FJ1346 from ashes to... Well, we'll see...

[ribbert]

So how did you compensate for the clearance that the coating took up in the bearings?

I've been meaning to ask that same question from the start.

Also ,how do you control the thickness and the uniformity of it in a backyard environment?
Did the motor turn over easily by hand after assembly?
Did you check the main and big end clearance bolted up?

Noel

[1tinindian]

I see that it sold.
I hope you were the one that got it!

Leon

Yeah, I got it Leon. I figure I can nickel and dime myself to death for a while. Thanks for the link.

I've done nothing special,(just cruising ebay for parts) and I just hate to see this project come to an end and I though you couldn't beat the price of those case halves.

Makes me wonder though about the coatings and sand blasting, what are the chances that there was some contamination from those processes that may have lead to the extra hole in the motor??

I guess I fail at understanding what is to be gained verses what you have already lost.

Good luck with the new build! I hope this next one will be the charm!

Leon

[fj1289]

Not exactly apples to apples (but it is an air cooled Yamaha!) - a great article on engine development and the advantages of some very early engine coatings

http://justyamahard350.com/articles/dale_1.htm

[skymasteres]

So how did you compensate for the clearance that the coating took up in the bearings?

I've been meaning to ask that same question from the start.

Also ,how do you control the thickness and the uniformity of it in a backyard environment?
Did the motor turn over easily by hand after assembly?
Did you check the main and big end clearance bolted up?

Noel

Okay, I thought I addressed this back when I started doing the coatings, but I'll go a little deeper.
Here is the commercial for the coating that I used on the bearings, crankshaft, and rod small ends.


CermaLube is a ceramic coating, designed to be used, on any rigid or semi rigid surface experiencing sliding, rotating or oscillating friction. CermaLube is designed to carry loads in excess of 350,000 PSI as well as lubricate at temperatures in excess of 1600F. CermaLube is a combination of a unique water based ceramic resin and lubricating solids including, a ceramic lubricating frit. CermaLube combines the durability of a ceramic resin with the lubricity of the ceramic lubricant. CermaLube works well in light duty applications as well as in applications where high temperatures, high loads and high speeds are experienced. When higher temperatures, than most other types of coatings can provide protection at, are experienced, CermaLube is fully capable of carrying the load. CermaLube is gray in color and acquires a glass like finish in use. CermaLube is formulated to provide a cured film thickness of ".001" or less.

It's not so much that the coating is compensated for than it is prepared in such a way that it's addition
is insignificant. This stuff "burnishes" when it is loaded. The final preparation step is to take scotchbright
pads and polish the coating down to its minimum thickness. It behaves kind of like graphite in this regard
with the bits that might be thicker or high spots breaking off and turning to powder. The scotchbright is
not abrasive enough to fully remove the coating from the base metal, just the excess thickness.

Yes, the motor turned over quite easily with the bottom end assembled. I really don't think I had a
clearance issue.

No, I did not plastigauge the crank. I did however move from blue to brown bearings on reassembly.

Makes me wonder though about the coatings and sand blasting, what are the chances that there was some contamination from those processes that may have lead to the extra hole in the motor??

I would characterize the chances of contaminants from the case preparation process being the root
cause of the failure as remote.  I was soooooo paranoid about making sure that I got all of the abrasive
out of the cases that I spent a considerable amount of time with a rifle cleaning set going through all
of the passages cleaning them out. I also flushed everything multiple times and fished bore cleaning
snakes through them.  The cases were clean.

I guess I fail at understanding what is to be gained verses what you have already lost.

That's not really a fair statement Leon. It wasn't a question of doing these coatings KNOWING that
there was an increased risk of grenading the motor. In fact, coatings of this sort have been used long
enough in industry that their benefits and characteristics are well understood. My goal was reduced
friction and increased longevity. I didn't think of it as a trade off between reliability and performance.

The main benefit of going all crazy with the coatings was to take advantage of the oil retaining nature
of the coating to all but eliminate startup wear from the motor.  That and provide additional protection
from the event that there was metal to metal contact of the bearings. 

One thing to note about this build, 10W-40 oil was too heavy. I noticed that on particularly hot days
(105F+ air temp 210F-220F oil temp) the engine would have much more power and behave "freer" than
on cool days where the temperature was below 80F (190F oil temp)  I was planning on switching to a
10W-30 oil on my next oil change when I went over to synthetic. The main advantage there being that
the lighter oil will incur lower pumping and friction penalties thus improving overall efficiency.

