Question re: High balance tube manifold

[jbcollier]

My apologies. The stock air box has "room" for trumpets but you will have to modify them to fit.  One way would be to cut out the trumpets for the mounting bolts.  Myself, I would use short bolts to secure the backing plate and trumpets and then use an airbox cover from a Weber/Dell set-up for which you would have to make up custom mounts.

[Pfreen]

on our dyno tests the larger the balance pipe (without going overboard) the more power & a smoother engine will be made on SUs & Strombergs, this is in line with David Vizards findings, it also pays to flow / blend the balance pipe entry from the manifold.

Do you know if there have been any dyno runs to determine if air trumpets on Strombergs or SUs make any difference in power. I don't think, just eyeballing the stock airbox, that there is enough room to fit trumpets inside the airbox. Also, I'm assuming trumpet length makes a difference on power.

On balance tubes, any idea if the location of the balance tube make any difference? One of my TCs have a balance tube moved to the cast portion of the head where the inlets are siamesed to the intake flange.

I answered this question in June of 2020.  I don't know how to reproduce that post here.  Search under balance tube.

Anyway, the engine runs great and was dynoed at 130 HP at the rear wheels.  I have trumpets but they would never fit in the stock air box.  Photo attached.  I do not have a back to back dyno test however.  Bell mouth inlets are much better for airflow than a sharp edge, which the carb has without the trumpet.

[literarymadness]

@jpane: I would love to see what you did. Please post a photo if you can.

[jpane]

I will get one tomorrow, and post. My mechanic made a bracket for the throttle cable out of angle aluminum.
Right now we've got a fitting in the breather opening, and will put a hose on that and maybe look at the filters for crankcase venting. When I got the car it just had a rubber tube fitted that curved down and just venting to atmosphere.

[Kendo]

I just bought two of those trumpets from RD. I still haven't figured out how to bolt them into the stock air box, since it has those molded in mounting tubes. Any ideas?

[jbcollier]

Quick and simple. cut reliefs in your new bell mouths to clear the mounting bolts and spacers.  You will still have way better flow than stock.

Better, mount the bell mouths and backing plate using short bolts.  Adapt the air box cover from a Dell air box.