oil cooler

I need a recommendation for an oil cooler for an O-360 size engine, RV9A with Sam James cowl. Any recommendations on an Aero Classic and what size? They are about half the price of a Stewart Warner. Also the best mounting location, behind cylinders or firewall. Thanks in advance.
Ron
RV9A

Van's el cheapo

I, too, have the SJ cowl and plenum. I installed the cooler that comes with Van's FWFwd kit pretty much per Van's plans, but a little lower because of the way the plenum fits and the cowl being lower than Van's. Mine is an IO-360. It is plenty effective and has to be muffled in cool weather in Michigan. My guess is that a 320 would not over tax it.

I have the standard Oil cooler from Van's on my 7A with 0-360 A1A. I mounted it on the back of the baffle. Seems to be just fine. It's the $179.00 Stewart Warner style in Van's catalog.

Roberta

FWIW. I have the "standard" Van's Firewall Forward Kit cooler (which I guess is an Aero Classic?). My engine is a normally aspirated O-360-A1A and I have the stock cowl. The only problem I've had with the installation is that it ran TOO COOL. Ya, I know, it's cold where I live, but even flying "outside" (what we call the lower 48 states) in temperatures up to the low 80's I always had to block the airflow at least somewhat to get oil temps up into the 180's. I've since installed one of Van's adjustable shutters and only occasionally open it up a bit. It may well be that this would result in too much air flow restriction in really hot weather as even open all the way the shutter blocks about half the airflow. I offer this only to suggest that you may not need a bigger or "better" cooler than Van's offers. You might even consider a smaller one.

My experience here in Florida has been just the opposite. My 9A has an O-360 A1A (with piston skirt and cam shaft spray nozzles) and a stock cowl. The first oil cooler I installed was a Positech #4211 purchased from Vans that was baffle mounted behind the No. 4 cylinder. With ambient temps in the low 80's I had trouble keeping the oil temps below red line at 2500 rpm level cruise.

I replaced the Positech with a Stewart Warner 8406R and oil temps dropped below 220 degrees F under the same flight conditions. The archives are full of others who have had similar experiences.

I think if I were to do it agan I would go to a Stewart Warner 8432R as Pat Hatch describes here:

http://home.bellsouth.net/p/s/community.dll?ep=87&subpageid=26346&ck=

Jim Ellis
N155T
RV-9A, flying

I will vote for the Van's standard setup

IO-320 with CS prop and this last summer the high temp I got was 195 and now with the cooler weather I will be needing to block it off because about 170 is as hot as it is getting and we haven't got to the coldest weather yet.

This is in Oregon, so other locals my vary.

The cowl and baffles are standard.

Kent

Ron,

I also have an RV9a with an ECI 0360, Sam James cowl/plenum. I currently have about 90 hrs on the aircraft.

I saw three options for my application: 1. Mount on the baffle material behind the #4: 2. Mount on the motor mount behind the #4: 3. Mount on the firewall with a good air delivery system.

Mounting high behind the #4 cyl has proven to be the most efficient system for airflow but it does have some drawbacks--especially in my (and your) application.

I mounted my cooler (a SW 8406R--much more efficient at heat transfer than the positech and niagra) on the left side of the fw about 2/3 of the way down--with a slight exit air angle toward the cowl exit. It is fed off a 4" fg flange through a 4" sceet from above the #4 cyl. into a fg diffuser attached to the cooler. I did this for a couple of reasons: 1. Several friends who had baffle mounted units had cracking of the baffles from oil cooler wt and vibration--I wanted a solid trouble free mount. 2. The James plenum is mounted low on the top of the engine and therefore has less verticle room than do standard baffles for a cooler mounted behind the #4--whether on the baffle or the motor mount.

My initial results in our hot S. Texas summer with a tight new engine (with cam spray nozzles) was not acceptable--to me. I was running 205 to 218 degree f oil temps at cruise power settings. I tried a number of things to improve this such as increasing the volume of air flow to the cooler by going to 4 vs 3" sceet tubing, cleaning up the exit area of the cowl, making a lower restriction middle cowl brace, as well as other changes, all with little improvement.

I then installed some small louvers (4x6") on the bottom of the cowl just outboard of the cowl scoop and about two inches forward of the fw. Problem solved!!! My cruise oil temps dropped to the 178-188 degee f range.
It also dropped my chts from 360-380 down to 345-360. Based on tests before and after at similar density alt and power settings these louvers had no measurable impact on aircraft speed. They worked so well that I also made another set with even fewer vents to install during the winter. A pic is attached of the cooler diffuser--the pic was before I upgraded from 3" to 4" sceet. Click on the pic for a full screen shot.

