TI Valves

65ShelbyClone said:
The problem isn't the valves being titanium, it's the cam profile. CRFs are notoriously hard on their valves. The ones that don't break will recede instead. Yamaha didn't have either problem with their YZF's titanium valves. The YZFs are widely regarded as being more durable, more powerful, and lower maintenance than the Hondas. Why Hondas are more popular baffles me.
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Are the back-side of the cam profiles the same with the Honda and Yamaha?
 
arc100 said:
Are the back-side of the cam profiles the same with the Honda and Yamaha?
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Without actually knowing, I don't see how they could be. Using three smaller intake valves in lieu of two larger ones changes the valvetrain dynamics substantially. It's also worth mentioning that the YZ450F engine went to a 4v arrangement in 2010.
 
Something I heard from a Motorcross builder that was interesting was that the process to make new Ti valves has changed some from the old way. He says that the stem is attached to the head of the valve by way of a fusion spin welding Technic that has been further developed into a better valve than in the past. IDK as I was surprised that they were made that way to begin with.
 
That's how two-piece steel valves are made and it's done as a cost-cutting measure. The best Ti valves are still one-piece forgings.
 
Thanks, It's nice to learn more every day. He did talk and even point to a new bike that was sitting there by a bucket full of used ti valves. Is there a way to identify a two piece from a forged Ti valve?
 
If I remember right, on the old forum before it crahsed there was a guy with a screen name pro69nova I think that worked for a valve company. I want to say SI valve was the company. I've slept and drank beer since then so someone will prolly correct me.

In reference to the yamaha dirtbikes not being used, I think it was 2 things. I've heard the way the engine is positioned in the chassis doesn't let the yamaha handle as well as the other brands(Stewart even struggled on it). Which leads to the monkey see monkey do, since he struggled, Kawi's Suzuki and Honda did better and what wins, sells. After this weekend KTM will sell :)
 
You got the details right; pro69nova is with SI Valves. Haven't seen him around any of the forums for at least six months, though. I think a bunch of the drag racers moved talks to the social networks.
 
PD Power said:
I think CRS and I, and most certainly Roadkill can handle the seat pressure inquiries.
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I can help with ALL inquiries, being that I did what he is trying to do.

And use the iron seats instead of copper, they last a whole lot longer with a OHV motor that requires more spring pressure than a flathead.
 
We are not "trying" to do anything.
We have accomplished these things, and understand how they work......a multitude of times, in an enormous variety of circumstances.
Have gone from 525lbs of seat pressure on blown fuelers, to 12 lbs seat pressure on purple restrictor plate fheads.
The seats for ti valves are berrillium, by the way.
"Copper beryllium alloys are used for their high strength and good electrical and thermal conductivities. There are two groups of copper beryllium alloys..."...etc.
 
The question is about a Animal billet head I believe. I have pictures, titanium valve specs, seat dimensions, and different stems sizes.

He will hit me up if needed, I'm here to help.
 
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