tunnel ram and 2 4's?

I'll have to pull a carb off and look at my mounting holes on my tunnel ram - all of this talk has me curious

 

Many tunnel rams do have two sets of holes(I believe all of the 351c intakes do). Niether of the ones for a 302 (Wieand or Offenhauser) do.

 

Mike I had carbs mounted sideways on my Weiand for a while but they were way to big. When I had the money, I swapped them to inline mounted 600's which were still to big. All in the day when this kid thought bigger was better.

Had I not had the sideways mounted carbs, I would not have experienced over centering the linkage and locking 2-4's wide open in a small parking lot. I can laugh about it now but one of those things I check for today.

 

you had to have crapped your pants. I know I wouldve

 

Carb

If You step up to the tunnelram go with the 390's. They are vacume secondaries where the 450's are mechanical. To run the 450's you will have to throw a much larger cam in, headers, up the compression. Also with the 450's because of the mechanical secondaries you will have to experiment with the primary squirters and up the accelerator pump size to the 50 cc . The 390's are more tuneable for mild street applications.

 

I have had the 450s on mine for about eleven years with 9.2: 1 compression ,and the stock accelorator pumps.

As I said in post #13 it runs pretty much "perfect".

 

I stand corrected. The Weiand DOES have bolt holes for sideways mounting.

I owned (never ran ) one back in the late eighties, but I had forgotten this.

 

Another note on the Weiand is the top half is the same as a small block Chevy. When I got mine it had a single 4 top and I purchased the dual top later.

 

After seeing your picture, I don't have to take one of my carbs off of my Weiand now to check - I remember it having the 2 sets of mounting holes

 

Just like anything else things need to be mod'd to compliment each other and fine tuninmg can do wonders sometimes. But IMHO, many over estimate that their little engines require 900 cfm of airflow when in reality they barely need 600.

The basic rule is that smaller diameter venturies provide better booster signal. Period. Having stronger idle/off-idle signal is not a bad thing on a tunnel ram'd street car so long as the engine gets all the air it needs and throttle response/average torque will almost always go up. That's why annular discharge mod's work so well with big intake/cam/carb combos because they compensate for poor signal with the stronger booster. And in many cases some even swap their straights for downlegs or annular even at the expense of total airflow capacity. That's because average power across the band will almost always be better for a street car and it will be quicker and funner to drive.

From all that I've built.. seen.. and raced.. it surely appears that small displacement engines, regardless of who mfgrs them..the 390 is much better for the street with milder cams/gears or added weight.. and the 450's are better for lighter hotter cars. You'll likley need to run 50cc pumps on the 390's though.. whereas the 450's can sometimes, depending on cam/exhaust.. avoid having to use them if the pump cam/squirter is agressive enough. The lighter the car and shorter the gear.. the less pump you'll need.