68 Corvette 467 Performance Potential
Thread Starter
Racer
Joined: Aug 2011
Posts: 493
Likes: 217
68 Corvette 467 Performance Potential
The car: 1968 Corvette, street car, 3.55 gears, turbo 400, unknown TQ converter.
The engine: 467 4.310 X 4.00, Scat 9000 series crank, GM 3/8 rods, Mahle pistons, 9.8 compression, Hyd roller 553/578/228/238/112/108, GM 049 oval port heads ported, 1.880/2.190 valves, Performer RPM intake, 850 Holley, 4 quart GM oil pan.
My questions are:
Crankshaft HP potential?
Dragstrip potential in Florida air?
The engine: 467 4.310 X 4.00, Scat 9000 series crank, GM 3/8 rods, Mahle pistons, 9.8 compression, Hyd roller 553/578/228/238/112/108, GM 049 oval port heads ported, 1.880/2.190 valves, Performer RPM intake, 850 Holley, 4 quart GM oil pan.
My questions are:
Crankshaft HP potential?
Dragstrip potential in Florida air?
Race Director
Joined: Jan 2000
Posts: 13,018
Likes: 2,262
From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
Easy deep 11 sec car with traction.
HP depends on who ported the heads......but could be 550-600.
JIM
PS- OOPS...I just noticed who ported the heads!!! LOL.
High 10's now!!
HP depends on who ported the heads......but could be 550-600.
JIM
PS- OOPS...I just noticed who ported the heads!!! LOL.
High 10's now!!
Last edited by 427Hotrod; Aug 29, 2017 at 12:19 AM.
Race Director
Joined: Dec 1999
Posts: 11,096
Likes: 990
From: Sierra Foothills CA
The car: 1968 Corvette, street car, 3.55 gears, turbo 400, unknown TQ converter.
The engine: 467 4.310 X 4.00, Scat 9000 series crank, GM 3/8 rods, Mahle pistons, 9.8 compression, Hyd roller 553/578/228/238/112/108, GM 049 oval port heads ported, 1.880/2.190 valves, Performer RPM intake, 850 Holley, 4 quart GM oil pan.
My questions are:
Crankshaft HP potential?
Dragstrip potential in Florida air?
The engine: 467 4.310 X 4.00, Scat 9000 series crank, GM 3/8 rods, Mahle pistons, 9.8 compression, Hyd roller 553/578/228/238/112/108, GM 049 oval port heads ported, 1.880/2.190 valves, Performer RPM intake, 850 Holley, 4 quart GM oil pan.
My questions are:
Crankshaft HP potential?
Dragstrip potential in Florida air?
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Drifting
Joined: Jun 2008
Posts: 1,565
Likes: 111
470-480hp without some secret sauce on the heads. 540-550hp@5,600 assuming head flow and minimum CSA can support it. The car should run 11's with traction at sea level.
Last edited by Neil B; Aug 29, 2017 at 03:54 PM.
Advanced
Joined: Oct 2012
Posts: 74
Likes: 0
From: Cape Coral Florida
Good guess Jim. It made 609 at 6100 rpm and 598 ft-lbs at 4200 rpm. I'd post the dyno sheet but I'm too lazy to try and figure out how to do it.
It is on its way to Cape Coral, Florida. Christmas in September!!!
Here is the youtube address for the video if anyone wants to see it:
https://www.youtube.com/watch?v=rYF_...ature=youtu.be
Last edited by 68 Issues; Aug 31, 2017 at 05:10 PM.
Drifting
Joined: Jun 2008
Posts: 1,565
Likes: 111
There's some serious Mojo in Colorado. Most 496's with aftermarket heads and much bigger cams don't make those numbers. Can Mark give us any details on those heads? 6,100 rpm peak with a 228 cam?
Advanced
Joined: Oct 2012
Posts: 74
Likes: 0
From: Cape Coral Florida
Oh crap, I can't get this darn grin off my ugly mug
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
I'd love to see flow data and final port/chamber volumes for those heads. I'm assuming this is your piece being dyno'd?
https://www.youtube.com/watch?v=rYF_fTD5AlY
https://www.youtube.com/watch?v=rYF_fTD5AlY
His combo's definitely work.
68 Issues, if you have any questions about setting it up in the car, lemme know... I was the crash test dummy for VP engines in C3s..
Advanced
Joined: Oct 2012
Posts: 74
Likes: 0
From: Cape Coral Florida
Not enough. The timing on my improvements to the car has been terrible. About two years ago I was trying to decide between buying a motor from Mark Jones or just adding a bunch of bolt on parts....I opted for spending a little less money (duh!). After going the bolt on route, I then sent the differential to Van Steel's to rebuild with HD yokes, caps, solid u-joints and change the gears to 3.55s. About two years later, the motor came apart. In a sick way I was sorta happy, cause now I could justify calling Mark like I should have in the first place! Oh, and I have some new 3" half shafts ready to go in.
So, the stock rear end is fresh and upgraded but probably still not what I will be needing going forward. I suspect it will live as long as I leave the old Radial T/As on it. But, to keep the windshield facing in generally the the same direction the car is traveling (I like it that way in my older age), I will probably be switching to some MT drag radials. This is a street car and won't be getting flogged all the time so I am hoping I can nurse the old differential along until I can save up yet more money.
Anyone have any good suggestions on who to turn to to get some numbers on what the new differential is going to cost? I sure hope my kids win the lottery!
So, the stock rear end is fresh and upgraded but probably still not what I will be needing going forward. I suspect it will live as long as I leave the old Radial T/As on it. But, to keep the windshield facing in generally the the same direction the car is traveling (I like it that way in my older age), I will probably be switching to some MT drag radials. This is a street car and won't be getting flogged all the time so I am hoping I can nurse the old differential along until I can save up yet more money.
Anyone have any good suggestions on who to turn to to get some numbers on what the new differential is going to cost? I sure hope my kids win the lottery!