What you smoking this morning The oil doesn't magically circulate through the engine

The oil pump is fairly integrated...it isn't an easy thing to change. When you rebuild your engine...there are mods to the oil channels etc that might be applicable to the Renesis...I'm hoping Charles will have a goo look on his rebuild project and see what can be done

 

Well, a quick search didn't find me anything...I'm guessing this is a system driven off the eccentric shaft and the oil that flows through it...we have oil metering gears - or at least the older 13Bs did, so I'm kind of assuming the same setup here...

 

It might be easier\cheaper to upgrade the OEM oil coolers. I've never seen the RX-8 OEM ones, but if they are like the FD ones; then there are a couple of options for you:

-Fluidyne
-Mocal
-B&M

Also, don't forget the external thermostat if you go with a custom cooler.

 

from my recollection, the reason the stock oil coolers are so small is because of the air opening on the front bumper...

My plans on upgrading the oil cooler is going too happen after I get a different front bumper, specifically the Accolade C-spec.

What point does oil cooling exist for if the only air cooling you are supplying is a fan? Change the stock ones first...

 

The oil pump is bolted to the front plate underneath the front cover. I'm waiting for Charles' plates to arrive here so I can port them. I'll look into the oil passages. I want to see how they're different from the 13B and if the same mods apply.

 

As far as I can tell, there are no significant differences in the size of the passages from the oil pump.
Really, the only difference up in front of the motor is the lack of a distributor drive.

 

An oil/air intercooler can be significantly larger than the opening that leads to it. The cooler its self blocks the majority of the air flow and funnels it through its passageways. A 1ft² opening might flow enough air to support 2ft² of heat exchanger. Extra air flows around or stagnates against the cooler. When the exchanger is larger than the opening, ducting becomes a little more important to encourage the air to flow through the extra face space of the cooler and not the empty space that might be accessible to a near side.

Sooo.......if you replace your oil coolers, you can go a little larger if you can fit it. If the cooler extends passed the clear opening a fair amount, you might want to work out some ducting to spread the air more predictably.

Hmmm........ Seeing as the oil coolers are primarily in front of the wheel wells, how much would a vent in the wheel well liner improve flow? Maybe it wouldn't help at all.

 

I thought I would get someone's attention hehe with that.
There are pretty good vents in the wheelwell liner--behind the stock coolers, it is a little crowded.
One interesting thing i have noticed is if you coast for just a little(1/8 mile?), oil temps will drop about 10 degrees on mine. Absent of so many flame fronts? Slowing of the oil being pumped giving it more time in the coolers therefore exposed to more airflow? Both? ---probably.
I agree is replacing the oem or the oems. I also like a fan for "those" occasions.
Has anyone counted how many rows we have?
OD

 

Quick note: Heat transfer is proportional to the temperature difference so the most heat is rejected when the hottest oil is present. The hotter the oil coolers are, the more heat that is flowing out of them. This might actually favor higher flow rates for total heat rejection. As for less combustion cycles, that's absolutely true. Running at low throttle, less rpms definitely inputs much less heat to the system while the heat rejection of the oil coolers remains high due to the high oil temps.

I need to get my gauges installed. This way I can play with numbers too!

 

please do. like what you said about heat rejection--.
what is the thoughts on the efficiency of our coolers, therefore--staying on topic---would it be best to replace or add an additional?
OD

 

Yes, delta T is needed for the three types of heat transfer (conductive, convective, and radiant). However, without air flow you have no convective heat transfer at all - which is where the largest amount of heat transfer from a radiator can be seen.

The other 2 modes of heat transfer will just try to heat up the chassis and bake the airdam.

 

and --replace ot add?
aod

 

I haven't really considered adding another oil cooler myself yet, but I do enjoy reading threads about design improvements. My initial thoughts would lead more toward improving air flow to the existing coolers and/or replacing the OEM coolers with higher efficiency ones. I don't actually know what the core material of the stock oil coolers is. Next time I feel the need to pull one of my wheel well liners, I'll take a better look at the pathing. R0tor is absolutely correct. Air being an excellent conductive insulator, if it does not flow for convective heat transfer, your performance sucks.

 

http://store.summitracing.com/partde...5&autoview=sku

I'm thinking that maybe using just one of these behind one of the oil coolers might work well. It could be switched with a thermostat. I think it will fit, and it moves quite a bit of air, 1800cfm.

 

I have this one from Fluidyne hanging in front of my intercooler. Its plumbed in-line with the stock coolers. Its just about the most efficient cooler available. Made for NASCAR. In fact, I bought mine from a NASCAR team.

With regards to allowing the oil to heat to operating temps rapidly enough: the stock coolers have a thermostat. Oil won't circulate until the thermostat opens. So, plumbing it like I did means that the additional cooler isn't contributing to longer warm-up times.

 

I have a JDM spec with only one oil cooler . You guys with two should count yourselves lucky .
Has anyone upgraded a stock cooler yet ? If so where did you get it from & what $
I see japanpartsonline have a few kits available but they are like $1000 + !!!

 

well just completed a 3 day track w/e. approx 250 miles on the track completed. ambient temps highs mid to upper 80's. I TRIED TO GET THE OIL TEMPS OVER 230F by running HARD, keeping revs between 6.5-9.2 all the time. For approx 20 mins of hard driving. Only one straight on this track(Roebling Rd savannah) in which speeds were over 100mph. Oil temp never when over 230F. Coolant temp never went over 205.
AND once I backed off--temps came right down. On cool down lap temps dropped to approx 190-200 F oil and 180F coolant. I was using 10/40w royal purple and i run a 65/35 blend coolant. No screens and rotor symbol in the front air dam removed. undrive pulley on.
I know once ambient temps get over 95 things may change--but for right now --i'm good.
I used approx 2 quarts of oil on those tracks days. Thats good.
OD

 

If you are measuring oil temps entering the engine and not exiting then 230*F is about 20*F too hot.

 

measuring from rb oil filter adaptor--mechanical gauge. pressures and temp. I would like to see what the return from the 2nd cooler is but havent had time to rig one up.
coolant tempt from heater hose--i dont like that as well as the radiator hose or engine itself, but what the hell.
olddragger

 

The oil filter comes right after the oil cooler, so you are in good shape there.

Why measure water temp at a heater hose? Whey not right at the thermostat housing?

 

maybe for the 20 year old oil when that was written...

 

Why not just run 230* coolant temps too? Oil is the only COOLANT for your rotors! 1/3rd of the total engine heat goes out the oil system. It has nothing to do with the oil breaking down over 210*F. Yes the higher the oil temps the shorter the life span but 210* isn't enough to kill it quickly. It's all about cooling. A higher quality oil can't help that aspect of it's job in a rotary.

 

RG--one thing I am curious about is the coolant temp vs oil temp. At certain times I can have a 15-20 degree differance(since my fans now activate at 180F) example coolant 185---oil 200. In recips i know that really doesnt matter much but in the rotory ---welll---i dont know. The most i have seen is 30 degrees for a short period of time on the track. i have seen 20 degrees on the street rarely.. . Concerns? or not
olddragger

 

Your oil and coolant temps "should" be within literally a few degrees of each other if everything is done right. When are temps at their greatest range? Is it while moving or while sitting still? If one is higher than the other, you know which one to improve. I know people say that a certain temp is fine for the oil. That may be so but what is optimum for the engine is different.

 

while moving. If setting still --in just a little while---it evens out. Not talking about getting a red flag on the track --then the difference widens. The difference is directly related to how hard I am running the car.
OD