Thanks guys, I did look at old posts prior but found no answers to my specifics but I may have glanced too fast at some of it.
I have a friend checking on ferrea valves for me, but also sounds like maybe KW stainless may be a good way to go.
Regardless which valve I get, any good machinist worth being called a machinist can fit them to my head, and any machinist who screws it up needs to find a new line of work.


MrHP funnny you should mention the quality of the stock valves, I mentioned the cupping because I have read so much and been told so much about them on here, but fact is mine have not cupped to my knowledge.
I adjusted my valves at 100 hours with the stock shim setup - the intakes were only off a couple thou - and shortly after that I installed big cams and heavy dual springs with shimunder kit from Web, and its been over 400 hours of motor time since then and I have not had to touch them. I set gap at .008" and check the gap every 6 months, and they are all 4 still in.

Maybe they cupped before I installed my spring kit, I did not look at them closely because at the time it was of no concern, but they sure haven't done any cupping since. perhaps the cupping I've heard so much about is a product of over-reving on stock springs with aftermarlet cdi's, causing valves to slam shut from coming off the cam lobe at high rpm?



Okay, furthermore for more curiosity, how about titanium valves, pros and cons? I mean I think I know the pros, but aren't there downsides other than cost for some applications? This bike will remain a trail/dune bike, it is not just for racing..

 

once you start doing custom valve jobs, if you ever bend a valve it can be a hassle to replace. you're stuck with the supplier who did the work originally. if you're keeping stock size valves with no porting around the seats just stay with stock valves.

I use stock valves. If I bend one, nothing needs to be done to get the new stock valve to seat properly.

 

I had KW in my bike and that is what broke. 3 year old valve springs and too high of rpms I hope is what did her in cause I put KW back in. Same cams same piston .080 clearance valves to piston.

 

Titanium valves are very soft and loose their seal quickly compared to a good stainless. Quickly means one race season to me. You cant run the stock type tripple groove locks. You need to run lash caps to keep the tips from mushrooming. Lashcap changes the valve length so you must figure how much shorter to order the valve. Lashcap also sticks up above the shim under retainer rim so you need custom retainers to allow the shims to be used. Tip length is critical so the lash cap doesnt hit the valve locks. Titanium valves should also be run with Berillium valve seats to make the valve seal last longer.

All this being said I love titanium valves because they make my race motors VERY happy. [img]i/expressions/face-icon-small-happy.gif[/img]

 

If the stock last longer, and are stronger what are the benefits to the titanium?

 

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If the stock last longer, and are stronger what are the benefits to the titanium?[/quote]

They are much lighter, it lets the high lift cams open and shut the valves faster!!

 

So when should you go to larger valves?? And what performance to the power band? Low Midrange Topend? D all above? Yes I do understand that if you do go with larger valves the head should be flowed also.

 

I would really like some of these $22 valves, but they told me they that part # for stock size valves was $57.82 each??
Help
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You would think so, but you wouldn't believe how many screw this up!! It's a never ending problem
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[quote]
Originally posted by: DragonDJ11
Ti valves are lighter, so they don't stretch as much as a heavy valve at high rpm - you can run less valve to piston clearance= more compression. And because they are lighter, they require less valve spring pressure to close them- this is always good since the motor has to fight spring pressure to turn rpm. That being said you can run more aggressive camshafts on the same spring pressure. Titanium shouldn't float as easy as a heavier valve or bounce on the valve seats when shutting.

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