Got Some Runs On The 489 [Archive] - Chevelle Tech

: Got Some Runs On The 489


Rock68SS
Sep 28th, 04, 9:32 PM
Got to the track last week. I'm running a 68 with a 454 30 over with the Eagle stroker kit as follows;
Steel Eagle 4.250 stroke crank
Eagle 6.385" 4340 H-beam 3D rods
SRP forged lightweight calculate 10.3-1 pistons
J&E plasma moly file fit rings.
Comp solid cam: 294S
(248 / 248 @. 050 & .595 / .595
Crane Gold 1.7-1 Roller Rockers
Ported Edelbrock rectangle port aluminum heads. 300cc short and 315 long intake runners, 2.19/1.88 valves
True roller timing chain
Moroso 6 qt oil pan, high volume pump, windage tray.
Weiand X-celerator port matched intake
Holly 950 CFM with billet base plate and metering plates. Jetted 78/80
Carter 172 mechanical fuel pump
HEI with MSD 6AL
WEIAND action-plus aluminum water pump
2” Headman headers.
Through a M20, Moroso Carrier with 4:10 gears, ET Streets. Launching anything above 3500 goes up in smoke. Brought it out at 3000 as soon as it rolls punch it. Best is listed below. I bumped the jets for cooler air 80/82 and removed the front sway bar. Hoping to squeak a little more out of it. Temp was 75 last week, expecting mid 60's tomorrow. Any thoughts?? :D

Purs
Sep 28th, 04, 9:38 PM
sounds to me like you need some slicks.

Bob West
Sep 28th, 04, 9:42 PM
Did the 396 have the same heads?

Purs
Sep 28th, 04, 9:49 PM
.. :(

gatewayracer
Sep 28th, 04, 9:49 PM
Your 60ft was hurting you before and it's still hurting you.

Once you get your 60's ironed out you'll be making an 11 second pass.

If lower ET's is the goal then work on the tranny/converter/chassis/suspension/tires

Rock68SS
Sep 28th, 04, 9:50 PM
Yep, comp ratio was about 8:1 with stock flat top pistons.

Bomber '67
Sep 29th, 04, 1:55 AM
How did it perform compared to what you were expecting?

The parts combination of the engine is decent enough, although I would have prefered an old factory L78 intake.

Have you run it on a chassis dyno yet? Your mph is less than I think it is capable of - perhaps the carb and ignition are not well tuned. The chassis dyno is great for sorting out ignition and fuel curves. Tell us about your fuel system from the tank to the pump. If you have never removed the fuel pickup from the fuel tank you may be suprised what you see inside there. There is a nylon strainer "sock", that if original is probably a huge flow restriction, and can hurt your top end charge.

Your biggest performance bottleneck will be found in your chassis setup. Especially with a stick, you really need a loose front end that comes right up on launch. There are a lot of posts you should search through to help you understand how to totally setup your suspension front and rear. The fact that 3,500 rpm launches with E.T. Streets renders your car a burnout machine tells me that little, if any, weight transfer is occuring. Fix that, and let the fast times fly!

Thomas

Rock68SS
Oct 1st, 04, 7:52 PM
Local Sheriff's rented the track this afternoon. Since they know me so well I was invited. Got 10 runs in. Best was a 12:16 114.6 mph. 60's are still poor at best 1.81. Worst and first was a 12:54 113.4. Tires are still smoking. I had a guy offer up his Hoosier drag slicks 29X9.0X15 on Weld Draglites for $200. He said it was his first time out and was done dragging his 69 Camaro. He had it towed home. He actually drove on them to the track. I got his number. They looked like new. Might be what I need for a 11 second run. :rolleyes:

427L88
Oct 1st, 04, 9:49 PM
I might lean the jetting back out and see how if affects mph. Did you make the 114.6 run back at 78/80?

Runs stout and like there's more in it with tuning/tires. Beautiful 68 btw!! graemlins/thumbsup.gif

Rock68SS
Oct 1st, 04, 9:56 PM
The 114.6 mph & a 114.4 run was with the 80/82 jetting. BTW I have Metco adjustable suspension with KYB shocks all around. Actually got some air a couple of times under the drivers side front tire on the launch on film.

Rock68SS
Oct 4th, 04, 8:41 PM
Just picked up the Hoosier drag slicks. A little taller (28"/29")and wider (8.5"/9")than the ET Streets. How noticeable of a difference should I expect? Any launch pointers? Hope to get out Wednesday. Thanks in advance.

Bob West
Oct 4th, 04, 8:56 PM
In your signature it shows 1.17 60ft time...don't need no help there ;) ...I'd launch like you have been and go from there,too much spin back it down 2-300 rpm.

Rock68SS
Oct 4th, 04, 9:01 PM
Thanks Robert. I should've proof read my updates. It should have been 1.817.