Anyone have any inexpensive tips and tricks / mods to improve the cooling on an 85 rx7? Currently the car runs at normal temps all the time except when driving hard up hills the temp guage tends to creep up a bit.. so im just lookin for ways to bring it down a little bit when the car is under load.

 

I just installed an electric fan but I have always thought these cars run cool as a rule of thumb. Are you sure there is nothing else going on?

 

Im pretty sure there is nothing else going on... what should I be looking for in a cooling problem?

 

Rotarys run hot when there is a heavy load put on them.
The E-fan with an adjustable heat switch, ought to really help. Put in a lower temp thermostat.

Good luck, and make sure you dont over heat it. These wankels dont like to get to hot.

 

Thanks,I didn't know that. I don't even have to run my fan right now it's so cold here.

 

Ive had my radiator cleaned and rodded out and backflushed the entire cooling system twice this year. The backflushing included running Purple Power through the system twice and thoroughly rinsing with the engine running and heater on for over 30 minutes until the water was crystal clear.
Refilled back with 70% distilled water 30% coolant and Redline Water Wetter.. now the temp gauge needle barely goes over 1/4 and almost no warm air coming from the heater .. too cold now I suppose
Fully stock cooling system and fan with new water pump and always ONLY a new factory Mazda thermostat.

 

the 12a's will run hot under load up hills. Redline chemmicial co. makes this stuff called 'waterwetter'
added to the cooling system fluid. this **** really works.
it breaks the surface tension of the h20 and fluids in the cooling system. they advertise a 9' degree difference
lower temp. then without it. it's about $13.00-$14.00 dollors for a pint 16floz.

 

have you ever seen what that purple stuff does to alum.? i oversprayed( dam gust of wind) my alum (mirror polished) rad. and it instantly went white and it took me for ever to get if back to a good mirror shine. i would think running that stuff throught the motor even deluted would cause the waterjackets to ash and that would cause worse cooling. i would drain the sys and flush it with water till it was clear. then add a flush/cleaner to it and let it run with the heat on high for a good 30 min then drain and flush that stuff out good. then take the rad to a shop and get it acid cleaned. refill with 50/50 mix also have you checked the fans clutch?

 

changing my radiator did the trick for me. I'm in So Cal and during the summer the temp gauge would go past half as soon as I would go on the highway or go on a long uphill. Even with no thermostat. Got a new radiator, no big deal, you can see it here http://cgi.ebay.com/ebaymotors/ws/eB...tem=2434562646 , and put a stock thermostat. Have a stock fan. Now I drive daily on an uphill for 10 mins in third at 5,000 rpm and the gauge doesn't even move from it's 1/3 position. Or I can go 100 mph down the freeway and the gauge barely moves.

 

BadAssRX-7... am I reading your reply wrongly or did you not understand my mine and now implying that my car has a cooling problem?

Yes some alkaline based detergent cleaners can have a discoloring effect on certain grades of aluminum which is why I tested the Purple Power first full strength before using by degreasing the outside of the engine with no ill effects... Im not worried about it discoloring the inside.
I had to do the coolant seal fix http://www.rotaryresurrection.com on the $100 overheated engine that I bought and installed and it worked... I cant afford a rebuild yet
Theres no more oil mixing into the coolant... and I will exemplify: temp gauge does not rise above 1/4 even in SoCal summertime traffic.
Plain water has more than twice the heat transferring capability than antifreeze/coolant... which is why many race teams run water only and a water pump lubricant.. not a smart thing to do for a street car though, but yes I would use a 50/50 mix if I drove or stored my car in a close to freezing climate.

 

Thats the problem right there...The heated up water doesnt give the radiator a chance to cool off the water but recirculate it right back into the engine because its flowing too quickly.
Slowing down the water flow even with a gutted thermostat helps aid in the cooling process.
Always use the Mazda thermostat with the jiggle pin pointed up at 12 o'clock, if not the valve will open up at a different temperature.

Im feeling helpful tonight but now off this topic

 

you have the water/oil cooler, yes ?

change it for a later model air/oil cooler.

I got mine from the junkyard for $15, you will want to get the hoses, and possibly other things for the swap.

it would be worth it I think.

 

bah, you guys and your bashing of the beehive. i still say it works great. i just replaced the bottom o-rings on mine and now my car runs even cooler than ever. sits just a tad past the second cold line and never moves no matter how much load it's under.

 

That's only part of the problem. Having no thermostat leaves the bypass valve open which means some of the coolant won't even see the radiator.

 

Good stuff guys. I'll just add this. Keep your radiator shrouds (including the undertray/skidplate) intact and keep a nice tight seal around the radiator. You want the air to go thru the radiator, not around it. Air will take the path of least resistance, remember that. Go take a look at your car. Also, the fan is most effective at low speeds (below 30 mph or so), after that, ram air does all the work. Alot of road racers dont even run a fan. Food for thought.

 

yeah, i took my fan off (it stoped working, and its winter) and my car stays at 1/3 unless i get stuck going <20 mph

 

Cooling problems are generally easy to diagnose because its such a simple system.

Thermostat
Radiator
Waterpump
Fan

Oh ya a ditch that POS filter mounted oil cooler!!

 

check the condition of your radiator. they will ften oxidize from the inside. they do this because of the minerals in regualr water. they form mineral deposits on the inside of the radiator and reduce the flow of coolant. if you chance the radiator, use distilled water. it will never again form mineral deposits.

 

not bashing, simple observation.

the beehive adds heat to the water, if the water is getting too warm remove a source of heat, the beehive.

or ADD more coooling, oil or water.

 

are there any known, reliable upgrades to the stock radiator caps?