chiefblueman]

No needle bearings in the conrod assy.

 

[hppants]

Oil analysis is out of the question, here. The motor oil got water in it from sitting outside.

Great learning experience for me in this thread (and on the shop table). I'll be incorporating all of your thoughts as I continue.

Fred is likely right, but we will continue to be hopeful.

One thing I'm really impressed with so far - this bike's motor is built tough. I mean BEEFY. I've split a few cases before (not many, but a few), and I can tell you that this motor has really large sized bearings and gears and other components for what it is. It's no wonder the FJR is designed (and in fact is) a mileage eater.

 

[Spud]

The more I read the happier I am that I live where it's cold as hell and once I'm out of town (5 min) I'm usually at "haul the mail" speeds, until the next town comes along.... I knew my FJR loved it here~!

 

[Patriot]

Well, on the other hand, I do ride 365 days a year !

 

[escapefjrtist]

Thanks for taking on and documenting the tear-down 'pants. Lots of good information to be shared here...and lots of parts!

--G

 

[dcarver]

Hey 'Pants...

When you get done with that engine.... :rofl:

 

[Patriot]

I thought to split the cases I would push the "tough" engine off the roof of my house to my concrete driveway.

 

[RossKean]

hppants

It might be interesting to find out a little more about the metal (or other) particulates that show up in the dissection. Aluminum alloy, steel, bearing material, "dirt" etc. Composition could be a useful indicator of the failure mode; although it might be difficult to determine the difference between cause and effect.

If you can get me a sample of particulates from oil passages or the oil pan, I would be happy to perform some chemical analysis to characterize the material. Obviously, it would have to be an uncontaminated specimen, i.e. excluding particles from cutting open the oil filter or drilling out broken bolts.

Don't need a lot of material - can manage something with as little as a few milligrams but a larger amount might provide some more analytical options. If there is a suspect source of the particulate, I could also analyze a piece of it to confirm trace element ratios to see if there is a reasonable match.

No charge, of course. PM me if you are interested in pursuing this...

Ross

 

[hppants]

Ross - PM will be forthcoming. I'll try to follow your direction and we will see what we get.

Didn't do much last night. I picked up some bolts to use with my puller to remove the rotor. Got that hooked up and I started pulling on it. That bugger is on there. Before I break something, I think today I'll try my new-found mechanic's trick and put some heat on the shaft to see if she'll budge.

I also verified that the metal shavings resting in the oil cooler reservoir in the case, as shown on my picture above is actually shavings from having to drill out the broken bolt there. I also determined that the particles identified on the bottom of my oil filter are magnetic (possibly not bearing material?).

My goal today is to bag and tag what's on my table, pull the rotor (one way or another), and split the cases.

 

[BikerGeek99]

I just gotta say that this is one very interesting thread, even for a mechanical moron like me.