JMD

Ten Thousand and Six....

jonward786

is that with stock heads or have u done anything to them? (porting, gasket matching ect)

JDraper

My '66 289 put down 230 rwhp/250 tq corrected (about 290 hp/312 tq) at the flywheel if you assume a 20% drivetrain loss) thru a World Class T-5 transmission with the following setup:

289 Block bored .040" over
Edlebrock Performer 60 cc heads 1.90"/1.60" valves
Edlebrock Performer intake
204°/214° Duration, .448"/.472" Lift cam
Holley Street Avenger 575 cfm carb
Holley Fuel pump/regulator
Crane 1.6 roller rockers
Accel electronic ignition
MAC long tube headers
Summit balancer
A good Tune!!

Here's the Dyno Sheet on it:

THUMPIN455

My 289+178 makes around 700... I dont have any 289s. Just wanted to brag about the **** nasty Pontiac I have..

Norm Peterson

Any idea why the curves have that sudden jump in the 5100 - 5300 rpm range? Or maybe I should be asking why does the torque curve have a sag in the midrange?

I'd happily give away a few ponies off the 230.7 HP peak in exchange for filling in that valley in the torque curve between 4000 and 5150. I have an idea what I'd tinker with if it was EFI, but don't really know how to tweak only a specific range with a carb (it's got to be deeper into the carb tuning than just jetting/power valve/accelerator pump tuning; maybe it involves emulsion tubes or air bleeds).


Norm

JDraper

My tuner and I talked about it, and our conclusion was it might have something to do with the timing. I've got an Accel Billetproof distributor with a combo vacuum/spring advance setup. Unfortunately, at the time the car was on the dyno we didn't have enough different spring combos to work on it further. We did re-jet, change the vacuum secondary opening rate and changed the power pump rate to get it where it is. I had to go down 2 jets on the secondaries, open the secondaries slower and slow down the power pump squirt to fix the a/f ratio issues we had out of the box. The car was dumping fuel and going way rich on initial tip in, then going lean as hell before the secondaries kicked in, then went rich again. When we slowed down the power pump rate, it fixed the initial tip in, but still went lean as the secondaries kicked in and then went rich. We downjetted the secondaries and slowed the opening of the secondaries which got us to a reasonably smooth a/f ratio curve. The drop and bump in the curve was there pretty much all the time, so we're leaning towards the springs in the distributor not expanding linearly.

phish

hijacked this thread to its death

dcohen

i am hoping for 350-360 flywheel hp out of my 289

but thats with performer rpm heads, performer rpm intake, stiff cam, roller rockers, hooker super comp long tubes, and some other odds and ends

phish

with all the 289's out there that all the response i get????? anyone else??

Nick.Simonds

I wouldn't think that a lot of people have taken theirs to the Dyno.