3.9 versus 4.6 - plenumchambers

[greenstream]

Hi

I've recently biought a 4.6 without the inlet and plenum.

I do have the parts from a 3.9 - are these interchangeable without detuning the 4.6 ?

Or should I simply opt for a 4.6 inlet and plenum ?

Thanks

Morten

[Hybrid_From_Hell]

Yes

3.5 3.9 4.0 and 4.6 (non Bannana type) all interchange.

Trumpets are the same hight etc

The differences between the various plenums are

3.5 4.0 4.6 - no Stepper on the rear and differnet pipe in / out arrangements 4.0 and 4.6 very similar

TPS different on 3.5+3.9 vs 4.0 4.6

3.9 has steeper motor on rear can be plugged

port air entry same on them all, 3.9 3.5 are reputedly better cast to rev, 4.0/4.6 cast more for grunt

3.5 3.9 vs 4.0 4.6 have different length bolt to bolt to trumpet - same thread shortwer on 4.0 / 4.6

HTH

Nige

[greenstream]

Yes

3.5 3.9 4.0 and 4.6 (non Bannana type) all interchange.

Trumpets are the same hight etc

The differences between the various plenums are

3.5 4.0 4.6 - no Stepper on the rear and differnet pipe in / out arrangements 4.0 and 4.6 very similar

TPS different on 3.5+3.9 vs 4.0 4.6 Please explain TPS

3.9 has steeper motor on rear can be plugged

port air entry same on them all, 3.9 3.5 are reputedly better cast to rev, 4.0/4.6 cast more for grunt Are we still talking about the plenum here ? Edit self, you are talking about the "tubepart" of the inlet, from the trumpets and down towards the inlet valves ?

3.5 3.9 vs 4.0 4.6 have different length bolt to bolt to trumpet - same thread shortwer on 4.0 / 4.6 So I have to beware of which bolts I Use ?

HTH

Nige

Thanks for your reply, could you please look at my comments.

Could I use the 3.9 injectors as well ?

I take it from your reply, that by using the 3.9 parts then I will not detune the engine ?

Thanks

Morten

[Hybrid_From_Hell]

TPS = Throttle Position Sensor

3.5 3.9 vs 4.0 4.6 are different and loom / plugs are not the same

the 3.5 3.9 are a smother / more flowed Plenum which can assist high flow of air at higher rpms vs the coffin shaped 4.0 / 4.6s which are more for bottom end grunt

3.9 4.0 4.2 and 4.6 hotwire all share a common injector, so same on all

you must not only use the plenum of choice but use the bolts that come with it !

Hope this clears it up

Nige

[greenstream]

Yup - thats more like my "lingo"

Thanks Nige.