I've been running a 24 inch double pass,on the hottest nights it will run 230 considering a 28 inch tripple pass. my question is i know how much better a double pass is over a standard radiator how about the tripple pass over the double pass
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I've been running a 24 inch double pass,on the hottest nights it will run 230 considering a 28 inch tripple pass. my question is i know how much better a double pass is over a standard radiator how about the tripple pass over the double pass
Go to stewart pumps website and read about the double and tripple pass radiators and why they do not do what a lot of people think they do.
I agree with everything they say but my experience is the more the water flow is exsposed to air flow the better. I do believe they may be consimming more hp over standard radiators. Ive never ran a restrictor even on a standard rad. Ive see people buy high volume water pumps and then slow them down with pulleys and restrictors never made any sents to me
im running the 24 because it what i had from me metric mod. im not running a shroud, i run a shroud for years, tried differnt fan blades, found that the 19.5 chevy part# four blade pulles far more air than any other . I quit using a shroud and put the radiator 1 inch from fan. this what i see the latemodel guys do and you dont see them running to the water after a race. and why do you tape up the bottom of the radiator?
If your pump is flowing X and the radiator is Y in width and you put in a radiator that is dual pass now you have to double Y but it is 1/2 as high. The only way that is possible is to double the speed the water is moving thru. So for a double pass the water has to move 2 times as fast as a single. You have the same amount of tubes and fins so you are not exposing it to any more air than a single pass. The only way to expose it to more air is either add size to the radiator of find one with more tubes or fins per inch but to many fins can cause issues with the air flow thru it. This happens every once in awhile when someone picks up a Nascar take out speedway radiator and tries to run it on a car on a short track.Quote:
Originally Posted by racingford
If a 800+ HP iron block late model can run a single pass radiator on gas and stay cool I do not see where a smaller motor requires something different.
You don't want to speed up water moving throw the radiator. What you just said make no since at all again. The reason you run a double pass radiator is to let the water run throw the tubes twice. A single pass aluminum radiator will cool most S.S. engines, a lot of pavement tracks won't even let you run an aluminum radiator. As long as you have a decent fan, and shroud you should be able to run just about any radiator you want. Until this season I ran 4 core stock truck radiators. The problem this person it having is 1 not having a shroud and having his fan to close to the radiator. Back the fan up and get a decent shroud and you'll be fine.Quote:
Originally Posted by Egoracing
find a rocket shroud they do wonders when running that close to rad..Quote:
Originally Posted by racingford
What brand rad are you running there are some out there that are junk..??
If the water is flowing thru the whole radiator using the pump as pressure how do you send all of the water thru 1/2 the radiator twice without making it move faster? It is only a bunch of tubes and if you have water flowing thru 30 1 inch tubes all at once and you connect them to put them into a U shape now you only have 15 tubes to keep the same rate of flow you had water speed and pressure will have to increase to move the same amount of water.Quote:
Originally Posted by LowTechRacing
Quoted from Stewart Components: "Double pass radiators require 16x more pressure to flow the same volume of coolant through them, as compared to a single pass radiator. Triple pass radiators require 64x more pressure to maintain the same volume. Automotive water pumps are a centrifugal design, not positive displacement, so with a double pass radiator, the pressure is doubled and flow is reduced by approximately 33%. Modern radiator designs, using wide/thin cross sections tubes, seldom benefit from multiple pass configurations. The decrease in flow caused by multiple passes offsets any benefits of a high-flow water pump."
Where it says pressure is doubled in a dual pass, that is because you are moviing it thru only 1/2 the number of tunes as a single pass thus doubling pressure to create equal flow.
i have a c&r radiator and a stage 3 stewart pump and yes i was talking imca late model. and ego, when a creek floods out of its banks the waters dont flow in all directions it only floods in all directions. the flood water will cut across fields. my point is water flow in a standard rad. wil take the path of least resistance and the effective flow will be no more than the volume of the smallest water passage of your system weather it be your upper hose, therm housing or passages in the head. yes more flow is better to point get to that point and all you do is make pressure. just my thoughts but an engineer Im am not
I run the 24" double pass rad 18" 6 blade with a shroud & 1 to 1 pulleys & motor runs 200 that fan cracked so I got the big 4 blade first nite out with that set up 170 & it was hotter out that
You are right, the way that the cheaper companies save money it use smaller and thinner tubes. Also look at the pressure rating. We had too get a Speedway radiator local once and it said to only use a MAX of 20psi cap where AFCO's used to come with a 30lb cap on them in the late 90's.Quote:
Originally Posted by stock car driver
We are talking a closed system NOT an open river. A double pass radiator cuts the radiator in 1/2 and the water has to make a u turn to get back thru SO the water only has 1/2 the area to flow. It would be the same as taking a 24 tall and 24 wide radiator and then running 2 12 tall X 24 wide radiators. Go to Stewarts web site and read, this is someone who makes ZERO $$'s off of radiators and he has a bunch of proven tested information on there, then if you do not agree call him up, They are easy to call and will spend time on the phone with you if you have their products or not!Quote:
Originally Posted by racingford
We run a 26" Howe double pass, 28-32 lb cap with no restrictor, an Adams waterpump, 15% reduction pulleys, 18" 4 blade GM fan and a good shroud and even in 105* afternoons, we run 2 rows of tape to keep heat in engine...Cool weather, we will have 4-5 rows of tape to keep heat in...This is a gasoline, 820 HP Dirt Late Model
thanks everybody keep them coming
in the south i ran a double pass 28" with no restrictors, 22-24 lb cap, stock long heavy duty Oreillys brand water pump, cheap 4 blade with no shroud and this past summer it was like 100 to 120 degrees outside in Texas. My car got to 240 one time at the end of the 15 lap race. my 4 blade without the shroud is about 6 inches from the radiator, i changed to a 6 blade 15" with a shroud and the blade half in and half out of the shroud. Have not tested yet due to offseason.Quote:
Originally Posted by racingford
we use a 4blade fan from a local chevy dealer
open or closed doesnt make any difference, my thoughts are the flow in a standard radiator only flows through a portiion because it doest have to, the other portion is just resorvoirQuote:
Originally Posted by Egoracing
i must rather have an afco pair with a stewart pump great combo
Stock car on dirt, stock water pump, welded a circle piece of metal on the back of the impeller the same size, good fan and fan shroud with no leaks. Tunneled the air from under the front bumper to the radiator. 190 off the track after the race. No holes in the front bumper.