New Corvette engine (Z06) beats previous OHV RPM limits
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CL Community Team
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New Corvette engine (Z06) beats previous OHV RPM limits
February 9, 2005
Pontiac, Michigan - GM engineers have achieved a feat many speculated was not possible. The new LS7 7.0-litre OHV (overhead valve) V-8 engine for the 2006 ZO6 Corvette will not only achieve 500 horsepower but will be capable of running up to 7100 rpm. The previous limit was 6600 rpm in the 6.0-litre LS2.
With this new engine GM is showing multi-valve overhead cam performance is achievable with a two-valve cam-in-block engine. For the new ZO6, higher rpm allows the driver to remain in first gear to just over 60 mph, contributes to higher top speed and improves overall vehicle performance. The LS7 is one of the first automotive OHV production engines in the industry capable of over 7000 rpm.
The new ZO6's sub four-second 0-60 mph time is achieved in part by the extended rpm range and the ability to remain in first gear past 60 mph. The over-190 top speed of the ZO6 is partially due to the speed capability of the engine. As aerodynamic drag becomes a factor at higher speeds, the capability to run higher rpm allows the transmission to be run in a lower gear generating more effective torque at the rear wheels. Also, having the ability to shift all gears at higher speeds improves elapsed times whether on a road course or drag strip.
"For a production engine to run at this high of an rpm blurs the lines even more between OHV and OHC (overhead cam) design," said Dave Muscaro, assistant chief engineer for small block engines. "We took a complete systems approach to achieve the high rpm. We have a tight valvetrain design along with some race-inspired materials for the reciprocating components like titanium intake valves and connecting rods."
OHV engines use pushrods to activate the valves via rocker arms, whereas with OHC engines the valves are typically actuated directly via finger followers. The extra mechanical movement and weight of the components of an OHV valvetrain present challenges to higher rpm. The LS7 design and use of lightweight, stiff components, along with GM's economy of scale, make higher rpm obtainable in a production OHV engine.
source : canadiandriver.com
Pontiac, Michigan - GM engineers have achieved a feat many speculated was not possible. The new LS7 7.0-litre OHV (overhead valve) V-8 engine for the 2006 ZO6 Corvette will not only achieve 500 horsepower but will be capable of running up to 7100 rpm. The previous limit was 6600 rpm in the 6.0-litre LS2.
With this new engine GM is showing multi-valve overhead cam performance is achievable with a two-valve cam-in-block engine. For the new ZO6, higher rpm allows the driver to remain in first gear to just over 60 mph, contributes to higher top speed and improves overall vehicle performance. The LS7 is one of the first automotive OHV production engines in the industry capable of over 7000 rpm.
The new ZO6's sub four-second 0-60 mph time is achieved in part by the extended rpm range and the ability to remain in first gear past 60 mph. The over-190 top speed of the ZO6 is partially due to the speed capability of the engine. As aerodynamic drag becomes a factor at higher speeds, the capability to run higher rpm allows the transmission to be run in a lower gear generating more effective torque at the rear wheels. Also, having the ability to shift all gears at higher speeds improves elapsed times whether on a road course or drag strip.
"For a production engine to run at this high of an rpm blurs the lines even more between OHV and OHC (overhead cam) design," said Dave Muscaro, assistant chief engineer for small block engines. "We took a complete systems approach to achieve the high rpm. We have a tight valvetrain design along with some race-inspired materials for the reciprocating components like titanium intake valves and connecting rods."
OHV engines use pushrods to activate the valves via rocker arms, whereas with OHC engines the valves are typically actuated directly via finger followers. The extra mechanical movement and weight of the components of an OHV valvetrain present challenges to higher rpm. The LS7 design and use of lightweight, stiff components, along with GM's economy of scale, make higher rpm obtainable in a production OHV engine.
source : canadiandriver.com
Lead Lap
Joined: May 2003
Posts: 773
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From: Texas
Good article...that is pretty impressive with a OHV. You really have to start wondering about the longevity of this engine...some of those space age materials they use are light and strong, but you gotta give up something in return such as durability/longevity.
Originally Posted by SexySC
February 9, 2005
Pontiac, Michigan - GM engineers have achieved a feat many speculated was not possible. The new LS7 7.0-litre OHV (overhead valve) V-8 engine for the 2006 ZO6 Corvette will not only achieve 500 horsepower but will be capable of running up to 7100 rpm. The previous limit was 6600 rpm in the 6.0-litre LS2.