Okay, now you've done it. Now I'm going to have to go back to my Tribology book to show you guys
what is going on behind the curtain...

Imagine that you have a 3 quart bowl of water, and a mixer with a single beater on it running in the
center. After a finite amount of time this "system" will reach equilibrium. There will be a whirlpool with
the lowest point being around the beater and the highest point being the edges. The initial instinct is
that the fluid is just "flung" out away from the beater, that's part of it, but it also demonstrates
Bernoulli's principle. (For you other engineers out there allow me to profusely apologize for this over
simplification. I know the error here for a incompressible working fluid here would be HUGE) The higher
speed of the fluid at the center contributes to a drop in local pressure.

So, that's a 3D example. For journal bearings (pretty much everything in the FJ engine with no balls
in it) let's use a simpler 2D model. (There isn't going to be much difference at the edges anyway.)

Let's look at the flow of a working fluid over a flat plate.




There is a LOT of information here, but first look at the velocity gradient on the right hand side. 
Consider that the plate is the stationary part of the bearing (like the engine case) and imagine
that you are looking at a cross section of the oil that flows over it that is so thin that it doesn't
reach the part rotating above it. The important thing here is that you note that the oil is NOT
moving where it is in CONTACT with the "plate" and the velocity increases as you rise above the
plate. This is the single greatest reason for the importance of the "clearances" in the engine with
respect to the bearings.  The pressure gradient is the invers of the velocity gradient with the
maximum pressure being at the stationary part of the fluid film.  We are not concerned with the
turbulent boundary layer as the oil is "contained" by the part rotating in it so we never have a
"free streem" on the other side to get fully developed flow.  Since the bearing is fixed, and the
part being supported is moving you end up with a velocity profile that looks more like an "S"
because the parts are "moving" in different directions. 

How about another picture?
(I'm trying not to be too wordy here and failing miserably. It's a lot to try and explain)




This image shows a three step sequence of the supported shaft from a stop to running state. 
The important concept to grasp here is that the pressure is maximized where the oil film has the
greatest "static" area. This is not necessarily where the film is at its thinnest (due to the increased
velocity) The balance between clearance and oil viscosity is where you determine what the
behavior of the bearing is.  Too light an oil with too great a clearance and you will get cavitation
in the film and your load capacity is destroyed. Too heavy an oil with too little clearance and you
create excess drag and shearing forces.


Now let's look at the surface of the bearings themselves. In spite of how smooth they look, they're
really not.  There are all kinds of little surface imperfections that provide pockets that need to be
filled.  The virtual "surface" of the bearing starts at the tips of the peaks.

This image shows the lubricated bearing surface as it starts to move before there is a full oil film
supporting the bearing. It's just enough to reduce friction, but not enough to prevent metal on
metal contact.






Here you can see the fully developed oil film and how it supports the bearing surfaces. 
There are pressure and velocity gradients within this layer.




Remember that boundary layer? Well here is where it really comes into play. It basically smoothes 
out the flow around all of these imperfections and creates a stabilized layer between the two
surfaces.  The biggest part the oil retaining coatings serve is to create this state right from startup
and eliminate the metal on metal contact.  It also creates a larger static boundary layer which
allows for more favorable pressure distribution on the bearings. This reduces film shear and drag.





Now let's talk about oil retaining vs. oil shedding. (Basically a non-polar vs. Polar example) Imagine a
waxed hood on a car. What happens when you pour water on it? It flows over the surface until you
run out of water and it beads up. The water doesn't stick to the wax coating and its surface tension
causes it to bead. If you were to pour water on an un-waxed hood with an acrylic finish it wouldn't
bead because it would stick to the finish. Then it slowly evaporates off leaving minerals and what
not behind.

With the oil retaining coating you are basically creating a surface the attracts the oil and creates a
strong film even when the oil isn't "flowing"


Ultimately the whole point of the coating is to reduce losses due to friction and shearing forces.
I hope I've been able to help illustrate the mechanics behind how that is accomplished.

[1tinindian]

No offence intended.
My lack of understanding these coatings just brings up questions.
You seem to know the subject far better than I.
Like I said, I wish you luck with the next build.

