cast iron intake vs aluminum high rise dyno test( round 2)

[Kenth]

Apple to apple would be using a carb that bolt up on both intakes w/o any adapter of any sort.

Today everybody knows an adapter between a squarebore carb and a spreadbore intake kills power.

[Cliff R]

Glad you said it Kenth, as I hate to be the one to point out that NOTHING about that test was "apple to apple".

Installing a square bore carb on a factory spread bore intake with an ADAPTER doesn't correct the HUGE miss-match between the two components. The miss-match causes the air to have to make several "bends" to enter the plenum areas, which will kill power.

To be perfectly honest, I'm surprised the numbers are as close as they are......FWIW......Cliff

[The Boss]

Thanks for sharing the results - the customer must have been happy, that's a noticeable change!

[johnta1]

In defense of Harry, the customer is using that carb along with the necessary adapter to run it on that intake.

So he would gain HP by the aluminum intake.

He didn't do a test for optimum combos for each?

If all I had was this carb, what would make me the most power?

My 2 cents.

[elefantrider]

I still think the test is interesting and thanks Harry for posting it.

If you open the plenum up on the iron intake to match the carb, I bet a 10+HP gain.

[Skip Fix]

As far as adapters-track swap-Brad Urban Carb Shop modified 800cfm 73 SD SR Q jet on an HO intake ported E heads 259@ 0.050 solid roller.Swapped on a Demon(yea one of those crappy things) 850 DP WITH spread bore adapter-idled great out of the box and picked up 0.25 seconds and 3-4 mph.

So if it hurt flow(and yes I matched it and cleaned it up) I guess it would have gone faster!

That said swapping the same Demon on a Torker II on this motor really picked it up and smoothed out the idle even more.

[David Jones]

Thanks for sharing.
This proves that in this case, one combo as installed made more power than the other as it was installed on this car at this time. If somebody is interested in making exactly the same swap....you can possibly expect this result.

[Bruce Meyer]

Thanks for sharing Harry. We need more unbiased test results published here. This confirms testing I did decades ago at the dragstrip. The stock UNMODIFIED manifold was not ever the best choice.

[Skip Fix]

Most the SS racers using Q jets use an adapter be they Chevy or Pontiacs.

I'm just not seeing than many bends using this,more a funnel or reverse funnel depending which direction it goes.

http://www.tdperformance.com/site/?d...art=10&limit=5

Now this Edelbrock adapter might transition it a little smoother.

http://www.edelbrock.com/automotive_..._spacers.shtml

Maybe like how the 75-78 D secondary EGR intakes flow so bad-might not be that significant.

[Bill Eveland]

I guess that explains the chevy orange paint. With just loosing the adapter it seems to be some of the differance between the 2 no?

Originally Posted by harry k

As much as i know i will:
its a 400ci maybe 30over rebuild by local engine builder machine shop,no relation to me
it has 670 casting heads and 175psi cyl pressure i checked and its doing fine on our Ca. piss 91 octane, i dont know whats the pistons used in it (meaning SCR where it is) cam wise again i dont have details but it has 16to17" vacuum at idle and its 4spd manual car
the best part get this, its in a 1964 Chevrolet Impalla SS.

[Cliff R]

"Most the SS racers using Q jets use an adapter be they Chevy or Pontiacs."

Skip, last time I looked ALL of them were using adapters of some sort, and NONE of them had stock intakes under them.....Cliff

[Tom Vaught]

Thanks for the testing, Harry, and Merry Christmas and Happy New Year!

Tom Vaught

[rohrt]

Thanks for the testing info.

Anyone know the height difference between the intakes?

[Steve C.]

Presumbing the Crosswind is the same or similar height to the Performer RPM intake ?
If so Edelbrock suggests their RPM intake is about 1-1/4" taller than a "stock" intake.



.

[Skip Fix]

Cliff my point was the SS guys are making lots of HP and using an adapter so yes they might not be perfect flow but might not be as bad as we think in flow or mixture distribution. And early Rochester on a SBC and a Victor really looks weird! I remember back when there were lots of 2 BBL classes seeing them on an aftermarket intake looked off too.

Maybe someone with an RPM intake(Crosswind)use a square bore carb with an adapter(since intake has a plenum shaped for both), then the same carb with the same thickness square bore spacer if we want to really see what just the adapter does.

[Region Warrior]

By the graph, doesn't look like the original set up was optimum to begin with.

[harry k]

Originally Posted by 66 Gas Tires Oil

great post thanks for sharing. also, even if the plots were a perfect overlay the aluminum is much lighter and that in itself is a performance gain. just wondering why you mark the horsepower points where you did and not at the peak position. again thanks for sharing.

