Hey Guys,

I have a quick question as to what the normal operating temps are on the 20B. I have the two fans on all the time on the radiator and one fan pushing from the condensor core. I also have one running on the single oil cooler. Now, I live in florida and its hot down here. I have a SPA digital water temp guage and Without the A/C running I am around 200F in stop and go traffic. WITH the A/C running I am running 220-230F. Is that normal? Also, should I get another fanned oil cooler, will that help? Is the gauge that I have way more sensitive than other gauges?

Thanks,

Marc

 

Your temps are higher then I like to see.

What radiator are you using? What temp thermostat?

What are your oil temps?

 

I am runnig a KOYO radiator. I dont have a oil temp guage, so I am not sure what my oil temps im running. I have a 185F thermostat in with a 50/50 glycol mix. I also have a exhaust manifold that is not wrapped. I am going to wrap the exhaust and add a second oil cooler and see what that does. If I am not mistaken, 40% of the cooling for the rotary engines are oil cooling?

Thanks for any inputs

 

Koyo N-flo?

What size is your current single oil cooler?

What water pump and housings are you using?

 

I dont know what type of KOYO radiator it is but the oil cooler is 10x8x1 1/2. the water pump and housing is the FD that was originally on the car. I was mistaken about the thermostat, I have stock fd thermostat.

 

you need 2 oil coolers that size minimum

 

The N-flow has a bleeder on the top. http://www.banzai-racing.com/20B/20B_ebay_05-26-10.jpg

Oil coolers are measured by rows, 15,25, 30 etc. It sounds like you have a 15 row, just for comparison I run twin 25 row coolers with a mocal oil thermostat.

You might want to consider installing the Mishimoto racing thermostat, it has helped other 20B owners on this forum with temp issues Thermostats

 

Sometime this summer I will install a temp gauge in my 20b cosmo and see what they run stock.

 

I'm getting ready to install a 3 row supra aluminum radiator with dual 25 row oil coolers. Im running a rebuilt 20b water pump. We'll see how the temps look when im done here in the hot south.

 

Since there is a thread open already. I am wondering the same question but for Evans coolant. I'm wondering what is too hot for the engine, not the coolant since it will never boil. I went to the track 2 weekends ago and with the limited amount of laps I did it got up to around 215*F with around 16.x PSI. That's pretty good for a peak but it wasn't for many laps and it was a little cool so it will probably want to go higher then that when its really hot out and a longer session. I figure I can push it to at least 230*F as a max? I am not running any thermostats at all, its all straight with the electric water pump.

thewird

 

Hi guys, im running 4 fans, 2 suck and 2 push on alu FD rad and no thermostats, 20B waterpump, dual oil coolers (stock FD), L-shaped V-mount set up where rad stands in normal position and IC lays horizontal.(Large front mount IC brought temps to 134C and was instantly removed!) Daily driven im seeing 78-85C on 25C days here in Copenhagen but under 1,0 bar boost it quickly jumps to 99-104C and have a real hard time comming down again. I read about someone with a 20B in an airplane with cooling problems who found under rebuild that the iron center plates had rusted in the coolant channels and so had less flow, any thoughts? Also Ive bought a new 20B waterpump from Atkins, is the 20B pump sufficient or do I need to go with an electric?

 

^ You need a bigger radiator and bigger oil coolers. Also, 20b and fc mechanical water pumps are the highest flowing pumps for a rotary. I had my 20b water pump rebuilt.

 

Ive found that if I reach critical temperature (100C) after a several pulls I can bring it down immediately just by turning of the engine for like 30 seconds while still moving and let the fans go on. When I turn the engine on again temp drops to 90C in an instant and then falls slowly to 85C if I drive normally. I guess im suffering from heatsoak?

 

The rad is still being cooled once you shut the engine off so after you start back up, that cooled coolant circulates and its natural your water temps would come down lol. 20b's need big rads and oil coolers, period.

thewird

 

I'll have to look into bigger rads then. Boy this engine is mental even at 0,7 its just pulls your head off! Its seems we are out of fuel and have to install the 1600cc pri and 850's sec, oh well more fuel more boost!!!

 

You can run the Evans at 0 pressure for track days. Evans will typically run a bit hotter but this is not a problem. The problem with regular coolants at higher temps are internal hotspots (which is why they need to be pressurized in the first place) and increasing pressure within the system as temps rise. This is an issure with rotaries because of the tendency of the o-rings to fail under more extreme conditions. Running a zero pressure system eliminates that issue.