Hello to all,
I'd like to thank Cliff for all of the great info provided in his book, and also for that which can [so easily] be gained through this forum!
Today was the day of reckoning for my lil' ol' Chivvy'
406.
She got strapped to the dyno with her 'new' Q-Jet.
This is strictly a street motor, and I was more than happy to sacrifice a few ponies at the very 'top' for crisp bottom end throttle response and midrange grunt.
With this goal in mind, I ran a Q-Jet Performer RPM fully divided(!) side to side (but open front to rear).
!.5" total spacer height (again totally divided)
800 Q-Jet (originally from a 1980 truck)
I
do confess to having gone overboard with a bunch of mods to this carb, but suspect that a stock one (properly built) would have showed nearly as good.
I just like playing with the fine details, thats all.
A quick engine rundown: 10.2 CR, 'off the shelf' Comp Cams 274S flat tappet, AFR 195 Street Eliminator heads, and a fair bit of overall attention to the [aformentioned] 'detail stuff'.
Cutting to the chase: Motor made 492 HP@ 5700 rpm with torque peaking 522 lb/ft@ 4000.
Lowest RPM recorded during pull was 3489 rpm with the motor already making 506 lb/ft.
BSFC .397 to .420 'ish' throughout pull.
Motor is happiest at 34 degrees total (within 1 hp of 36 total)
The thing starts just unbelievably quick. I mean hit the key on the dyno console ... and instantly(!) it's running.
Even had it idling happily at 500 rpm... not where I'll run it, But Man!!!
The graphed computer readout was incredibly smooth... none(!) of that sawtooth stuff to be found.
The shop where all of this took place today is run by two good friends (both multiple time NHRA record holders in both Superstock and ProComp).
They confided *that in their honest opinion, the motor was making a little better power than it had (~ two years ago) with a near $1000.00 custom built Holley then in place atop a Performer RPM w/1" open spacer and reworked plenum etc.
The 'big' number at that time was 503.7 HP peak, but(!) recent changes to the dyno setup have proven to give lower numbers than previously tested-and [now] recently retested 'known and freshened up' engines.
They were both highly impressed with the Q-Jet's performance.
And these guys don't impress easily, believe me.
Should quickly note that torque production has moved another 400 to 500 rpm down the rpm scale (widened!) with no sacrifice towards the top.
If you think that maybe I'm happy with the days events... you're not mistaken.
So once again, please allow me to express my sincere thanks to Cliff for helping make this good day happen.
Cheers!
