Classic inlet plenum inspiration needed 😁

[sonus]

So I am going all out on a new engine for my TVR Vixen. I am sticking with the hemi 2500cc Daimler V8 currently in the car, but have had it bored 150-thou over making it 2800cc, custom cast pistons to raise compression to 11:1 static, heads ported, bespoke billet camshaft made to my own spec. Intake and exhaust will be pulse tuned to achieve more than 100% volumetric efficiency 😁 All has been done after simulating the engine with computer software. The simulations has shown that a plenum intake will produce quite significant more torque than itbs which I intentionally wanted. Although I am fuel injecting the engine running a DTA Fast S80Pro ecu and coil packs I want it to look as if it might have been done in the 70s. I have therefor been searching for inlet plenum for inspiration without much luck. So what I am hoping is for the collective knowledge of RR to help me with some inspiration for plenum inlets that would not look our of place on a 70s car. And of course it will have to be bespoke as no one makes anything off the shelf for these engines (although the Porsche 924 inlet gasket is almost identical in bore spacing to the Daimler 😉)

Links to websites that sell diy parts for inlet manifolds are also very welcome 👍

Here’s the car in question, all 350cm of it 😂

[metalshapes]

Probably not what you are looking for, but I love the look of the old Mopar Ram intake.

And since you are going to calculate the exhaust for shockwave tuning, you could do the same with these...

[sonus]

metalshapes I have done the calculations already and the runner length from plenum to valve seat will be 165mm with a internal diameter of 34mm. The cross ram intake would probably need a snake nest of an exhaust each side to match 😅

[skkylinedave]

Twin plenum either side , injectors hidden underneath.

[tonycocacola]

Again, probably not what your after, but type Hilborn injection plenum into Google, go to images and enjoy.

[sonus]

Jun 24, 2019 18:31:51 GMT skkylinedave said:

Twin plenum either side , injectors hidden underneath.

That is what I hope to do. The mating face on the heads are at 45 degrees so will run a 45degree bend and fit the injector boss on the outside curve aimed directly down the inlet runner. Have been looking at Magneti Marelli Pico injectors IWP048 should fit my use well.

Also twin separate plenum would probably be much easier to make than one single. Not sure which one gives better torque characteristics yet.

Her’s a picture of a drawing I did while still working on the itb idea

[sonus]

Jun 24, 2019 18:38:49 GMT tonycocacola said:

Again, probably not what your after, but type Hilborn injection plenum into Google, go to images and enjoy.

I know of ONE set of Hilborn mechanical injector itb set in the world for the Daimler V8. Hilborn reputably made 8 sets, but only this single set is known to have survived. I have tried to buy it, but the owner won’t sell as they used to be fitted to his Daimler SP250 racer.



Will try the google search 👍

[skkylinedave]

Just something else to think of , have you though about where the injector is aiming ? Might be worth looking at the best place as it might be better going slightly across the air inlet stream .

Also need to look at angle of the valve in relation to the stream of fuel .


I think it will be ok for twin plenums , you just need to work out how to get them looking period fitting [ which might be difficult as they do not seem to have exsisted back then ] , and that stuff would have been cast back then rather than fabricated .

[Phil H]

If going twin plenum, see if you can get them joined by a flap valve to optimise both low and high rpm characteristics. Works a treat on the V6 Omega engine and the Cossie 24V V6, to name but 2. I think there are other V6’s from the 90’s which used it to great effect - as well as the GM 24V in-line 6 in the Carlton and Senator too.