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Cooling & Hi Torque Cam


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Two totally unrelated things but;

Long story short my rad is shot. Kinda a good thing anyway as it's a 3.9 rad shoved into a bod/chassis designed for a 3.5 rad. Whats the difference? The 3.9 rads are taller and the 3.5 chassis (apart from different mounting bracketry) has two bumper support brackets welded to it that prevent the taller rad from sitting down far enough. It's not a huge problem in that it can be made to work by a genius like me :D but it's just not ideal.

So... I want to reinstate the old 3.5 rad. Hell no you say well hear me out and tell me if you still think its not gonna work.

The 3.9's have the oil heat exchanger built in, and the auto has a gearbox heat exchanger too. I've had both a 3.9 manual rad and a 3.9 auto rad side by side and presumably because it doesn't have to cool the gearbox oil too the manual rad has considerably less fins. I'm talkin like half the amount of fins and quite a few less rows. Put it this way you can see through a manual rad whereas you can just barely see through the auto.

What I want to do is re fit the 3.5 rad (smaller again to the 3.9 manual) and with the 3.9 vicous unit, but stick in maybe a 13 row oil cooler to handle the oil. Oil at working temp is running like 90deg and up to 120deg in real heat... taking that out of the cooling equation has to make a huge difference to the rad right? Does anyone know the coolant circuit, as in starting from the reservoir the coolant goes... See I'm thinking if the 3.5 even with a seperate oil cooler wouldn't handle the heat I cold put a little 7 row cooler in one of the small lines approaching the coolant reservoir. Trick is not over heating but not over cooling too.

What do you think?

Will I need a high pressure oil pump to cope with the cooler?


In the mean time I'm gonna do a total rebuild, I'm pricing around but where should I get all my engine internals? Who's stuff is quality or genuine parts and at good prices? RPi?

Hi torque cam, I'm not interested if it's gonna cost me more in fuel - is that the case and if not then which is the one to go for. I use my Rangey as my daily, do lots of long trips surfing (across the country) and the most off road I get is on the beach and the odd dunes. I've got the LT95 and it'll have an O/D on it soon too...

Happy New Year!!!!

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I suspect you're comparing 3.5 carbed rad with 3.5/9 EFi rad, and then there's different ones of those as the aircon models had thicker cores then normal ones. I would stick with the biggest one that'll fit personally.

Oil cooler - well many V8's don't have one at all so anything more than nothing is an improvement. My 3.5 EFi certainly doesn't (or if it does I've never found it!). The oil cooler helps to dump heat directly from the oil rather than having to wait for it to soak though the block to the coolant and then get dumped through the rad, on vehicles that get hot / work hard they do make a big difference. I wouldn't worry too much about the size of it, stick whatever you find in there.

The stock oil pump should cope fine, although RPi would probably tell you you need to buy their uprated oil pump bits and bobs :rolleyes:

I would buy bits from Real Steel, IMHO are one of the few Rover V8 co's around who are any use whatsoever. They probably sell oil coolers too. Failing that there's Think Automotive, Merlin Motorsport, Rally Design and Allisport.

Oh and a high torque cam should not cause any more fuel usage if you drive the same as you did before, it's when you start to use the extra power that you will be able to eat fuel more quickly.

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Hey FF!

The one I want to throw back in is the original 3.5 carbed version. The two I compared were both 3.9 and neither were from air con models.

It a guessing game really isn't it. Maybe measuring how much fluid each rad actually holds might give a better insight.

Funny you should say RPi and the pump. the only reason I thought of it was cause I saw their hi flow pump :D


Cheers btw for the links!

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