Any idea what the cause of this failure was, yet?

Leon

[FJ_Hooligan]

Not trying to pour salt on a wound, just curious.  What is the typical crankshaft bearing clearance?  I have no numbers in front of me, but I seem to recall it being in the thousandths of a inch.

Could 0.001" on the bearing surface and 0.001" on the journal result in a potentially significant loss of useable oil space in the bearing clearance?  Is that why you changed the bearing size/color?

Again, I'm no expert, just asking.  In following this thread, it seemed you were doing everything correct.  I'm just stunned that the motor exploded.

[movenon]

Mike. I feel bad for what happened. It's a real pain (heart ache) after you put so much effort and thought into it. But please don't forget that Leon now has a bike with 186,000 miles on it and its still going. And there are other members with high mileage stock engines.

Just from looking at that one rod it looks like it just let go down in the rod bolt area ? Might be to simple of an answer. I have seen small bock Chev rods fail in the same manner when rebuilt with old rod bolts and nuts. Most were also run at close to if not over there design limit.

As a group is there anything you want us to keep an eye for for to get you back on the road ?
George

[aviationfred]

Off of the subject of the engine rebuild.

I do have a set of center stand shoulder bolts to replace the one that departed before the engine mishap. Let me kknow if you need one.

Fred

[JMR]

So how did you compensate for the clearance that the coating took up in the bearings?

My thought exactly. No disrespect intended but I have built many NA engines doubling the original output and haven't had any problems over the years. Didn't you have problems with the bucket bores clearances etc etc. I'd do another motor and stick to crown and skirt coatings. I have just skirt coatings on my 1314 engine and it makes well over 150.....reliably. 

[fintip]

I know nothing compared to most people in this thread. 

But how exactly would lack of clearance in the bearings cause a rod to snap?

I imagine bearings would have increased wear, which would match the constant flow of metal shavings he was seeing, but... Do the bearings go bad from excessive wear, causing a slight amount of 'play' in the rod, causing the snap? Is that the theory being pondered?

Would it have happened so soon? I kind of expect that kind of wear would take, I dunno, a few tens of thousands of miles to really manifest. It's not a 16k revving motor, it's a 9, and while 9 is still fairly high, he wasn't riding it that hard when it happened, or overall, and we'd be talking about (I think?) a very, very small effect on the quality of the bearings.

One thousandth of an inch--or less!--being a problem is hard to imagine; is there a chance that that the surfaces weren't quite scotch-brighted well enough?

Sky, that was a great explanation (I constantly feel like I'm reading engineering articles on wikipedia in this thread...), but while I understood the simple point about the oil retaining vs oil shedding, what was the point with the blender analogy? The idea of the bearings flicking away oil, perhaps? But if they're submerged, I can't see why that would apply, and I've always assumed they were submerged.

Then again, if that's true, then why would you need an oil retaining coating? It would be coated even when cold. So I'm at a loss somewhere.

[ribbert]

For you other engineers out there allow me to profusely apologize for this over
simplification.

For we non engineer simpletons you choose to educate with baby talk and pictures, I, and many others, understand everything in you post (not sure if the beater/bowl analogy is the best example though) but fail to see any relevance to you goal. All this has already been adequately addressed by the engineers. Look at any high mileage FJ out there, or any other modern engine for that matter, the bottom end out lasts the top end anyway.
Modern engines have in recent years become near enough to "sealed for life" units. It has taken 100 years of development, along with lubricants, to reach this point. Why reinvent the wheel. That's a lot of development to try and improve on.
You could reasonably expect to buy a new vehicle today and do 400,000km's + without putting a spanner to it.

I have read the CermaLube hype and their claims seem a little unrealistic. Anyway, the primary use of the product seems unlikely to be the problem.

The unabated appearance of metal on the magnetic plug would suggest there will be a very obvious source inside the motor.
If this motor was brought to me with it's immediate history known, I would have to consider that with the unprecedented amount of things that were not fitted properly, left loose of fell off externally, that something similar may have happened internally. Not being unkind but it is a reasonable avenue to investigate.

I do not believe there is any connection between the ambient temp and oil viscosity with only a 20F difference in oil temp. Certainly not to the extent you observed, particularly when the 40 is the recommended oil.

