turn a ZL1 engine into a ZR1 engine ?

[kinpin]

Originally Posted by jessrayo

I don't think the titanium rods in the ZR1 are as strong as the forged rods in the ZL1. They are much lighter but I saw one ZR1 break one of those titanium rods with excessive engine breaking..... I don't think that would happen with a ZL1 even though the car weighs 1000 pounds more. More exotic and lighter does not necessarily mean stronger. It is hard to beat good old fashioned steel for strength.

Good point... I thought they where stronger

[hotlap]

Originally Posted by Sven59

I believe the main difference is the supercharger, the ZR1 runs a bigger one, but I believe displacement wise they are close. Maybe some internal upgrades to handle the additional boost.

LSA is 1.9L @ 8 PSI. LS9 is 2.3L @ 10.8 PSI. Same engine displacement

Originally Posted by jessrayo

I don't think the titanium rods in the ZR1 are as strong as the forged rods in the ZL1. They are much lighter but I saw one ZR1 break one of those titanium rods with excessive engine breaking..... I don't think that would happen with a ZL1 even though the car weighs 1000 pounds more. More exotic and lighter does not necessarily mean stronger. It is hard to beat good old fashioned steel for strength.

I wondered about this and looked up generic values for Ultimate Yield Strength and weight. Forged steel was 750 MPa on the high end and Titanium was 950 MPa. ~27% stronger.

Titanium is also ~35% lighter so the engine will rev faster.

I've read many of Kingpin's posts and sense he is looking for absolute reliability when he mods. The ZL1 is a big investment. My own goal is to help it breathe as well as possible with a slight increase in boost. CAI, PTB, Kooks, CATS and pulley. I'll sleep well at night

[kinpin]

Originally Posted by hotlapZL1

LSA is 1.9L @ 8 PSI. LS9 is 2.3L @ 10.8 PSI. Same engine displacement



I wondered about this and looked up generic values for Ultimate Yield Strength and weight. Forged steel was 750 MPa on the high end and Titanium was 950 MPa. ~27% stronger.

Titanium is also ~35% lighter so the engine will rev faster.

I've read many of Kingpin's posts and sense he is looking for absolute reliability when he mods. The ZL1 is a big investment. My own goal is to help it breathe as well as possible with a slight increase in boost. CAI, PTB, Kooks, CATS and pulley. I'll sleep well at night

Yes i guess i am . I would like to mod but just worry about my once in a life time ZL1 .... Unless i hit the lottery this is it . So in the end if i do mod it will be only with thing i know are safe . So i think i will not be doing allot of mods .

[Rat]

For what it costs to buy/build a LS9 you could build a very reliable motor that will punish a LS9. New blower or turbo of your choice. Well IMO!

[jessrayo]

Originally Posted by hotlapZL1

LSA is 1.9L @ 8 PSI. LS9 is 2.3L @ 10.8 PSI. Same engine displacement



I wondered about this and looked up generic values for Ultimate Yield Strength and weight. Forged steel was 750 MPa on the high end and Titanium was 950 MPa. ~27% stronger.

Titanium is also ~35% lighter so the engine will rev faster.

I've read many of Kingpin's posts and sense he is looking for absolute reliability when he mods. The ZL1 is a big investment. My own goal is to help it breathe as well as possible with a slight increase in boost. CAI, PTB, Kooks, CATS and pulley. I'll sleep well at night

Yield testing uses a standardized cross-sectional testing method that does not take into to account the overall mass or design structure of the rod. If I build an H beam rod for instance it will be stronger than a solid forged piece. In theory the titanium should be stronger.... I don't think it is. Either way, these LS motors are pretty tough to break. They can take a lot of abuse.

[hotlap]

Originally Posted by jessrayo

Yield testing uses a standardized cross-sectional testing method that does not take into to account the overall mass or design structure of the rod. If I build an H beam rod for instance it will be stronger than a solid forged piece. In theory the titanium should be stronger.... I don't think it is. Either way, these LS motors are pretty tough to break. They can take a lot of abuse.

