I'm spinning this off to a new thread, because the title of the old one doesn't apply to this new finding. Riot Racing regrind cams. I've had issues with several collapsed lifters at different times. Pulled the cam this time to find this. How is this possible? Any experiences?
Bob
previous thread:
https://www.bimmerforums.com/forum/s...il-pan-upgrade
Last edited by BobInIndy; 08-21-2017 at 11:33 PM.
wow ... that's serious damage. It sure looks like the vanos was pushing hard against the cam to do that. I'm not sure oil pressure is enough, I would suspect it was a mechanical jam. How were are the timing plates and washers? Nothing dumb like the cam trays mixed up (E is intake, A is exhaust) or cam caps mixed up?
Yikes! Ugly indeed.
In the previous thread you mentioned getting an intermittent VANOS mechanically stuck error code. That's usually due to incorrect timing of the VANOS gear on assembly, but in this case maybe not?
It's a bit hard to tell looking at the photo, but is there damage to the cam cap bearing journal itself as well as to the thrust face? The face gets its oil pressure from the journal feed (visible in the photo), so any oil restriction would affect both.
But there shouldn't be a large thrust load on the cam as long as the VANOS spiral gears are meshing smoothly together. Is the spline in the RR intake cam in good shape, and are you planning to remove and reuse it, or replace? The Schricks don't come with one installed, or at least mine didn't. You have to recover it from the original cams.
Update: I had to go and refresh my memory on this. I'm referring to #13 here: http://www.realoem.com/bmw/enUS/show...60#11361738468. It installs in the end of the intake cam and takes massive torque to break free. Installation torque is 40nm plus 60 degrees, reputed to be equivalent to 250 ft-lb.
Neil
Last edited by NeilM; 08-29-2017 at 11:25 AM.
The vanos gears were fine. I replaced that shaft with new. But.....
All,
Well everything is fixed with the removal of the Riot Racing cams, and install of the Schricks. I went ahead and pulled the head. All oil passages wide open, and checked the oil check valve-good too. What I discovered is that the Riot Racing cam was LOOSE in the trays! I couldn’t tell this when it was installed against the lifters/springs/valves in the car. The clearance s at the cam bearing journals varied around the neighborhood of 0.006, when they should have been 0.002-0.003 at the most. So, there is where I was losing oil pressure and volume. I’m sure that caused the collapsed lifters, and finally the wear at the thrust surface. I have put 200-300 miles on the Schricks. Quiet as a church mouse.
For the record, the cam bearing journal problem was not the cam tray. New one was the same. All the Riot Racing cam bearing journal surfaces were way undersized. Todd H at Riot Racing tells me they grind these down to “straighten” the core cams, but he denies that this was their fault. First, he said I installed them incorrectly, then he says it’s my fault for running with low oil pressure.
Live and learn
Bob
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