It is the mere mortals on the site that offered enormous help and support through this build and I find the above remark condescending. Plenty of very knowledgeable people here manage to offer simple explanations without the need to show us everything they know.

As I have said previously, I feel you pain and disappointment after going to so much trouble and hope you get it sorted quickly and move on from build reports to trip reports.
BTW, what is your field of engineering?

If longevity and reliability are your target, leave it stock (internally anyway) and treat it well.

Noel

[skymasteres]

No offence intended.
My lack of understanding these coatings just brings up questions.
You seem to know the subject far better than I.
Like I said, I wish you luck with the next build.

Any idea what the cause of this failure was, yet?

Leon

I have my suspicions, more on that further down.

Not trying to pour salt on a wound, just curious.  What is the typical crankshaft bearing clearance?  I have no numbers in front of me, but I seem to recall it being in the thousandths of a inch.

Could 0.001" on the bearing surface and 0.001" on the journal result in a potentially significant loss of useable oil space in the bearing clearance?  Is that why you changed the bearing size/color?

Again, I'm no expert, just asking.  In following this thread, it seemed you were doing everything correct.  I'm just stunned that the motor exploded.

It's possible that I may have tightened up the clearances more than I thought, but I am really hesitant to hang the bearings and coatings as the smoking gun for this failure. (Especially since I have been doing these coatings for the local motorcycle shop on engine parts for their customers)

The bearing color change was due to the fact that APE Racing removed the bearing numbers from the crankshaft, without writing them down, when they lightened and balanced it. The engine originally had four blue bearings and a yellow one. But I'm not sure which position which one was in. This was of course after talking to randy and trying to determine what the numeric difference between the bearing sizes was. (The end result was Randy didn't have equipment sensitive enough to measure the difference) Since I didn't have the numbers I went with Hank Scott's advice and just ran brown bearings to open it up a little.

Mike. I feel bad for what happened. It's a real pain (heart ache) after you put so much effort and thought into it. But please don't forget that Leon now has a bike with 186,000 miles on it and its still going. And there are other members with high mileage stock engines.

Just from looking at that one rod it looks like it just let go down in the rod bolt area ? Might be to simple of an answer. I have seen small bock Chev rods fail in the same manner when rebuilt with old rod bolts and nuts. Most were also run at close to if not over there design limit.

As a group is there anything you want us to keep an eye for for to get you back on the road ?
George

George, you know the funny thing is I was thinking along the same lines. (There's a dent that I'll go into more detail about below.)   

Thanks for the comment. I know this whole thing is surely my fault as engines don't just "explode" for no reason. And the rod bolts might be the smoking gun everyone is looking for. As far as looking for parts, I'll have to keep that in mind when I find out what all I can salvage.

Off of the subject of the engine rebuild.

I do have a set of center stand shoulder bolts to replace the one that departed before the engine mishap. Let me kknow if you need one.

Fred

Fred, I ended up using a 1/2" shoulder bolt with a 5/8" sleeve over it as a temporary replacement. But I definitely wouldn't turn down a stock bolt.  (My jury rigged bolt and sleeve is slightly loose for the hole)

I know nothing compared to most people in this thread. 

But how exactly would lack of clearance in the bearings cause a rod to snap?

I imagine bearings would have increased wear, which would match the constant flow of metal shavings he was seeing, but... Do the bearings go bad from excessive wear, causing a slight amount of 'play' in the rod, causing the snap? Is that the theory being pondered?

Would it have happened so soon? I kind of expect that kind of wear would take, I dunno, a few tens of thousands of miles to really manifest. It's not a 16k revving motor, it's a 9, and while 9 is still fairly high, he wasn't riding it that hard when it happened, or overall, and we'd be talking about (I think?) a very, very small effect on the quality of the bearings.

One thousandth of an inch--or less!--being a problem is hard to imagine; is there a chance that that the surfaces weren't quite scotch-brighted well enough?

Sky, that was a great explanation (I constantly feel like I'm reading engineering articles on wikipedia in this thread...), but while I understood the simple point about the oil retaining vs oil shedding, what was the point with the blender analogy? The idea of the bearings flicking away oil, perhaps? But if they're submerged, I can't see why that would apply, and I've always assumed they were submerged.

