Radiator question, for thermodynamics/heat transfer experts |
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Radiator question, for thermodynamics/heat transfer experts |
bondo |
Feb 2 2005, 12:26 AM
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#1
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Practicing my perpendicular parking Group: Members Posts: 4,277 Joined: 19-April 03 From: Los Osos, CA Member No.: 587 Region Association: Central California |
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. |
BIGKAT_83 |
Feb 2 2005, 07:30 PM
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#2
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Senior Member Group: Members Posts: 1,798 Joined: 25-January 03 From: Way down south Bogart,GA Member No.: 194 Region Association: South East States |
Bondo I've seen and ridden in 2 914's that had junkyard radiators from a corvette and both of these cars ran cool in the heat of the summer. I really don't see a need for anything special.
I think the main thing is to have a expansion tank that will bleed the air from the system. If you look at the pictures of BOXSTR new yellow V8 914 you can see how it needs to be plumbed up with a larger hose from the bottom of the expansion tank to the low pressure side of the radiator(feed to the water pump) and then a feed line from the high pressure side(hot water from engine) of the radiator to a point about 1" from the top of the expansion tank. This will bleed all of the air pockets from the system. On my V8 car all I do is put water in and bleed the air from the top of the radiator and drive. If you look at most of the new cars this is the way they are plumbed. Here is a picture of the expansion tank I'm using on my new V8 car Attached image(s) |
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