If you will be in a southern climate (read warm) much of the time I would recommend the SW cooler vs the Positech or the Niagra. If you are good at fiberglass work you could probably make an extension to the back of your James engine plenum and mount the cooler to the motor mount--which would provide a relatively vibration free mount and still get direct airflow to the cooler. If you do not want to modify the engine plenum you could mount to the fw but you would really need to have an efficient way to deliver air in and out of the cooler.

Hope this helps.

Cheers,
db

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Stewart Warner

Stewart Warner. Period!!!!! I've tried every brand out there and nothing matches them. Spend the money on a SW and be done with it.

Thanks everyone for your recommendations.
DB can you post any pictures of your louver setup.
Thanks
Ron

Stewart Warner "style"

...not too far from needing an oil cooler, but I have wondered what the difference is in the Stewart Warner "style" cooler that Van's sells and Stewart Warner.
Are they one in the same?

Ron,

Attached is a pic of the left "summer" louver. I also have a set of louvers with only 3 vents in each that will be installed for the winter. The louvers (032 aluminum) were purchased from RVtraining (Alex DeDemonicas) and are speciafically for the RV7 or 9. They were originally 4.5 wide by 12" long but I cut them down to a 6 vent set and a 3 vent set. Since the pic they have been painted to match the cowl.

Hope this helps.

Cheers,

db

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7A_@ABI said:

...not too far from needing an oil cooler, but I have wondered what the difference is in the Stewart Warner "style" cooler that Van's sells and Stewart Warner.
Are they one in the same?

Click to expand...

Absolutely NOT!
The Stewart Warner is much, much higher quality. In this case, you get what you pay for.

PJ
RV-10 #40032

louvers & aluminum AN fittings

Hmmm. Am I assuming correctly that the louvers help the oil cooler because the air flow over the louvers effectively sucks air out from inside the lower cowling area, increasing the air flow through the cooler?

Also, I note that some of the pictures posted in this thread show aluminum AN fittings on the oil cooler. Not sure where, but I remember reading that aluminum fitting were a no-no here, one should use only steel fittings because galling etc would thrash the threads, ruining the oil cooler. No?

erich weaver

erich,

I am not sure if air is actually being "sucked" out of the cowl as you mentioned---others with fluid dynamics backgrounds could answer that question far better than I. What I do know is that after working this issue for the past 5 months, in my case in S. Texas, the effective cowl outlet area was insufficient for the heat my engine transferred to the oil. The louvers simply add additional outlet area to my A model RV in a slightly different manner than simply cutting the cowl outlet forward of the firewall as others have done. The left louver was also close to my fw mounted oil cooler so I got a significant improvement there--which was my primary objective. If you look forward into the outlet area of an A model you will see that the weldment for the nose gear (as well as fuel lines, scat tubes, exhaust pipes, and cables) contributes to a great deal of outlet area turbulance and therefore reduces airflow. It is also interesting to note that the cooling requirements of individual engines varys greatly as some with 360s have this issue while others, with identical airframes, do not.

Reference the aluminum fittings, Pacific Oil Coolers (a very highly regarded oil cooler vendor) recommends steel fittings in the cooler while Vans sends aluminum with the FWF kit (or at least did in mine)---since it is an experimental aircraft you can make your own decision when you get to that point. If you decide to go with the aluminum I would recommend that you use some fuel lube on the threaded portion of the fitting---this will lower the risk of galling.

Cheers,

db
RV9a/ECI0360/James cowl & plenum/Catto prop-90 hrs and a permanent smile

DB thanks for the pics of the louvers. can you provide a way of contacting Alex Dedemonicas at RVtraining ?
Ron

Ron,

Try the following linik:

http://www.rvtraining.com Look under products. Best Wishes, Dave B.

DB thanks for the info. I just went to the RVtraing site and found their louvers and noticed that they have 11 exits. Did you experiment with them before cutting down to six exit outlets. I just won a new stewart warner oil cooler 8406R on ebay and would like to set up the same rigging as you have proven out ,since we both are using the Sam James cowl, plenum an O-360 setup. I live in southern Indiana so I don't experience the same heat you have in Texas. Have you thought of just speed taping over a few of the outlets in the winter to reduce the cooling effect of the louvers.
Thanks
Ron
RV9A finishing

Ron,

You are right that the louvers from Alex have 11 openings each. I made myself two sets from the original larger set of two. One set has 6 louvers (as shown in the pic) and the second set has only 3. The 6 is for summer and the 3 is for winter. In your location you probably don't need the same flow as did I and fewer openings would work. However, I would recommend that you fly the plane before you install any louvers. Lycoming engines are very individual in their cooling needs and you may not even require the louvers. If you do it will be easy to add them later.

