New heads and intake on LS7
12 Second Club
Joined: Jul 2003
Posts: 3,371
Likes: 0
From: Atlanta
Originally Posted by The Alchemist
Talking about exhaust, did anyone else pick up on the fact that it will have a bypass (read electric cutout) that will open at higher rpms....
Talk about factory listening to the market. Around town at low rpm the car will be quiet. As you get up in the rpm the exhaust will open up to release a nice growl. That's what I call PIMP.
Talk about factory listening to the market. Around town at low rpm the car will be quiet. As you get up in the rpm the exhaust will open up to release a nice growl. That's what I call PIMP.
On The Tree
Joined: Dec 2004
Posts: 124
Likes: 0
From: Northville, Michigan
Originally Posted by FAST LS1
The specs for the LS7 are pretty impressive, but the heads look like they'll be a big improvement over the current offerings.
"CNC machining is also utilized on the new aluminum heads, which boast an 18% improvement in airflow over LS2 units. Nearly straight tunnel-like intake runners feed the air/fuel charge through huge 2.2-inch titanium intake valves while 1.62-inch, sodium-filled hollow exhaust valves let spent gasses back out. A hydraulic-roller cam provides a significant .591-inch lift,"
"Despite the massive displacement, lightweight internals give the LS7 a 7000-rpm redline in roadgoing trim"
Seems like the intake will have to be bigger/flow better than the LS6 or LS2.
The heads have massive valves and some stout springs to support 7000rpm reliably. The question then becomes how expensive will these parts be for everyone else that has an LS based engine. Also what will it take to retrofit them on existing LS based engines.
"CNC machining is also utilized on the new aluminum heads, which boast an 18% improvement in airflow over LS2 units. Nearly straight tunnel-like intake runners feed the air/fuel charge through huge 2.2-inch titanium intake valves while 1.62-inch, sodium-filled hollow exhaust valves let spent gasses back out. A hydraulic-roller cam provides a significant .591-inch lift,"
"Despite the massive displacement, lightweight internals give the LS7 a 7000-rpm redline in roadgoing trim"
Seems like the intake will have to be bigger/flow better than the LS6 or LS2.
The heads have massive valves and some stout springs to support 7000rpm reliably. The question then becomes how expensive will these parts be for everyone else that has an LS based engine. Also what will it take to retrofit them on existing LS based engines.
In reading the text of the Corvette Magazine it talks about the LS7 cam being activated by massive rocker arms. Does anyone know what the LS7 rocker arm ratio is? The C5R uses Jesel Mohawk aluminum rocker arms, and I believe their ratio is 1.80:1. If the LS7 uses that same rocker arm ratio, then the cam could be the '02 to '04 Z06 cam, with its 117 degree LSA. The LS6 camshaft delivers .591" lift at the valve with 1.80:1 rocker arms.
Also, the LS7 will have a 4.125 inch bore and a 4.00 inch stroke.
Time will tell.
TECH Resident
Joined: Dec 2004
Posts: 881
Likes: 1
The LS7 uses 1.8 rockers. Other than the heads, it really looks like someone just moved a lot of aftermarket parts to product. For example, the single scavenge stage, stock oil pump pressure stage dry sump at ARE (drysump.com).
The cam sounds like the Comp Cams Xtreme RPM for LS1 High Lift in a 212 or 214 size. Those are 265-267@.006 tappet lift.
David
The cam sounds like the Comp Cams Xtreme RPM for LS1 High Lift in a 212 or 214 size. Those are 265-267@.006 tappet lift.
David
Launching!
Joined: Mar 2003
Posts: 293
Likes: 0
From: TX.
Originally Posted by The Alchemist
Talking about exhaust, did anyone else pick up on the fact that it will have a bypass (read electric cutout) that will open at higher rpms....
Talk about factory listening to the market. Around town at low rpm the car will be quiet. As you get up in the rpm the exhaust will open up to release a nice growl. That's what I call PIMP.
Talk about factory listening to the market. Around town at low rpm the car will be quiet. As you get up in the rpm the exhaust will open up to release a nice growl. That's what I call PIMP.
pretty awsome though.
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TECH Apprentice
Joined: Jan 2002
Posts: 356
Likes: 0
From: Texas
Originally Posted by Pumba
In reading the text of the Corvette Magazine it talks about the LS7 cam being activated by massive rocker arms. Does anyone know what the LS7 rocker arm ratio is? The C5R uses Jesel Mohawk aluminum rocker arms, and I believe their ratio is 1.80:1. If the LS7 uses that same rocker arm ratio, then the cam could be the '02 to '04 Z06 cam, with its 117 degree LSA. The LS6 camshaft delivers .591" lift at the valve with 1.80:1 rocker arms.
Todd
