RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   Race Car Tech (https://www.rx7club.com/race-car-tech-103/)
-   -   double pass w/heat exchanger (https://www.rx7club.com/race-car-tech-103/double-pass-w-heat-exchanger-720847/)

Derek King 01-13-08 12:42 PM

double pass w/heat exchanger
 
just wondering if anyone has used or heard anything good about running a double pass radiator with a oil heat exchanger in there track car. Im kinda skeptical of the oil temps staying cool enough and also not causing water temps to heat up even more.
but then again thats what nascar uses and all other circle track guys use and they run around the track for hours.

28x18x3 is what i am planning on using .

Black91n/a 01-13-08 01:18 PM

I've heard of a number of failures where the oil cooler bursts inside the rad. Do yourself a favour and keep them seperate.

RETed 01-13-08 01:29 PM

I haven't found an integrated rad + oil cooler that is big enough to control the heat on a rotary track car.
It's a lot more flexible to keep them seperate.


-Ted

Derek King 01-13-08 04:52 PM

alright thats what i had figured. my plan was to try it and then if it didnt keep temps down enough i was giong to run a stock oil cooler after the exchanger. currently i have been running dual stock coolers and have been fine with temps but want to make more space up front keep it less cluttered , possibly to keep more clean airflow to the rad and intercooler

Eagle7 01-13-08 05:00 PM


Originally Posted by Black91n/a (Post 7733952)
I've heard of a number of failures where the oil cooler bursts inside the rad. Do yourself a favour and keep them seperate.

+1

jgrewe 01-13-08 05:57 PM

We tried a water/oil heat exchanger on an EP car and it couldn't keep up. It was good for an ARCA car with a V8, no where near enough for a ported rotary. We run huge stock car radiators that we modify to make a dual pass.

The cars now have dual stock oil coolers.

Derek King 01-13-08 06:52 PM


Originally Posted by jgrewe (Post 7734854)
We tried a water/oil heat exchanger on an EP car and it couldn't keep up. It was good for an ARCA car with a V8, no where near enough for a ported rotary. We run huge stock car radiators that we modify to make a dual pass.

The cars now have dual stock oil coolers.

thanks i appreciate the info.
how long would the exchanger keep the oil temps below 210 before they starteted creeping up when you were tracking the car.?

jgrewe 01-13-08 09:33 PM

Less than 8 laps of the Sebring short course, so under 15 minutes.

Derek King 01-13-08 09:51 PM

oh geez. alright thanks alot

speedturn 01-15-08 07:37 AM

jgrewe said "The cars now have dual stock oil coolers."

Amen to that. I have tried several different aftermarket oil coolers on my PP road racer, and nothing is as efficient at shedding heat as the stock Mazda oil cooler. One stock oil cooler was not quite enough for my peripheral port motor, so I now run two coolers, and the oil stays nice 180 degrees F entering the motor.

Proper air ducting is critical to good heat exchange.

TeamWireRacing 01-15-08 09:49 AM


Originally Posted by Black91n/a (Post 7733952)
I've heard of a number of failures where the oil cooler bursts inside the rad. Do yourself a favour and keep them seperate.

+2.

If you still desire a oil/water heat exchanger, the Fluidyne unit is a good choice.

tims 01-16-08 05:37 PM

likey could be custom built by a good racing radiator shop, but maybe to large to fit in car. seperate water to oil coolers can work also but the plumbing can be difficult. best not to reinvent the wheel for no good reason.

Derek King 01-16-08 09:08 PM

thanks guys. as far as fabbing stuff i think i can manage, but like stated earlier i want to keep the plumbing and clutter down. I have ran dual stock coolers before and had no problems at all, then i fabbed up a cooler that holds about the same capacity of the 2 stock coolers to get rid of the clutter and get more air to the radiator but didnt get the results of the 2 stockers.
from the info gathered from you guys i think im going to go with a 28x18x3 double pass radiator and run my fabbed cooler with some more extensive ducting and see what i can get out of it.
thanks again

mustanghammer 01-17-08 11:42 PM

Well, just to be different, several of the EP cars here in KC run Ron Davis dual pass radiators with built in heat exchangers with a stock oil cooler plumbed in series. They work great and have for many years. No issues on hot summer days or cool fall races at the runoffs. In fact the OE cooler needs to be tapped over to get the cars to operating temps on cool days. One advantage is that this setup is more compact than trying to find room for a monster radiator and two external coolers.

In these cars the heat exchanger is plumbed first and then the oil flows through the sock cooler before returning to the engine. I'm guessing but I would say the radiators are 19x26 in size. The cars were built by KC Raceware - www.kcraceware.com.

I run two factory coolers on my IT car and a smaller 19x21 Ron Davis dual pass radiator. I have to run a smaller radiator because it must mount in the factory location per the rules. This setup works well even on hot days but I would need a bigger radiator for a street ported E Production engine. Finding room for both factory coolers was a PITA by the way.


All times are GMT -5. The time now is 04:13 AM.


© 2024 MH Sub I, LLC dba Internet Brands