"ACE" Style throttles now available

The issue is the same as with our other rear-mounted throttle.

The throttle is basically an airflow reducer. To work properly, airflow must be reduced. With SPI, air is permitted to flow into the crankcase thus negating, or at least fighting, the airflow reducer.

Someone could possibly test the contraption with an SPI engine but we doubt that RPM would drop much below 10,000.

Yes.. I can understand that.. but there is one difference with this design. The plunger will block the spray-hole when the throttle is closed. The engine obviously won't run without fuel. Your throttle for the sure-start doesn't work this way. Fuel can still be sucked in when the air restrictor is closed.

Well, if we can get someone that has actually used the throttle on an SPI engine to also confirm this, then we would remove that caveat. It is just that we have never tested one, let alone on an SPI engine and don't want buyers complaining.

That's certainly understandable Bernie. There is one consideration.. "Most" Bee's have a .063" opening at the air intake on the backplate. A plunger-needle having an .0625" diameter will effectively close-off both; air and fuel when it enters past the taper on the plunger. A larger hole (.082" for example; found on Black Widows and some Golden Bees).. would require a larger diameter plunger (.078") to work in the same way.

I have one of your SPI Tee Dee P/C sets on my Bearcat. I'll see if I can swap it to a Bee style tank/backplate and bench-run it soon.

Below is a stock Babe Bee backplate, showing an Ace plunger inserted past it's taper. Notice that the fuel spray-hole is blocked.



This is the reason why I like this throttle. It's more of a metering valve for both air and fuel. Closing the throttle doesn't richen the mixture as much as metering the air alone would.

Thanks for that Roddie

Cox International wrote:Thanks for that Roddie

My pleasure Bernie. Your offering looks to be very well made and priced fairly. I hope that many people will give it a try!

Wish listed. Sorry, no budget right now for these toys, hopefully next month or so...

Phil

Bump.. Has anyone bought/tested one of these venturi throttles for the Babe Bee yet?

Babe Bee Throttle

It's primarily an RC mod.. but much more useable "today" than it was when Ace first introduced it.. because of today's lightweight Nano-radio gear. These throttles work very well and would add an exciting new dimension to a Babe Bee powered model. It's always nice to be able to throttle an engine.. as opposed to being committed to running-out an entire tank of fuel at w.o.t. if there's a problem.