Don Terrill’s Speed-Talk

Have a friend that had a 511 cube 426 Hemi with the Indy Stage 4 heads and Indy intake that was like that Tunnel Port intake.
He ran dual 750 Holleys on it and the throttle response and mid range pull was excellent.
Looking back on the FE 427 Tunnel wedge intake in my 1969 Ford Muscle Parts catalog it was recommended for 6000 up RPM and not for
street use.
I don't know what runner size Jim had planned for that intake.

I'm just going to keep what I'm running now for all around street use. What I put together is packaged well and I'm in my sun setting years of hot rods now.

427dart wrote: ↑Sun Feb 11, 2018 1:30 pm I'm just going to keep what I'm running now for all around street use. What I put together is packaged well and I'm in my sun setting years of hot rods now.

I'd still like to tempt you to try your 2 4bbl carbs on a 2x4 carb adapter bolted onto
your single plane 4bbl racy intake. It will be a lot like a tunnel port, AND have the benefit of the Progressive throttle, + big max carb cfm capacity and "streetie" carbs too. You cannot get that with a single BIG 4 bbl carb. (4500 holley)

Much more top end than your dual plane 2x4. Much more throttle progression
than a big single 4 bbl. Small primaries for "crusing" (driving it). Big cfm and RPM at WOT when you want power.

You are good at fabrication and can do this with what you got to get the best out of it overall. You will end up with something uniquely better than you can buy.

The Indy ModMan 2x4 intake gets improved low rpm torque and throttle response
by adding a plenum divider. You can make this intake BETTER for a street car with this tweek. A tunnel port style tunnel ram (Ford FE Tunnel Wedge intake) can also benefit from tweeking the plenum (divider etc) for a street driven car.

We must also remember the intended use for the Tunnel Port design..... Kick butt on the Superspeedways and operate in a very small but high RPM range!

While they look awesome...other designs will blow them away in street apps....just my opinion though. 427dart I believe you would see a good gain from a long runner Tunnel ram such as what I am doing.
..after having the new Holley Hi-Ram in my hands and flowing it on the bench. I filled in the bottom of the runner about a .5" with clay and DIDNT see a flow loss..., I think the runners are too big to produce what I would call good street manifold. On a 7500-8000 427-440 is where that baby should shine...

Once we get my junk on the Dyno perhaps we will see.

David has a 427 with Trickflow heads that are flowing around 340cfm hopefully we can see the benefit of it on his setup...

F-BIRD'88 wrote: ↑Sun Feb 11, 2018 1:40 pm

427dart wrote: ↑Sun Feb 11, 2018 1:30 pm I'm just going to keep what I'm running now for all around street use. What I put together is packaged well and I'm in my sun setting years of hot rods now.

I'd still like to tempt you to try your 2 4bbl carbs on a 2x4 carb adapter bolted onto
your single plane 4bbl racy intake. It will be a lot like a tunnel port, AND have the benefit of the Progressive throttle, + big max carb cfm capacity and "streetie" carbs too. You cannot get that with a single BIG 4 bbl carb. (4500 holley)

Much more top end than your dual plane 2x4. Much more throttle progression
than a big single 4 bbl. Small primaries for "crusing" (driving it). Big cfm and RPM at WOT when you want power.

You are good at fabrication and can do this with what you got to get the best out of it overall. You will end up with something uniquely better than you can buy.

But what about the angle the a/f flow would have to make traveling from the out board carb venturies?
The rear carb primary barrels would be a good ways from the manifold plenum opening with the rear carb being backwards for linkage and fuel bowl clearance.

Casper393W wrote: ↑Sun Feb 11, 2018 2:00 pm We must also remember the intended use for the Tunnel Port design..... Kick butt on the Superspeedways and operate in a very small but high RPM range!

While they look awesome...other designs will blow them away in street apps....just my opinion though. 427dart I believe you would see a good gain from a long runner Tunnel ram such as what I am doing.
..after having the new Holley Hi-Ram in my hands and flowing it on the bench. I filled in the bottom of the runner about a .5" with clay and DIDNT see a flow loss..., I think the runners are too big to produce what I would call good street manifold. On a 7500-8000 427-440 is where that baby should shine...

