Hood Scoop

[GTXJim]

I've going to fit a cowl induction hood scoop on me belve, But I don't know too much about them, like how far away from the windshield do you have it, and do I cut it to make the profile the same, as it's further away at the bottom than the top.
Also I've cut a smallish hole in the hood for the carb to come though do I seal the carb to the hood, then mould the scoop to the hood or do i cut a BIG hole in the hood and mould the hood to the scoop.
Or mount the scoop to the carb then cut the hood around the scoop and attach zuse fasteners to hood and scoop, I had this arrangement on Cooky's Dodge but with an areo scoop.
So what's the current thinking on this hopefully I will be going quite fast so it's got to be very secure and work.
I'll be down garage later to take pic's as this might help.

[Dave-R]

I don't know the science behind it but I know what i would do if it were mine.

First the opening. I would have it the same distance from the windscreen from top to bottom following the profile of the glass.
The bottom of the opening I would have flush with the back edge of the hood.

I would seal the carbs to the scoop. Or at the very least keep the opening for the carbs as tight to the carbs as possible.

[Kev]

hopefully I will be going quite fast

I love a man with a plan!!

[GTXJim]

Dave, I think you're right about keeping the profile the same ,but how far away from the screen should the opening be?
As for sealing carb to the hood this wont be a prob.
Also should I run a big old air filter?

[Dave-R]

Dave, I think you're right about keeping the profile the same ,but how far away from the screen should the opening be?
As for sealing carb to the hood this wont be a prob.
Also should I run a big old air filter?

I would have said the scoop should not be any further back than the rear edge of the hood. if you think the pressure effect would be better with the scoop closer to the screen then do that. I doubt it is critical myself. Just go for what looks best.

An air filter is good for longer engine life. But if you fit one do the sums to see what sort of filter area you will need.

Square inches of K&N filter required for an engine = CID x Maximum RPM / 20839

The K&N website gives you the dimensions of their various filters so you can work out the area of each one. Go slightly bigger than your engine needs to take into account the thick frame on most K&N filters.

[mopar_mark]

Hi There,
I fitted my scoop so it was approx 1"away from the screen

I made a frame up which mounted on the motor plate and one which came off the back of the motor plate and welded Zeus tabs so I could secure scoop to the frame. The hood then slid over the scoop and also Zuessed to the scoop. Never had a problem with scoop trying to lift & was very secure.
Hopefully photos will make a bit of sense

[GTXJim]

Cheers Mark, I was kinda thinking along those sort of lines, mounting the scoop then cutting hood around to suit, then I can lower it abit as it's pretty tall at the moment.

[Dave-R]

Hi There,
I fitted my scoop so it was approx 1"away from the screen

Yeah but Mark your scoop has a bloody great hole in the front for enough air to get in. A cowl induction scoop will need more space between the scoop and windscreen to allow enough air in.

[mopar_mark]

Yeah but Mark your scoop has a bloody great hole in the front for enough air to get in

Fair point Dave, I forgot about the bleedin big hole

When posting, I was thinking more along the lines of how I fitted my scoop, in hindsight i shouldn't mentioned the 1" away from screen

[AllKiller]

Put a big NACA duct in the top of the cowl....
That would get more air in for the big motor, keep it streamlined and allow you to mount the cowl closer to the screen.