Don Dunbar, Dave Mccandless and I took a close look at this Revmaster carb for
use with rotary, One would need two to get over 200 HP.
This looks like a good low cost and simple solution for the fuel system.
It appears to be a Mikuni flat slide carb of some kind with the float
bowl removed. However I cannot find the exact Mikuni model or on what vehicle
it was used. I suspect the float bowl is removed to allow the mixture
to be adjusted using a low pressure gravity fuel feed. Rather brilliant
idea on Joe Horvath's parts. Joe is charging $330 each so I'll bet the
original version with float bowl is a lot cheaper.

Any body recognize this carb body?


Paul Lamar


It looks like a variation of a quicksilver carb.

http://www.edelbrock.com/motorcycle/carbs/carb_internals.pdf

http://www.edelbrock.com/motorcycle/carbs/intro.shtml

Jim Pollard


Yes. They are for a whole wide range of off road vehicles.
They all seem to have about a 40 mm bore in common.
Therefore they are limited to about 40 to 50 HP per carb.

On second thought not a good solution for a rotary.

You need at least two 48 to 50 mm bore carbs for a p-port rotary.
That gets us back to the Big Mikuni size carbs.

Now you must figure out a way to lean them at altitude.
Not easy. I think the float bowl is already pressurized
by dynamic pressure.

Paul Lamar

Looks like we're back where we were 12 years ago, using weber carbs off
the racing Mazda P port engines. We flew those a bunch of years. Didn't
have alt.comp.
Skip Gorman

No worries mate. We can do what Joe Horworth of Revmaster did and take the
float bowls off and convert them to gravity feed.

Or better yet buy a couple of these cheap low pressure
regulators to control the low pressure and lean the carbs.

The approximate $250 each or more cost of the Mikuni 48 mm carbs is still
higher than a 555 EFI system and that is why I will continue to pursue
that avenue.

Paul Lamar



Exactly Paul. Even a so, so efi is better than a carb. And setting up an aircraft engine would be very easy.

The other thing I'd like to see is mass air flow set up. Any engineer will tell you that.

Skip Gorman.

That is what we are working towards. Mass air flow sensor.

http://www.rotaryeng.net/simple-cheap-555.html

Paul Lamar