air flow?

[Capn Crunch]

:-

Hi guys,

I'm currently building my first gas deep vee and I'm installing an air scoop atop the hatch. It occurs to me that there needs to be some sort of exit for the air that is "scooped", am I right? Am I in danger of creating more drag with the air scoop? Surely the engine does not use all of the air that is forced into the engine compartment, or does it?

thanks for any help,

-capn crunch

 

[wavejumper]

As long as the scoop is not to large it could be very helpful. Of course if it is to large you could run in to all kinds of problems the most serious of course being a blow over because your just getting to much air.

 

[Capn Crunch]

Thanks, yeah that was another concern of mine. I like the looks of the scoop but I certainly don't want it to become a big drag-chute . I mainly just want good air flow to the carb, the engine will have adequate water-cooling.

-Capn Crunch

 

[nitrotoys]

See i think a scoop is asking for problems, for one water, roost spray will kill it out, Plus i think it will suck in more air than the scoop will give you.

You need to keep carb from water. alittle water will kill it out. probably fine if your running alone.

 

[MarkScott]

CC,

Instead of a external scoop, why not one of those fancy scoops that are built into the surface? Can not think of the name of this type of scoop, but they are used on several FAST movers (jets, helio, nascar, F1, Indy, IRL, etc).. These may allow limited water to be captured, but it will allow air to enter..

Mark

OB Nut Racing: Cap'n Crunch, I'm getting hungry!!

 

[Bruce Burns]

OB nut

Is this what you mean. I think its called the NACA duct.

Bruce

View attachment 505

 

[MarkScott]

Bruce,

That's it!!! 8) Doesn't disturb airflow like a normal air scoop, but will allow air to be brought in.. ;D

Mark

OB Nut Racing: I'm getting dizzy, too much AIR!!!

 

[jaso]

Has anyone used one of the NACA ducts in a boat and tell of the results if so?

 

[Bruce Burns]

I used it on a mono I had. I only had 1 small one just before the carb and it worked good. The engine had enough air and I never got water in through it. They aren’t as affective as the scoops but there is much less drag and you don’t get much water in them. I don’t know about the petrol boats though they seem to need more air.

That’s just my opinion I am sure there are other guys on here that know more then me.

Bruce ;D