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Del West makes Corvette LS7 Ti valves

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As we all know, the new 505 HP Corvette LS7 engine comes with Ti intake valves (and rods!) directly from Chevy, but I wasn't really sure of who was manufacturing the valves. Turns out they're made by Del West who also makes the Ti Pro Circuit valves for CRF's and other bikes. I was aware that Del West supplies valves to F1 and NASCAR, but if Chevy is putting a 36,000 mile warranty on the LS7, they must have a lot of confidence in Del West durability. BTW, I found the pic in a pretty cool article over at SuperChevy. Just FYI...

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Interesting. I wouldnt think the rods would be durable enough to handle 500 hp... i know drag cars with titanium rods are only good for about 200 quarter mile runs.

Off topic, but has anyone seen the factionmx titanium wrist pin? Seems like a good idea, seeing how freaking heavy the steel oem wrist pin is. Only problem is it costs 175 dollars :applause:

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has anyone seen the factionmx titanium wrist pin?
Hadn't seen those. Seems like a good place to lose some weight though...

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Trust me, we are the most willing to work on lowering the price for consumers on our products. Ti and the necessary coating are only going up in price though, it is way over inflated due to the demand in the aerospace industry. Eventually it will come down and we will pass the savings along to our customers.....I just dont know how soon!

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Interesting...Any idea how much less the Ti weighs compared to the stocker? This could be a good application for one of the big bore kits where the piston is a few grams heavier. There was concern that the extra piston weight causes undo stress on the rod long term, not to mention slowing the revs. This could negate it. I would assume the BB wrist pin is also longer.?.

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Skip,

I think you are mistaken on one of your points. Del West is a manufacturer of High end Ti valves, but most of the PC stuff is made by Xceldyne :applause:

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Another point to be taken is that a Corvette isn't being run at 13,000 RPM's through a dirty dust track.

Any valve in a dirtbike will be outrun by a valve in a car anyday...

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Skip,

I think you are mistaken on one of your points. Del West is a manufacturer of High end Ti valves, but most of the PC stuff is made by Xceldyne :lol:

I was told 2 years ago during informal discussions with Del West employees that they were making the PC CRF valves at that time. Maybe things have changed since then, but there's still a Del West logo on the valve face pictured on the PC site. Seems Xceldyne wouldn't like that kind of advertising :applause:.

Another point to be taken is that a Corvette isn't being run at 13,000 RPM's through a dirty dust track.
True, but 36,000 miles of 7,000 RPM blasts with a 0.593" lift/211 degree (0.050") cam and 56 mm diameter intake valves isn't exactly a walk in the park either. Plus, I could be wrong, but I think the ZO6's are still using a dry paper air filter element which isn't nearly as good at filtering as an oil/foam filter like we use. If an LS7 eats a valve, the repair cost will probably run the price of a completely new CRF, and Chevy can't use the "sorry, no warranty" line :applause:.

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Skip,

I think you are mistaken on one of your points. Del West is a manufacturer of High end Ti valves, but most of the PC stuff is made by Xceldyne :applause:

This is not true, I just put new PC valves in 2 customers bikes (a Honda & a Kawasaki) and they're marked with the Del West logo right in the bottom of the valves along with the PC Logo.

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the procircuit ad in motocross action says delwest/procircuit ti valves with coating 350$..
That's not really a terrible retail price. When I spoke to Del West, I could get the same Ti valves at around $120 each in a volume purchase.

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do you think they are any better than oem??
I'm not positive, but I am pretty sure you can't get better Ti valves than those from Del West. It's my understanding that many lower cost Ti valves (probably including OEM CRF valves) are made as separate stem and valve head which are then joined together by friction welding or some similar process. It's also my understanding that Del West valves are CNC machined from one solid piece of Ti. The Del West approach should yield a mechanically stronger valve and is definitely a more expensive machining process. Additionally, I suspect that after working with F1, NASCAR and GM Del West has probably the most experience in high endurance Ti valve coatings. Do stock CRF applications benefit from the added quality of Del West valves with no other changes? Would Del West valves last more than twice as long as OEM valves to justify the added cost? I don't know; those are a couple of data points I haven't been able to nail down.

