ASA New Product Video is up! (July 2014)

Engine/prop

Allan,

What engine and prop is in your RV-9A test aircraft? You mentioned everything was full foward during the test. For clarification you had your mixture full rich during your climb to 8.5K? If so you were burning a bit of fuel I would imagine.

Typically I reduce my burn rate to ~9 gph and climb out at 115-120 kts to keep my CHT's below 400 degrees in the hot AZ morning temps. If I were to climb out with full mixture I would be buring ~15 gph. Running full rich will help keep the CHT's down a bit but isn't my normal TO procedure once I get to a few thousand feet AGL.

I am trying to figure how effective the cowl flap might be in my RV (IO-360, CS Hartzell BA).

Any addition data points would be helpful.

Pmerems said:

Allan,

What engine and prop is in your RV-9A test aircraft? You mentioned everything was full foward during the test. For clarification you had your mixture full rich during your climb to 8.5K? If so you were burning a bit of fuel I would imagine.

Typically I reduce my burn rate to ~9 gph and climb out at 115-120 kts to keep my CHT's below 400 degrees in the hot AZ morning temps. If I were to climb out with full mixture I would be buring ~15 gph. Running full rich will help keep the CHT's down a bit but isn't my normal TO procedure once I get to a few thousand feet AGL.

I am trying to figure how effective the cowl flap might be in my RV (IO-360, CS Hartzell BA).

Any addition data points would be helpful.

Click to expand...

... I guess I failed to give all the information! The engine is a 0-320/160hp, carbureted, 1 light speed and 2 X 2 exhaust system. The prop is a variation of the whirlwind RV 200. At full rich (usually 14gph, @ 2,750 rpm) my carburetor is a little on the lean side and we are entertaining the idea of re-jetting and adding a little more fuel as the egt is a little high at lower altitudes with full throttle. Thanks, Allan...

Allen, my new to me RV6A does not have the honeycomb type cowl construction so I suspect when I go to cut my new cowl flaps in this weekend they are going to protrude a good amount.

I am planning to mount with nut plates and #6 screws for easy removal so I could add shims later very easily.

Do you expect to have shims made anytime soon? If so I will hold off on trying to make my own as I am not at my home shop and making these kind of things is not as easy as when I am based at my own shop.

I can't wait to see how much better the CHTs and oil temps react on climbout down here in the Hot Country.

Randall
Carlsbad NM, but home is Sedona AZ.

Randy said:

Allen, my new to me RV6A does not have the honeycomb type cowl construction so I suspect when I go to cut my new cowl flaps in this weekend they are going to protrude a good amount.

I am planning to mount with nut plates and #6 screws for easy removal so I could add shims later very easily.

Do you expect to have shims made anytime soon? If so I will hold off on trying to make my own as I am not at my home shop and making these kind of things is not as easy as when I am based at my own shop.

I can't wait to see how much better the CHTs and oil temps react on climbout down here in the Hot Country.

Randall
Carlsbad NM, but home is Sedona AZ.

Click to expand...

... All you need is some aluminum, wood or plastic strip about 1/2" wide and correct thickness. You can spot the holes through the flap flange and screw them on. It will be some time before we have spacers available and we also need some cowl thickness feedback info so we make the correct spacers. Thanks, Allan..

Hey Randy,
Really happy with the one cowl flap on my RV-4. It is keeping the temps under 400 on climb out in the mornings here in Phoenix.

rvator51 said:

Hey Randy,
Really happy with the one cowl flap on my RV-4. It is keeping the temps under 400 on climb out in the mornings here in Phoenix.

Click to expand...

Can you please give us a bit more details, what would your temp be with the cowl flap closed during the same condition? Also a bit of info abou the engine/prop also could go a long way.

Much appreciate it

Thanks for all your products Allan! looking forward to getting two of these.

As a buyer and not a builder,

What process did you use the cut the hole ? What tool to cut the fiberglass ?

jgoehl said:

As a buyer and not a builder,

What process did you use the cut the hole ? What tool to cut the fiberglass ?

