yet another oil cooler thread

Hey Guys- I'm still noodling around with how to best route oil cooler lines. My firewall mounted oil cooler is about 1/2" too high for this to be easy. i.e. I've got an engine mount tube in the way of the outboard hose port.

I've talked with Tom at TS flightlines. While I'm sure he would build any contraption I come up with, he suggests that it really would be in my best interest to try to avoid having angled fittings on both ends of a hose both for better flow and to minimize manufacturing frustrations with trying to get the clocking right.

I've got a few options, but the cleanest by far would be to just flip the cooler upside down. I'm aware of the potential for trapped air and no way to purge it, but honestly is that really a thing?

I have yet to find anybody who can verify that air in an oil cooler has really ever been an issue. Furthermore, upside down is the standard orientation for the Showplanes remote cooler mount, and those seem to be working out ok for folks?


Option 2 is to run the cooler lines down and forward. I've got them mocked up that way right now and the outboard one comes across the face of the cooler at a distance varying between 1" at the top and 3" at the bottom for about the first 5" of its run.

I'm not worried about the air coming out of the cooler doing anything to a firesleeved hose, but I really don't have any idea of how hot it is there or how it might effect cooling.

Option 2

I've attached pix of the mockup for option #2. As always, comments and critiques are welcome.

Edit- Can someone please tell me why my pictures have started posting sideways and how I fix that?

Desert Rat said:

Edit- Can someone please tell me why my pictures have started posting sideways and how I fix that?

Click to expand...

I don't know why exactly (something about lense observer orientation embedded in the exif, or whatever...). Just open the picture on your desktop and rotate it 360° (yes, one complete rotation), then upload...

I believe, and the aerodynamicists can confirm, that having a 90° turn in the duct is a problem -- the efficiency of the cooler will suffer as a result, which may require that you have a larger oil cooler...

I mounted the cooler to the firewall directly, fabricated a diffuser/plenum to transition the round duct (SCEET) to the rectangular face of the cooler.

Firewall oil cooler

Mine wasn't fun and it's not flying yet so I don't know how well it's going to work. Mine is close to how yours is mounted. Tom helped a lot. My inboard fitting at the cooler is a 45. Outboard fitting is a 90. I didn't have a big problem with the lines although they are very stiff, I'm more concerned about the wet dog shake. There's slack but they are stiff as a board. Maybe they get more flexible under heat.
The problem was the duct. No way to get a nice straight run and almost every solution hit the top cowl. I even fabricated a fiberglass plenum. It didn't work either. I finally found a combination with SCAT that fits, but it's not straight by any means.
My FWF is standard Vans cowl but inlets are sealed to the plenum. RV10 oil cooler. Butterfly valve at the baffle. I figure even with the bends in the duct, there will be more cooling than a stock RV7 cooler. I talked to several builders with our set up and virtually every one had so much cooling they had to close the duct. That's why I added the butterfly.
Time will tell.

Hey Brian, thanks for the assist with the pix.

Re the oil cooler- I understand what you're saying. I don't think you have to be an aero genius to see that any time you start trying to bend air around you're hindering it's efficiency. My setup is already the RV10 plenum with the big 13 row oil cooler.

At some point in the future, I have visions of a fiberglass elbow coming off the plenum like a periscope with a nice smooth elbow into a short length of straight scat tube to the engine baffle so that I can minimize losses here, but I have to get the darn thing plumbed first!

Looking back at it now, I think that it would have been better to do something akin to what you did, but the RV10 setup was a known quantity and people have reported good success with it, so that's what I went with.

Larry- With the way that they're run in the pictures, no worries about the wet dog. Because of the proximity to the engine mount where they loop down, they will both get adel clamps close to the cooler, leaving the majority of the hose to flop around with the engine as they see fit.

My vision for a snorkel would be something that isn't necessarily round except on each end. Where it transitions over/around/through the engine mount it can take on an oval shape or whatever. Then it can stop a few inches shy of the aft baffle and be transitioned with a few inches of 4" SCAT or whatever to allow for engine movement

Not an original idea for sure. I just looked at the frankensnorkel that gets air to the horizontal induction and thought something like that might be better than just a single run of Scat that bends every which way.

But, that's a project for another day. I've got bigger fish to fry right now.

Do you per chance have any pictures handy of how you routed your lines? I've looked at a bunch online and none of them seen to work for me unless I'm willing to live with some less than optimal compromises. I just mounted this thing 1/2" too high.

