Running on the Dyno with my LS6 on Friday

[Chevy454]

I was hoping you'd stop by! I tried to get my heads done at the same place, but never could get it set up...plus, getting them to Michigan and back would have been a chore.

I know it's hard for people to understand, especially when you see all these magazine articles hyping this and that. Unfortunately I think a lot of the articles are just "info-mercials". It doesn't take voo-doo to get a BBC running through stock (read: unported) manifolds to get 1hp per cube. Heck, if I can do it, I know it can't be THAT hard!

So, Jim, got that LS-6 squared away? Find out what wiped out the cam?

[JLerum]

Their are so many lessons to be learned from my motor build up and it makes me cry. lesson number...............


1. Don't take your motor to someone that doesn't believe what you do even if they are a well known machine shop.

2. Don't take their word it is done the way you want when they have a different falocify.

3. Make sure you go to someone that understands the events you run. Because as stated the shop doesn't beleive for a second that you can run low 12's with a blue printed motor on Wide Ovals at 3800lbs.

I waited 9 months to have someone set me up with 148lbs of seat pressure on a cam that requires 120 and refussed to setup a cam retarded unbenounced to me. The list goes on. After over pressuring these people to get the job done and $1500.00 later I'm the looser. FASTIMES MOTOR works did me s**t work.

The motor on a dyno(not FASTIMES) pulled 420hp@4900RPM and 518 ft/lbs@3600RPM. After some pulls it was obvious the moter was loosing power and high oil temps made us stop. The leak down was 15-20% and the exhaust lobs on #7 and #8 were going down.

After disassemly the cam was 6 degrees advanced 148lbs on the vavle springs. (max spring pressure for non single spring breakin is 130lbs). Their is more but I'm not going to go there. I can not stress lesson #3 enough. The motor should make 470 to 480 HP and around 535lbs of torque to my best estimations. Yes compression is important. It makes big ports work and give strong signals to the induction system.

JIM

[Chevy454]

Boy, Jim, reading you post made me even more nervous about putting the finishing touches on the L-72! I'm *suppsoed* to pick it up Tuesday...

[JLerum]

The only thing that could of gone worse is a rod through the block and the heads getting damaged. If you beleive in your machine shop and no previous problems before I would say you're good to go. Don't look back now!!!!!!!!!

JIM

[Mr70]

Is Dan Jensens LS6 the Fathom Blue one that Gilbert Probst restored for Floyd Garret?
I have a Videotape of an Old "My Classic car" segment with Dennis Gage and Dan at the dragstrip running this Chevelle 3X with a Camerman in the backseat to boot!
Pretty impresive times..

[Seattle Sam]

Mr70,
Would you share the peak hp @rpm and peak tq @rpm for the 1970 L78? Are these numbers through cast iron manifolds, open exhaust, or??

TIA!
-Sam

[JLerum]

Yes, that is Dans car before he did his rebuild. I should say that he has an x-pipe and the long 25 inch DynoMax ultra flow SS mufflers on the car now.

JIM [img]/ubbthreads/images/graemlins/biggthumpup.gif[/img]

[SS4Real]

I had my LS5 on the Dyno at Superior Engineering in Anaheim, Ca last year. The numbers showed 287.6 peak HP at the rear wheels with 415.7 max torque. The engine is stock (balanced and blueprinted) running stock exhaust manifolds. The only upgrade from stock is 2 1/2 exhaust with Dynomax mufflers. Your LS6 should be better than that in proper tune and condition.

[Chevy454]

Those numbers are right on where an LS-5 should be, SS4! [img]/ubbthreads/images/graemlins/biggthumpup.gif[/img] That puts it in the 320 NET hp range, or 360 GROSS hp range...right on!

[COPO]

OK it's Saturday now, what did it do?? [img]/ubbthreads/images/graemlins/[/img]