[ta man]

Originally Posted by Formulajones

I doubt the carb size hurt the numbers. If anything the 950 size probably helped a bit up top and wasn't run low enough to matter. In reality all that comes into play with drivability anyway, and that's not something that can be determined on an engine dyno.

I've seen those 950 carbs on 350's on up over 500ci, they are pretty versatile. Once jetted properly for the combo they work pretty well.

I think you did well for the combo you have. I personally would have liked to see more compression with that cam, or maybe a cam more suited to the compression you have, but overall it's not bad and should be pretty fun once in the car. Plug it in and enjoy it.

x2 if is a 950HP..they work well on almost anything..really only a 830cfm

[Tom Vaught]

Just a comment made by some Flow Bench Experts on the Flow Bench Forum
(on some of this Flow Bench Testing on Pontiac heads). Good accurate info.

The first flow benches from Neal Johnson (owner and designer of the first SF-110 flow benches, were blower (motor) centered SF-110 flow benches.

FACTS:

One easy way to prove the "theory" is to set up two identical orifice plates in series flow, and measure the two pressure differentials. They will be the same, even though the first orifice works in higher density air than the second. Swap the orifice plates around and repeat the test. That should prove to you that the ratio-metric method DOES work.
Superflow 300, 600, & 1200 benches were "orifice plates in series flow" benches

"The only real way to screw it up is to add (or remove) significant amounts of external heat to the air between the two orifice plates, as will occur in a "blower centered" (110 type) flowbenches.

That is the single main attraction of an orifice style bench, ambient air changes make absolutely no difference to the results. Both restrictions in the flow path will have exactly proportional pressure drops. This is why a SF300, 400, 600, 1200 reads the same each day even with different atmospheric conditions.

As soon as you begin Adding Corrections and Fiddle Actors to any type of measurement, you can start getting into real trouble fairly fast."


(Like changing Test Ppressures on Flow Benches from a Industry Standard 20.4" of water test pressure) to other values.

Tom V.

[Skip Fix]

Steve the typical 3/4" Qjet/4150 adapter, granted I smoothed the casting flashing and opened it up the manifolds 4 holes(so not even modified to 2 holes like Cliff's).

The biggest thing I will saw with RAIV heads after running 4 different cams and 2 sets of headers, you can see on Jay's flow numbers- the E/I ratio is pretty high so it needs to be cammed to match, and can be prone to reversion if the exhaust system does not scavenge well. When I had the RAIVs on a 400(changed the class rules so no longer legal on a 455) I picked up using smaller 1 3/4 headers and a "reverse split" cam 242/236 @ 0.050. John Angeles on the SS RAIV car runs a single pattern cam for the same reason.

And mine with gasket match and pocket clean up were around 253cfm @28 on intake-corrected from 10" and a calibration plate calibration that day on the smaller SF -110 bench. Tom my buddy with the small bench bought 4 calibration plates like the "pass around plates" and has tweaked his bench to match them. 85% E/I ratio!

[Steve C.]

ta man's comment regarding 830 cfm on the 950HP is close to what I've used for input into the Performance Trends program. In the past I've been able to manipulate the input to the program to provide results to mimic my actual engine dyno sheets VERY close. If memory serves me right on the carb cfm input for my 950HP I used 823 cfm.


.

[taktikian]

Assuming I will be using this square bore carb does anyone think going to a dedicated square bore intake would help top end ? i.e. Torker 2 or Performer RPM. I hate to throw more $ at this but I also kind of want to get what I expected rightfully or wrongly

[78w72]

Originally Posted by taktikian

Assuming I will be using this square bore carb does anyone think going to a dedicated square bore intake would help top end ? i.e. Torker 2 or Performer RPM. I hate to throw more $ at this but I also kind of want to get what I expected rightfully or wrongly

the rpm isnt square bore dedicated... its a dual pattern for square & spread bore.

[Skip Fix]

On my small roller 259@ 0.050 swapping the same Demon on a Torker II it idled better and picked the car way up. Yours is mild enough it might not make as big an impact.

You could always modify the intake to take a square bore like Cliff did his. Chevy had a GM performance cast iron intake for class racing that had a Qjet and square bore patterns also.