While searching for exhaust valves for my motor, I came across these bad boys! Titanium exhaust valves for about the same price as a Ferrea Stainless Steel Valve. I love the opportunity to reduce any weight of the internal assemblies. As you can see in the pics, the stock exhaust valve weighs in a 46 grams. The Titanium piece comes in at only 28 grams!!! That more than makes up for the added weight of the (heavier than stock) titanium spring retainers on my valve spring package. (the stock aluminum retainers are super light!)

Sorry for the crappy camera phone shots. I don't know where my dSLR is.

 

VERY nice find.

 

Where did you find these? What brand and I'm assuming they're made specifically for the VQ?

 

They're Nismo valves.

 

Does titanium stand up to FI heat well? I always see them in high hp NA cars...

 

+1. My understanding was that the stronger steel parts will better withstand the stresses of FI. For the high temp exhaust valves, inconel is the material of choice (again based on reading from a while back).

EDIT: I recall now reading about a boosted Cobra that had Ti valves fail. According to the poster, Ti will fail under boost - just a question of time. That statement is generally true for all things so not that helpful but I do recall some mention of lowering the rpm limit down to 8k and going with SS or inconel.

Unless you're shooting for a high rpm monster, what's the point of the weight savings?

 

Hmmm... The weight savings sounds cool.

But what about for 1mm and 1.5mm oversize valves? Correct me if I'm wrong, but Nismo doesn't make oversize valves in titanium, do they? And what about inconel valves for the exhaust side? I know the Cosworth heads feature inconel exhaust valves.

I'd like to hear opinions from some of the shops on here. I'm curious to know what guys like Sam, Sharif, Julian, Jeremy, Hal, or IntenseFab think about these Nismo valves or titanium exhaust valves in general versus the Ferrea stainless steel ones or inconel valves.

Edit: I see Alberto and rcdash addressed the issue as I was writing this. I think I recall hearing or reading the same thing about titanium valves, now that you guys mentioned it. I'm still curious to see the shop guys weigh in on the subject.

 

12 exhaust valves with 18 grams savings each = .48 lbs worth of weight saved

...I'd rather go with a tried and true SS valve

 

I thought Ti had a really high melting point. Why would it fail under boost?

 

I want to go with the Ti valves because I am looking to have some pretty radical lobes cut from my cams. The duration (seat-to-seat) won't appear to be crazy just by looking at the numbers, but that doesn't tell you anything about the shape of the lobes. I am goingto have my cam grinder make some really fast lobes with as much lift and duration as possible within the shortest reasonable seat duration. Turbos don't like alot of overlap, and this will allow for more open-valve time for the given duration, compared to the off-the-shelf grinds currently available.

anyway, here's a brief article on performance valve alloys:

Performance Valve Alloys
Materials that may be used for performance valve applications include carbon steel alloys, stainless steels, high-strength nickel-chromium-iron alloys and titanium. The alloys that are most commonly used for performance engines include various high chromium stainless alloys for intake valves, and 21-4N (EV8) for exhaust valves.

Inconel® refers to a family of trademarked high-strength austenitic nickel-chromium-iron alloys (a "superalloy" material) that is sometimes used for exhaust valves because of its superior high temperature strength. Inconel is a nickel base alloy that is sometimes thought of as a super-stainless steel, with 15 to 16 percent chromium and 2.4 to 3.0 percent titanium. Inconel 751 is classified as an HEV3 alloy by SAE. This alloy has been used for the exhaust valves in some late model GM medium duty truck engines (to prevent premature valve erosion), but is not commonly used in performance exhaust valves. For most performance applications, the exhaust valve material of choice is 21-4N - or titanium.

Titanium is often viewed as the ultimate valve alloy material because of its lightness. Titanium is about 40 percent lighter than steel, making it a good alternative for high revving engines. Lighter valves also allow more radical cam profiles that open and close the valves more quickly for better off the line performance and low end torque. The durability of titanium is similar to that of stainless steel. But from a cost standpoint, titanium is way beyond any steel alloy. A single titanium valve may cost $70 to $90 or more. Spending $1,200 or more for a set of valves may be peanuts to a professional racer with deep pockets, but for the average guy that's a lot of money. Yet titanium valves are being used in many street performance engines as well as everything else. Titanium valves are even being used in some production motorcycle engines these days.

One supplier of titanium valves said they use the same alloy for both intake and exhaust valves: a 6242 alloy that contains 6 percent aluminum, 2 percent moly, 4 percent zirconium and 2 percent tin. But a different heat treatments are used for the intake valves and exhaust valves. The heat treatment is very important because it determines the ultimate strength and hardness of the metal.

Titanium valves are often coated with moly or another friction-reducing surface treatment to reduce the risk of stem galling. Coated valves are recommended for street performance applications, but may not be necessary in drag racing or circle track applications where engines are torn down and inspected frequently.

Titanium valves will work with stock valve guides and seats, but for the best results they should be used with copper beryllium seats (to improve heat transfer and cooling) and manganese or silicone bronze valve guides.

 

Does someone make bronze valve guides for our heads yet?

 

I think I recall seeing bronze valve guides listed in one of the GTM threads.

 

i believe ferrea and supertech make bronze valve guides.

 

another thing is titanium is more brittle than steel.

That makes me wonder if a situation happens where a SS valve might bend, maybe the titanium valve would actually break given enough time. I don't know, just thinking out loud

 

Damn. thought Ti was more flexible than Stainless...

 

I believe the stock valves are stainless with a coating on them.

A few weeks back, I asked forum members if anyone had any issues with stock exhaust valve failure. The response was a resounding "NO."

So, for a few hundred bucks to be able to pick up some Ti valves, I went for it.

 

stainless is far more maleable than Ti. there is no perfect alloy out there. some are better choices than others though.

Ferrea makes beautiful valves, but there valves for the VQ don't neck down to a smaller diameter at the location of the keeper. because of that design, you have to go with Ferrea's valve spring packages. I wanted to keep my choices more open. In fact, I am trying to get a set of beehives made for the VQ.....but I'm not sure if it is going to be cost effective.

 

this is completely off topic, but this thread reminds me of the one a few months ago when some dude came on here asking where he could get a titanium engine block made for his 350Z, lol

 

And I told him where he could but he never responded....

 

glad someone else remembered that ridiculous thread. I've been up studying for quite a while now (its 4am where i am) and my brain is a bit fried.

oh, and by the way, titanium is old news. what you need is a carbon fiber engine block