Modified Carburetor to Inject Alky?

[Dubwho]

Looking to due an experiment on an old turbo motorcycle (another backyard engineered system) to see if a modified carburetor (foam filled float, sealed, etc.) can be fed alky and installed inline with the gas carb. Basically its a dirtball way to inject alky without a high pressure pump. The key is to only allow alky to flow under boost, not vacuum.

Two ways to do this I can think of. First, a two barrel carb with each barrel wide enough to flow adaquate air with just one at a time. Modify the throttle shaft to open one plate and close the other when flipped back and forth. One barrel is fed from the bowl and the other is permanently blocked. You get the idea of just flipping the throttle between the alky barrel and the dead barrel.

Second, use a "too large" carb that cannot pull alky until enough air (boost at this point) pass through.

Has anyone done anything like this? Remember its just an experiment and I know pressurized alky injection works, but I just want to see if I can do it this way with junk parts.

 

[Dubwho]

Well, I did ask for evidence if this has been tried before, so if it hasn't, I shouldn't expect responces. Maybe I need to the first to fail!

I think I should put a y pipe after the turbo, with the alky carb on one parallel and a straight pipe on the other with another y to converge the two back to the intake manifold. Keep the throttle plate in the alky carb and connect it to a boost activated diaphram to open only under a set boost. Then jet the alky carb to dump enough that when the alky/air mix from the alky carb parallel converges with the air from the other parallel, the alky/air ratio will be correct in the intake manifold. When not on boost, all the air should pass through the parallel with no alky carb.

And maybe the alky carb could also be set up to add extra gas as it adds alky.

Maybe.

 

[Nocooler]

Have you thought about a dead-head style system?

 

[Dubwho]

Are you refering to a pressurized tank system? I did a search and couldn't find the exact definition of a dead-head system, just some references.

 

[Nocooler]

Yeah, it is a pump less system - and alky only flows under boost.

 

[Dubwho]

Do you connect the tank to the compressor exhaust side and the nozzle to the compressor intake side? The tank would stay equallized until the compressor spun fast enough to make boost and push the alky into its inlet. I am assuming correct?

 

[Nocooler]

Correct - you should be able to find some plans for one using google. Basically boost would pressurize the container forcing the alky out.

 

[Nocooler]

Deahhead is the wrong ternimnology here.......maybe someone will chime in and correct me.

 

[Dubwho]

Makes sense to me. Thanks for the insight. There must be some advantage to using a pump pressurized system over this, since that seems to be what most people here use. I like this idea, because it it progressive with boost pressure. I imagine it is difficult to regulate the correct amount, since you are at the mercy of the low boost pressure.