Nissan Patrol 4x4 (Africa)

Cedric, do you have a boost measurement, and is there any chance you can do some temperature measurements at intercooler inlet and outlet?

Then we can calculate relative volumes...

marakasmalan wrote:
What does interest me, is if the manufacturers setup did in fact take into account the use at high altitudes. The use of an altitude compensator on the TB42S patrols hint towards this, but if the range actually includes altitudes of up to 3000masl as we have in Lesotho remains an open question.

The fancy crowd with EFI have the ECU regulating the air mass/pressure as opposed to mere volume control. I think using "Peters Rule" will leave enough redundancy for adverse barometric conditions, but is there any way to determine the optimum diameter for the plumbing?

Thanks for a very interesting discussion.

Useless factoid: The CFM for a Rolls Royce Merlin engine is ± volume of a double decker bus/minute!

Interesting factoid, particularly considering that the Merlin was quite slow revving (only about 3000RPM). Would be interesting to know what variant that is, as the power output (and thus air requirement) virtually doubled during the engine's life.

Getting to the air intake/filter's design and high altitude, I doubt it makes any difference on our normally-aspirated engines. The air volume should remain fairly constant, as the engine is effectively a positive-displacement pump. Power will obviously be less, because although the volume should be constant, the mass will be much less. The mixture needs to be adapted as a result of the mass of oxygen being less, but the velocities are fairly constant, thus without the compensator the engine would run rich.

For a turbo engine, the above may not apply, as the engine is not the pump anymore, the turbo is, and that can spin faster if it wants to.

I don't have any of the above, just a guestimate that I'm boosting about .5 to .6

Ok Gents, I have fitted the snorkel so far but have not yet connected it to the air cleaner yet.

Also fitten my new 33" tyres and I like the look

Peter Connan wrote:as the power output (and thus air requirement) virtually doubled during the engine's life

And a lessor known fact is that the reliability quadrupled many times durings its life. In the beginning a lot of stuff breaked. Understandably, the pilots were unhappy. From then on they always had a set number of Merlins, selected randomly from every factory, running at full speed under full load until it broke. Desected, send the part that broke back for "redesign".

It must have been a Melin X or upwards, the ones using the two stage superchargers. The exhaust gas exited the engine at 2100 km/h. Additional 52kW of thrust was obtained by adding rearward facing jets to the exhausts. The Merlin was a 27 litre V12. The swept volume was not as immportant as its ability to consume air mass efficiently, which means the swept volume is important, but the superchargers were just as important.

between 2004 and 2008 I went to see every P51 Mustang, Spitfire and Lancaster I could - that machine makes a beautiful noise!

Peter Connan wrote:The air volume should remain fairly constant, as the engine is effectively a positive-displacement pump.

So, the standard plumbing can be used as reference for any alternative solution. Thanks Peter

I am currently looking at the air box of the ZD30 as well as the 4.5 as I think both of tjem will fit perfect in tje engine bay.

What do you guys think of the 4.5 air box?

I can't recall the look of that.... Have you got a picture of it?

I was searching on the net for 4.5 air cleaner housing and found the following. Not sure if this is actually how it looks, but this looks like the 3.0 filter housing?

How does yours look Cedric?

Yip.... mine looks almost identical to that... I think that is actually a 4.2 diesel with the ZD30 airbox.

Yes it is a 4.2D if I am not mistaken.

Found this one as well which might be the 4.5 air box