C-FAH Q

C-FAH Q

Well Known Member
My RV7 IO-360-A1B6 seems to run a tad warm. The cowling is tight and everything sealed up very nicely. I was thinking of adding a small second cooler to the system for summer operations. Has anyone tried this? any success?
 
Oil Cooler IO-360 200HP

Hello Gary,

What oil cooler do you have? It would be much simpler to install a better and/or bigger cooler to keep the oil temp in check versus adding a second coller. I am using a SW 10599R cooler with an IO-390 installation in an RV-7 -- no problems keeping temp below 200?F even during the hottest time of year. Temp during cruise is a constant 190?F.

Bill
RV-7 N151WP
 
You planning on installing in parallel or series? In parallel, how are you going to balance the flow? With two coolers, you've increased your chance of failure significantly. Keep it simple - revise what you have or enlarge the single cooler installation. Too many people successfully running Lycomings with single coolers out there to consider otherwise.
 
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Dual Oil Coolers

Gary, I've seen two oil coolers installed on an RV-6 down here in Southeast Texas. It was a slightly tweaked IO-360 parallel valve engine developing more than 200 hp, and if I remember correctly, they were originally having trouble keeping the oil temps down during summertime climbs. The original configuration had the main cooler installed on the firewall with SCAT tubing feeding it off the back of the plenum.

The new & improved version had a small oil cooler between the inlet and the #2 cylinder that was plumbed in series. I'm going by memory, which is dangerous for me :rolleyes:, but I believe that's the way it was done. But it did solve their high temp problem.

Now, I don't want to second guess your problem, but I used to work in Ontario years ago and I don't remember it getting very hot during the summer. Is it possible that there is something else going on that's causing the higher temps? Maybe some sort of air path restriction? Without knowing how your system is configured (i.e. cooler location, size, type, plenum, etc.), it's tough to really say.

So yes, it is possible to install a secondary cooler and others have done it --but I'd be looking for a reason why your one cooler isn't doing the trick.
 
Second oil cooler

I ADDED SECOND OIL COOLER WHEN TEMPS WERE GETTING HOT ON A REGULAR BASIS. THE RESULT WAS ZERO IMPROVEMENT. I THEN TOOK PLANE TO LYCON IN VISALIA CA WITH PROBLEM AND THE PROBLEM TURNED OUT TO BE THE THERMOSTATIC VALVE FOR THE OIL TEMP. THEY ALSO COVERED MOST OF THE ADDED SECOND OIL COOLER. TEMPS CAME DOWN TO NORMAL LEVELS. JUST A THOUGHT. THE ENG WAS A ANGLE VALVE IO-360
 
OIL TEMP

I HAVE INSTALLED A SECOND COOLER ON MY -6. IO-360 ANGLE VALVE, VERY TIGHTLY COWLED. YES IT IS TWEAKED A LOT! THE COOLER IS A 7 ROW INSTALLED IN SERIES, UP FRONT OF THE #2 CLY. MY TEMPS WENT FROM 200-220 TO 170-190 WITH OAT AT 90-100. NO PROBLEMS EVEN DURING LONG CLIMBS TO ALT. IT ADDED 7lbs. INCLUDING OIL. THX FOR LISTENING. DENMAC
 
I didnt even realize there was a thermostatic vavle for the oil. I will check into that. Not adding anymore weight is always a good thing. My angle valve 7 comes in at 1099, prefer to keep it thier.
Thanks
 
Cooling the oil can be fun.....

This may help, but I have found that cooling is as much an art as a math
problem. The way every thing is fitted and sealed as well as shaped. Changes
the cooling to some degree. Two engines just alike in two aircraft just alike
will in most cases not cool the same. We have a none standard IOX-360, with all 8 cooling jets installed. That puts us in the midle, not 180 bhp. not 200 bhp. The answer was one cooler behind number 4 per plans, but not 7 row. We found that you could fit a 9 row in the same place, only 2 more rows.
This gave us aprox. 22% more cooling area, for the aprox. 7% more than standard bhp. A good infer-red temp. gun comes in handy on these jobs. It can take a lot of time to get it just right, Go slow..
Yours as always REA III #80888
 
IO-390 Oil Cooler

billgill said:
Gary, I can send photos of my installation if there's interest.

Bill
Click to expand...

Hey, Bill... Noticed you are using the SW10599R cooler for your IO-390.
I'm at the baffling stage right now & am returning the smaller Van's oil cooler and looking at the larger SW coolers. Do you have a pic available of your installation that you could send me? Would greatly appreciate it!

My email is [email protected]

Many thanks in advance.
Bob Walden
Atlanta, GA
RV-7A TipUp with IO-390 Mattituck
 
Oil cooler stuff

Most oil cooling problems come about from not supplying an adequate amount of cooling air to the cooler. Let's take the case where you take an output from the back of the plenum through, say, 2" diameter scat tubing. The air in the plenum has already been brought down to very low speed and near to stagnation pressure. You then place an expander duct at the entrance of the cooler to expand it from the 3 sq.in. area of the duct to the 15 -18 sq.in. area of the cooler, and then you just dump the output into the area behind the engine where it competes with the engine cooling air for exit from the cowling. It just won't work well. First, you have to take the low velocity air in the plenum and speed it up through scat tubing whose effective cross-sectional area is probably 50% to 75% of the tubing area because of the spirals and rough interior. Air loss number 1. But that would also mean that you are trying to increase the velocity of the plenum air, which is going to require a lot of pressure to make it go faster. But the air in the plenum would much rather go through the relatively-less pressure drop of the cylinder fins than be spent in trying to get the air up to velocity through the draggy tubing and draggy oil-cooler fins. It's a losing battle. Now if you had a similar smooth 2" diameter duct facing forward in the outside airstream, THEN going through an expander duct to the cooler, increasing pressure and reducing velocity along the way, THEN supplying a contracting outlet duct from the cooler to the bottom of the cowl and firewall, facing to the rear, your cooling problems would be over, and your cooling drag would be less. A 2" diameter inlet at 180 mph will supply up to 25 lb/min of air to the cooler. The inlet for the oil cooler on my 125 HP engine has a 2 sq.in. area for 200 mph. A 3 sq.in. inlet area should give good cooling for about 50% more HP or 187 HP, and a 4 sq.in. inlet would be money in the bank!
 
Paul,
As it turns out, my cooling issues had more to do with the engine not being broken in. The temps settled in and dropped significantly after about 30 hours of flight. I plan on making a plenum on the back of the cooler with a 3" duct running down to the rear of the cowling near the exhaust outlets. This is in hope of reducing some cooloing drag and gain a little speed. I also need to reduce the air flowing through the cooling fins as my cht's only get to about 290 degres.
 
I are about to order a Firewall Forward kit for my IO360 A1B6 200HP. The kit comes with the smaller oil 7 tube cooler.

The Catalog implys that we would be better off with the larger 13 core cooler which I think we will go for as we are about ISA +15 often here of the summer. How hard is the bigger oil cooler to mount on the fire wall and is there enough room there to get it mounted.

Thanks:confused:
 
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