NHMS Winter National

[RobLav]

Anyone going? I'm signed up. 10-11 April.

[RobLav]

I guess I'm the only FB - am heading there tomorrow morning.

[RobLav]

It was great to get back out on the track and to remove the cobwebs. Unfortunately for me, I had a major oil blowout on about lap 8 of the race and DNF'd. Much apologies for making a mess on the track and especially to Roger Feghali, who was behind me at the time.

I don't know the full extent of the engine damage yet.

[RobLav]

Engine seems to be OK. The noises I heard must have been the valve train with the gasket blown out.

[RussMcB]

Glad to hear that.

Did you come to any conclusions about the cause?

[RobLav]

Yes Russ - the blocked off reed valves. The original system will go back on for the NHMS school (instructor) at the end of the month.

[fredvs]

Rob

Our 08 gsxr1000 has just a hose connecting them straight across.

[glenn cooper]

What engine?

[RobLav]

Yamaha Coop...

[RussMcB]

Thinking out loud ...

At one time I thought the reed valves were part of a system that vented the upper cam area, sending air to the air box - like a PCV system in cars.

However, at least on my '07 Kawasaki, I think the system is really to introduce air (filtered from the air box) into the exhaust. I think it is for reduced emissions.

It seems to be pretty common modification to use some method for blocking off the reed valves or hoses. I've read about it on motorcycle and race car forums. I don't think I've ever read anyone having a problem caused by this mod.

So, Rob, I wonder if the pressure that pushed out the cam cover gasket is going to be reduced if you put the reed system back the way it was. (on edit - I just remembered I had a scavenge pump problem that same weekend, which may have been a factor in that oil leak since it wasn't sucking oil/air 100%.)

Are you pretty sure that your engine's ventalation system works good - can always vent pressure? How is that plumbed?

Maybe just a good gasket sealer will take care of it. I had a cam cover oil leak during a first outing with an ebay engine. Luckliy, simply snugging the bolts at the track solved it.

[RobLav]

Russ,
- There is a little mini-motor air pump on top of the cam cover.
- The reed valves seem to be rather permanently attached to the cam cover, and I had removed the reed valve covers and epoxied the holes closed and re-mounted them.
- And there is an air line under vacuum from the airbox to the mini-motor (which I had removed and plugged)
- There is another crankcase ventilation air hose from the crank to the oil tank...


So I will envestigate the manual more, but I suspect that the air pump helps ventilate the excess combustion gases.

A clue to the forthcoming problem on Saturday qualifying should have been the 1/2 quart of oil in the puke can that I emptied Sunday morning. The engine oil had one event on it from last September, and I had never touched it all winter.

(The cam cover gasket blew out at one of the half moons.) I'll use a good gasket sealer at the half moons when I put it back together this weekend. I'll also finally install the STM slipper clutch that I bought almost a year ago.

All I want is one more season with this engine. It is clearly down on power from what I had expected (and about 50 lbs overweight), so I'll be looking for another engine over next winter. That new BMW engine sure looks pretty good. Next winter is looking like a major re-do of a lot of stuff.

[RobLav]

R1 engine is Kaput - rod bearings knocking. Car is OOC for a while.

[RussMcB]

Sorry to hear that.

Maybe the bright side is you'll have a newer engine a year earlier than you expected.

And you'll probably find there are plenty of sell-able parts with your current engine. Have you sold stuff on ebay? There's a huge audience out there who would like to have your parts (head, crank case, etc.) for their project.

Good luck.

[RobLav]

It's too soon and too expensive right now to change engines Russ. I'd rather install new bearings and spend the money to replace my homemade bodywork with the real stuff - nose, sidepods, and engine cover.