Then again, if that's true, then why would you need an oil retaining coating? It would be coated even when cold. So I'm at a loss somewhere.

It's funny the tone of your response vs. Noel's below.  I'm sorry to both of you for the mixing bowl analogy. I guess it wasn't the best one to use. I was just trying to paint the picture of the different velocities that you have in a working fluid. When you start looking at high pressure high speed flow some counter intuitive things start to happen with respect to pressure and viscosity.  (Kind of like convergent and divergent nozzles behaving differently at subsonic and subsonic speeds)

The point was you have a lower pressure right next to the moving part where the velocity is faster.

The bearing doesn't so much "flick oil away" as it displaces it. That grove in the center of the bearing serves as a "D" shaped pipe that spreads oil across the 360 degrees of the bearing surface. The oil flows from the center out to the edges, creating an oil film that the crankshaft rides on.  At startup there is no oil pressure to provide this film and the initial support is given by the bearings themselves as the crankshaft rides against them until oil pressure builds to the point that this film is created. This is where the metallurgy of the bearings is so important and why people say that most of your engine wear occurs at startup. 

The point of the "oil retaining" coatings was to hopefully have a bearing surface that would retain a thin oil film during this startup phase in absence of the pressure that normally washes it across the bearings. (Yes, I know that there would be significant heating under load but it should be cooled the instant oil starts to flow in volume)
A little spot of the coating not being scotchbrighted enough shouldn't have been a factor. In fact, I think it would be impossible for me to achieve the coating's final thickness via polishing with a scotchbright pad without damaging the surface of the bearing itself. The pressure achieved on startup would be significantly greater than any pressure I could create with a scotchbright pad.

Bearings go "bad" when they have worn enough that there is enough room for the oil film that they support to become turbulent. When this happens you get micro cavitation, variations in temperature, and pressure, and possible metal on metal contact. If this contact continues the temperatures rise to the point that you start burning your oil film and risk "spinning" the bearing. This is just where the bearing sticks to the moving surface and the non-lubricated part starts spinning. One of my initial thoughts was that the connecting rod bearing welded to the crankshaft and that's what caused the failure.

For we non engineer simpletons you choose to educate with baby talk and pictures, I, and many others, understand everything in you post (not sure if the beater/bowl analogy is the best example though) but fail to see any relevance to you goal. All this has already been adequately addressed by the engineers. Look at any high mileage FJ out there, or any other modern engine for that matter, the bottom end out lasts the top end anyway.

Noel, you know, initially I was kind of angry at the tone that you start off with here.   (Even went to bed frustrated that you would feel that way) Then I realized that real irony of it and had to laugh.  One of the first things they tell you when you're giving a briefing is to "know your audience". On an internet forum like this where people have all manners of backgrounds and experience levels I was making a genuine apology to the readers like yourself that don't need the simple analogies or pictures to grasp a concept.   One of the struggles that I have here with conveying some of this stuff is, that while the operation on the macro side of the machine is simple and straight forward, all of the little things that have to line up to make it work can become overwhelming.  I don't want to write a book or boor people to death with more information than they need or care about, so I trend towards using example and analogy as a means to keep it lite while providing enough information that everyone can get something out of it. (I feel that diagrams and pictures are huge in making concepts easier to grasp) I would be happy to chat offline with anyone with different views or just want to ask a more general question then bring it from global function to "in the weeds" operating principles.

Modern engines have in recent years become near enough to "sealed for life" units. It has taken 100 years of development, along with lubricants, to reach this point. Why reinvent the wheel. That's a lot of development to try and improve on.
You could reasonably expect to buy a new vehicle today and do 400,000km's + without putting a spanner to it.

You are EXACTLY right with this statement.  Although I would say that the availability of quality lubricants probably plays the bigger role here.  I had an engineering professor in college that had the firm belief that the perfect car was one that arrived from the factory with the hood welded shut. If there was an issue you'd bring it in for service. There would be no end user (i.e. idiot) to mess with the well-engineered machine. One of his favorite sayings was, "Every time we make something idiot proof they come along with a better idiot"

I have read the CermaLube hype and their claims seem a little unrealistic. Anyway, the primary use of the product seems unlikely to be the problem.

You're right about some of the claims being "hype" but, then again, that's the point of marketing.  I'm glad at least someone isn't blaming the coatings outright. I also feel that the coatings were not a factor in the failure. 

