Titanium valves- yes or no?

[Squid4life]

Shooting for 8.xx's sooner or later and wonder if I should use the titanium valves on my heads or not. I have 2 sets of heads, one set I plan to sell after replacing the valves and fixing a few little issues. (they have a few bent valves) Another set I have that I plan to run, also have Titanium valves. One of the guys at the shop said to replace them with stainless if I were to spend the $ on valves.

I have read a few places TI valves are not the best for turbo application, mainly on the exhaust. Should I throw my TI valves in the other heads to sell, and buy all new stainless for my heads? Should I run the TI intakes in my heads and buy stainless exhaust valves for my heads?

What is the general consensus with TI?

 

[J-B Racing]

I noticed that with SS Valves no matter how good they are, the Exhaust Valves always tend to warp a little. I just bought a complete S2 and the BMS Heads have TI Valves, the car it was in ran 8.50's and I took the Valves out and they pretty straight. I am kind of happy they are there..

Joe

 

[Squid4life]

Thanks for the reply Joe, much appreciated.

This is the thread that I got the idea of whether I should be running them or not. Donnie is running alcohol, which burns cooler, and I will be running E85 most of the time, unless I really choose to push it and will run race gas:

http://www.turbobuick.com/forums/threads/titanium-exh-valves-in-turbo-motor.366933/

 

[Squid4life]

Another good one:
http://www.turbobuick.com/forums/threads/titanium-valve-question.314351/#post-2467120


Another thing that I feel is important to note:

This car will be street driven too. Plan to drive it to work once a week or so, to cruise nights, etc. It will see city and highway driving. Just wanted to throw that out in case it affects someones opinion on valves.

 

[Mike E]

TI is fine on the intake side. How many rpm do you plan to turn the motor? The only advantage to TI is reduced weight. Stainless, and moreso Inconel, handle heat much better and cost less. If your not turning more than 7000 rpm why waste the money on the exhaust side. If your buying new, get Ferrea superalloy.

 

[Squid4life]

TI is fine on the intake side. How many rpm do you plan to turn the motor? The only advantage to TI is reduced weight. Stainless, and moreso Inconel, handle heat much better and cost less. If your not turning more than 7000 rpm why waste the money on the exhaust side. If your buying new, get Ferrea superalloy.

Good info, thanks brother. I am not sure what RPM I will be turning it, I still need to get a cam since the one in the new car was broken. Once I get a cam I will figure spring pressures and RPM I imagine. If I were to guess, the motor would probably make power to 7,300-7,600 but unless absolutely necessary I would keep it at or below 7,000. Going to try to make this thing last.

I may just throw the TI valves in the "sell" heads and buy new good ones for my heads. Would probably be smarter to buy my heads the good valves then to spend money on new stainless on the heads being sold. I am a little scared to price Inconel or super alloy...

 

[Alky V6]

I would not use Ti on a car that might be driven on the street. There is a life span associated with Ti valves. That's why I cringe when people are thinking of using used Ti valves. It's like using used roller lifters. There's no way of knowing what stresses they've already been through.
Some Ti valves have an anti-galling coating that can be worn through over time. When this coating is worn through, galling can occur between the guide and the valve.
If you plan on running gasoline at high loads, stay away from the Ti for the exhaust valve.
If you run Ti on the exhaust side, limit EGT to a high of 1400 degrees F.

 

[J-B Racing]

After looking over my Heads, my Exhaust Valves are SS and not Ti. So the people who assembled them in the past must of thought of the heat....
Good Point Don.

 

[Mike E]

... I am a little scared to price Inconel or super alloy...

They are cheaper than good TI valves. Not much more than a regular stainless valve.

If you want it to live with street driving, keep the lift and rpm down and spend money on good valve springs.

 

[750H.P.V6]

I would not use Ti on a car that might be driven on the street. There is a life span associated with Ti valves. That's why I cringe when people are thinking of using used Ti valves. It's like using used roller lifters. There's no way of knowing what stresses they've already been through.
Some Ti valves have an anti-galling coating that can be worn through over time. When this coating is worn through, galling can occur between the guide and the valve.
If you plan on running gasoline at high loads, stay away from the Ti for the exhaust valve.
If you run Ti on the exhaust side, limit EGT to a high of 1400 degrees F.

Don,

I know we're talking about exhaust valves for the most part but you wouldn't run a Ti intake valve in a street car either? You know factory LS7's come with Ti intake valves and a 100K mile warranty right?

Neal

 

[Mac in SD]

Back when I was putting my S2 together in 99-00, the conventional wisdom was to stay away from Ti valves for ANY street engine. Only AFTER I spent some significant coin on a set of stainless Ferrea's, did the word come from Kenny D. that, at relatively low spring pressures like I was running with a HR cam, then Ti valves were no problem. I guess it all depends on spring pressure and expected RPM.
Neal's got a great point: they're stock in the LS7's.