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my dad has a new vette and that thing is maintenance free. amazing considering the vast power that it has :applause: it is meant to be a daily driver : )

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all of the large titanium valves are friction welded by the majority of the companys producing them .The smaller valves are usally friction welded up in the upper part of the stem area where i have never seen one fail there are some companys working on forging dies to produce a complete machinable part from one forging .i have used all the major titanium valve manufactures for valves over the last 25 years @ least theones in the us and they are all good even if there a 2 peice valve.

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It's my understanding that many lower cost Ti valves (probably including OEM CRF valves) are made as separate stem and valve head which are then joined together by friction welding or some similar process.

That’s a common misconception. The O.E.M. valves are actually a one piece forging. The head of the valve is pounded into shape which disturbs the grain structure of the titanium. This causes a weak spot right where the stem transitions into the head of the valve (the are that is most likely to break). The O.E.M valves are typically made in China out of poor quality titanium.

The process of “welding” the stem to the head is called inertia welding. To my knowledge there are only 2 companies in the U.S. that are capable of building inertia welded valves. That would be Del West and Xceldyne. Two piece inertia welded valves are much stronger than a forged Ti valve. The majority of Nascar and Indy car teams use this type of valve and every Formula 1 team uses the 2 piece valves. It is a more expensive process but produces a stronger, more reliable valve that is less likely to fail due to stress. I do know that 100% of the Xceldyne valves are 2 piece inertia welded including the bike valves.

Do stock CRF applications benefit from the added quality of Del West valves with no other changes? Would Del West valves last more than twice as long as OEM valves to justify the added cost? I don't know; those are a couple of data points I haven't been able to nail down.

The coatings used on both the Xceldyne and Del West valves are much better than that of the O.E.M. valves but there are other factors. The typical coating thickness is around 4 microns. In inches that would be 0.00003937 thick. Once you wear through this coating the titanium is exposed and begins to wear fairly quick. The stock seat material in the Honda’s is extremely hard and this is a big part of the problem. Having the stock seats replaced with an Ampco 45 or Beryllium Copper material will increase the life of the valves. Not only are they softer but they remove much more heat from the valves which in turn will increase valve life.

To answer your question, replacing the stock valves with Xceldyne or Del West valves alone will probably not give a big increase in overall life but when combined with all of the other components such as quality seats and guides along with proper set up (machine work) valve life can be increased while the failure rate is significantly reduced. Maintenance, rider abuse, and other factors will play a role in the overall life as well.

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That’s a common misconception. The O.E.M. valves are actually a one piece forging. The head of the valve is pounded into shape which disturbs the grain structure of the titanium. This causes a weak spot right where the stem transitions into the head of the valve (the are that is most likely to break). The O.E.M valves are typically made in China out of poor quality titanium.
Thanks for clearing that up. I was hoping you'd chime in :applause:.

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Two piece inertia welded valves are much stronger than a forged Ti valve. The majority of Nascar and Indy car teams use this type of valve and every Formula 1 team uses the 2 piece valves. It is a more expensive process but produces a stronger, more reliable valve that is less likely to fail due to stress. I do know that 100% of the Xceldyne valves are 2 piece inertia welded including the bike valves.
I found an interesting patent document (assigned to Del West) for the inertial welded Ti valve process. It appears to indicate that inertial welded 2-piece Ti valves are less expensive than traditional Ti valves. What is the more expensive "traditional" Ti valve manufacturing process?

"A titanium engine valve is fabricated with discrete head and stem portions, preferably joined by inertia welding and/or diffusion bonding....... The resulting valve is, therefore, much less expensive to manufacture than a conventional titanium valve without sacrificing any mechanical characteristics in the portions of the valve subjected to high stress and temperature."

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