Desert Rat said:

…….I've got a few options, but the cleanest by far would be to just flip the cooler upside down. I'm aware of the potential for trapped air and no way to purge it, but honestly is that really a thing?

I have yet to find anybody who can verify that air in an oil cooler has really ever been an issue. Furthermore, upside down is the standard orientation for the Showplanes remote cooler mount, and those seem to be working out ok for folks?

Click to expand...

The heat exchanger effectiveness will take a hit if the cooler isn’t completely full. You want every bit of the surface area of the cooler in contact with the fluid(s). Sorry I can’t quantify the effects or tell you if there’s enough design margin to make it “OK”. Does the show planes config use the same cooler or one with extra surface area (usually more rows for packaging convenience)?

Anyway if you’re forced to proceed this way and you have temp issues, oil
flow direction would be one of the first suspects. Sorry I couldn’t nail the effects down better.

Well, that's the thing isn't it? What you say makes perfect sense, but nobody seems to be able to step up and say "yeah that works/no it's a horrible idea". We've all heard that it can lead to entrapped air but doing we really have the data to back that up?

I question how much air would actually be left in there once oil starts squirting through there at 100 psi, but I just don't know.

In theory, every oil cooler you see laying down flat should also have air trapped in it since the ports are about 1/2 way up the horizontal plane, but there are tons of them out there. Not the same thing as being completely upside down, but still makes you think.

The showplanes setup uses either a 10 or 13 row cooler. I've currently got a 13 row cooler because I shoved a 390 under the hood and need the additional cooling. Which is how we got to this conversation

You know what? I respect you guys a ton, but it just dawned on me that I should follow my own advice that I've given countless times.

Rather than ask random people on the inter web, I'll just go to the source; I just fired off an email to aero-classic and asked them "is it a problem to mount P/N 8000215 upside down?"

I shall report back with the results.

In the meantime, does anybody see a problem with the routing I've got mocked upon my pictures? It would be nice to have shorter straighter runs because this one results in one hose being about 20" and the other one being about 30". (mounting the cooler upside down would shorten up those hoses considerably, as well as tuck the runs back parallel to the firewall i.e. more out of the way of other stuff). But other than that?

Its of little help now, but we run in to things like this all the time. Absolutely nothing wrong with remote coolers, infact some benefits to using a larger cooler in alot of cases. Hypothetically, when youre going to incorporate a different accessory, the cooler and plenum box in this case, generally youre putting something larger into a more confined area. In this case, the engine mount tube is really close to the cooler fitting.

What we try to do (if logistics work out) is to do a mockup without permanently mounting any of the systems and the new accessories. WE know the bolt holes for the engine mount in the firewall are a set location, and so is the engine mount itself, so those cant be changed. So the location of the cooler/plenum has to be located to work with the engine mount and OTHER accessories. In Terry's case the RV7 firewall has that box cutout in the center that removes some needed space to work with.

As an example, we built a full scale cabin mockup of the 14A for doing development work and for show and tell at airshows. We didnt have access to a fuselage under construction, so we bought the parts to do our own. This way we had actual OE Vans parts, so the original unchangeable dimensions would be the same. We could then design brake and fuel systems that might be different that the stock Vans accessories, like Beringer brakes, Control Approach pedals, SDS and EFii fuel systems, and even our AFP boost pump conversion.

Tom

Pictures

Desert Rat said:

Larry- With the way that they're run in the pictures, no worries about the wet dog. Because of the proximity to the engine mount where they loop down, they will both get adel clamps close to the cooler, leaving the majority of the hose to flop around with the engine as they see fit.

My vision for a snorkel would be something that isn't necessarily round except on each end. Where it transitions over/around/through the engine mount it can take on an oval shape or whatever. Then it can stop a few inches shy of the aft baffle and be transitioned with a few inches of 4" SCAT or whatever to allow for engine movement

Not an original idea for sure. I just looked at the frankensnorkel that gets air to the horizontal induction and thought something like that might be better than just a single run of Scat that bends every which way.

But, that's a project for another day. I've got bigger fish to fry right now.

Do you per chance have any pictures handy of how you routed your lines? I've looked at a bunch online and none of them seen to work for me unless I'm willing to live with some less than optimal compromises. I just mounted this thing 1/2" too high.

Click to expand...

I'm usually reluctant to post photos of mods. I put the parts in place and shot a couple photos. Let the flames begin.

