I have done a bit of reading, and there is a recent post about cooing, so thought I would bring up my issue.

I have a large water rad and a oil rad. The water temp is good, if anything a little low. The oil rad is higher than perfect. I am going to duct some of the air from the water to the oil to help things but want to check other details. Current the oil rad sits in front of a well directed water rad.

Is it best, when stacking rads, to have them right up close to each other, a little gap or maximum gap achievable?

My gut feeling is that rad exhaust air is soo turbulent that its best to stack rads as close as possible, the further apart, the worse the stalled messy air.

Thoughts? Ideally backed up by proof and pics. No gut feelings or finger in the air guesses, leave that to me!

Thanks,

Biz whaa

Best to have the oil cooler in front right up against the water rad.

Oil generally runs a bit cooler than water. The oil cooler on a st170 is simply the coolant going round a jacket at the base of the oil filter.

Rad I'm using on my jeep has the oil cooler built into the bottom of the rad. I'll be sticking the transmission cooler in front of the rad.

From memory, I think it was in an Allan Staniforth book I read it in, it concluded that there was no real measurable difference about gap, but there was quite a bit of discussion about getting the air out of the back end of the rads, that made more of a difference and is more often over looked.
I wish I could remember what book it was in as I would go back and check for you.

When I bought a transmission cooler for the SAAB from Kenlowe their techie advised putting it tight up against the other rads.
They supplied a fitting kit which was four pads and four mushroom headed zip-ties - see here on fleabay :-
Universal Car Electric Radiator Cooling Cooler Fan Mount Fitting Kit Slim Line
I was concerned there was no other support but he reckoned providing they were tight together there wouldn't be a problem - years on he seems to have been correct.
HTH.
Cheers, Pewe10

The Ford modine oil cooler found on the St is little more than an oil warmer for emissions purposes.

I've seen turbo installations where the charge cooler, oil cooler and water cooler are all stacked up. From memory the charge cooler sits up front, then oil then water?