PCV system with IR carbs

[maineSSS]

I've been slowly working up an Individual Runner carb set for my '49 Power Wagon- 3 CVK 40 Harley carbs. THe PW has a Positive Crankcase Ventilation system instead of a road Draft Tube, since it often did stationary PTO operation for hours at a time.

There is a pipe leading from the rear of the block to a fitting on the intake manifold plenum where crankcase vapor is fed into the cylinders. I'm thinking I could lead a tube into one carb runner (would feed 2 cyl), or into all three (would feed all 6 cyl). Feeding all three would "balance" -hopefully- the crankcase vapor input across all cylinders, and might also even out vacuum differences between cylinders.

I've heard of a "balance tube" used with dual/triple carb setups on cars, but have never seen one used on multicarb bikes. What, exactly, are they supposed to accomplish?

[greg g]

The balance tubes on a car engine tends to equalize the intake pulses as each carb is not feeding an individual cylinder. Plus as you noted they provide a place for steady manifold vacuum rather than depending on 2 or 3 pistons.

[40P10touring sedan]

If it were me, I'd try and feed all carbs...thinking of it this way, not only would you balance them out, but if you had any residual oil coming into the carbs, it wouldn't be sent to just one{2cyl} and start to darken just those.

Neat idea with those carbs...can we see a pic?

I've got this recent bug up my backend to try a pair of mid 80's single TBIs onto my twin intake manifold...the set up would be off of a camaro with the crossfire manifold and TBIs. Only thing holding me back is the electronics..otherwise it looks like it'd work...the motor was a 305 I think so they'd be just a tad oversized but they'd regulate that when set up properly.

[maineSSS]

40P10-

If you go to "Higher Performance 230 Rebuild", you'll see pics of the CVK 40 & manifold at post #63 (1st page).

I know of 2 instances where TBI has been used on the 230, one was a Lebaron unit and computer/harness, the other was a mid 90's Chevy TBI and computer/harness, both single throttle bodies. They supposedly worked pretty well, self-tuned thru the harness sensors. You might have a problem trying to control two throttle bodies via a single computer, and dual computers would likely have a constant competition with each other- I'd stick with one computer/throttle body setup.