Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG. This site is not affiliated with Porsche in any way.
Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners.
 

Welcome Guest ( Log In | Register )

> Radiator question, for thermodynamics/heat transfer experts
bondo
post Feb 2 2005, 12:26 AM
Post #1


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.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
 
Reply to this topicStart new topic
Replies
scotty914
post Feb 2 2005, 09:06 PM
Post #2


suby torque rules
***

Group: Members
Posts: 1,528
Joined: 20-July 03
From: maryland, the land of 25 year
Member No.: 924



QUOTE (bondo @ Feb 2 2005, 12:22 PM)
Interesting.. My mustang has a 3 row radiator, and each row is about 1/2" deep. This radiator I'm hacking up for experimentation has a single row that's more like 1.25". I wonder if that's why.

simply the reason why the old radiator is 1.25 for a single row, is simple. look at it this way radiating the heat to the air is a surface area thing. the larger the fins the more heat each tube can give out. the more tubes the less the area of the fins. now in a modern radiator there are many tubes with less fin depth, but i would think that the tube surface area ( water side ) ratio to the fin surface area ( air side ) to the over all size works out to about the same for every maker, to engine size. with a modern radiator they have had years to figure the best cheapest stongest way to make the radiator.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post

Posts in this topic
bondo   Radiator question   Feb 2 2005, 12:26 AM
Mueller   I think by the time the air hits the 3rd layer, it...   Feb 2 2005, 01:10 AM
neo914-6   http://www.914world.com/bbs2/h...   Feb 2 2005, 01:59 AM
redshift   Ask Seanery, he knows all about heat transfer. <...   Feb 2 2005, 02:02 AM
skline   So you are not in a hurry to finish your car and d...   Feb 2 2005, 05:28 AM
SpecialK   "that won't work" http://www....   Feb 2 2005, 06:04 AM
ArtechnikA   i think you're going to have a hard time getti...   Feb 2 2005, 08:00 AM
bondo     Feb 2 2005, 09:15 AM
v82go   Hi I recently replaced my custom 6 core radiator w...   Feb 2 2005, 09:50 AM
SLITS   Rate of water flow thru a radiator is very importa...   Feb 2 2005, 09:53 AM
bondo     Feb 2 2005, 09:54 AM
914GT   I find this to be some interesting stuff and when ...   Feb 2 2005, 10:29 AM
andys     Feb 2 2005, 11:00 AM
davep   Ah, a topic dear to my heart, and a little within ...   Feb 2 2005, 11:15 AM
bondo   Ok, it looks like I'm looking at a couple diff...   Feb 2 2005, 11:34 AM
scott thacher   all this talk about water flow, air temp rise, del...   Feb 2 2005, 11:44 AM
ArtechnikA     Feb 2 2005, 11:56 AM
bondo     Feb 2 2005, 12:43 PM
bondo   Thanks for all the info and suggestions.. what a g...   Feb 2 2005, 01:22 PM
ArtechnikA     Feb 2 2005, 01:37 PM
bondo   The pump will be mounted at the bottom of the fron...   Feb 2 2005, 01:43 PM
ArtechnikA     Feb 2 2005, 01:47 PM
bondo     Feb 2 2005, 02:19 PM
bondo     Feb 2 2005, 02:22 PM
914GT     Feb 2 2005, 02:39 PM
v82go   On my application I use aluminum condit instead of...   Feb 2 2005, 03:30 PM
v82go   CONDUIT (yes I can't spell)   Feb 2 2005, 03:33 PM
914GT   Bob, The conduit looks good. Hell of a lot easier...   Feb 2 2005, 03:52 PM
bondo   Nice, where do you get aluminum conduit? The stuff...   Feb 2 2005, 04:26 PM
v82go   Check with any electrical supply place. They also ...   Feb 2 2005, 05:44 PM
BIGKAT_83   v82go the fan and shroud look like they are from o...   Feb 2 2005, 05:55 PM
bondo   Whenever I need to design something unusual I turn...   Feb 2 2005, 06:39 PM
SpecialK   Good thinking on the aluminum coduit v82go, defini...   Feb 2 2005, 06:43 PM
BIGKAT_83   Bondo I've seen and ridden in 2 914's tha...   Feb 2 2005, 07:30 PM
BIGKAT_83   Here is Boxstr new yellow 914 this is what I was t...   Feb 2 2005, 07:51 PM
MattR   You guys are all wrong, the 914 is AIRCOOLED!...   Feb 2 2005, 07:56 PM
914GT     Feb 2 2005, 08:00 PM
marks914   Here are some pics of my setup during the build. ...   Feb 2 2005, 08:14 PM
marks914   Here is another, I have cutout the wheelwells sin...   Feb 2 2005, 08:15 PM
marks914   Here are the hardlines under the car when I was te...   Feb 2 2005, 08:17 PM
scott thacher     Feb 2 2005, 09:06 PM
tesserra   With all this talk about too much flow of coolant ...   Feb 2 2005, 11:24 PM
bondo   Well there are two deltaTs. One is water to air, t...   Feb 2 2005, 11:59 PM


Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



- Lo-Fi Version Time is now: 11th July 2025 - 08:55 AM