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Discussion Starter #1 (Edited)
Hy fellas,
I decided to take the cylinder head apart for porting, and at the time of having the camshafts in my hand, realized that the intake (race kit cam) had 3 lobes worn out :suicide:
The worn out lobes are, from left to right: 4, 5, 7. Its crests are completely rounded and lost about 1mm height.
Tappets have erosion signs, but not enough to show valve clearence change. By fortune I measured it before disassembling the cams and showed the same value set at installation.
Installation was made precisely according to the instructions given in the service manual (moly oil application, torque, etc)

I have put only 600 km since the race cam was installed. Total odo is 8300 km.

Exhaust side is OK, and so was the stock intake cam when it was replaced by the race one, thus meaning the tappets have not caused the problem.

Seems to be some kind of hardness process failure. My mechanic is sending it for analysis.

No noise was heard; no external signs at all. Last dyno run showed a drop of 10cv, and we really didnt know where the lost came from... It wasnt really a "butt noticeable" power drop, but the top end was a bit soft.

I would strongly recommend to everyone running a race intake cam to check out its integrity.

Didnt take photos so far, but I will try to get some good macro ones to post.
 

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Hrm... still using stock springs too? Flat cams suck.... I've seen a few killed with over-aggressive profile/spring combinations... though most of 'em are from piss poor oil or break in. ...have seen a few that were just plain bad... never in a bike though :(

Make sure you get a couple good oil flushes in to get all that fine debris out of the engine.
 

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Sorry to hear.

I've had the race cam in for about 2k miles and had the head off at about 1k miles to check everything. The shop said all was good and the bike dynoed basically the same as it did when the work was first done.
 

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Speed Freak
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damn sorry to hear, I think this is the first time we have heard on this forum about that happening.... I've got about 20k miles on my race cam with no problems
 

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Discussion Starter #10
That 85 always sound weird. Thats not even covering the machining process.

I promise to post pictures on Monday by the afternoon. My mechanic has the cam and he is analizing if it can be repaired or something.
I repeat that the exhaust side is OK, along with the stock intake by the time it was taken out, not long ago.
Oil I was using is Mobil1. I dont think this has to do with the wear out.

Thanks for all the inputs. I´m kinda devastated with this:sad:
 

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Supercharged Mod
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I've heard rumblings from various sources complaining about the new engine oil formulations not having enough anti-wear additives. Don't dismiss the possibility of oil-related failure unless you can actually rule it out.

Some auto manufacturers are going to manufacturer-specific oil specifications because of stuff like this.
 

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Rent this space
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By faceted do you mean a series of flat spots ??

I have seen this with coil bind on valve springs or tight valve stems.
 

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Discussion Starter #13
No, I dont rule out the oil, but I thought Mobil1 was one of the best oils money can buy. I´ll be changing brand no matter what.

FAF, there are flat spots as you describe. Valve springs are the stock ones, so I discard the posibility of coil binding. All valves have already been taken out and are like new; everything ok about this.
No Ti intake valves BTW. I´ve read somewhere that they were Ti. Thats not the case at least in the 04
 

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By faceted do you mean a series of flat spots ??

I have seen this with coil bind on valve springs or tight valve stems.
Yup yup... I've seen it when someone 'misses' a bit on the clearance of new valve guides too.... Nasty thing that is. Does the race cam have that much more lift (don't have the specs on hand)?

And just an odd note: what did the valve clearances look like post-mordem? I'm assuming that there wasn't any damage/wear on the back sides of the cam lobes, right?

G'luck getting it sorted... at least nothing underwent "Energeric Disassembly". That's always a plus. :mrgreen:
 

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Supercharged Mod
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"energetic disassembly" - I'll have to remember that one!

I remember someone local drained the oil out of an engine after hearing odd sounds, then after seeing metal flecks in the oil, proclaimed that "badness has occurred" ...

Or the local vintage racer who jokingly claimed his bike stopped because of an electrical failure. Yeah right ... the alternator stopped, after a connecting rod broke and punched a hole in the crankcase ...
 
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