OIL COOLER LOCATION

[rv7guy2]

Hi Guys

I was wondering what the general agreement is where to mount the oil cooler on the left rear baffle. How far down (or up) the baffle should it be, taking into account non interference between the oil lines and the engine mount. I have a boosted Lycoming 10-360 that my engine builder says puts out well in excess of the "normal" 180 HP. Obviously I don't want it to cook on those hot summer day climb outs. A friend off mine placed the cooler on his 160 hp RV-9A one inch below the top of the left rear baffle and if anything, he's running cool.
Just trying to get an idea before I start cutting the cooler hole in the baffle.

Davee C
RV-7 C-GCPD (reserved)

 

[erich weaver]

I have not flown yet, but I mounted mine as high as I possibly could on the baffle, which maximizes the exposure of the plates on the bottom of the cooler to a clear air flow path (I think the extreme bottom portion of the cooler still overlaps slightly with the cylinder head fins). I would rather deal with a "too cool" issue than a too hot issue. I think Checkoway actually skewed his cooler at an angle to take this principle a step further - check his website.

There has also been a fair amount of discussion about securing the cooler to the engine mount rather than the baffles. I like the idea, but loathed the extra time it would take to fabricate a custom fiberglass cooler intake and exhaust plenum so eventually nixed this idea.


erich weaver

 

[Ironflight]

Davee,

This was one place where I came really close to screwing up! I eyeballed the position of the oil cooler based on looking at pictures of other folks installations that looked well done. I also wanted to mount it fairly high, figuring that if I got too much cooling, I could always block parts off. The gotcha came when I started trimming the baffles to fit the top cowl - I came pretty close to not having enough material left....part of the problem was that the pictures I had eyeballed were for -7's, and I was building an -8 - the top cowl shape is different!

I still think mounting it high is a good idea, just make sure to plan ahead. In fact, that's just another place where I learned the valuable lesson that when you deviate from the plans (or have to make something up because the plans are vague), look very carefully (far ahead) to see what land mines you might be setting for yourself!

Paul

 

[fodrv7]

After Baffles.

As Paul and Erich have said and you have anticipated, you need to finish the baffles before you can work out the position of the cooler.
The baffles (from memory) are supposed to have 3/8" clearance from the cowls. One trap is that when starting and stopping the engine, it almosts rocks this much at the outer extremities of the baffles- right where the Oil Cooler goes. One of my mates did not allow enough for this and had to trim the baffles after he found rub marks on the cowl from the baffles. So I went for 1/2" at the outer extremities of the baffles.
The next problem you will have is trying to work out how much cleance you have between the baffles and the cowl, as you can neither see or get your hand inside the cowls once they are on, particulalrly when you are doing the final trimming and the cowl is all the way down.

Solution; I placed small blobs of plasticine on the top of the baffles, fitted and removed the cowl and then used the depth end of my digital vernier micrometer to measure the clearance as indicated by the squashed platicine.
Once this was done I found I could position the Oil Cooler with 1/2" clearance from the cowl and the opening at the bottom of the cooler was JUST above the Horizontal baffle on the cyclinder. I see oil temps on Australian summer days between 80-85?C. Lycoming state 80?C is the 'desirable' temp.
You also need to beef up the baffles where the Oil Cooler attaches. Some who didn't ended up with cracks.
I did it with aluminium Angle, such that I boxed in the dog leg, making it easier to fit the rubber seal. It's not light, but I don't eat at McDonalds so it's not a problem.
The hoses cleared everything well, using Vans FWF Kit with the 45? fiting on the top and the 90? on the bottom.


Good Luck
Pete.

 

[Norman CYYJ]

I am a firm believer in mounting the oil cooler on the firewall. Oil coolers mounted on the rear baffles usually end up cracking. And there is a whole lot less head scratching to do.