Once we get my junk on the Dyno perhaps we will see.

David has a 427 with Trickflow heads that are flowing around 340cfm hopefully we can see the benefit of it on his setup...

I'll be watching for your dyno results!

With correct plenum shape and height it won't matter much.

The car will drive mostly on the front carbs (in your case)
primaries, which are near centered.
Use progressive throttle linkage.
You could also do this with 3 x 2bbls.
Or do it like my dual qjets scheme by only using 6 of the 8 barrels. Those far away primarys are not used , not exposed to the plenum either. This gives you a symetric venturi pattern over the plenum. A "six shooter" using 2 4 bbl carbs.

You could do this with your 2 holleys or use 2 Qjets
or try both.

In your case with the 600 vs carbs I would use a all 8 barrels.
1200 cfm + vs 's + progressive linkage.

2x4 afb or AVS(2) carbs is another option.

F-Bird'88... have you seen this setup for streetrodders

https://www.speedwaymotors.com/Three-Pl ... vUQAvD_BwE

Andy

Is this what you are kind of suggesting?

run this on the street no drive ability issues up to 24 mpg highway,

Casper393W wrote: ↑Sun Feb 11, 2018 4:18 pm F-Bird'88... have you seen this setup for streetrodders

https://www.speedwaymotors.com/Three-Pl ... vUQAvD_BwE

A

Is this what you are kind of suggesting?

No, this is way too log style. I am thinking something with a slopped floor.
A more of a funnel under the carbs. But yes with a bolt on removeable top.
This is way too simple and $$$$.

This blower carb adapter plate could be a start point.

This Holley Hi Ram top could be used as a base if flipped over (cut your own 4500 pattern hole) Then a dual carb top plate bolts to this. BUT fill the inside "plenum" so it has a V funnel shape with floor ribs instead of a flat floor. Give any wet fuel direction. If you can tig weld you can weld up your own V funnel shaped base.

Make the V funnel transition say 2.5" to 3" tall for a smooth transition.
It still ends up shorter height than a tunnel ram overall.
The front and rear walls/to floor shape of the adapter will be angled
depending on the top carb spacing. EG 2 holleys inline or 2 afbs's inline.
Inline mounting allows for a internal divider and simple throttle linkage.
Once the top is bolted on whats inside this "plenum box 2x4 adapter" is your lil secret.
3x holley 500cfm 2bbls would be fun too. Use a progressive mechanical linkage.
Once the bottom base is built you can use and carb top plate you want on it.

2x4 side ways mounted holley double pumpers is a option.
EG 2 750 HP's

This Edelbrock split plenum adapter could be a starting point for the base.
V out the holes lengthwise to create the start of the V funnel transition.
Dual carb to single manifold transition.

https://www.speedwaymotors.com/Edelbroc ... 08808.html

A split plenum will help a racy single plane manifold be more street friendly.
The divider can be full or partial..
Think about what I can fabricate. Not what I can buy.
Anybody can buy shit.

Here is a B&B 4 hole 4500 carb spacer you can use as a start point base.
Add a plenum divider under it that splits the Dominator intake manifold.
V out the 4 holes in the spacer into 2 V funnels. Build a 2x4 to single V Transition spacer on top of it. Add a bolt on 2x4 carb top.
This is not that hard.
http://www.jegs.com/i/B-B/128/65710/10002/-1

I've got an old Weiand tunnel ram with 2 850 Carter Thermoquads on my 605. Starting, low speed drivability, cruise, and WOT are amazing. It makes more horsepower, and more torque than any single 4 manifold and carb I have tried. It made 765 ft lbs. at the start of the Dyno pull,(3500 rpm). The throttle linkage is 1 to1, driving it nice is 10mpg. 4.56 gears, 4800 convertor, .767/.676, 288/292@.050.