With this new engine GM is showing multi-valve overhead cam performance is achievable with a two-valve cam-in-block engine. For the new ZO6, higher rpm allows the driver to remain in first gear to just over 60 mph, contributes to higher top speed and improves overall vehicle performance. The LS7 is one of the first automotive OHV production engines in the industry capable of over 7000 rpm.
The new ZO6's sub four-second 0-60 mph time is achieved in part by the extended rpm range and the ability to remain in first gear past 60 mph. The over-190 top speed of the ZO6 is partially due to the speed capability of the engine. As aerodynamic drag becomes a factor at higher speeds, the capability to run higher rpm allows the transmission to be run in a lower gear generating more effective torque at the rear wheels. Also, having the ability to shift all gears at higher speeds improves elapsed times whether on a road course or drag strip.
"For a production engine to run at this high of an rpm blurs the lines even more between OHV and OHC (overhead cam) design," said Dave Muscaro, assistant chief engineer for small block engines. "We took a complete systems approach to achieve the high rpm. We have a tight valvetrain design along with some race-inspired materials for the reciprocating components like titanium intake valves and connecting rods."
OHV engines use pushrods to activate the valves via rocker arms, whereas with OHC engines the valves are typically actuated directly via finger followers. The extra mechanical movement and weight of the components of an OHV valvetrain present challenges to higher rpm. The LS7 design and use of lightweight, stiff components, along with GM's economy of scale, make higher rpm obtainable in a production OHV engine.
source : canadiandriver.com
Pontiac, Michigan - GM engineers have achieved a feat many speculated was not possible. The new LS7 7.0-litre OHV (overhead valve) V-8 engine for the 2006 ZO6 Corvette will not only achieve 500 horsepower but will be capable of running up to 7100 rpm. The previous limit was 6600 rpm in the 6.0-litre LS2.
With this new engine GM is showing multi-valve overhead cam performance is achievable with a two-valve cam-in-block engine. For the new ZO6, higher rpm allows the driver to remain in first gear to just over 60 mph, contributes to higher top speed and improves overall vehicle performance. The LS7 is one of the first automotive OHV production engines in the industry capable of over 7000 rpm.
The new ZO6's sub four-second 0-60 mph time is achieved in part by the extended rpm range and the ability to remain in first gear past 60 mph. The over-190 top speed of the ZO6 is partially due to the speed capability of the engine. As aerodynamic drag becomes a factor at higher speeds, the capability to run higher rpm allows the transmission to be run in a lower gear generating more effective torque at the rear wheels. Also, having the ability to shift all gears at higher speeds improves elapsed times whether on a road course or drag strip.
"For a production engine to run at this high of an rpm blurs the lines even more between OHV and OHC (overhead cam) design," said Dave Muscaro, assistant chief engineer for small block engines. "We took a complete systems approach to achieve the high rpm. We have a tight valvetrain design along with some race-inspired materials for the reciprocating components like titanium intake valves and connecting rods."
OHV engines use pushrods to activate the valves via rocker arms, whereas with OHC engines the valves are typically actuated directly via finger followers. The extra mechanical movement and weight of the components of an OHV valvetrain present challenges to higher rpm. The LS7 design and use of lightweight, stiff components, along with GM's economy of scale, make higher rpm obtainable in a production OHV engine.
source : canadiandriver.com
Lexus Fanatic
Joined: Oct 2003
Posts: 94,460
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From: Virginia/D.C. suburbs
Originally Posted by 1SICKLEX
That is incredible!! over 60mph in 1st gear??? Wow!
In general, the taller the gearing in the transmission and drive line, the faster you can go in each gear and the higher the top speed will be........at the cost of acceleration, and in some cases lugging the engine. Shorter gearing will give you drag-strip acceleration but then you run out of RPM on top end. Once in a while a rare car like this comes along that, at least to an extent, combines both.
Still, the best way to get acceleration AND top end at the same time is just to have more gears...or a CVT. CVT's, though, have not yet been perfected for engines this powerful...they are currently used only in fours and lower-power V6's.
Last edited by mmarshall; Feb 10, 2005 at 06:39 AM.
Lexus Champion
Joined: Jun 2003
Posts: 2,375
Likes: 21
From: California
Yeap. It is. 
But it's also definitely doable. I remember the old ZR-1's first gear being good for about 55mph.
Jon
But it's also definitely doable. I remember the old ZR-1's first gear being good for about 55mph.
Jon
Originally Posted by 1SICKLEX
That is incredible!! over 60mph in 1st gear??? Wow!
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