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.

[914GT]

I find this to be some interesting stuff and when it comes to 914 V8 conversions there's not a lot of real engineering available on what's an optimum cooling system design. I wish my co-worker mechanical engineer (PhD, specializing in thermal and numerous patents in cooling electronics packaging) was interested but he's not into cars. (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif)

I think that for a given engine and radiator setup there is an optimum coolant flow for the system, and this is independent of the power output of the engine. In other words, the flow rate should remain fairly constant and if the engine is dumping more heat into the coolant, then there should be a corresponding increase in the heat loss at the radiator (more air flow). There must be a rate of max. efficiency, if plotted it would peak out at some particular flow rate. Too low (or zero) obviously things would overheat. Increase the flow too much and the same thing happens. Would be interesting to attach a few thermocouples in a system and play around with this.

This is where an electric pump has an advantage as it can keep a constant flow independent of engine RPM and power output. Or its flow can be varied easily according to conditions. I've been very pleased with how mine is performing and I think I basically lucked-out finding a well-matched system. But I would like to understand it better as to why it works so well.