Carb Clearance

[Wayne Johnstone]

How much space is required above the carb inlet / venturi to enable sufficient are flow to the motor, on my 21 JAE it is very close, no danger of the carb hitting the cowl but air flow may be restricted? Any suggestions / opinions greatly appreciated

 

[Tim_Duggan]

That's way too close Wayne.

 

[shoboat]

Wayne,

We use a airplane canopy and make it fit on the boat to give them more room on our

21 & 45 boats.

Thanks,

Mark Sholund

 

[brad nichols]

Some people say a 1/2" and some say 1" of clearance. Move the cowl forward.

Brad

 

[Pumpin]

Hi Wayne,

You could put a little reverse air scoop on top of the cowl over the carby inlet and cut a hole into the top of the cowl ???

I have done this many times works a treat, some jag 111 riggers have them for the same reason.

Kevin.

 

[Charles Perdue]

Gentlemen, when testing the carbs on my flow bench, I found out by using smoke and the spraybar draw numbers, that the MINIMUM carb bell clearance without ANY interference, is right at 1/2 inch in every direction around the bell.

When the carb is drawing air into it, it tries to suck a hole in the air at the entrance to the carb bell and the surrounding air rushes in from EVERY direction to fill this void.

Charles

 

[Blackout]

Gentlemen, when testing the carbs on my flow bench, I found out by using smoke and the spraybar draw numbers, that the MINIMUM carb bell clearance without ANY interference, is right at 1/2 inch in every direction around the bell.

When the carb is drawing air into it, it tries to suck a hole in the air at the entrance to the carb bell and the surrounding air rushes in from EVERY direction to fill this void.

Charles

Good info, thanks!

 

[shoboat]

Charles,

Thanks for sharing your testing information with us all.

Hope the air conditioning business is going well at your shop this time of year?

We are a little on the cool side 60's and 70's mostly so far this Summer. Cherry

season is getting ready to start soon, I will have to send you some samples.

Mark Sholund

 

[Charles Perdue]

Mark, some sample cherries sound very good.

Charles

 

[dr gary turner]

Charles, are you back??????????? I HOPE SO. COME TO OUR RACE IN AUGUST. DOC

 

[BradSpencer]

Wayne,

Have you got a KRE carb to try? I reckon the bell would sit a 1/2 inch lower with one.

 

[Neil LaGarry]

The aftermarket carb is too long ,Go stock

 

[David Ashcroft]

Wayne ,my seaducer21 nova dd has orlic carby and has very minimal cleareance ,but goes like the powers of ----

I agree with Kevin and put a reverse scoop ,,

David

 

[aaron alberico]

See scoop on my cowl for my 45!