Single Plane vs Dual Plane Intake ?

[C_Stock_409Chevy]

saying I "beat Edelbrock" ? ?
Of course not. Stupid thing to say, all by itself. I simply made an over-the-top statement, to try and level out the over-the-top comments that were obviously being said, to try and cut me down to size.
Lets be ABSOLUTELY clear here. The factory cast iron intake for these small port W blocks, is best suited to a powrglide,pulling a travel trailer. Up until a few weeks ago, the only other single 4 barrel, was the Edelbrock Performer RPM. A damn good manifold, as dual planes go. Out of the box, it typically picks up about 20+ HP over a stock intake. In this case, because of a nice cam, it picked up 35 HP.
What's wrong with that ?
And now there's talk of the factory aluminum pieces ?
Holy-oh-schitt-face, batman ... have you ANY IDEA how much of a piece of crap the factory intakes are for the large port engines ?
I built and at the moment, run the fastest NHRA legal Stock Eliminator 409 car in the world ( at the moment... a guy out east may best that pretty soon ). There are about 5 of us out there, with 409 Stockers. We have been victimized first hand, by the mind-numbing inefficiency of the factory aluminum intake... single or dual 4 barrel. A number of tests with the Edelbrock 2X4 have been done, showing that their new intake, that doesn't have those astonishing jagged right angles in the runners, typically picks up 18-22 HP, with no other changes.
It's still just a dual plane.
On these goofy engines, as I mentioned, these is a fundamental design chracteristic, that can be overcome, ONLY with a single plane intake manifold... of \some configuration.

Vortec.. dyno tests for my Stocker engine ?
Hee HEE !
In Stock / Super Stock world... those are "secret":
423 CID... 490 ft lb torque @ 4500-4700 RPM... 530 HP @ 6500-6600 RPM.
Shift at 7000-7100. At sea level, goes through the traps at 7250.
I've had a few gremlins though. The intake lobe on the cam, has proven to be virtualy impossible to control ( very heavy valve ). And, my old Mcleod soft lock clutch, has been a slipping nightmare since day one. Rob Youngblood is looking after that.

[novadude]

saying I "beat Edelbrock" ? ?
Holy-oh-schitt-face, batman ... have you ANY IDEA how much of a piece of crap the factory intakes are for the large port engines ?
I built and at the moment, run the fastest NHRA legal Stock Eliminator 409 car in the world ( at the moment... a guy out east may best that pretty soon ). There are about 5 of us out there, with 409 Stockers. We have been victimized first hand, by the mind-numbing inefficiency of the factory aluminum intake... single or dual 4 barrel. A number of tests with the Edelbrock 2X4 have been done, showing that their new intake, that doesn't have those astonishing jagged right angles in the runners, typically picks up 18-22 HP, with no other changes.

I've always wondered the reasoning behind the sharp. 90 degree bends in the ports on the early Chevy performance intakes. 63-66 340/350/365hp 327 mainfolds all had the same right angle bends as the 409 manifolds.

Does anyone know why they were designed this way? It just looks all wrong from an airflow perspective. Did the engineers have some theory that these sharp bends would keep fuel in suspension or something?

Those early-60s manifold designs were worlds apart from the L72 / Z28 manifolds they started introducing in the 66-67 time period.

[SchmidtMotorWorks]

I've always wondered the reasoning behind the sharp. 90 degree bends in the ports on the early Chevy performance intakes. 63-66 340/350/365hp 327 mainfolds all had the same right angle bends as the 409 manifolds.

Does anyone know why they were designed this way? It just looks all wrong from an airflow perspective. Did the engineers have some theory that these sharp bends would keep fuel in suspension or something?

Those early-60s manifold designs were worlds apart from the L72 / Z28 manifolds they started introducing in the 66-67 time period.

Often times, designers don't know how to design for casting so they have a pattern maker make a prototype and start from there with the intention of improving it later. In that era, a pattern maker would have used wood working tools like band saws and he probably had no clue about design for flow. By the time the prototype is done, priorities change, they forget about plans to improve it and they just make a drawing of the prototype and go into production.

[F-BIRD'88]

I've always wondered the reasoning behind the sharp. 90 degree bends in the ports on the early Chevy performance intakes. 63-66 340/350/365hp 327 mainfolds all had the same right angle bends as the 409 manifolds.

Does anyone know why they were designed this way? It just looks all wrong from an airflow perspective. Did the engineers have some theory that these sharp bends would keep fuel in suspension or something?

Those early-60s manifold designs were worlds apart from the L72 / Z28 manifolds they started introducing in the 66-67 time period.

Often times, designers don't know how to design for casting so they have a pattern maker make a prototype and start from there with the intention of improving it later. In that era, a pattern maker would have used wood working tools like band saws and he probably had no clue about design for flow. By the time the prototype is done, priorities change, they forget about plans to improve it and they just make a drawing of the prototype and go into production.

Or they were designing for a specific runner length and carb pad height, without much reguard for flow and top end horsepower. Most were after low rpm torque and stock OEM drivability.

[rally]

Yes maybe some of those early small bloc and big block factory intakes were not the best designed, but the L-72, L-78, L-88, ZL-1 intakes were pretty good and still used today on drag strips. I sure Duntov had some say on those BB Chevy engines and when those intakes were designed. Lot of these intakes were copied by after market companies. Bill Howell the famous Chevy engineer worked on those ZL-1 projects.