True. The cross section affects the bending neutral axis and moment of inertia. Based on the LS9 higher red line (6500) and torque (604 lb-ft) along with GMs conservative nature, I'd bet it is a stronger peice.

Your engine is most heavily built I know of. What rod did you go with and why?

[RLHMARINES]

I wonder if the durability tests that GM performed has more to do with the difference in boost pressure and not the parts material between the LSA and the LS9 as it relates to this statement below.

Regarding quality and durability. The 6.2L Supercharged LSA has been validated beyond 100,000 miles and accumulated more the 6,400 hours of dynamometer testing. It has run over 270 consecutive hours at wide-open throttle without a failure. (The LS9 has only accomplished 100 hours of this sort of testing!!!) It's been road tested in the world's extreme climates and track-tested under racing g loads on some the world's most demanding circuits. It has completed actual and simulated 24-hour track tests.

[gm_joe]

Titanium rods are light, hard and brittle. Oh yeh, and expensive.

[hotlap]

Originally Posted by gm_joe

Titanium rods are light, hard and brittle. Oh yeh, and expensive.

"The most common Ti alloy is 6Al-4V, and the steel that is common for rods is usually 4130 or 4340. Since a large percentage of the rod stress is self induced due the mass in motion, the mass to strength ratio is very important."

http://forums.corvetteforum.com/c6-z...ged-steel.html

http://www.matweb.com/search/DataShe...32b9de0d7d6c1a

http://asm.matweb.com/search/Specifi...bassnum=MTP641

[hotlap]

Originally Posted by RLHMARINES

I wonder if the durability tests that GM performed has more to do with the difference in boost pressure and not the parts material between the LSA and the LS9 as it relates to this statement below.

Regarding quality and durability. The 6.2L Supercharged LSA has been validated beyond 100,000 miles and accumulated more the 6,400 hours of dynamometer testing. It has run over 270 consecutive hours at wide-open throttle without a failure. (The LS9 has only accomplished 100 hours of this sort of testing!!!) It's been road tested in the world's extreme climates and track-tested under racing g loads on some the world's most demanding circuits. It has completed actual and simulated 24-hour track tests.

Wow! I'd never hear this before. The LSA is bullet proof. I think your right in that the higher boost creates more torque in the LS9 and the lighter mass allows it to have a 300 rpm higher rev limit (6500 vs 6200).

I wish GM had put the LS9 in the ZL1. The drivetrain could handle it and the extra $4000 would have been worth paying

[jessrayo]

Originally Posted by hotlapZL1

Your engine is most heavily built I know of. What rod did you go with and why?

Callies Ultra H-beam. My engine builder says they are the best.

[kinpin]

Originally Posted by jessrayo

Yield testing uses a standardized cross-sectional testing method that does not take into to account the overall mass or design structure of the rod. If I build an H beam rod for instance it will be stronger than a solid forged piece. In theory the titanium should be stronger.... I don't think it is. Either way, these LS motors are pretty tough to break. They can take a lot of abuse.

HUH in layman's terms

[kinpin]

Originally Posted by hotlapZL1

True. The cross section affects the bending neutral axis and moment of inertia. Based on the LS9 higher red line (6500) and torque (604 lb-ft) along with GMs conservative nature, I'd bet it is a stronger peice.

Your engine is most heavily built I know of. What rod did you go with and why?

HUH in layman's terms

[hotlap]

Originally Posted by kinpin

HUH in layman's terms

They take a bar of standard dimensions and pull it until it breaks. Measure the amount it stretches to determine elasticity. Measure the force required to determine it strength. By testing different material using standard bar sizes, you can compare.

Jessrayo was pointing out that the material strength is only part of the equation. The cross section (shape and thickness) also determine the rods strength.