Topic: CycleX SuperFlow Valves

[Nic]

Yeah alright, it's blue then lol. This whole thread is all about the nitride coated CycleX superflow valves and how the coating comes off etc. So that's why the smoke me thinks.

[Retro Rocket]

Yeah alright, it's blue then lol. This whole thread is all about the nitride coated CycleX superflow valves and how the coating comes off etc. So that's why the smoke me thinks.

Yeah, I'm with it Nic...   Just commenting on the color mate.... Color blind....

[PeWe]

I was close to write about the color too. Oil smells different too.

Constant oil or only when driving the bike on higher rev,  decelerate with throttle and give a little bit more throttle. The smoke usually appear now, oil pass via the valve guides/seals.

Constant smoke when accelerate is the oil via the bores, bad rings...right?

I had a car once that caused heavy mist on the road.

[70CB750]

I had a car once that caused heavy mist on the road.

Didn't we all? 

[PeWe]

It was fun to make mist with the pedal. I became really worried when looking in the mirrors..2+2-lane road where cars drove 100-120km/h had very limited sight... An old Volvo that consumed 3-4 liter oil on a 350km trip :-) I had some extra bottles in the trunk when the oil lamp told me to refill.

[Bailgang]

My engine is now blowing black smoke on first start up with 2500Ks on the rebuild so I'm thinking the guides and or seals are kaput now. Have engine out and will inspect shortly and post results. While I have the engine out it is getting cheap 836 pistons and new trans bearings, starter brushes and oil pump stopper valve n spring.
Putting Yamiya valves in this time. I used a block n tackle and strapping with a U shaped hook to get the engine out, it was so easy, had no help and it was a dream to get out. Took 3 1/2 hrs from start to engine out.

I'm interested to see what the valves and guides look like once you have it apart. I put the cycleX valves in my 77 F2 with new guides and so far no smoke and it runs fantastic, I don't quite have 2k miles on it yet but close to it.

[Nic]

Ok, I've had a look at the head, the inlet valves have shiny stems now but the guides seem good, the exhaust valves still have the coating on the stems but the guides are worn a lot.  I would have expected the opposite myself. Seats and seals all look good. I'm thinking now that maybe the machine shop did a flunky job of the valve to guide clearances, at the time I put the valves in my mind was elsewhere and I didn't even give the valves a wiggle, shaking head now. I'm just too damn trusting 
So not the disaster I was anticipating but still need new exhaust guides and I have a full set of Yamiya valves.
On a side note, it appears cylinder 4 was running hot, air leak at rubber intake?
After 2500Ks the hone marks are still visible. Next time I'm gonna do the flog it run in instead of babying it. Oh and just a note on the head gasket, geez I couldn't believe the lack of torque on the head nuts. The 4 x 6mm bolts under the pucks were doing nothing. The two 6mm bolts either side in the middle of the head outside of the cover weren't much better and the 8mm nuts wouldn't have had 5lb on em. I had no leaks at 2500Ks but this time when I get the bike running ( I have Frank's frame kit) I'll be pulling the cam and cam blocks out and pulling up the pucks and re torquing the whole damn thing and hope it stays torqued some time before 500Ks I reckon.
I have Ape HD studs but they look to be longer than the stock ones, I think I'll just go with the stock ones, I reckon 18ft lbs should be plenty now that I've seen this thing with all the head nuts n bolts pritt near bloody loose.
In the end, what's the verdict on the superflow valves? Dunno!

[MRieck]

The exhaust guides wear more than the intake guides as they are subject to a lot of heat.....it is very common (with stock cams and springs).
Honing the guides for proper clearance is far superior to reaming....no arguments there. Honing allows more control on increasing the ID and leaves a better, oil retentive finish.
I replace those 4, 6mm bolts with 6 cylinder CBX exhaust studs and smooth bottom 6mm flange nuts.
What is the stem OD on both the intake and exhaust valves? Before saying they completely suck I'd like to see measurement taken with a mic. All coatings (and materials) wear it is a matter of how fast. DLC is very tough but it is very expensive....how many people want to pay an additional 20.00 or 25.00 per valve?