[cjperformance]

C-Stock-409Chevy do you have some pics of the stock intake for the 409? I have never seen a factory intake for these. And would you have some more pics of your new intake. Thanks.

[rally]

1962 63 64 Chevy Impala SS 409 2 x 4 Factory Dual Quad Intake Manifold 3814881 | eBay Try this cjperfoamane, go to ebay and type this in. Great pics of a factory dual quad 409 intakes. Good breathing capabilities.

[C_Stock_409Chevy]

Rally, you're just not gonna let go of that dual plane stuff, are you ? !

You can search 409 400 horsepoer intake ( aluminum large port, single 4 barrel )
The small port, which is what goes with the heads on the test engine, is a 1963-1965 409 340 horsepower intake.
There was an extremely rare aluminum single 4 barrel for the high perf 348 engines, late 1959-1961. I've never even seen one before.

[vortecpro]

Thanks for the dyno numbers. What weight do you run at, and how fast do you go?

"The intake lobe on the cam, has proven to be virtualy impossible to control ( very heavy valve )."

Remember: Theres alway a way.

[rally]

C-stock good luck on your intake project. Looks to be a nice piece for sure. Yeah i am old school and love factory hi po parts Chevy designed for their engines back in the day. I let the dual plame debate go. I have seen some real quick 409 dual quad 62 Chevys in my day with the factory intake setup at the strip. This single plane- dual plane debate is good. I like dyno testing, but i like to see results on the strip. Thats just me.

[C_Stock_409Chevy]

What weight do you run at, and how fast do you go?

"The intake lobe on the cam, has proven to be virtualy impossible to control ( very heavy valve )."

Remember: Theres alway a way.

Even with 5.13 gears, it doesn't 60 ft very well. Needs some experienced tuning for sure.
However, my minimum for C Stock is 3635, wih me in it.
At 3670, I went 11.06 @ 122.74. ( a 1.60 60 ft )
It'll run high 10's, but I gotta get the 60 ft where it should be... upper to mid 1.40's.
My new clutch will help.
Since I ran last, I got a few pounds out of the car, ( and I lost 25 pounds myself ! )... so I typically weigh in right at minimum..- 3640.
No ballast in the car, which probably effects the car's weight transfer a bit. Trouble is, weight would put me in D, and I'd have to add about 190 pounds. Don't like that.

Always a way ?
Not with that intake lobe, there wasn't !
After going back and forth with Comp... they finally said... "you can't rev that lobe" !
That's what I've been trying to tell ya' ! ! !
They have "torque lobes", and "RPM lobes".
THe rep that i dealt with, ran with that sick old adage... "that 409 makes a lotta totrque"
That gets old
They don't.
3.5 inch stroke... it needs to see some RPM.

[novadude]

What do you use for a rear axle in that C/stock car? Those 55-64 rears were fragile even for stock 409 cars on street tires. My uncle had a 64 425/409 back in the day, and I think he said he tore up 9 rears in two years of street-only use (daily driving and street racing) back in 1966-1968.

[289nate]

High 10's are a decent 60ft away and Rob Youngblood will be able to help with that. I have one of Rob's entry level clutches and one of his flywheels. I've been very happy with his product and service.

[vortecpro]

What weight do you run at, and how fast do you go?

"The intake lobe on the cam, has proven to be virtualy impossible to control ( very heavy valve )."

Remember: Theres alway a way.

Even with 5.13 gears, it doesn't 60 ft very well. Needs some experienced tuning for sure.
However, my minimum for C Stock is 3635, wih me in it.
At 3670, I went 11.06 @ 122.74. ( a 1.60 60 ft )
It'll run high 10's, but I gotta get the 60 ft where it should be... upper to mid 1.40's.
My new clutch will help.
Since I ran last, I got a few pounds out of the car, ( and I lost 25 pounds myself ! )... so I typically weigh in right at minimum..- 3640.
No ballast in the car, which probably effects the car's weight transfer a bit. Trouble is, weight would put me in D, and I'd have to add about 190 pounds. Don't like that.


Always a way ?
Not with that intake lobe, there wasn't !
After going back and forth with Comp... they finally said... "you can't rev that lobe" !
That's what I've been trying to tell ya' ! ! !
They have "torque lobes", and "RPM lobes".
THe rep that i dealt with, ran with that sick old adage... "that 409 makes a lotta totrque"
That gets old
They don't.
3.5 inch stroke... it needs to see some RPM.

Thanks for the data! Looks like the clutch is your problem, C going to be a tuff road to climb, good luck.

[140Air]

I've always wondered the reasoning behind the sharp. 90 degree bends in the ports on the early Chevy performance intakes. 63-66 340/350/365hp 327 mainfolds all had the same right angle bends as the 409 manifolds.

Does anyone know why they were designed this way? It just looks all wrong from an airflow perspective. Did the engineers have some theory that these sharp bends would keep fuel in suspension or something? .

In manifold design the first order configuration is the "log" manifold. You see it in ventilation systems as well as engine manifolds of all kinds. The log gives a reasonable distribution of flow to all the branches. If you were going to cobble up a manifold blind, you should make it a log. Blind means without flow porting. Poster "ras" said that Chevy did not do flow porting in the '60s. The existence of those log manifolds is supporting evidence of that claim. I question ras' claim when it comes to the 66-67 Z28, 302 hirise that looks and works like it was flow ported.