Bonnet Scoops

[element]

The current set up on the Lampredi twin cam we have is the standard Weber34ADF carb. Despite extensive research, I can't find a plenum chamber to fit it to enable a cold air feed. The engine suffers from lack of air under higher load.
So, if I have no other option, I'll have to consider cutting a hole in the bonnet and fitting a scoop. If I have to do this - then I might as well go for a twin carb set up and do it right. Do folks buy scoops for such situations or make them?

[dcunn]

Re: Bonnet Scoops

Have a look at Tech Tips Aug/Sep 2000 showing one way to make your own

Alternatively rather than cut the bonnet, do you have room for example to have a "funnel" underneath at the front to collect cold ram air which could be ducted to the carb ?

DC

[element]

Re: Bonnet Scoops

The problem is the current air filter is touching the bonnet when it closes. So when the air is sucked in - it only really comes in from around the sides of the filter and virtually nothing from the top (where the most efficient air should be drawn in). Not a lot of options...

Sudden "LIGHT BULB IN HEAD" moment!!! staring me in the face all this time... Why not modify the current air filter and feed it cold air from down below as you suggest (which is what I have been trying to find a way to do). I am sure I can cut a hole in it and arrange a redesign of its function - instead of drawing warm air from around the filter... Close off the filter itself but for an entry tube with a ram pipe feeding it. No need to change the bonnet in any way - just modify the filter unit. ... Time to do some drawings...

[chris_cussen]

Re: Bonnet Scoops

On my engine swap I used some trunking to a remote filter and put the air intake above the radiator so it gets cool air through the nose. The remote filter came from CBS and the trunking from Auto Silicone Hoses. There is a picture on this thread http://www.marlinownersclub.com/foru...an-engine-swap

[Michael Turpin]

Re: Bonnet Scoops

Bonnet scoops sure do improve cool air supply
Have a look at Pitstop mags - title of article is misleading but it does cover bonnet scoops
Issue 196 October – November 2016
A Gearbox change…………Part 1 Michael Turpin page 8
the end result -

IMG_7618.JPG