What are the disadvantages to titanium intake and exhaust valves? I know the advantage would be decreased weight. Is this a racing only application or could they be used in a street/strip application.

 

Shane I had a set of titanium valves for my heads and they sure were light but I chickened out and sold them. I think Monty is either using them or knows about them so maybe he will chim in. I got my set for $100 CDN after being used on a dyno engine for testing. They were a little discolored but other then that perfect condition.
I ended up going with severe duty stainless valves for my blower. I did spend alot of money on the guides. I wanted the very best regardless of price and had them honed to .001 clearance on the intakes and .0015 on the exhaust.
I always check anyones work after I get it from the shop, I trust no one and other then one guide which was .002 all guides were perfect.

 

they're strong as hell too, maybe if you had a ton of boost or really high CR? i dont think it would really be worth it in a street engine, but i dont really know what im talking about

 

I run Ti intake valves and used to also run Ti exhaust valves( I switched to Inconel exhaust valves when I added the turbos). The benefit of Ti valves is that they are lighter than stainless, and typically will extend your rpm range a couple hundred rpm. For the most part, they aren't really needed for steet engines unless you're building a 7000+ rpm engine. The only real disadvantage is the additional cost.

 

Just curious, wouldn't they also cause less wear on the cam lobes and lifter springs due to the weight reduction?


[Modified by Clink69, 8:06 PM 2/22/2003]

 

Ti vales are great in that they will accelerate/decelerate easier than a stainless valve. This will allow you to run a more aggressive cam profile. They are easier on valve springs. (valve weight is not a factor on lobe wear) and will increase your safe useable RPM range by 200 - 300 RPM. Anything done to lower reciprocating mass will help make the motor more throttle responsive.

Titanium is susceptible to high heat cycling / thermal fatigue. Repeated high heat cycling will make them brittle. For that reason we never use TI exhaust valve for more than 1 freshening cycle (800-1000 laps / 400-500 miles) before replacing them. Intake valve don't show this problem and will easily go 2 to 3 seasons before needing to be replaced.


Ti valve have a very low dollar/performance gain ratio. For that reason they are one of the last upgrades to do on a motor. We only sell them on high end motors that have had just about every thing else done that can improve performance and still need that last little bit of power/drivability.

If you have a big budget on your project go with them other wise the money may be spent better elsewhere.



[Modified by Pete79L82, 7:30 AM 2/23/2003]