Click to expand...

... I laid it out as in the video with the template. Drilled the holes in each corner, removed the template, scribed the lines on the outside of the drilled holes. Then used a cut-off wheel in a die grinder to make the cuts. A Dremmel tool will also work very well for this job. Then use a sanding block to finish edges to final fit size. Thank, Allan...

Bavafa said:

Can you please give us a bit more details, what would your temp be with the cowl flap closed during the same condition? Also a bit of info abou the engine/prop also could go a long way.

Much appreciate it

Click to expand...

Its a RV-4 with O-360 with high compression pistons with carb and 4 pipe exhaust.
Here is the graph of takeoff from Goodyear Airport and flight to Casa Grande.



I flew to Casa Grande and landed and went inside for 10 min to simulate a heat soaked engine then came back out and flew back to Goodyear.
This is the graph of the takeoff and return flight to Goodyear.



Before both rear cylinders would have got up to around 415 on climbout before reaching pattern altitude.
Really happy with the oil temperatures. I attribute the low oil temps to mounting the standard Vans oil cooler on the engine frame instead of on the #3 cylinder baffle.

rvator51 said:

Its a RV-4 with O-360 with high compression pistons with carb and 4 pipe exhaust.
Here is the graph of takeoff from Goodyear Airport and flight to Casa Grande.

I flew to Casa Grande and landed and went inside for 10 min to simulate a heat soaked engine then came back out and flew back to Goodyear.
This is the graph of the takeoff and return flight to Goodyear.

Before both rear cylinders would have got up to around 415 on climbout before reaching pattern altitude.
Really happy with the oil temperatures. I attribute the low oil temps to mounting the standard Vans oil cooler on the engine frame instead of on the #3 cylinder baffle.

Click to expand...

so would it be safe to say that it has lowered the temp by around 15F?

EZ Cool Pirep

I flew with my EZ Cool cowl flaps for the first time yesterday and I can say I am happy with the results.

My engine instrumentation does not give me a digital readout like I am used to so I don't have much in the way of hard data to offer, but, I would definitely say it made the difference I was looking for.

Temps on the ground in Pecos TX were around 98F. Without the cowl flaps I know my oil temps would have gotten up into the yellow zone on the analog oil temp gauge which starts at 220F. I was able to climb directly on up to 7,500' using about 120 MPH climb speed with power on the IO360 w Hartzel CS set at 24 square mixture set ROP. Oil cooler is Vans stock unit mounted to the baffle.

Once I leveled out, I left the flaps open until I began to see the oil temp coming down a little from it's max temp during climb of about 210. With the flaps closed and the cruise speed of about 160 knots the oil temps remained right around 195F. I guess that means at least 10F difference in oil temp but I rally think it is more than that as I would not have climbed like that before because the oil temps would have gone higher than I am comfortable with.

In the past the oil temp would get up into the yellow, above 220F even just from descending down into the desert heat if it was above 100F on the ground. Descending back into Carlsbad this time, with ground temps of about 102F the oil temps stayed easily below the yellow zone. I opened the cowl flaps as I got close to turning final.

Interesting to hear the difference in the sound of the engine as the flaps close up. I noticed a speed increase of about 3 knots from closing the flaps.

I had to put 1/8" shims under mine as the cowl is not honeycomb style. To get the installation really right I may need to install some different shims as one corner of the flaps still protrudes a bit. I plan to end up with flush screws going into nut plates on the inside when I take them back out for painting.

I experienced a bit of binding at first to the point where one corner would not close all the way, but opening up the fiberglass hole a little more in the tight spots took care of that.

Sorry I cannot more actual data but I can say that these cowl flaps have obviously given me what I had hoped to achieve when I purchased them and that is full functionality of my RV6A in the summer temps of the SW desert.

I will report more after more flying time in high temps as it happens.

