Don Terrill’s Speed-Talk

Anyone tested and compared a single plane intake in contrast to a tunnel ram with a single carb top?

What was your personal findings?

Thanks in advance!
-Poppy

curious myself

like the intake above against a single plane.

I have tested on a good SB Chevy, and when you get the tunnelram right, it will be about 35 or 40 HP better than say a super victor. It is hard to get a single four barrel on a tunnelram to work right. This was on a 400 Chevy that made 822 with two 850 carbs, 804 with one Dominator, and 765 one dominator on a super victor.

JO SHERMAN RACING ENGINES

Greetings, speedtalkers,

An interesting synergy just struck me in reading the question and the intake photo posted by bigpoppapreston and bigjoe1's earlier comment about the early Torquer manifolds not performing well. Joe's experiences were similar but different to my frustrations with the early Torquer on a 302 SBF. His BBC required much leaner main jets. My SBF required much richer idle and off-idle. Trying to make it work, I had to build a four-corner idle Holley back before they were sold by Holley. Street-driven fuel economy was down by 25% over a dual-plane F4B and standard DP Holley. Power was up not at all.

Here's the thing - the early Torquer intake angled the carburetor and the runners in an attempt to equalize all eight insofar as possible. For whatever reason, my guess is the sharper turn from the intake runner to the intake port, it didn't work as hoped.

The pictured intake and tunnel rams in general raise the carburetors high, uses a large plenum and keeps the intake runners a straight shot down. This may be why the tunnel ram works so well with two 4-bbls and is much more difficult to tune with one carb.

Bottom line, every tunnel ram in my experience made more horsepower and torque than any available single plane intake, if the heads and cam were up to the challenge. I have visualized a dedicated single-carb top for a tunnel ram which would raise the carb yet higher, but smooth the transition from the plenum to the runners. (This vision may have been inspired by photos of the original Ramchargers Ram Rod '49 Plymouth coupe tunnel ram setup I saw in November '59 HRM at an impressionable age. Tunnel rams became an industry standard, but the megaphone exhausts never caught on. Looked trick, though)

I have never played with a tunnel ram but was thinking maybe two two barrel carbs would work better than one single four barrel. Maybe even 3 dueces.

[quote="1989TransAm"]I have never played with a tunnel ram but was thinking maybe two two barrel carbs would work better than one single four barrel. quote]

You hit the nail on the head with this one. Many tunnel rams with a single 4bl do not work as well as a good cast single 4bl due to the fact that the runner placement was designed for two carburetors.

From what I've seen if you are limited to running 4 barrels, than using a good tunnel ram with two 2bl carburetors is the way to go. I've got some guys out there running Small Blocks like this without an issue, we just did a pair of 2.400" Butterfly 2bl's for a sand dragster.

But here's the thing, many classes do not allow split carburetors as their are viewed by those who consider them 2 carbs instead of one thats been split.

It would however be nice if one of the classes that I plan on running in allowed a single dominator thats been split into two halves like the one pictured below.

bigpoppapreston wrote:But here's the thing, many classes do not allow split carburetors as their are viewed by those who consider them 2 carbs instead of one thats been split.

It would however be nice if one of the classes that I plan on running in allowed a single dominator thats been split into two halves like the one pictured below.

What class are you racing in?

I plan on running in 2 classes at a local track here in Milan Michigan. Milan dragway specifically.

The classes are N/A 10.5 and Outlaw 10.5.

The latter is pretty much no hold barred and allow anything you can put on 10.5w tires including tube chassis door cars.

The N/A 10.5 is a true 10" tire all muscle class that only allow cast intakes and a single carb.

So you can run a tunnel ram intake so as long as it's cast.

Since you are allowed only to run a single carb, no split dominators are allowed as they are viewed as a 2 carb setup unless you run just 1 half.

By the way, a N/A 10.5 car here at Milan ran in the 8.30's at 2950 lbs with a nasty small block ford with a modified cast tunnel ram intake.

bigpoppapreston wrote:The N/A 10.5 is a true 10" tire all muscle class that only allow cast intakes and a single carb.

So you can run a tunnel ram intake so as long as it's cast.

Since you are allowed only to run a single carb, no split dominators are allowed as they are viewed as a 2 carb setup unless you run just 1 half.

That sucks... Most of the classes down South let us do that. Talk to the tech people and see what they say.

Yeah they say it's really two instead of one.

Hello poppy

what tunnel ram is that SBF running? What distributor??? If you see the car with his hood up next time - could you take a peak??

Thanks

talon wrote:Hello poppy

what tunnel ram is that SBF running? What distributor??? If you see the car with his hood up next time - could you take a peak??

Thanks

Here's some video of the car on a stout pass.

Click--> http://tinyurl.com/2dbbab