Anyone out there ever tried one of those Mocal Oil-to-water oil coolers? If so which one do you recommend for an 86 – 92 13b?

 

IIRC, The FC (86-91) uses a regular air cooled oil cooler. Are you using this in an FC?

 

Gracer7-rx7:

Many thanks for the response. Tough this is a 13b application if is not an automotive application. This is an aviation application. Since 1lb of glycolized liquid can absorb much more heat energy than 1lb of flowing air *AND* since the under cowl area in an aircraft application is quite small I thought I could save both some space and weight by doing the oil to water thing. As well I thought that by dumping all of the heat into the radiator's liquid flow stream I'd be able to up the efficiency of the cooling fins on the radiator by making the radiator that much hotter than the air flowing through it. The thing is I don't want to size the oil-to-water cooler too small as that would defeat the purpose of using this method to cool the oil. Any thoughts?

James

 

while that may be true how much water are you able to move compared to how much air is flowing past the cooler? especially in some kind of airplane.

i don't see how adding more "load" to your radiator is going to make it more efficient. upgrading radiators at the same time would make sense, but simply adding more heat no. (unless it is already being underutilized which i highly doubt if it is the OEM unit)

im no expert but thats just my 2 cents.

 

This doesn't make sense. If you introduce more heat into the radiator, it's not going to increase its efficiency. Here's an efficiency equation for a heat exchanger (radiator, intercooler, etc...):

E = (T_in - T_out) / (T_in - T_ambient)

T_in = inlet temperature
T_out = outlet temperature
T_ambinent = ambient air temperature

Efficiency is essentially fixed, so increases to T_in will result in increases to T_out. You could end up dumping more heat into the radiator than it is capable of dispersing, which means overheating the engine.

 

I don't think you will get many benefits by trying that. oil plays a role in temp/heat management. Packaging might not be ideal by having 2 heat exchangers (coolant and oil) but it will likely be more effective.

 

wont they be near the same temp though or am i missing something?

 

they could be but if you start combining them you may increase the temp of both because your radiator can only dissipate so much heat.

 

Yep. What he said.

It becomes a vicious spiral, one liquid gets too hot for some reason and affects the other since they use the same heat exchanger. If they are separate, you can manage overall efficiency of each liquid via its heat exchanger (radiator or oil cooler).


On the FD with dual oil coolers, oil temps generally exceed coolant temps by 20*C +/-. IIRC, Oil temps fluctuate faster than coolant temps rising and falling quicker than coolant temps. With a single FD oil cooler the above temp difference is higher.

 

Many thanks for the replies. I think I may have started a religious discussion here (sorry for that). My intent in asking about the oil-to-water setup was to find out if A) anyone had done it *AND* B) if they had, what was the result AND what parts did they use? Overall it seems the idea of using an oil-to-water setup is being decried as a not so good idea. Hey ... that's cool, that answers the question(s) I asked. Now I don’t have to be the dude that does it, and then has to answer this same question later by having a bad experience. Many thanks for providing me feedback. Any additional thoughts are gladly welcome. Have a great day.

-J

 

care to share your project here? aviation is always interesting especially when it involves a wankel

 

Keep in mind we are by no means experts. Just offering opinions.

If you do wind up going forward with it, let us know your results so we can all learn.

 

Ahh yes .... links to some pics of my project. Well, in that case take a look at these links ->

http://tripleaser.com/AcftPics/BeastStands.png

http://tripleaser.com/AcftPics/Clean...ealChannel.png

http://tripleaser.com/AcftPics/EngineinAir.png

http://tripleaser.com/AcftPics/EngineOnLift.png

http://tripleaser.com/AcftPics/EngineOnPlane.png

http://tripleaser.com/AcftPics/3_8ths_material.JPG

http://tripleaser.com/AcftPics/EngineSideCenterPortsProper.JPG

http://tripleaser.com/AcftPics/FlangeOnMotor.jpg

http://tripleaser.com/AcftPics/RunnerSideCenterPortsSpread.JPG


In regards to this particular thread, I'll be mounting my radiator(s) slung below the engine with a big ole air intake duct to channel the cooling air to the fins of the radiator. The cowl I'm using is the same one as seen at ->

http://www.jamesaircraft.com/Jim_and...ary_RV-8_s.jpg

On the intake flange pics above, that’s a custom 4 port flange I had EM burned at a machine shop. I have 4 extras if anyone needs to buy one for their project.

So far it's been a F-U-N project. Any thoughts?

-J

 

hey James.
get a hold of this guy : reginald.leblanc@sympatico.ca He is making an aircraft engine engine also.and maybe you two guys could bounce ideas off each other.
tell him his CUZ Dave told ya to Email him..ahaha..I found out he is a Distant relative.through name anyways!!!
OH.he would be looking for a 4 port Manifold for his ZERO Hour Engine.

 

cool pics. I"ve never seen a rotary in a plane.

 

thats awesome man. make sure to post some vids of that thing running/flying!!

 

So, since I'll be hanging my heat exchanger(s) below the engine and since the engine could find itself spinning in the 6700 to 7500 RPM range what oil pressure should I expect to see at that RPM? Also, on the exhaust stack I plan on using .049 wall thickness SS321 that's JetHot sprayed (the same as my rotor faces). Is .049 thick enough to tame the "Flames of Dante" Rotary exhaust gas heat / Sonic response? Thanks in advance.

-J

 

mine on the stock gauge goes up about halfway, which is like 5-6 lb/cm3 (i think thats the measurement?) at that speed
what kind of oil are you planning on running in that thing?

 

I will run Mobile1 10/40 as this is the standard oil flavor used for Rotary aviation purposes..