single dominator vs tunnel ram

[Bob Hollinshead]

I seen a pontiac at the track once that had a tunnel ram and two q-jets and that manifold was made for them.

[pdq67]

I seen a pontiac at the track once that had a tunnel ram and two q-jets and that manifold was made for them.

Don't have a clue, but Offy made all sorts of Q-Jet manifolds back in the day..

pdq67

[LaVelle]

It seems the TR runner length plays a big part in the differences.
So what would happen with a single 4 intake designed with long runners of the TR to a regular single 4 plenum at TR height of 10" or so instead of 5"?

[F-BIRD'88]

You'd have a taller single plane manifold with longer length runners that tunes differently than a shorter runner single plane manifold does. The cross sectional taper of the runner also has a effect.

[67RS502]

It seems the TR runner length plays a big part in the differences.
So what would happen with a single 4 intake designed with long runners of the TR to a regular single 4 plenum at TR height of 10" or so instead of 5"?

Or what would happen if you had a webber set-up with the entire runner length (from tip of stack to valve) set for the desired rpm of you XXX cubic inch engine?
It would make great power in that rpm range, having the ideal intake track length for the harmonic, assuming the csa and taper are proper.
And we wont get into rpm-adjustable runner lengths like F1 engines.

[BrazilianZ28Camaro]

It seems the TR runner length plays a big part in the differences.
So what would happen with a single 4 intake designed with long runners of the TR to a regular single 4 plenum at TR height of 10" or so instead of 5"?

Or what would happen if you had a webber set-up with the entire runner length (from tip of stack to valve) set for the desired rpm of you XXX cubic inch engine?
It would make great power in that rpm range, having the ideal intake track length for the harmonic, assuming the csa and taper are proper.
And we wont get into rpm-adjustable runner lengths like F1 engines.

The t-ram plenum also do wonders.

[MadBill]

..Or what would happen if you had a webber set-up with the entire runner length (from tip of stack to valve) set for the desired rpm of you XXX cubic inch engine?
It would make great power in that rpm range, having the ideal intake track length for the harmonic, assuming the csa and taper are proper.
And we wont get into rpm-adjustable runner lengths like F1 engines.

Unfortunately, there are no Webers big enough to properly feed most V-8s. A 6500 RPM 383" would ideally need ~ 58 mm bores.

[wyrmrider]

Let's see
DOHC Ford
4 intake tracks and a weber per cylinder

[MadBill]

It sure would look cool...

[67RS502]

ok, if weber wont work (I think Vizard did it) ... then some old mechanical injection with stacks. That will make it ideal.
But it just comes down to the right csa, runner length, shape (straight at the valve) and taper, and than theres the plenum too.
So which intake is closest to what you need.
Theres too much going on in the plenum for me, it over my head.
A lot going on in the floor of a single plane, but the TR doesn't really have one, does that help?

[prairiehotrodder]

Has anyone had experience with the Holley Pro-dominator BBC tunnel ram? Its not being made any more. The part number is 701R-32 and 300-32. The carbs are slightly offset from each other instead of being perfectly inline. I found a used one that comes with a pair of Dean Nicherson Methanol carbs.
Brian

[Newold1]

Hey guys,

Why don't we start thinking out of the box here! Lets quit putting so much thought and effort into trying to take old technology and bolt it on newer modern better performing heads and engines and come up with a fairly moderate new idea that's doable.

When you consider how expensive racing Holley carburetors are ( 2 required for a tunnel ram) and the fact that most all the current single carb and tunnel ram manifolds need expensive porting and need spacers. Why don't we think of making a new intake manifold that brings all four runners on each side of the V-8 engine into a simple center base where the need for a big plenum in eliminated by having an inline 4 barrel carburetor with the throttle sizes somewhere between 2-1/4" and 2-1/2" each that each feed two cylinders opposite one another but the ports will be very even in volume, shape and allow a straight tapered entry into the head port with all the runners being equal in length. Why do tunnel rams need plenums, Its because the individual throttle blades in the carb are not of sufficient size to feed the total cfm with 1.5"-1.75" throttle blades. This design intake and carb combo should provide up to about 2000cfm which should feed most of the hungry monsters we are discussing here. For fuel injection the carb would present as a throttle body only and the intake would have to be drilled bungs for separate individual injectors. Why keep trying to make a single carb intake manifold feed all eight cylinders evenly form a single center location where the runner lengths are uneven and the intake manifold runners have to curve and change direction especially in carb applications where the air mass is mixed with fuel (wet) as it leaves the carb.

Look, I am not saying there are not already many fabricated tunnel rams using 2000-3000cfm billet spread port Accufab throttle body intake systems being used and that are available. The point being these are $4,000 to $8,000 intake systems and more! What I am talking about here is a simple casting intake that should with reasonable quantities should cost in the $500-600 range and a simple billet 4 throat carb should be able to be manufactured and sold in the $1000-$1200 range maybe less in quantity. This would mean the whole system should price out at about $1500-$1800 range about the same as one would put out for a good new tunnel ram and two good Holley racing carbs with linkages and fuel line couplers. This system would also have the advantage of what should be a smoother more street friendly or street strip friendly intake system with nearly IR type manners.

Just my musings here on a better mousetrap! What are your thoughts?

[prairiehotrodder]

Newold can you please take down your post. Maybe start your own thread on the subject if you like.
Brian

[Old School]

Has anyone had experience with the Holley Pro-dominator BBC tunnel ram? Its not being made any more. The part number is 701R-32 and 300-32. The carbs are slightly offset from each other instead of being perfectly inline. I found a used one that comes with a pair of Dean Nicherson Methanol carbs.
Brian

Brian, I have ran tunnel rams since 1981. I find them more consistent, more power and torque everywhere. Let me clarify that I did not drive them on the street, but bracket only race car.

I have run the Holley, Weiand, and Edelbrock tunnel rams. There is very little difference in performance with the same carbs on either intake. The Edelbrock has the longest runners, the Holley the shortest. All picked up .02-.03 over a good 850dp and single plane in the quarter. Carb size will not make as much difference in et as you would think if tuning is close. I have not run methanol carbs so I cannot offer any advice there. I would think the alcohol would make more torque in your application.

Getting back to the carb size. I had a friend that ran a 2450lb pro built Lumina. He had a 406 small block with tunnel ram and 4779 dp Holleys. He traded the 406 to a 632 and all the carbs he had was the 750's. We mounted those on the 632 just to try the engine. The car ran 4.84-143 in the 1/8th. Thinking a pair of dominators would run a lot quicker
he bought two new custom 1150's for the 632. The car picked up to a 4.79-143.8. He tried different dominators but all ran about the same, still faster but the 750's weren't too bad. Just trying to tell you from experience, not I heard or someone said or I read on the internet.

This was 15-20 years ago. The single plane intakes are better today and the carbs are more tuneable so maybe a tunnel ram will not show the gains it did back then. I still think the TR will show you improvement.

[Newold1]

Yes Brian
I will take down my post.
Sorry , not trying to distort or hijack you single versus tunnel ram thread
Newold1