Straight talk on valves. Builder vs Builder, SS vs Ti

[ace402]

Alright, so I've checked a few different forums and found a few different answers. I'm trying to come up with a general concensus as to the pro's and con's of each. So here are the questions:

What are the best valves to run and who are the best head builders?

It seems that a lot of people on TT rave about Ron Hamp and his valves/machine work. If you go on DRN they rave about Kibblewhites and Eric Gorr. That makes sense, they both moderate on their respective forums, it would make sense to be promoted on them.

Some people say stick with Ti valves because they're cheaper and last just as long if you keep your air filter clean. Others say stick with SS but use Faction valves because they're cheaper than Kibblewhites.

Sorry if this seems jumbled. But again, What's the STRAIGHT talk on these issues?

Thanks

 

[_JOE_]

It all depends on what the application is.

 

[ace402]

motocross

 

[_JOE_]

It's very hard to generalize what is "better". There are a ton of factors. Each material has it's strengths and weaknesses. The Ti valves are lighter and stay under control at extremely high RPM better than SS. Ti are much more sensitive to dirt. I have heard but never witnessed increased cam bearing wear with SS because of the additional spring load on the cam.

I would say if you run it hard at the track and use good maintenance practices Ti would be best. If you tend to keep it in the midrange more and don't stick to a tight maintenance schedule you might be better off with SS.

 

[_JOE_]

I also beleive that the manufacturer spent some time testing to come up with the design they used. Everyone always cries about the CRF250s eating valves. People saying they had 20 or 30 hours on them and they zeroed out. I have to think there was a reason they failed so quickly. All it takes is a few specs of dirt to ruin the coating on the valve. I found a buildup of dirt in the carb above the slide that was being sucked in through the breathers and down through the hotstart/choke. About 8 hours ago(at 60 hours), I replaced the piston and valve springs and 1 valve was out of spec by .0005. It had had tightened .0025 in 6 hours and everyone said to get ready to put valves in. So I did a ton of research and settled on OEM parts and seat cuting by a good reputable local guy. That valve hasn't budged since I cleaned out the gunk in the carb and put filters in the lines. I went with OEM because the cost was good. I paid 44 bucks a pop for the valves and 6 bucks each for springs, plus seals at 12 or so. I just looked and the total was 119. I'll have 75 bucks on labor because I'll pull it apart myself. Budget and confidence in the OEM parts pretty much made the decision for me.

 

[whenfoxforks-ruled]

Where on earth did you hear ti valves are cheaper? Somewhere over 300 dollars! Faction?, 105 dollars. And Kibbles, 40 dollars. Pro circuit has just the head for you, stage 3 for 3 grand! I do not know anything about Mr. Hamp. He has access to the same valve market, he chooses faction? Never heard of any performance gains, never heard any issues with kibbles longevity?

 

[Jaybird]

It will take a pretty clean air filter to make the Ti's last as long as SS.

 

[_JOE_]

It will take a pretty clean air filter to make the Ti's last as long as SS.

Indeed. Or a really dirty one to make SS wear as fast as Ti.

 

[whenfoxforks-ruled]

Now I was under the impression that the stock honda intakes were ti-coated? Them expensive ones from pro circuit are the real mccoy. No known horsepower increase, in dirtbikes. Ti valves get set up differently than the SS. I do not believe there is anyway that the ti will come close to the SS life. And I am talking about the Kibbles. What do you think is the chances that 3,000 dollar head from pro circuit has beryllium valve seats? How else could they justify the outrageous price? Wonder how often the rebuild on them seats are? But all is for not without a quality porting, high compression and a decent cam? And, you do not want to rebuild it every 4~6 hours?

 

[Tom68]

If you run at the top of the rev range Titanium with good springs so the valve shuts without bouncing that way you'll get max horsepower. If you're running in the midrange run whatever you want.

 

[whenfoxforks-ruled]

If you run at the top of the rev range Titanium with good springs so the valve shuts without bouncing that way you'll get max horsepower. If you're running in the midrange run whatever you want.

Has anyone documented valve flutter with ss valves on a dirtbike? It is not a roadrace bike.

 

[SFO]

Application is a YZF?

Cut to the chase.
IMHO, valve train queries are design specific, not to mention peak goals.
This guy vs that guy is kinda redundant?
Some forums have moderation via the borg of the sales team header and some are modded by real professionals who care about technical reality?
This and that.
What do YOU want?, For what level rider? What do you want for a maintenance schedule?
Are you a troll?

 

[_JOE_]

Has anyone documented valve flutter with ss valves on a dirtbike? It is not a roadrace bike.

From what I understand the flutter comes from inadequate or fatigued springs. SS being at a disadvantage because of the weight, but Ti still being suseptible if run with fatigued springs. The nice thing about Ti (at least on my bike), is you can replace the springs for about 6 bucks a peice. The spring kit alone for Kibbles is 200 or more. I would think the springs would have a service life? Even if you only replaced them every 75 or so hours, you would still have more in springs than a complete intake valve job with stock parts. I guess I would need to have some personal experience with SS before I could make the investment. Too bad most people I know are going back to oil burners. :debil:

 

[whenfoxforks-ruled]

Here again, have you ever seen a fatigued spring on a dirtbike? All you have to do is measure the free length. Take Joe's bike, for kibbles: 120 for the valves, 210 for the springs and what not. Faction(wow, they have the black coating?) 130 valves and 265. CNC machined ti: 700( if they even set them all up with ti?) and 355 for the rest of the parts. OEM: 174 valves and 90 for the rest. The only kibble set up that I have seen wear out, was a bad seat to begin with. And that was over 50 hours on a 450. There are applications that supposedly ti shows dyno increase, not dirtbikes. The only advantage that I see, is they cup out and run crappy when they are shot, the ss merely fall off into the head. As far as I know the service is about the same, they are both good to the 3rd or 4th reshim. Everyone that I have met, and has a problem with Forward Motion, usually falls into the eye candy porting, or a c class guy figuring his issue is his motor. The 450 stock is too fast for mx, and is already shut down in ax. The 250, you must have some deep pockets to go messing with an engine that puts the rering at 15 hours stock!