Hello all,
This is my first post here, thank you for this forum. I'm rebuilding a 996, and I have a question regarding half rings. I'm replacing all the rocker arms in this engine. I have the new rockers, but not received the new half-rings. I would like to get my shims ordered ASAP, but I'm wondering if using the old half-rings for the measurement will give me bad data. In other words, should I wait for the new half-rings to get my shim measurements. Thanks for any input.
Josh
I just did the valves on a 996 and the new half rings tigtened all the closers up by .002, so it can and probably will affect your clearences a slight amount. I would wait, but I am very anal in the way I like to set the valves.
Duckracer speaks the truth....at the ends where they are clipped tend to burr and usage over time will flatten the burrs while the ring seem to compress. Some hone the ends to get a much better final fitting ring.
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2001 Yamaha Zuma Leo Vince ZX pipe, 5,5 gram rollers, Bandito kevlar belt, NO2. Much more!
if the old ones aren't overly marked i'd reuse them. the new ones will just settle like the old ones anyway, and the clearance will move accordingly in a fairly short time. file / grind / rub the burr off - they sit in much nicer and move less, plus tend to break less in higher rpm usage ime.
Thanks for the feedback. Maybe I should measure the clearances with the old and new rings for curiosity sake. While I'm waiting on the new rings I can get the body work done or something.
This is my first Ducati, it's a 1999 996 with 16k miles. It was suspected of having a bad transmission, but it turned out that the clutch components were just totally worn out. The transmission is perfect. I'm replacing all the bearings just because, but everything else in the trans is right in spec. I found one crank bearing with a scored ball bearing. Maybe a piece of chrome from one of the rockers got in there, but it was still spinning and no damage to the crank. The timing belts were just barely holding together with two bad idler bearings, and the rockers are all getting retired as I said before. The cylinder walls look like BMW's , after 16K miles there was still plenty of cross-hatching on the walls. They should go to a finer cylinder finish at the factory, it looks like the rings have no problem seating.
Overall I'm really impressed with the engineering. First rate components and a nice tight package. I can not wait to hear this engine come back to life.
WTF!!!! Talk about a not maintained motor! HOLY SHIT, I've never seen damage like that on the belts before, or the rockers.
Yes, this bike is lucky that I came along. I think that driving one more mile would have killed it. The rocker in the photo was the worst by far, but I decided to replace them all, just to have confidence at 10,000 rpm. If either the belts or the crank bearing had failed... well I would hate to hear the sound that followed, that's for sure.
Yes, this bike is lucky that I came along. I think that driving one more mile would have killed it. The rocker in the photo was the worst by far, but I decided to replace them all, just to have confidence at 10,000 rpm. If either the belts or the crank bearing had failed... well I would hate to hear the sound that followed, that's for sure.
im really glad someone willing to fix this catastrophy got there hands on that bike...your a saint.....
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2000 748 biposto
Ducati MacGyver
transplant complete! if she only had a brain...
im really glad someone willing to fix this catastrophy got there hands on that bike...your a saint.....
Thanks man, but really I'm lucky that I got an opportunity to own a Machine like this for an affordable price, plus there is nothing better than riding a bike that you know inside and out. It is shaping up to be a great summer.
Where are you getting your shims? If you don't know, a buddy of mine is well versed on the subject, he owns EMS which sells shim kits for all Ducatis. He is also very good about providing technical advice and next week he volunteered to assist a mutual friend do his valves on his 748R. He also attended a workshop I hosted for the Testastretta motor. Great guy, his name is Mike Guidera or Ducatimike.
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2003 HD FLHRI
2003 Ducati 999R #189
2009 Buell 1125CR (sold)
2007 Ducati 1100S MTS (sold)
2005 Honda 600RR (totalled)
2001 Ducati 900SS (sold)
1995 Ducati 916 (sold)
2004 Ducati 999S (sold)
2005 Honda 600RR (Oops, I did it again, this time in red/black - sold)
+1 for Mike of EMS. I helped him with heat treating issues a few years ago. First rate products with fine attention to detail.
Half rings:
Photon,
I bought half rings for my 998 when I went through the valves at 20,000. I don't know what idiot vendor Ducati uses for these but the parts are pathetic. (and you think you are anal?) Half rings are made on a spring winding machine from a spool of wire and as it is fed they are clipped off to form the ~170 degree radius. Then they are put into a reducing atmosphere shaker hearth furnace and quenched for hardening then a batch furnace to temper them.
Of the umpteen I bought they vary in thickness up to .03mm. Like WTF,, put a thick one on one side and a skinny one on the other now you have a valve shim that is cocked. Can't these guys control the diameter of the wire?
The cutting action does raise a burr which makes the end cuts thicker. I use a fine sharpening stone to knock these down until the ends are the same diameter as the main wire.
* So don't feel bad about compulsing over these. Most people just put them in and run it.
Half-ring variances, old vs. new?
, after 16K miles there was still plenty of cross-hatching on the walls. They should go to a finer cylinder finish at the factory, it looks like the rings have no problem seating.
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