Hey everyone ,last night I read an article on the acura nsx and it claimed the car had titanium parts in the engine that dramaticaly reduce friction and weigh close to nothing ??? (I think it was the piston rods ).Then I thought Why have I never heard of titanium Stock or aftermarket part for the corvette , Besides the almighty zo6s titanium exaust!!!Any thing else out there To increase the performance made of this light weight metal.

 

Don't know why you haven't heard about it (but probably because titanium parts are very expensive), but titanium rods, valves and main caps have been around in the aftermarket for over 20 years, and the current Z06 LS7 engine actually has, for the first time from GM, titanium connecting rods and intake valves in the engine.

 

WE WERE USING TITANIUM ENGINE PARTS IN OUR RACE ENGINES IN THE 70'S.



BILL SR

 

and even before that. Valves, retainers, bell housings {Blast shields}. nuts and bolts.

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ZR-1, Z06 rods are titanium I believe.

 

Titanium is strong and lightweight, but seems to be brittle. The C6 Z06's, like everyone else are doing forced induction, but some are having trouble breaking rods from what I hear. I'm more comfortable with the forged H-beams in my motor.

 

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and make for great valves,

I dont know where the breaking information came from. Blast shields are made of titanium if you can afford it, and one of the most important safty items on a race car

 

I have always been told that Titanium can't handle the heat on the exhaust side of high performance forced induction motors and Inconel or super alloy should be run. Also if you look at Katech's $32k lightly blown LS7, why would they go to the trouble of changing out the rods from titanium to forged steel if it can handle more load? Their engine only makes 750hp. I guess the rods GM is using are more focused on weight than strength because nobody I know is using the GM titanium rods in any significant forced induction build. Not Lingenfelter, not Katech. My SFI scatter proof bell housing was made of thick steel. I've seen Kevlar too. Never seen titanium blast shields but I never raced in Top Fuel either, so maybe that's why I haven't been exposed to it. I have also been told that titanium scratches really easily and it will eventually destroy the rod if it's not polished and they have to be coated because of their porosity. I know titanium has to be mixed with other metals, so maybe it's just certain alloys that have these problems. Or maybe I listen to people I respect too much.

 

Excerpts from Wiki.
titanium loses strength when heated above 430 °C (800 °F)
It is fairly hard although not as hard as some grades of heat-treated steel, non-magnetic and a poor conductor of heat and electricity. Machining requires precautions, as the material will soften and gall if sharp tools and proper cooling methods are not used. Like those made from steel, titanium structures have a fatigue limit which guarantees longevity in some applications.

 

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I use and so does many racers, titanium valves that are subjected to exhaust fire which you must agree is super hot.

Ok, another question, isn`t the new 600 HP Vette engines using titanium rods. It seems to me that In read just that in one of the previews.

 

Yes, both Z06s and ZR1s use titanium rods and valves.

Formula 1 engines have been using them for years since they have the budgets for them and I bet they would have quit using them many years ago if they broke regularly.

 

Yeah the C6 Z's both use titanium rods, but Lingenfelter, Katech and other companies are taking them out when adding the extra cylinder pressure. Like I said but probably didn't say well enough. I guess GM went with just enough of a titanium rod to satisfy the design, but not enough to handle much more power.
Are you running large amounts of nitrous or any type of high boost forced induction? As you know those will raise the combustion and exhaust temps to much higher levels than naturally aspirated. I have been told that Inconel and super alloy is better able to handle the high temps. Anyways, just a few ideas of mine.

 

If high boost means supercharging, then National drag racing Champion and record holder in several supercharged Gas and Nitro classes would be me...

 

Well then titanium valves must be the ticket!!


I still say GM must have chinched out on their titanium rods for everyone to be yanking them out in high hp applications.

 

I think Titanium valves for an LS series engine run around $1000. Something like Manley race valves (what I went with) were more like $270. If money was no object I'm sure it would make sense but the cost to performance is not really there.

 

Ti doesn't conduct heat very well, so they are not good in high heat applications (like an exhaust valve). Usually in a race engine, Be-Cu (beryllium copper) seats are used for their superior thermal conductivity to evacuate the heat from the Ti valve. GM must have worked something out in their sintered metal combos to provide something similar for the LS7, or there really isn't that much heat to be an issue.

Speaking of, I am under the impression the LS7 rods are sintered metal, like in the other LSx engines, but with a high Ti content to consider them "titanium rods". Not exactly what you would find in a rod from, say, GRP.