X-Mozilla-Keys:                                                                                 
Paul wrote:

Gary C. Buster LPT wrote:

Ok guys... you've got my interest... I'm running the NA Dellorto DHLA 48
with the Racing Beat intake....  these guys obviously have some horns to fit
my carb application... now I need an education for determining what the size
is (dimension "B" and "C") that I would need for my application.   Please
remember I am using a ported 12a at 7k rpm max with Ross 2.85 and Warp Drive
4 blade 68" on my gyro and need a ton of bottom end, "right now" torque!!!

Does anyone have "the scoop"????

Gary C. Buster LPT
gbuster@ballistic.com
Tyler, Texas

Gary the way you get bottom end is use long intake runners.
In your case with a 2.85 PSRU you have a lot of prop torque to begin
with. I assume your prop is limited in diameter by the geometry
of your gyro so changing to a 3:1 and a larger prop will not work.

So your best bet is to mount that carb out on the end of long
intake runners. I would say 24 inch runners might be in the ball park.
Apparently putting long horns on the carb does not work nearly
as well although it has been done.

Your exhaust pipe should be about 32 inches before it joins the 
other one. This should give you good HP at 6000 RPM and your
PSRU will convert that to torque so-to-speak.
 
You may lose HP at 7K.

The other possibilty is go to peripheral intake ports and
get a lot more HP at 6000 RPM. I would guess maybe 20 more
HP. Paul Yaw probably has a much better handle on this as
most of the work has been done recently with the 13B and 
not the 12A by the late Everett Hatch and PowerSport.

Have you considered a supercharger?

Paul Lamar
 
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