Strength of ls7 titanium rods?
11 Second Club
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From: Albuquerque NM - The Land of 8000ft DA
Originally Posted by Katech
Days of spin testing
Countless dyno time
DOE?
Countless dyno time
DOE?
You guys count how many cycles (compressive and tensile) you put the rods through?
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Titanium has excellent fatigue properties, this is why titanium is one of the best spring materials you can find.
I cannot comment about the rod strength becasue it depends more on geometry, forging process, and many other design features to give an ultimate strength rating.
TITANIUM is NOT the strongest material, however, where titanium really shines is in the "strength to weight" ratio.
I cannot comment about the rod strength becasue it depends more on geometry, forging process, and many other design features to give an ultimate strength rating.
TITANIUM is NOT the strongest material, however, where titanium really shines is in the "strength to weight" ratio.
Here's a quick one on piston speed:
Lets take the 427 LS7
It has a 4 inch stroke and redlines at 7000 rpm, its piston speed is 4675 FPM (Feet Per Minute)
Now lets take a 600 cc Yamaha that redlines at 17,500. This has a piston speed of 4870 (due to their tiny 1.67 inch stroke).
Now lets take my well built LS6
With a stock bore and stroke it doesnt even come close to matching the LS7 in terms of piston speed even given its 7500 redline.
Piston speed say allot about how well designed a motor is and how much stress is being placed on it. High piston speeds and large pistons as in the LS7 is a dangerous combo.
(Stroke x RPM)6 =Mean Piston Speed
One thing that amazes me (it dont take much) is that a piston must stop and reverse directions at the top and bottom of every stroke.
One more thing, having spent 21 years of my life in the AF working with exotic metals like Ti I can tell you it is an amazing stuff. And not all titanium is created equal, there are many varieties.
Lets take the 427 LS7
It has a 4 inch stroke and redlines at 7000 rpm, its piston speed is 4675 FPM (Feet Per Minute)
Now lets take a 600 cc Yamaha that redlines at 17,500. This has a piston speed of 4870 (due to their tiny 1.67 inch stroke).
Now lets take my well built LS6
With a stock bore and stroke it doesnt even come close to matching the LS7 in terms of piston speed even given its 7500 redline.
Piston speed say allot about how well designed a motor is and how much stress is being placed on it. High piston speeds and large pistons as in the LS7 is a dangerous combo.
(Stroke x RPM)6 =Mean Piston Speed
One thing that amazes me (it dont take much) is that a piston must stop and reverse directions at the top and bottom of every stroke.
One more thing, having spent 21 years of my life in the AF working with exotic metals like Ti I can tell you it is an amazing stuff. And not all titanium is created equal, there are many varieties.
Originally Posted by 11 Bravo
The way I know about Ti is through cycling. If you compare a, say, ti road race frame to an aluminum one, they are both super light, the aluminum is alot stiffer but it breaks more easily. The ti frame is more comfortable because it flexes more. But it will last forever. And steel flexes like ti, but it is heavier and cracks a little easier. Of course ti is the most expensive. I'm not comparing bikes with rods lol, but just the characteristics of the different metals used. In no way is ti brittle.
There are many types of Ti that are very brittle. Some you can not even bend 45 degrees without snapping or causing stress fractures.
Its also very, very abrasive and is not well suited for things like wrist pins unless specialy coated.
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what about stock LS1/2/6 rods?? do people offten break them, i thought it was more the pistons that let go?? has anyone seen a bent or broke one (do caused by the piston letting go and causing the damage)? also anyone snapped/bent a LS7 rod yet??
Thanks Chris.
Thanks Chris.
Teching In
Joined: Nov 2001
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From: NY
Originally Posted by Stang's Bane
Prostock has even higher piston speed than nascar. With a much larger piston to boot.
I think prostocks are turning what 9900 rpm with 500 inches. 
Also prostocks must index their spark plugs with the electrode to the top of the chamber so the piston doesn't contact it. I think they run a 16 to 1 compression ratio.one more cool fact. GE's new high bypass turbo fan (jet engine) can vacuum out all of the air in madison square garden in FOUR seconds (taken from their website)
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Originally Posted by chuntington101
what about stock LS1/2/6 rods?? do people offten break them, i thought it was more the pistons that let go?? has anyone seen a bent or broke one (do caused by the piston letting go and causing the damage)? also anyone snapped/bent a LS7 rod yet??
