1199 Sudden Engine Vibration on track...

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bp_SFV4 said:
Yeah, but I don't think the racing schedule applies to track days. I mean, maybe if you're winning in A group, but that's not most track riders. It's great the valve train can keep up with the high RPM, but the lower end doesn't seem to be quite as able. I think this is the reason the R has a more severe schedule as it revs higher. I also don't know how much this deviates from other brands.

The Ducati engine builder which came up in another thread, @craig bush mentioned him, has a blurb on his site saying when they blueprint a Ducati engine they use Corse spec tolerances which are actually looser, making spinning a bearing less likely. The same builder said 5k track miles was all he expected out of one of these engines which seems to be in line with Craig's experience.

IIRC, Craig got to 5k before his V4 detonated, but he didn't take a bike with a failing water pump to the track. If spinning a bearing in the bottom end is the death knell of the V4, mitigating heat and keeping it well oiled is the priority.
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Yep, that’s what Mark Sutton @ DucShop said.

@SuperDomestique is correct regarding rod bearing inspection - in the performance car community, it is fairly common to pull the oil pan to inspect rod bearings. Happens in the supra community (turbo 3L making 2-300 hp/liter) often - every year preventively if you’re running the car hard (drag racing or half-mile runway events). And definitely as soon as you hear what might be rod knock as in this case - rpm dependent knocking is rod knock until proven otherwise afaic’d (I’ve lost a supra motor and a pv4 motor to a sound bearing). Bearings should have been inspected. I’m surprised the motor lasted another lap.
 
bp_SFV4 said:
In your case wasn’t it a main bearing that failed? Was it the same one that the OP has pictured?
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We think it was the rod bearing that failed - bearing looked like it got really hot and the rod was broken. It’s my understanding that rod bearing failure is more common, and main bearing failure doesn’t break the rod as often.

The reason rod bearing failure causes knock is because as it fails the clearance opens and the rod big end starts to wobble on the crank journal with each direction change - “rod knock” (rpm dependent obviously, so it gets louder and faster with revs).

It’s also my understanding that as the rod bearing fails and the oil is contaminated with bearing material, it can cause main bearing failure secondarily. So while you might see both rod and main bearing damage, it’s usually the rod bearing that failed first.

Catastrophic motor failure (seizing and high-siding or splitting the cases and oiling the track) is definitely a risk with a spun bearing. No vehicle making an rpm dependent knocking noise should be driven until rod knock has been reasonably ruled out. If you choose to risk it and you oil down the track when the motor grenades, you should expect being labeled “that guy” that ruined everyone else’s session, and if it caused accidents…
 
craig bush said:
We think it was the rod bearing that failed - bearing looked like it got really hot and the rod was broken. It’s my understanding that rod bearing failure is more common, and main bearing failure doesn’t break the rod as often.

The reason rod bearing failure causes knock is because as it fails the clearance opens and the rod big end starts to wobble on the crank journal with each direction change - “rod knock” (rpm dependent obviously, so it gets louder and faster with revs).

It’s also my understanding that as the rod bearing fails and the oil is contaminated with bearing material, it can cause main bearing failure secondarily. So while you might see both rod and main bearing damage, it’s usually the rod bearing that failed first.

Catastrophic motor failure (seizing and high-siding or splitting the cases and oiling the track) is definitely a risk with a spun bearing. No vehicle making an rpm dependent knocking noise should be driven until rod knock has been reasonably ruled out. If you choose to risk it and you oil down the track when the motor grenades, you should expect being labeled “that guy” that ruined everyone else’s session, and if it caused accidents…
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Rod knock that has been identified and not thrashed has a high likelihood of being fixed. Like if you hear/feel the knock at idle shut the engine down and fix it. Don’t keep riding it thinking it’ll be all good. It’s only when you stress the motor do things go south.
 
