Oil Cooler Spray

[tweiss3]

Alright, I am very lightly modified (catback and new cat) and NA and so for the most part the stock oil cooler does a great job. Although, on some very hot days when I hit heavy stop and go traffic around town, i see creeping oil temps up to 210, which i don't like. I know those temps are "ok" but i'd like to be able to keep them down below 200.

Is there any danger in using the spare wiper fluid container and pump i have to spray a water mist at the oil cooler when its that hot?

[Pete_89T2]

I don't think it would hurt all that much if the mist were distributed equally over the surface of the cooler. That said, I'm not sure how much this effort would really buy you in actual oil cooling. Seems to me you would have to dump lots of water on it to get the temps down.

Do you have problems getting the oil temps back down below 200F once the car is moving again? If so, check to verify you have all the stock radiator air ducting in place, to include the plastic undertray and foam sealing strips on the bottom of the cooler & rad. This makes a big difference in how effective the oil cooler & radiator can cool respective fluids. Also, since the stock system was engineered around the stock clutch fan, if you switched to an e-fan, you'll need to ensure whatever ducting you have pulls air thru the oil cooler properly too. If you still have the stock fan, check the operation of the clutch per the FSM.

[tweiss3]

No, it does drop pretty quickly once i can get it up over 20 mph, but when i sit at a light for over 2 minutes creeping, it scares me. I think im going to mock it up tonight and see how it works. I am going to NYC this summer in late july, and thats really where i am getting scared. I want to atleast be able to make a dent in the oil temp if i were to be stuck below 15 for an hour.

What about running a water/ethanol mix for the cooling fluid?

[Pete_89T2]

If that's the case, it sounds like your oil cooler & overall engine cooling system is doing its job as it was designed to. If you're stuck in creeping NYC traffic for hours, adding a water mister to help is not going to be a practical solution since you'll need more water than you can carry. You may be able to drop the temps a few degrees, but the effect won't last long once the tank runs dry.

Better way to keep your oil temps down is to read the traffic, and just shut off your engine whenever you know you're not going to be moving anytime soon.

I also recall reading that racers running synthetic oils in rotaries found they tend to run cooler oil temps than conventional oils. Not to get into the synthetic vs. conventional oil debate, but if you've modded your car to run nothing but premix for apex seal lubrication (i.e., block the OMP & run premix in tank OR use the OMP & Rotary Aviation adapter to run premix via separate tank so you're NOT burning any crankcase oil), switching to a synthetic engine oil might be worth a try.

[tweiss3]

I can't go synthetic as of yet, stock OMP is in place. I full agree reading traffic, but I am doing this as a backup. You now, being in a tight spot, creeping temp but having to move, that i can atleast spray and move before shutting down for a while. I'm gona mock it up tonight and see how well it works.

[Pete_89T2]

Ok, I'd be interested to see what results you get when you test this. I would suspect you will need to spray a significant volume of water over the cooler before you see the oil temps drop a few degrees. Reason being is you need to cool off the thermal mass of the oil cooler itself before it can start to cool the oil. That's a big & hot hunk of AL.

One idea for a quick test before building anything. Pick up/borrow a tank sprayer (gardening type). Then run your car till the oil temps are heat soaked to the 200F mark, and let it idle. While idling, get an assistant to use the tank sprayer to apply a constant fine mist over the entire surface of the oil cooler. Monitor your oil temp gauge and time, record the oil temperature vs. time. You're trying to measure temp drop over time. Since you're using a tank sprayer, and if you run it till empty, you've also measured the volume of water required to obtain the temp oil drop vs. time. When the tank is empty, test is over, and you'll have a pretty good characterization of how the system would work.

[tweiss3]

That would work, but honestly, im not sure this will take all that long to just mock up and put in place. I have the pump and resevior (a spare) and just mount it somewhere, ziptie the nozzle or nozzles in place, and 30 minutes wiring max. I think thats what im going to do and see how well it works this week, that way i get a decent amount of variety of weather conditions.

I will be posting my results, or my extreme failure, either way, since I believe its a good test and could be beneficial to know. I got the idea cause a buddy with a twin-turbo mazda6 recently installed a spray bar for his intercooler where he sprays nitrous right at the IC. I know thats much colder and more efficient, but its also about $400 than my proposed water setup.

[TitaniumTT]

My SOP for rebuilt engines is run them for 1/2 hr at first starup. I did one in the summer when it was about 85* out. Coolant temps were fine but oil temps started creeping. It took a garden hose on my 19row Mocals to cool them off. Mocals of course being much smaller and effiecent. I don't think a washer fluid bottle of cold water is going to show any significant improvement on oil temps.

[tyler]

Hey man long time no see, well if u got the $$ you could do I did on the gtu...I bought a C02 show purge kit that ran off a paintball tank and just aimed the dual nozzels at the coolers and radiator. Its a little pricey for somthing you barly use but it worked for till I got the koyo rad in. I figure if u only use it when stoped a 20oz bottle should last a good bit and they easy to refil\replace since plenty of places carry the tanks and will refil one that size for around 3$.the kit could be made for pretty cheap if u can get a solonoid. id give ya mine if I didt sell it to my bud for his mustang. Haha first ricer mustang I've ever seen.

[j9fd3s]

when you're stopped, oil temps don't really matter that much...

but if you're still paranoid, a friend of mine used some old computer fans on his oil cooler. he had a front mount intercooler, so his oil temps were 250+ moving, and the computer fans dropped it to normal