 

[Alky V6]

Don,

I know we're talking about exhaust valves for the most part but you wouldn't run a Ti intake valve in a street car either? You know factory LS7's come with Ti intake valves and a 100K mile warranty right?

Neal

I'm not familiar with the technology of the LS7. Maybe advances in surface treatment or Ti alloys has improved. Or, maybe guide material or treatment of the guide bore has improved for Ti combatability. I have no idea. I'm only passing on what the company that supplied my valves told me and what I've experienced. I have had to replace a few valves and guides that developed galling between the valve stem and guide.
Do you know what sort of valve spring pressures they're using on the LS7?

 

[Alky V6]

Back when I was putting my S2 together in 99-00, the conventional wisdom was to stay away from Ti valves for ANY street engine. Only AFTER I spent some significant coin on a set of stainless Ferrea's, did the word come from Kenny D. that, at relatively low spring pressures like I was running with a HR cam, then Ti valves were no problem. I guess it all depends on spring pressure and expected RPM.
Neal's got a great point: they're stock in the LS7's.

That's what I was thinking when I was replying to Neal. A production engine, I would think, is not going to see the sort of lift and spring pressures that would be used in a strictly competition engine.

 

[750H.P.V6]

Do you know what sort of valve spring pressures they're using on the LS7?

Don,

Here's what I found for spring pressures: 101# closed and 310# open with a valve lift of .591". I know these wouldn't be on par with the kinds of pressure you'd see running a solid roller cam but it is an OEM cam grind.

Neal

 

[Alky V6]

Don,

Here's what I found for spring pressures: 101# closed and 310# open with a valve lift of .591". I know these wouldn't be on par with the kinds of pressure you'd see running a solid roller cam but it is an OEM cam grind.

Neal

Do you know what sort of rpm limits the production LS7 has?
A better question would be, what rpm does the production cam pull to?

 

[Alky V6]

Another thing to consider. Alcohol fuels lack the upper cylinder lubrication quality that gasoline helps greatly with. At least I know that is very true with methanol. Not sure about E85. I do use Klotz upper cylinder lube additive which helps greatly with the corrosion factor associated with methanol, but I'm not sure how much it helps valve stem lubrication. Especially in a Ti valve/valve guide situation.

My next engine teardown should be interesting. When I first put this engine together, I didn't use upper cylinder lube with the methanol. I had the valve stem wear with that earliest build.
This latest engine build, about 3 years old now, has been run religiously with upper cylinder lube, and these valves have many cycles on them, considering that my supplier recommended changing out the valves every racing season in a competition engine. The valves are going to be changed out regardless, but it will be interesting to see what the valve and guide wear looks like.

 

[750H.P.V6]

Do you know what sort of rpm limits the production LS7 has?
A better question would be, what rpm does the production cam pull to?

Don,

The factory redline on the LS7 is 7000RPM. Here are the cam specs on the cam:


.050 Cam degreed at
210 Intake Duration
230 Exhaust Duration
116 Intake Centerline
120 Lobe Separation Angle
.330 Intake Lobe Lift
.594 Intake Valve Lift
.328 Exhaust Lobe Lift
.590 Exhaust Valve Lift

 

[Alky V6]

Don,

The factory redline on the LS7 is 7000RPM. Here are the cam specs on the cam:


.050 Cam degreed at
210 Intake Duration
230 Exhaust Duration
116 Intake Centerline
120 Lobe Separation Angle
.330 Intake Lobe Lift
.594 Intake Valve Lift
.328 Exhaust Lobe Lift
.590 Exhaust Valve Lift

I think if someone were to try using Ti valves for the street, it would be worthwhile to study the technology their using in that engine. It may be hard to get information on the metallurgy, treatments and/or coatings of the components, though. Do you have any specific information about any of the components being used, Neal? Such as valve alloy, coatings, treatments, valve guide material and coatings, if any. Valve seat material. Valve tip treatment.
edit: Valve seal design and recommended oil type, too.

 

[750H.P.V6]

Don here's what I've been able to gather so far. The valves themselves come from Del West. I'm not sure if they are Chromium nitrided or not. The LS7 uses a lash cap to prevent valve tip wear. The valve seats are sintered iron not beryllium copper typically associated with Ti valves. I believe the guide material is manganese bronze but I haven't been able to verify that.

Neal

 

[Alky V6]

Don here's what I've been able to gather so far. The valves themselves come from Del West. I'm not sure if they are Chromium nitrided or not. The LS7 uses a lash cap to prevent valve tip wear. The valve seats are sintered iron not beryllium copper typically associated with Ti valves. I believe the guide material is manganese bronze but I haven't been able to verify that.

Neal

I did a quick search of some LS7 valvetrain technology and it looks like there are some issues. More with the exhaust side sodium filled valve than the Ti intake.