SINGLE CARB MOD

This should get interesting...

 

Ditto on that. I just hope that the pictures keep coming as progress is
made.

 

Zookie are you going to retain the stock carb mounts to attach the manifold? Is the bike your building this for currently running?

 

i know it wouild be a total pain in the butt to make,but since you plan to stik a runner tween pots 2 n 3,would it not b better to use a couple of runners tween 1 n 2 and 3 n 4,and maybe angle them together to form a 1 into 2 into 4 mainifold.they would then b more or less identical lengths.

 

ditching the manifold rubbers and flange mounting to the cylinders?

 

theres guys on tcu that have single carb mods.

one guy has a kz1000 with a single carb that he just uses to ride around the farm, lol.

 

here you go bobe....not much but i worked on it for a few minutes again today. dont laugh at the welds, my smallest wire i have for the welder is .045, a little too hot for the thin stuff function over fashion!

i will be using the stock rubber intake flanges to save time.

this is how i got the runners lined up to be sure they would fit perfectly into the rubbers:


then i welded it up:


i broke my good camera, in case you didnt notice.

 

It certainly looks cool Zookie, but don't you think you may have problems with equal distribution to each cylinder. Think about it, it will be a short trip to the closest cylinder (Probably will run rich, but the one on the opposite end will be sucking wind because of the air fuel mixture being used up before reaching it. My opinion, it would work better with the single carb in between the number 2 and 3 cylinder, but try it your way first, I wouldn't want to interrupt you.

 

Welds look good to me. Putting the carb between 2-3 would probably give
the best fuel air mix to the cylinders. 2 and 3 will be a little bit richer but
for this experiment should not be a problem. When you get it running the
plugs will tell the story. If nothing else this mod has caused a lot of interest.

Bob

 

i am going to try and get the intake charge to come into the rail between 2/3 if i can. if not, i am not too concerned because it has never been a problem when tuning an inline 6 with unequal runner lengths.

 

That may be because the internal of the manifold are drilled to give equal flow, as is hinted by the separation of the chamber on the image you posted.

 

To help with the problem of a "dry" charge here, and a "wet" charge there, depending on the different runner lengths, you could secure a stainless scrubbee under the carb, so that the droplets wet-out into the mesh, helping to evaporate and homogenize there. Then each CYL gets a more uniform charge regardless of runner length.

Get fancy and plumb-in an oil line for extra vaporizing heat.
Check out vaporizer carbs here -

http://www.rexresearch.com/auto/carbusp.htm

 

the manifold i posted is a dual port, each runner has 2 ports in it, one for primary and other for secondary feed. its not for equalizing flow, but for keeping low speed velocities high. it just broadens the torque curve.

a heated carb spacer could be an option. a lot of people run them on the 300ci fords to improve vaporization.

 

Zookie do you mean dual plane?

 

Wouldn't the vacuum pressure of all 4 carbs create an equal amount of volume being distributed to each carb?

 

the longer the intake tract the worse the throttle response will be.
when it goes from one throttle setting to another the charge in the intake has to get used up first.
when going from idle to 1/2 or full will there be enough vacuum to draw fuel through the mid or main circuit ?
remember how bad a 4 barrel ran when the accelerator pump wasn't working

 

The subject line says single carb mod?
You have 4 hooked onto the pipes.
I guess Im not really seeing what the end result SHOULD be.

Is this going onto a car? I cant see how this will bolt up or squeeze into the manifolds OR are you trying to run two pods?

 

Bill, he is going to make a carb attachment of some kind on the middle of his creation similar to the last image on page two of this forum. The 4 pipes you see coming off the one or to attach to the intake side of the motor.

That why we are having this discussion of putting the carb in the middle, and the pipes closest to it would receive more fuel mixture than those on the outside.

Hope that helps.

 

And I assume he plans on capping off the ends of the main pipe. I see what you are meaning as far as the pods, but those will be closed.

 

wow lots of questions! ok....
-ends will be capped
-the higher volume intake tract should be ok when giving more throttle, but will have a "drive by wire" like delay when returning to idle. i am ok with that, within reason.
-Bill, i used the carbs to position the runners. now i know it will fit into the same rubber flanges that the carbs do. (the ones bolted to the head)
-waldo, dual port, very different than dual plane. there are not many good pics of it, this was the best i could find. each single intake port on the head of the engine would equal two ports on the manifold, each runner is actually two runners feeding the same single port on the head.


and for some more pics (yes thats a pipe fitting, i could not make a true bend that tight so i gave up and farmer'd it!)



and this is where the carb will sit, i havent made a mounting flange for it or welded the pipe in place, need to check it on the bike for position first!