Cooling a 101 with a 4.6

[101RRS]

Hi all 101 peoples [thumbsupbig].

I have a 4.6 in the 101 and it has the short timing cover meaning the the fan is a lot further back from the radiator and is a few inches lower and to the left so the original radiator shroud no longer works. There is enough room for the 4.6 fan to be fitted with the 3.5 shroud in place but the fan only covers 2/3 of the hole in the shroud and is about 2" back from the shroud.

Now with no shroud in place and with the engine cover in place, the standard 4.6 cools the engine fine but I have only driven it in cooler weather but there in guarantee that will apply more adverse conditions.

Obviously I could build a new shroud but that is not all that simple and would like to look at other options first.

1. The 101 tunnel is almost like a shroud but open at the bottom. I could fill the sides and bottom with rubber sheet and let the engine fan oull the air through.

2. I have a 16" electric fan and it fits the 3.5 shroud quite well and could mount it to the shroud and just mount it to the radiator as per the 3.5 set up. The fan would be in the same position as the 3.5 engine driven fan. I could still mount the engine fan as well for a little extra cooling.

3. Mount the electric fan as per how they are normally mounted against the radiator and also mount the engine fan with or without the shroud.

Open to suggestions and/or ideas. A pusher fan is not an option as the engine oil cooler is in the way and it would be awkward to mount it as new pipes would be needed and the cabin ventilation fan is in the way.

Any suggestions?

Thanks

Garry

[cjc_td5]

I'd ditch the engine fan and go electric fan only. Ideally with a shroud to get 100% radiator coverage.

[101RRS]

Thanks for that advice - the 16" electric fan can be mounted simply to the hole in the old 3.5 radiator shroud with heavy duty cable ties.

Cheers

Garry

[grey_ghost]

My 101 (although it's an ambulance body and not a GS) - has an upgraded (more cores) aluminium radiator (the original expired), and an electric fan - but no viscous fan.

I don't have a cowling.

My 101 engine bay (if you can call it that) in front of the radiator is a bit busy, as there is a trans cooler in there as well (because my 101 was converted to auto by the previous owner). I added a second, smaller radiator a while back because the 101 got hot driving up a long and steep hill, very slowly, going into Cooma..

I think that my (second radiator) setup is probably a bit over the top for a GS.

How do you find the 4.6? I recently drove a 101 GS with a 4.0 in it, and it flew... A 4.6 would be lot's of fun. :)

Cheers,
GG.

[101RRS]

How do you find the 4.6? I recently drove a 101 GS with a 4.0 in it, and it flew... A 4.6 would be lot's of fun. :)

Cheers,
GG.

The conversion is not complete so hard to tell - only driven about 150km for things like gas certificate etc.

Still has 3.5 manifold and carbs, still has 3.5 101 exhaust and has fixed 10BTDC ignition so performance is far from optimal - drives ok but because of the fixed ignition I have not pushed it over 2500rpm but you can notice the bit of extra torque going up hill.

Yet to finalise what induction system to use - I have a 3.9 hotwire system available and a Thor system which has actually been on but not run. The 3.9 hotwire system has a slightly smaller inlet than the Thor so in theory will produce less power and torque but in reality may not make much difference as the thor is stongest at lower revs. The hotwire is a simpler system. If I do go the hotwire system i will do as you have done and turn the plenum around for an easier fit.

I have P38 exhaust manifolds - the drivers side goes straight on but the passenger side is problematic due to the proximity of the chassis and the pto for the winch - not sure what to do on that side for the moment.

So for the moment just looking at sorting the cooling - fan and the thermostat is not opening until the engine is quite hot - installing an interim controller for the ignition and tuning the carbs as is to ensure best running and no lean spots that could damage the engine.

Induction system to come later.

Garry

[mick88]

Stick with the engine fan and build a shroud to suit, it will offer the best engine cooling by dragging the largest volume of air through the radiator when you get in slow hilly driving, or have a tail wind on a stinking hot day, which means airflow is poor, when you need it most. A leccy or two are good as an an extra.
The 101 are a big vehicle with poor aerodynamics, so your donk is always going to be a doing a bit of work, it will get red in face quickly if its down on airflow. It's worth taking the time, or spending the coin to build a good shroud, as rebuilding a cooked engine doesn't come cheap.
Just a side note, i believe the fan should only be half way into the end of the shroud, for maximum efficiency.

Cheers, Mick.