If you did need them you could simply buy one from Alex and cut it into two louvers of 5 openings each--and yes simply taping them up on the inside with high temp aluminum tape during the winter would probably work--or simply make a cover plate to mount on the inside from alum.

BTW, if you mount your cooler on the firewall like I did be sure to keep the area between the cooler exit and the cowl outlet as clear as possible. I originally mounted a fuel flow transducer on the fw between the cooler and the cowl exit and it was also contributing to turbulance and therefore inefficient air flow.

Hope this helps!!

Cheers,

db

Thanks DB, sounds like good advice, I'll try it without the louvers first.
Ron

DB, it looks like you have mounted your cooler to 2 angles rivetted to the firewall on one side but I cannot see how it is mounted on the other side (presumable to an engine mount). Would it be possible to trouble you for a couple more pix of the mounting detail. I'm sure everyone would be interested.
Also, did you make the composite transition for the cooler yourself. If so, how did you go about it....and has it been performing to your satisfaction.

Attached is a pic of just the mount for the oil cooler. I drilled out some rivets that go thru the fw into the angle structure behind the firewall, enlarged the holes for an3 bolts (watch your edge distance!), and bolted the mounting angles to the firewall. The middle bolts have backing plates on the inside of the fw. The flanges of the SW8406R cooler go above the angle on the top and below on the bottom--then use standard long an3 bolts to mount the cooler to the angle.

The oil cooler diffuser was made from fiberglass. I actually did the lay up on my oil cooler after covering it in celophane wrap. Doing the layup on the cooler insures a tight leak free fit. I used standard floral foam to create the form, smoothed it with polyester resin and micro, sanded the form smooth, waxed it, set in on the cooler (protected by celophane), and covered with about 4 layers of 8 oz cloth with West systems epoxy. If you do this make the transition from 4" sceet tube to the rectangular cooler shape as gradual as possible--this will insure the greatest cooling efficiency. Also smooth the inside as best you can for clean flow.

For extra strength I bonded a couple of pieces of alum angle (032) into the diffuser where it meets the mount. I am very happy with the result--my oil temps are running in the 178-188 degree f range.

Hope this helps!!

Cheers,

db[/URL][/IMG]

Firewall oil cooler mount

db1yg said:

Attached is a pic of just the mount for the oil cooler. I drilled out some rivets that go thru the fw into the angle structure behind the firewall, enlarged the holes for an3 bolts (watch your edge distance!), and bolted the mounting angles to the firewall. The middle bolts have backing plates on the inside of the fw. The flanges of the SW8406R cooler go above the angle on the top and below on the bottom--then use standard long an3 bolts to mount the cooler to the angle.

The oil cooler diffuser was made from fiberglass. I actually did the lay up on my oil cooler after covering it in celophane wrap. Doing the layup on the cooler insures a tight leak free fit. I used standard floral foam to create the form, smoothed it with polyester resin and micro, sanded the form smooth, waxed it, set in on the cooler (protected by celophane), and covered with about 4 layers of 8 oz cloth with West systems epoxy. If you do this make the transition from 4" sceet tube to the rectangular cooler shape as gradual as possible--this will insure the greatest cooling efficiency. Also smooth the inside as best you can for clean flow.

For extra strength I bonded a couple of pieces of alum angle (032) into the diffuser where it meets the mount. I am very happy with the result--my oil temps are running in the 178-188 degree f range.

Hope this helps!!

Cheers,

db

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Click to expand...

Dave
I'm getting ready to mount my oil cooler on the firewall. Do you remember the size aluminum angle you used for your mount? From your picture it looks like you bolted it from the side angle to the center 45 degree angle on the firewall support. Do you have any dimensions up from the fuselage bottom and it looks like the bracket is at about a 45 degree angle.

Thanks
Ron

Oil cooler mount

Dave
I'm getting ready to mount my oil cooler on the firewall as you did. Do you remember the size aluminum angle you used for the bracket. It looks like your bracket is set a about a 45 degree angle. Did that work out best?
Have you seen any coolers mounted on the engine mount that would work well for a SJ plenum?

Thanks
Ron