The unabated appearance of metal on the magnetic plug would suggest there will be a very obvious source inside the motor.
If this motor was brought to me with it's immediate history known, I would have to consider that with the unprecedented amount of things that were not fitted properly, left loose of fell off externally, that something similar may have happened internally. Not being unkind but it is a reasonable avenue to investigate.

While I may bristle initially at this comment, I have to admit its validity given the bare facts about what I have posted with my experience. That being said, I did find the root cause for every one of those "issues".  (Well, I'm guessing that it was metal fatigue on the brake and center stand bolts) The cam chain tensioner was an oversight on re-assembly after the head was removed to get at the oil galley plugs. As for "not fitted properly" I'm not sure what you mean, unless it was the omission of the plastigaging on assembly.

I have my suspicion of what the failure was. (The idea came to me while I was talking to Mark "FJMonkey" last week)  It actually is more in line with your line of reasoning than most of the other comments regarding it.  My "hunch" is that one or both of the nuts securing the connecting rod bolts on cylinder number three backed off. This would have allowed a gap to develop between the big ends of the connecting rod. This could also explain the new sound that developed less than 60 miles before the failure. The only evidence that I have to support this hypothesis at the moment is that the one connecting rod bot that I have is perfectly intact with undamaged threads and the piece of the connecting rod that I have has a dent on one side parallel to the axis of rotation.  As if it became disconnected and got dented when it struck the crankshaft. This would also explain the notch carved out of the cylinder. As if it bent when it jammed the piston up into the cylinder head, then got "cleaved" off when struck by the spinning crankshaft, and ejected through the front side of the cases.

I do not believe there is any connection between the ambient temp and oil viscosity with only a 20F difference in oil temp. Certainly not to the extent you observed, particularly when the 40 is the recommended oil.

I don't know for sure if this is going to be significant or not but, going by some simple figures, the difference in kinematic viscosity for Mobile one 10W-40 drops from about 19mm2/s at 190f to about 15mm2/s at 210F. It's about 12.5mm2/s at 230f and all the way out at 250f it drops to about 10mm2/s.  For that 20 degree difference there is a 21% drop in kinematic viscosity.  The next 20 degree span sees a 20% drop in viscosity. If you graph it it's pretty linear from 175-230F.  The 10W-30 oil drops from 15mm2/s to 11.5mm2/s for the same 20 degree increase.(190-210F)  So really between the two weights you only see a drop in viscosity at the operating temperature of 4mm2/s cold and 3.5mm2/s hot.  I don't know if this is significant or not. I'd have to run some numbers based on bearing size, oil pressure, make some assumptions on clearances, and so on. Basically go crazy taking a whole bunch of "real' measurements and setting everything up. (I think I'll have to finally figure out matlab if I'm going to go after that data.)

But what I do "know" is that the "seat of the pants" dyno noticed enough of a difference between the two temperature extremes with other factors being constant that it was noteworthy. 

That being said, until I went after it with the math to figure out a difference I was right with you on the 30 vs 40 weight not making a difference. I figured I was "over analyzing", being crazy, and making a mountain out of a mole hill.  Now I'm not so sure. (Although I still don't think it was a factor)

This actually goes to further show how preconceptions of the "way it is" can hide the truth from you. Of course I could be wrong with this as I haven't figured out how much of a factor in the bearings that the kinematic viscosity is going to be. (Is it multiplied? Divided? Squared? Etc...) As much as excessive math pains me, it is pretty much the ultimate way of finding the "truth" as to how things work...

Noel, you're most certainly right that the oil was not the only factor in my perceived difference in performance. I'm guessing that other factors probably included the ring gaps. I'm still thinking I had excessive wear on the rings and cylinders as this is about the only place you're going to get that much "free" iron. (Well, other than something going horribly wrong which is completely possible...)

Speaking of oil, I found this while looking for reference data on viscosity. It's a pretty cool graphical comparison between straight 30w and the 10W-30 multiviscosity oils showing the change in viscosity that the multiviscosity oil goes through in relation to temperature. Two things to note though. The scale on the left looks logarithmic, and it's in centistrokes. (The same as mm2/s if you are comparing to a time scale of seconds)

It is the mere mortals on the site that offered enormous help and support through this build and I find the above remark condescending. Plenty of very knowledgeable people here manage to offer simple explanations without the need to show us everything they know.

