40k miles on my S4, *no* flaking rockers. ;D
[thumbsup]
I'm pulling my cams out next month to check the rockers. :)
Quote from: Speeddog on October 22, 2010, 06:50:38 PM
40k miles on my S4, *no* flaking rockers. ;D
What kind of oil are you using?
You do realize now that you're doomed right?
Next post will be about how you shouldn't brag about your flakeless rockers
No worries, just preparing myself for 996 ownership ;D
Has this been a big issue with the S4's? Is there any easy way to check?
Quote from: Bill in OKC on October 23, 2010, 01:03:50 PM
What kind of oil are you using?
Bill, That was my first thought also. But isn't the problem due to fatigue of the plating bond and not due to any sort of wear? So it wouldn't make much difference what oil was used?
I had read that the problem was caused by poor oil feed during cold starts - the problem was rare in the horizontal exhaust rockers supposedly because they sat in an oil bath when the engine was off. The vertical exhaust rockers were the ones that were most vulnerable because it took a while for oil to reach them after the engine was started. A friend's street legal 748R had the problem, and again with Megacycle re-chromed rockers. It has over 30K miles now and they just found a problem with the main bearings, I guess they are narrower than the regular 748 bearings and stress the cases more, enough to have started cracking around the edge of the bearing :(
Quote from: Speeddog on October 22, 2010, 06:50:38 PM
40k miles on my S4, *no* flaking rockers. ;D
So...
what's the secret?
Secret? I wish! [laugh]
I've kept up on the valve clearances.
Tried to always let it warm up before getting the rpm very high.
Spectro dino oil, Spectro synth blend, Motul 5100 synth blend oils.
Seldom run the engine past 7k rpm.
The above, combined with a large helping of luck...
Quote from: Speeddog on October 25, 2010, 01:00:06 PM
Secret? I wish! [laugh]
<snip>
The above, combined with a large helping of luck...
I was afraid you'd say something like that. ;D
Anecdotal evidence is that rpm is the main thing, citing more flaking rockers on 748's than other DQ's.
I've got an ST3 waiting for 3 new opening rockers at 23k miles, I'm pretty convinced that was just neglect, as all the closers were .012"-.021"... :o
I know this issue is with the Desmoquatro motors but is there any similar issues with the Testastretta?
998 owner Rob
Quote from: DUCMONROB on October 27, 2010, 01:26:43 AM
I know this issue is with the Desmoquatro motors but is there any similar issues with the Testastretta?
998 owner Rob
Not as regularly as the Desmoquattro.
I hear that you'll see the occasional flaker.