@SuperDomestique do you have theory on my failure? did you see them pics? I didnt have a knock that i could hear until that final ride...and when i tore the motor apart the rods and bearings and whole bottom end looked great..... (sorry to hyjack OP)

JAG
 
SirJAG said:
@SuperDomestique do you have theory on my failure? did you see them pics? I didnt have a knock that i could hear until that final ride...and when i tore the motor apart the rods and bearings and whole bottom end looked great..... (sorry to hyjack OP)

JAG
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Tough to tell. I saw the rod and the surface looked ok visually. And if you’re saying the shells look good, then most likely it wasn’t the bearings. Valves also looked ok at least on the superficial head portion. If the stems look good and straight it wasn’t a timing issue. The piston has that spot where it's worn out or chunked. But something metallic was pinging around your cylinders. I’ve heard in other engines about piston squirters sometimes loosening or a screws loosening into the oil pump assembly. The weird thing is that crankcase became pressurized and dumped oil into the airbox. Any mods to the bike? Did it still have the PCV system? Someone in your post mentioned piston ring failure but you'd expect maybe some smoke as a tell-tale sign and not sudden catastrophic failure. But then again I'm no expert
 
SuperDomestique said:
Tough to tell. I saw the rod and the surface looked ok visually. And if you’re saying the shells look good, then most likely it wasn’t the bearings. Valves also looked ok at least on the superficial head portion. If the stems look good and straight it wasn’t a timing issue. The piston has that spot where it's worn out or chunked. But something metallic was pinging around your cylinders. I’ve heard in other engines about piston squirters sometimes loosening or a screws loosening into the oil pump assembly. The weird thing is that crankcase became pressurized and dumped oil into the airbox. Any mods to the bike? Did it still have the PCV system? Someone in your post mentioned piston ring failure but you'd expect maybe some smoke as a tell-tale sign and not sudden catastrophic failure. But then again I'm no expert
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just a upmap with termi slip on mod wise. I never saw or noticed any smoke until my boot was covered in oil. The piston was missing about 2cm^2 of material...my thought is the airbox was sucking oil past that hole.

The PCV system was still installed.

I appreciate your insights partner...
JAG
 
SirJAG said:
just a upmap with termi slip on mod wise. I never saw or noticed any smoke until my boot was covered in oil. The piston was missing about 2cm^2 of material...my thought is the airbox was sucking oil past that hole.

The PCV system was still installed.

I appreciate your insights partner...
JAG
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What coolant were you running?
 
SuperDomestique said:
What coolant were you running?
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Distilled water and WW

One time about two or three weeks prior to the failure my dash temp hit 240 splitting traffic in gridlock for about 10 minutes. I could only maintain about 15 mph. Once I saw the temp that high, I hit the shoulder and increase speed till about 50 and it brought it down. Total time that hot was probably less than 10 minutes.
 
SirJAG said:
Distilled water and WW

One time about two or three weeks prior to the failure my dash temp hit 240 splitting traffic in gridlock for about 10 minutes. I could only maintain about 15 mph. Once I saw the temp that high, I hit the shoulder and increase speed till about 50 and it brought it down. Total time that hot was probably less than 10 minutes.
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Interesting. How long was it in there? And did you get a look at the head gasket or water pump? Any signs of corrosion in the cooling system?

I say this bc water + WW needs to be refreshed frequently to maintain its properties. If you don’t, you can get electrolysis from dissimilar metals
 
SuperDomestique said:
Interesting. How long was it in there? And did you get a look at the head gasket or water pump? Any signs of corrosion in the cooling system?

I say this bc water + WW needs to be refreshed frequently to maintain its properties. If you don’t, you can get electrolysis from dissimilar metals
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Coolant changed when i first got the bike, and again heading into the first summer after I got it.
Head gasket and water pumps looked great, no signs of corrosion anywhere internally that I could see.
I never go more than 12K miles between coolant flushes...do you think thats too long for WW and Distilled H2O?

thanks for your comments and insight @SuperDomestique
 
SirJAG said:
Coolant changed when i first got the bike, and again heading into the first summer after I got it.
Head gasket and water pumps looked great, no signs of corrosion anywhere internally that I could see.
I never go more than 12K miles between coolant flushes...do you think thats too long for WW and Distilled H2O?

thanks for your comments and insight @SuperDomestique
Click to expand...
Sounds like that’s not the culprit.
 

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