The irony of it all is that the comment that pissed you off, was really meant as an apology for the members like yourself that don't need these concepts simplified. I wasn't trying to "show everything I know" I was trying to make my take on it accessible for everything. There's an interesting point to be made between what you "know" and what "is".  I have found on many occasions that things that I "knew" were really things that I thought.  (The magnet in the copper tube for example)

No, condescending would have been making a comment along the lines "If enough monkeys bang on a keyboard..." with respect to someone's comment. I offer the information that I can mostly because I get a kick out of thinking about this stuff. It's sometimes hard work trying to figure things out for real.

Edison said "It's amazing the amount of trouble people will go through to avoid the real work of thinking" Now I'm not a huge fan of Edison, but I think this is even truer today than it was in his time.

As I have said previously, I feel you pain and disappointment after going to so much trouble and hope you get it sorted quickly and move on from build reports to trip reports.
BTW, what is your field of engineering?

If longevity and reliability are your target, leave it stock (internally anyway) and treat it well.

Noel

As for leaving it stock, I have an affliction. I'm a mechanical engineer.  One of the underlying tenants of being one can be explained in the expression, "If it ain't broke, fix it till it is." That's not to say that I can't repair things, I just prefer to improve upon them while I'm in there.  I know that sounds presumptuous seeing as the companies that build these things employ whole teams on engineers that design these things, but I realized something back when I was working on Ford V-8s. The engineers that designed these machines had all sorts of constraints that they were working within.  Where the cost is a HUGE factor there are many times where ease of manufacturing and assembly are chosen over performance. Tradeoffs are made everywhere to offer a product for the masses.

It's like Randy has been saying with respect to the price of his new rear shock. Because it's custom designed for this motorcycle, that was only built for 10 years, he has a very small customer base. That means that the price is going to be a lot higher. The benefit is HUGE for us because we get a great product, but it needs to be paid for. When a car company builds a car they are trying to sell tens of thousands of them, so they are designed to fit the needs that the variations within those tens of thousands of people might have. This kind of compromise in design is where the people here who putter and modify can do better.  Since we are working on individual machines in a not for profit environment we accept the fact that we will not turn a profit on our time, at least not monetarily.

I know that I went totally overboard with this coating stuff. The reason you don't see camshafts and the like coated is you are getting into the barely measureable improvement category. (We're talking tenths of a percent improvement in frictional reduction) But, for me, since there was a measureable improvement... I figured "what could it hurt?" I'm hoping I don't have to eat those words...

On a side note, when Randy asked which hole the connecting rod came out of, I didn't know that "hole" was slang for identifying which cylinder. I thought it was a sarcastic attempt at humor. (I ran with it, but for those that haven't figured it out or haven't been reading it was cylinder number 3)

[Harvy]

QUOTE ----
My "hunch" is that one or both of the nuts securing the connecting rod bolts on cylinder number three backed off. This would have allowed a gap to develop between the big ends of the connecting rod. This could also explain the new sound that developed less than 60 miles before the failure
----END QUOTE..

BINGO!!!!

This is the exact scenario that occured when I broke a $15000 race motor in my ski boat. Broke a bolt at the big end of number 8 - developed a new noise and motoring back to shore completely let go. Punched a hole in the block between number 7 and 8, twisted the crank and snapped the cam into 3 pieces.

I rreally think you are on the right track with this "hunch"

Harvy

[fintip]

What with all the bolts that 'backed out' in this build, would be fitting that a loose bolt was the end cause.

[JMR]

But how exactly would lack of clearance in the bearings cause a rod to snap?

In general they don't....rods bend and break when they come in contact with something....like a cylinder head. That usually happens when rod bolts fail or the bolt (or nut depending on the rod design) back off. Lots of detonation combined with forced induction will bend and break rods though that wasn't the case here.
If you really burn a bearing up secondary to oil problems it will knock  (as the big end slaps around on the journal). If you let it go long enough it can cause the bolts to fail but it would take a while and you'd have to be a moron to overlook the hammer noise coming from the engine.
The intact rod bolt with the nut off and the threads in good shape is a clue.
My point was to keep it simple and triple check your work.