Chysler 440 (7.2L) EFI conversion (Jensen Interceptor)

[PhilipL]

I'm going to stick with EDIS

EDIS is a POTENT ignition system: https://www.youtube.com/watch?v=3uzT0PyqKaM

[DaveEFI]

The original flapper system was flat on my SD1 at low to medium revs. On fitting a wideband O2 before I went MS, it was obvious why. It was running too weak at all times other than full throttle. And being an auto, that resulted in it kicking down. So all or nothing.

With the MS, it now pulls like a train. I'm sure you could get more out of it at lowish revs by using a longer inlet tract - like the Thor - but as a compromise it's pretty good. To me, at least.

[PhilipL]

One must also bear in mind that the inlet manifold and cam profile go hand-in-hand.

I once tried a Kent H218 on my d4.6 Disco2 with the THOR manifold. Disaster.

I can say that the Thor manifold + Kent H180 is "very deliciously".

[Triumph-V8]

Nice job on the Jensen!
Seems to be a clean work
that looks like Ex-Works.
Congratulations!

[PhilipL]

Nice job on the Jensen!
Seems to be a clean work
that looks like Ex-Works.
Congratulations!

Thank you Adreas

I did my first "economy run" with the EFI and 4sp conversion just yesterday over a 217km trip trying to maintain 100km/h whenever safe/legal to do so, uphill and downhill. (Distance measured by GPS)

The figures are:
7.06km/L = 14.16L/100km = 19.94mpg (UK) = 16.6 mpg(US)

[Triumph-V8]

.. not too bad
Jensen is not a lightweight and 7.2 litres have to be warmed up!

[minorv8]

If I may make a suggestion:
1) if you want a high revving engine with lots of top end power, use the LUCAS type EFI manifolds with 3.9 or 4.6 cast into the top of the plenum

Advice is always welcome. I have chose a mid 90´s intake and since I like to fabricate it´s been modified with larger/shorter trumpets.





Also the plenum has been welded quite a lot and still needs a flange to be fitted. Looks like I also have to raise the top of the plenum. It would have been easier to simply fabricate a completely new plenum. The throttle body is a 75 mm item.

[DaveEFI]

Be interesting if you end up with before and after figures. Shorter trumpets will push the resonant frequency up - so increase the revs at which it has most effect.

[minorv8]

I don´t have the exact "before" figure. I swapped the cam last winter and was supposed to have it on my friend´s rolling road where all previous mods have been measured. But I suffered a ignition module meltdown, actually twice so there was very little driving this summer.

Current setup is a single plane intake with Edelbrock 500 carb so I am expecting a huge increase in low rpm torque and maybe something in the top end (less important) with the Efi manifold.

[DaveEFI]

If the low to middle end was more important, I'd have tended to leave the trumpets alone. Of course it may depend on the engine size too and other things.
On the Vitesse unit, the real 'kick' comes in quite high up the rev band.

But I assume easy enough to try a standard unit too?

[PhilipL]

so I am expecting a huge increase in low rpm torque and maybe something in the top end (less important) with the Efi manifold.

I always thought that shorter, wider trumpets aids top end at the expense of bottom end due to lower air speeds/momentum resulting in lesser cylinder filling at lower rpms.

On the Jag V12 forum there is always a lot of talk on the standard manifold tracts being too large in diameter for road use, that reducing them would result in better low end torque.

So, it would be interesting to hear what you find.

[Triumph-V8]

Did similar and without some calculation because
we can only build what fits under the bonnet.

My intention was that the EFI manifold was designed for the 3.5
and from that reason should be a little bit tight for a 5.0.

The WEBER DCOE have trumpets that can be clamped down
in the way WEBER uses them. Very easy to fit, only the trumpet base
had to be machined to accept the biger trumpets and new holes
had to be added to drain the base from fuel and oil.

This was the start:



Than I cutted a manifold to find the best position to locate the new
trumpets with longest possible length. Had different length an angles at hand to test:



It ended with a douple throttle plate plenum where I welded two
plenums together:

[Cobratone]

I'm going to stick with EDIS, since it seems happy enough at the peak revs on my 3.5.

Quite understand that. As the MS3 gives me the opertunity to go coil on plug then I decided to do so, my edis8 will be for sale soon. I've already stripped a dizzy out ready for the cam sensor, should be quite neat and small compared to a normal chevy HEI dizzy

[DaveEFI]

Are you actually going COP or just one coil per plug? I'd be interested in the former, as it would be the neatest looking solution.

[Triumph-V8]

Also you hopefully will not have to fiddle with electrical noise
The EDIS with copper leads did not work and made the
Megasquirt reset.

When the coil sits on the spark plug the only thing
to set up properly will be the dwell time and thats it?

A bit more expensive and often there is not the required
space availiable but is an interresting solution where it fits.

Would like to read details if somebody has that on a Rover!