Thanks Chris.
Thanks Chris.
GM did their homework on this engine design.
Originally Posted by 11 Bravo
Such as?
I havent been in the field for awhile but TI came up with a Beta 3V of Ti.
I once tried to make a motorcycle exhaust hanger out of some .080 Ti, I cant tell you how many pieces I broke trying to bend the damn stuff. Plus its very flexible in this sheet form. You could bend it about 20-30 degrees in a brake and the metal would go back to its normal shape, bent any further and it would crack.I finally ended up heating up to almost cherry red (not great for its properties and weakens the metal) then bending it.
It ended up breaking about 9 months later
But it looked cool as hell while it was on! 
Teching In
Joined: Aug 2006
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From: Carlsbad,Ca.
Originally Posted by sawedoff
Heck even the Mahle pistons in these engines are top notch for a cast piece, for most people to use.
GM did their homework on this engine design.
GM did their homework on this engine design.
Teching In
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From: Carlsbad,Ca.
Originally Posted by 2scoot
I once tried to make a motorcycle exhaust hanger out of some .080 Ti, I cant tell you how many pieces I broke trying to bend the damn stuff. Plus its very flexible in this sheet form. You could bend it about 20-30 degrees in a brake and the metal would go back to its normal shape, bent any further and it would crack.I finally ended up heating up to almost cherry red (not great for its properties and weakens the metal) then bending it.
It ended up breaking about 9 months later But it looked cool as hell while it was on!
It ended up breaking about 9 months later
But it looked cool as hell while it was on!
Originally Posted by NORTY
Lockhart-Phillips has 'em for $65ea. Got one on my Ninja.
I had a GSXR1000 awhile back and I chaged almost every bolt to either Ti or aluminum, probably cost me in excess of 2k....and guess what, I didnt notice a thing but man it looked cool. Peace!
Staging Lane
Joined: Aug 2006
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From: under the hood
Originally Posted by two step
Very true! but prostocks use Aluminium rods that must be changed every 40 passes or less due to rod stretch.. So thats new rods every 10 miles or so
That's a piston speed in the 6200+ zone. 
On The Tree
Joined: Apr 2005
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Originally Posted by Quickin
Just a cheezy marketing tool from GM. When I first heard of it I laughed. Titanium parts in a production car engine 
Go get some aftermarket forged rods from a good company that are good to 2,000 hp.
.
Go get some aftermarket forged rods from a good company that are good to 2,000 hp.
.
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From: Ft. Lauderdale, FL, USA
Originally Posted by Bowtiejoni
Ever heard about FERRARI ? If they use em , i am sure every backyard mechanic can too..
At the power levels and rpm's the LS7 was designed for they serve ZERO purpose.Ferraris don't need'em either.
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Last edited by Quickin; Aug 26, 2006 at 06:22 PM.
Banned
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From: North Bay, CA
I was under the impression that the Ti LS7 rods are powdered metal (sintered cracked cap)...which would mean that they may be very strong, but at the same time very brittle, and that it really comes down to the quality of the tune for how much power they can handle - too much timing - hense cylinder pressure at the wrong time and they will snap.
Cannot be compared in strength to a machined Ti rod of the right alloy.
Cannot be compared in strength to a machined Ti rod of the right alloy.
Originally Posted by Katech
Does anybody know the numbers? (stroke) NASCAR and F1
Originally Posted by 2scoot
There are many types of Ti that are very brittle. Some you can not even bend 45 degrees without snapping or causing stress fractures.
Its also very, very abrasive and is not well suited for things like wrist pins unless specialy coated.
Its also very, very abrasive and is not well suited for things like wrist pins unless specialy coated.
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From: Ft. Lauderdale, FL, USA
Originally Posted by Quick1998Z28
Sorry but it's not a marketing ploy.
Do you think if GM had used top quality steel forged rods the engine would have lost 50 hp? There would be no difference and the rods would be BETTER and handle a shitload more power and torque.
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Last edited by Quickin; Aug 28, 2006 at 12:10 AM.