8 port inlet port spacing

[Mark1Peachey]

Does anyone know the pitch of the inlet ports on a Arden 8 port? I would like to have a think about spacing of throttle bodies but don't know the measurement between centers of the ports.

[Astro]

Hi,

to cold today to measure. But it's about 78mm. Just take the distance between the head studs!

Best.

[guru_1071]

mark


the easy way would be to use a ready made weber manifold and bolt your throttle bodies onto that - most use weber type centres and fixings. from (distant) memory you can get a very short jenvey which will just about squeeze under the bonnet.

the problem using a 'standard' off the shelf body is that the manifold needs to be a certain length to be practical, this is why the modern minispares stuff was specially made to be 'direct to head' so that the inlet forms part of the throttle body.

this allows the 'manifold' part to be the right size and shape and slender enought to be able to get the plugs out with out having to unbolt the lot (which is what the older, super short, setup ive seen made involved), but at the same time allowing the throttle body part to be far enough back to allow a filter to be fitted and the bonnet to shut

[Astro]

or he may consider something like this?

[Mark1Peachey]

Thanks for both your replies. I must admit that I am worried about fitting it all under the bonnet as I don't won't it to be noticeable when the bonnet is shut. I'm only in the very early stages of my engine build at the moment so just getting some ideas really.

Cheers for putting up that photo Astro. Could you tell me what that set up is, looks nice and compact apart form the air box.

Mark.

[Astro]

Hi,

these are the carburettors of a Honda 800S (car). Spares offers a solution with four Amal carburettors that will fit under the bonnet, but you can use more modern cycle carburettors as well or the injection Spares offers as mentioned before. On this other photo you will see my own solution with short Maniflow inlets and Weber 40 DCOEs.

[Vegard]

Hi,

these are the carburettors of a Honda 800S (car). Spares offers a solution with four Amal carburettors that will fit under the bonnet, but you can use more modern cycle carburettors as well or the injection Spares offers as mentioned before. On this other photo you will see my own solution with short Maniflow inlets and Weber 40 DCOEs.

Does the bonnet shut with this setup?

[Astro]

Yes, but not with the standard lock plate and in addition I put the complete engine 20mm back.

[Vegard]

Yes, but not with the standard lock plate and in addition I put the complete engine 20mm back.

Oh, interesting. How did you do that? Redrill the subframe?

[Astro]

Yes, no problem with four new holes in the subframe for the engine, two for the gearshift and two adjustable engine stabiliser bars.

[Mark1Peachey]

Astro, what do you have planned for filtration ?

[Astro]

There are gauzes on the trumpets. OK, this mini will do perhaps 500km each year, just climbing hills and most time resting quite lazy on the trailer. Therefore it should be no problem.