Radiator question, for thermodynamics/heat transfer experts Options

[bondo]

Hopefully I can get some input on this without too much of the inevitable "that won't work" (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

I'm cutting down a large tall radiator into a shorter one.. 1/3 the height to be exact. The 3 layers of radiator will be set up in a cross flow, sequentially. The hottest water will enter the rearmost later, travel across, then across again in the middle layer, and across yet again in the front layer. The idea is the hottest water gets the hottest air, and the coldest water gets the coldest air. This way delta T stays pretty constant.. I'm thinking of it as trying to heat the air as much as possible, which would cool the water as much as possible.

So I realize that cooling capacity will be reduced, as I will be dealing with 1/3 as much air. But then the cooling capacity must be more than 1/3, because it's 3 layers thick instead of 1. My question is what percentage of the original cooling capacity should I be expecting? Would it do me any good to do 5 layers instead of 3? (by adding 2/3 of a second radiator)

The original radiator cooled the same engine just fine, in a heavier car, with an AC condenser preheating the air. I will be running an electric pump, so I will have an advantage at idle.

[bondo]

QUOTE (Mueller @ Feb 2 2005, 12:10 AM)

I think by the time the air hits the 3rd layer, it's going to be too hot to cool anything and be pretty much useless....

The third layer gets the hottest water so the air that hits it will have to be cooler than the water going through it. BUT, it may not be enough cooler to do much good.

The reason I've come up with this idea is because of the tidbits I've managed to squeeze out of Scott (Renegade) regarding WHY 914 V8s have trouble staying cool. He says the water doesn't spend enough time in the radiator to lose heat. Thus my idea of the multipass design. I have since heard that Renegade's radiator is a multipass design (not 100% sure on this, I just read it here somewhere).

I will have big fans moving the air. They will be at the outlets instead of on the radiator.

If it doesn't work, it would be very easy to flip the whole thing over and do it the other way.. hottest water in the front. That would give a very good delta T for the first layer, but by the third layer the air may be as hot as the water.

The other option is to just run all 3 cores parallel in a conventional 3 core setup. The radiator construction would be easier, but I'm not sure it would be more effective.

As far as just buying Renegade's radiator, there's no way I'm spending $1000 on a radiator. I'm much to big of a CSOB for that (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)