The V8 Owners Forum -

Had a guy from the states send over some interesting manifold photos used on racing TR8's - I like the cross ram one:
http://www.mez.co.uk/ms12.html#Michael

Still amazes my how many different types there are!

Eliot,

Quick question, does the 3.9 plenum fit on the 4.0 Gems manifold because I don't think the 4.0 plenum is going to fit even under my MGRV8 bonnet with the bulge.

Kevin

I can tell you that the gems plenum fits the old hotwire base, so i assume the answer is yes.
The gems plenum is slightly taller i think, so i'm not sure how it will solve your problem.
I have a 72mm one in the shed if you want me to take measurements.

Hi Eliot,

The 3.9 style plenum was use on the MGRV8 so should fit under my RV8 bonnet, I hadn't realised that the Gems plenum was square, so effectively higher at the front where I may have a clearance problem, I will do some measuring over the weekend.

If it doesn't then If the 3.9 plenum fits the 4.0 trumpet base I'll will have to get one.

Kevin.

I assume you are not using the gems ecu then?

Eliot,

No just have a complete Gems Plenum, Trumpet Base and manifold with injectors and fuel rail, no electronics at the moment and still not made a decision on which route to take with all the choices available.

Kevin.

Got some interesting photos for a very early brico electronic injection manifold:



http://www.mez.co.uk/ms12.html#brico

and a prototype from Lloyd specialist developments:

The 3.9 and gems plenum are both the same overall height. The gems is square and the 3.9 curves to the front and rear so would give more clearence front and rear.
Both trumpet bases are the same except differences in pipes for vacuum...etc.

I have just gone through an excersice to lower the plenum height. Took about 15mm out in total of the bottom and top face of the trumpet base, also lowering the trumpets.

I used the gems in the end as it has the idle control valve built into the throttle body so looks neater, but i'm using megasquirt.

Tom.