Oh. My. God.......
I'd had to head away for work the day following the track day so pretty much just un-packed the bike, gave her a lil' pat on the bum, and headed off. I was in luuuuurve! But imagine your new girlfriend is Eva Mendes: she's smart, she's quirky, she's funny, she's absolutely stunning.....but deep down you know that with her Latin temperament she would rip the flesh from your bones if you ever did her wrong. It was going to be one hell of a ride.....
.....and I've just discovered hell is closer than I thought.
So I've gotten home from work a few weeks later and skipped into the shed like Julie Andrews from The Sound Of Bloody Music: "Honey, I'm home, time for some ticklin!" and set to sorting
that fouled spark plug.
Only it wasn't black...
It wasn't oily...
...it was absolutely battered!
Like someone had taken to it with a ball-pein hammer kinda battered:
If I wasn't already kneeling down I would have dropped like a sack of spuds: something had been rattling around inside the combustion chamber. These are surface discharge 'plugs, so there is no side electrode as per "normal" 'plugs, but it had still copped some serious physical abuse. It should have looked like this:
WTF? We'd only done 2 sessions but enough to prove she was a pretty serious weapon. In 30min track time she had not missed a beat, not even the slightest hesitation and I'd rolled back into the pits thinking everything was absolutely fine.....what the hell had happened?
I racked my brain, desperately searching for a straw I could clutch at......but there was nothing. It had been running when I parked it up, I could have replaced the 'plug, crossed my fingers, and hoped for the best....but that was risking repairable damage turning into something catastrophic. Bottom line: the head had to come off.
And this is what I found:
The obvious evidence is the thread imprints left from a bolt of some description being ingested, the less obvious damage is the 3 bent valves with the remaining valve and seat well chewed even if they aren't bent. Righto, not quite worst case scenario, but there were a few beers sunk while I just sat and stared at what was still an awful mess: I was absolutely crushed.
FYI, it isn't immediately obvious from the cylinder head pic, but did you notice the lighter coloured ring imprinted around the combustion chamber? Talk to any high end engine builder and you reach a certain point where head gaskets become problematic, so Ducati have employed the practice of using a "fire ring", almost like a gapless piston ring clamped between the faces, and ditched the head gasket. That's the sky-high compression contained, but what about the oil and water? As you can see below each fluid port is machined for an O-ring. It's not a cheap exercise, something you don't normally see on road machines, but it is used on the trick 999R.
But back to the disaster laid out before me: where had the bolt come from?
I didn't have to look too far.....
The carbon air runners have a flange incorporating a foam seal where they bolt/seal onto the carbon Shift-Tech airbox. The flange bolts also clamp the Pipercross foam air filters inside the airbox, forming a multi-layer carbon fibre/foam/rubber club-sandwich. With the rubber involved you can't pull them down super-tight or you end up destroying the filters and carbon.
So I used M6 x 16mm button head stainless bolts to which I'd tack welded a small flat plate to form a sort of T-head to clamp more of the filter sealing surface from the inside, all secured by stainless nyloc nuts on the outside. Two of the three bolts per side are easy enough to access but the third is squirrelled away in behind the top frame rail and very awkward to see and/or access with the runner in the way. I'll put my hand up here: I can't see a nyloc nut vibrating loose, so I can only guess I hadn't quite caught enough of the nylon insert to properly lock the bolt.
Thinking of all the nuts/bolts on the bike that could come loose and it's hard to imagine a worse place: directly above the gaping maw of the horizontal cylinder throttle body intake trumpet (insert heavy sigh here).
Once I'd figured out what happened I noted the vertical section of the exhaust prior to the muffer and couldn't help wondering if the lil' bastard was still in there. Eventually I couldn't help myself and started pulling it to bits....
....sure enough, "rattle, rattle" And out it dropped:
It was quite surreal holding the remains of the bolt, almost weightless in my palm, and looking at the damage it wrought.
There really was no good news but part of me was quietly amazed at the durability of the thing: the desmodromic rockers (for those unfamiliar there are effectively no valve springs, levers/rockers are used to open and close the valves) were strong enough to open and close 3 bent valves at 11000rpm. I mean you can see where the valves have been distorted enough to smash into the edge of the valve pockets on the piston.....and it never missed a beat. Don't let anybody tell you these things are fragile!
That is a result of employing Del West, pioneers in valve and valve train components/materials/coatings in F1/MotoGP to make cutting edge rockers. For comparison here is a cast closing rocker out of my 748R/926 head (all desmoquattro rockers are the same, +/- flaking chrome) vs a billet testastretta RS rocker:
The quality of the RS rocker is obvious, it is both lighter and stronger, and DLC (Diamond Like Coating) for reduced friction. It is quite a beautiful piece of jewel-like engineering to hold in your hand (it would easily fit inside a matchbox).
It's gallows humour but as the ol' girl didn't actually mechanically fail I guess it could be described as an "electrical failure"....nah, I'm not laughing either.
Had this been almost any road going Ducati I could have sourced all the parts necessary inside a week, without spending a fortune. Unfortunately none of this statement could be applied to the RS: just finding the parts was going to be a mission, and paying for them was going to be another world of hurt.
