Re: Bought used SRt6, replace intercooler pump?
I have to get into this one, for what it is worth.
I don’t believe that the flow rate will adversely reduce the cooling of the motor or SC. More is better as the whole heat exchanger surface is then the same temp (almost) and gives the most rejection of heat overall for a given heat exchanger “H/E”.
Think about it, if there is a 1 or 100 degree difference between the motor and water on one side and between the water and the air on the other side, the faster the flow, the more material is run past the surfaces (liquid side of the interface) and the greater the differential, i.e. the radiator is held at a more similar temp top to bottom and the motor on the other side is experiencing a more similar temp on the cooling side, the greater the amount of heat moved into and out of the water / mixture.
I have been off the air for several reasons, but was going to publish some rather shocking findings about the SRT-6 cooling system as it relates to the supercharger. The problem[s] aint what you think, but that is for the next article.
First and foremost, the Johnson pump in a SRT MINE with the LET heat exchanger runs about 3.5 to 3.7 GPM.. I know this as I added a flow meter to see what the heck I was fighting in my car. I cannot get but 3 to 7 degrees delta in to out on the intercooler and the LET radiator assy. I have added baffles, ducted more air, induced the main fan motor / computer to run at a higher rate (speed), and tried taping off all air leaks that might allow air to bypass the H/E as it is called in the forum. My measurements are for a 55% antifreeze/distilled water mixture cold and hot motor conditions. I added a relay to command the pump and 4 fans that I put on the H/E, so that I can monitor the temps with and without pump operation…I have also flushed the 14,000 mile old system twice with radiator cleaner to be sure there is no gunk on the passages internally -motor and radiator.
At 3.7 GPM and assuming 8# / Gallon, about 6 degrees delta is only a lousy 177 Btu per minute extraction, and that is not enough for me. I have ordered a new heat exchanger to put this problem to rest, as it has about 280 inches of face or surface to reject heat. LET is about 5” by 20” and in my estimation too thick to allow sufficient airflow as it is installed. When I have RESULTS I will post them to show if I have anything worth the ‘paper’ it is written on.
The H/E and S/C water that I have been measuring ( with a differential digital monitor with plug in probes ) has been running between 120-135 degrees in the intercooler loop and that is against an 85 – 95 degree ambient. That should (I would expect, and won’t stop till I get there) allow the intercooler water LOOP to be more like about 105 - 115 degrees with a typical 20-degree differential (loss) across the intercooler and H/E interfaces.
If you were to allow the water to move slower (try to figure the rate it moves now in foot/second on a 3/4" hose, a good assignment for Brian} and allow it to get HOTTER, first the S/C is not cooled as much [That would be a bad thing] and second the H/E is not doing as much for the last part of the H/E core is much cooler than the first part. You would be wasting the H/E's capacity!
I had a customer who wanted me to help him maximize the heat that his wood stove delivered to his house? He was a bit of a geek, as he wanted to formulate an algorithm to operate a fan that would blow the air through his stove. Seems that he thought that the computer was needed to do this.
My answer was that the fan should run all the time as if there was heat in the stove he should blow the air to help SCRUB the heat exchanger surface as much as possible to cool it in an attempt to extract the Maximum heat in the stove. He thought about it and decided that this approach would do what he wanted with less hardware, durn it. The goal was to extract the max energy out of the system, and regulation of the home temp did not figure into his request.
Ill get to a bit more experimentation so that I can get the heat issue before the Forum.
P.S. I now have my thermometer gauge running at 2 clicks up on the dial with my 172-degree stat without additional fans or gimmicks. Stock is 3 clicks or mid scale, TA DAA
Further, I also still do not fully believe that the pumps are failing as often reported. To that end I still offer postage to anyone with a “dead stock pump” so I can do a ‘post-mortem on it, or them; ( as in several pumps - not the other forum members. I sorta know how you "guys" are/think )
ENJOY, WOODY
Last edited by waldig; Jul 30, 2008 at 12:36 PM.