Jim

Jim & most here
I have lots of other tests similar to this intake test & so many different components(carbs-headers-power spacers, camshafts, ignition boxes msc etc etc) dyno testing performed in my shop and i don't post results here on daily basis due to some critiques coments that i have to rebuttal back at,in anycase anyone is curious about specific item what they would like to know and happens that i have dyno test results,they can always pm me direct and i can give them unbiased direct results,it doesnt matter for me what the concerend persons intent afterwards is & what they want to do cause i am not selling them products nor services as some do here,
but anyways to answer why i marked the cursor in the graph where i marked it is:
in street cars peak hp don't mean didly, you have to look at "area under the curve what it makes oppose to peak numbers". hope you understand what i am saying.

Originally Posted by The Boss

Thanks for sharing the results - the customer must have been happy, that's a noticeable change!

indeed it is ,and i didnt have to say to the customer. wait oh no you have iron intake and spacer (not adaptor), i have to buy you a Q-jet first and install it and if it makes more power you're happy, if it doesnt now oh lets remove it and start all over

Originally Posted by johnta1

In defense of Harry, the customer is using that carb along with the necessary adapter to run it on that intake.

So he would gain HP by the aluminum intake.

He didn't do a test for optimum combos for each?

If all I had was this carb, what would make me the most power?

My 2 cents.

John i like the termenology you have elected to use"In defense of Harry"
cool thing there as you can see somes rebuttal at this as i said above!
i like what youre saying here
"If all I had was this carb, what would make me the most power?"
the results are posted there buddy thanks for making it clear to some.

Originally Posted by David Jones

Thanks for sharing.
This proves that in this case, one combo as installed made more power than the other as it was installed on this car at this time. If somebody is interested in making exactly the same swap....you can possibly expect this result.

Originally Posted by Bruce Meyer

Thanks for sharing Harry. We need more unbiased test results published here. This confirms testing I did decades ago at the dragstrip. The stock UNMODIFIED manifold was not ever the best choice.

David & Bruce Thanks for understanding cause we're on the same page.

Originally Posted by Tom Vaught

Thanks for the testing, Harry, and Merry Christmas and Happy New Year!
Tom Vaught

Mr boost engineer same to you, you mean don't have few cents to throw at this.

[harry k]

Originally Posted by Kenth

Apple to apple would be using a carb that bolt up on both intakes w/o any adapter of any sort.

Today everybody knows an adapter between a squarebore carb and a spreadbore intake kills power.

Originally Posted by Cliff R

Glad you said it Kenth, as I hate to be the one to point out that NOTHING about that test was "apple to apple".

Installing a square bore carb on a factory spread bore intake with an ADAPTER doesn't correct the HUGE miss-match between the two components. The miss-match causes the air to have to make several "bends" to enter the plenum areas, which will kill power.

To be perfectly honest, I'm surprised the numbers are as close as they are......FWIW......Cliff

as i said in my post#8 the black thingee is spacer not an adapter
lets get the controversial smoke blowers to agree that this is not ADAPTER

this is a 3/8"tall spacer that was mounted between the edelbrock carb and iron intake , and also FYI Edelbrock carbs baseplate have dual bolt holes as i am taking extra time to post pic here to demonstrate that there is no ADAPTER used, spacer only with cast iron intake and sealing plate with aluminum intake!

[Cliff R]

Adapter or spacer is a play on words, it plays the same role here. Anyone with half a lick of common sense can see that there is still a terrible miss-match between the bottom of the square flange Edelbrock carburetor and the top of the 4 hole stock intake.

This is NOT present when the same carb is used on an aftermarket dual plane intake, so it will ALWAYS make more power.

I'll post some pics later to show how horrible the miss-match really is between the carb and the intake, and that the "spacer/adapter used only raises the carb up slightly to provide a slightly better shot at the holes in the stock intake.

"Cliff my point was the SS guys are making lots of HP and using an adapter so yes they might not be perfect flow but might not be as bad as we think in flow or mixture distribution."

Skip, completely DIFFERENT deal than what is going on here. They just use an adapter to get the carb bolted to an intake under it that has a FULLY OPEN plenum. There is no "miss-match", or anything close to it. The Super Stockers spend countless hours playing with those "adapters" and find pretty big gains with them. I have witnessed HUGE gains in power between two different ones on back to back dyno pulls, so there is something to gain by playing with those things.......FWIW.....Cliff

[Skip Fix]

Cliff agreed there is a mismatch, but there was also one on my car using the same intake(no plenum divider massaging) different carbs with adapter and it still picked up the car significantly-so the mismatch might not make a big deal is all I'm saying. There is also soem mismatch using an open spacer even with a Qjet as some of the primary flow can use that 1" to try and turn into the secondary hole yet hits the flat factory area between the bores.

And that Q jet had slightly bigger primaries so if we say my motor needed that extra 50 cfm the Demon provided might not be that 50 cfm amount more. And the Qjet had dynoed equal to 850 Holleys on several motors-even a 500 hp Buick.