After seeing some of the "less than ideal". Ideas I've had do you really think there is going to be any flaming from my end?

Thanks, for sharing those, but I just realized you're building a 7A. The engine mount on the 7 is quite a bit different.

Desert Rat said:

After seeing some of the "less than ideal". Ideas I've had do you really think there is going to be any flaming from my end?

Thanks, for sharing those, but I just realized you're building a 7A. The engine mount on the 7 is quite a bit different.

Click to expand...

Here's the firewall mounted cooler in an RV-7 (Taildragger) and the diffuser. This is from another project I was working on.

The duct is 3", but could go up to 3.5". The oil cooler is an HE clone of the SW8406R. The mounting will accommodate any single pass SW/clone up to 10614R (8406R, 10599R, 10610R, 611R, etc.)

Flames

Desert Rat said:

After seeing some of the "less than ideal". Ideas I've had do you really think there is going to be any flaming from my end?

Thanks, for sharing those, but I just realized you're building a 7A. The engine mount on the 7 is quite a bit different.

Click to expand...

Not from you!

My RV10 oil cooler on my RV7 has taken forever and I'm not done. The cooler itself is mounted upside down and I can't believe that that's not ok. Aren't there lots of possible places inside the engine that could trap air? That said, I have a message to Niagara Air Parts asking that simple question. IF they respond I will share here. The Show Planes pic of the upside down cooler is encouraging. Anyone gotten a response from them?

This is how I intend to "hose" my cooler with Larry's adjustable baffle flap arrangement. It is clear of the cowl side and should be easy to implement once the baffle fitting is on. I've not seen anyone do it like this, but it seems like it will work.

wirejock said:

I'm usually reluctant to post photos of mods. I put the parts in place and shot a couple photos. Let the flames begin.
View attachment 38139
View attachment 38138

Click to expand...

@Larry. Not a flame, here. I too was reluctant to do a baffle mount. This was made more concerning as my cowling is lower to the cylinders and was afraid of robbing (too much) cyl 4 air. My initial layout (and hopefully final) is an engine mount, mount. Yes, I’ll have to make a scat to cooler transition piece. I’m also thinking about a baffle exit transition piece that extracts at a higher location. Still thinking through that one. Some layout pix attached.

N16KY said:

The cooler itself is mounted upside down and I can't believe that that's not ok. Aren't there lots of possible places inside the engine that could trap air? That said, I have a message to Niagara Air Parts asking that simple question. IF they respond I will share here. The Show Planes pic of the upside down cooler is encouraging. Anyone gotten a response from them?

Click to expand...

I asked the question on the aero-classic tech support email Saturday and got a response within a few hours. I'm waiting for permission to quote it verbatim here, but basically it was yeah, upside down, right side up, doesn't matter.

Mount mount

Freemasm said:

@Larry. Not a flame, here. I too was reluctant to do a baffle mount. This was made more concerning as my cowling is lower to the cylinders and was afraid of robbing (too much) cyl 4 air. My initial layout (and hopefully final) is an engine mount, mount. Yes, I’ll have to make a scat to cooler transition piece. I’m also thinking about a baffle exit transition piece that extracts at a higher location. Still thinking through that one. Some layout pix attached.

Click to expand...

Interesting approach. It actually makes it easier to swap out the cooler if needed. Also easier to fab a plenum. Keep us posted.

Wow

And I thought my 9A io320 was complicated. No flaming here. Been there yesterday.

Response from Niagara Air Parts to "Is it ok to mount a 260006A with the hose ports facing down on a Lycoming engine?":

"Yes, this is fine.".

So, I am thinking out loud here, and I have yet to see anyone do this yet but, has anyone considered a top cowl NACA scoop as a feed for the oil cooler yet?

If you put a 4" NACA scoop on the top cowl, you should have a more direct feed to the cooler and plenty of flow... thoughts???

(think... old school hot rod! hahahaha)

Sure, taking the top cowling off and back on again would be more complicated... some thinking would have to go into that as well, Maybe using a connection with baffle seal material would make that task easier?

CJ

I actually have thought about that. Decided that the juice wasn't worth the squeeze.

My buddy has a Glastar with a nana scoop on the lower cowling feeding remote cooler and it seems to me like it's a hassle to have to unhook the scat tube any time you want to take the lower cowl off. If it were the upper cowl, that would be even worse.

The only way I could consider it would be some kind of shaker hood scoop like arrangement, but that just seems like way too much complication when there's already a solution that seems to work.