Randall in Carlsbad

More results !!!

...I had some spare time on Sunday the 27th, so decided to go fly my RV-9. It was very hot here in so cal, 100 degrees and matching humidity. So as it turned out a good day to watch and check my temperatures with the new cowl flaps. I tried a 90 kt climb without the flaps open and the cht temperatures soared to 450 by 6000 ft. I descended and tried it again with both flaps open and the engine already heated up. Everything was identical conditions except the results. I went to 8,500 ft and could not get temps over 380 degrees, even with aggressive leaning. After doing this again, I am extremely happy with this products performance. I am very confident that if you are having heating issues, there is nothing you can do that is more effective at reducing them than this installation. This is not sales hype to move product but my actual results. Don't fight and chase this issue as we did for over four years with very costly, marginal results at best. We are confident that you will experience similar reductions in your temperatures should you install this product. Thanks, Allan...

EZ Cool Cowl Flaps Results????

...With almost 200 of these out there now and many installations in progress, I would expect that pilot reports should start coming in at a good pace now. If you have any information or suggestions to contribute, please do so as it helps others that are undecided. Thanks, Allan...

Well here is another one now with a bit more time on them.

Before the cowl flaps were installed my oil temps would climb up to 220 pretty easily in warm weather and especially if I wanted to do a hard climb. Now I find that in 85F OAT, I can sustain a 110 MPH climb on up into the cooler air while keeping the oil temps down below 200F.

The flaps really did make quite a difference on my 6A with IO360 and CS Hartzel.

Randall

Same Story

I'm finding that on 90 degree days I'm able to keep CHT right at 400 and climb aggressively, whereas before the flap I would limit climbs to 300fpm on a smiliar day once a couple thousand off the surface, and still see CHTs in the 410-420 range. O-320 with FP Sterba wood prop.

One suggestion for Allan concerning future kits, and this might make sense only to those familiar with the product: With the cowl off the plane, the connector with 2 male pins is attached to my engine mount with a zip tie over silicon wrap. On 2 occasions now, performing short engine runs without the cowling on, the male pins have swung in the breeze to contact something metal and blew the 1A fuse. If the female connector were what was attached to the plane, and a male-male wire used between the plane and the cowl flap, this would not be able to happen.

Personal inspection

Brantel said:

After running a 10K race in the pouring rain this morning, I changed the oil, finished the switch/wiring/led install for the cowl flaps (used a 2 pin molex plug for the disconnect), made another radiant heat shield for the non heat muff side of the exhaust, changed out some non-aircraft grade cushion clamps that were turning to goo and put the cowl on and took her for a spin.

I forgot to take one with em closed....sorry!

Too early to tell but I can say that I can already see a difference in CHT's during a hi performance climb. The cloud deck was not that high so I could not get a true test but the initial temps are promising.

I don't want to post numbers until I can go out and do some climbs with em open vs shut in similar atmospheric conditions. To do otherwise will just be a WAG and not very meaningful.

Straight and level in cruise @ 4300ft I am seeing a change of about 3 knots TAS open vs closed. The sound from the engine area changes when they are open.

Had the best wheel landing I have ever pulled off tonight. Too bad there was nobody there to see it!

Click to expand...

Brian I was able to find your plane at "OSH" and check out your installation.
Just beautiful. A professional job. Outstanding!. I may have to hire you to come and install mine.
Wondering what your impressions of them are now that you've taken a cross country in relatively hot weather conditions.

This Makes Sense!!!!!

krw5927 said:

I'm finding that on 90 degree days I'm able to keep CHT right at 400 and climb aggressively, whereas before the flap I would limit climbs to 300fpm on a smiliar day once a couple thousand off the surface, and still see CHTs in the 410-420 range. O-320 with FP Sterba wood prop.

One suggestion for Allan concerning future kits, and this might make sense only to those familiar with the product: With the cowl off the plane, the connector with 2 male pins is attached to my engine mount with a zip tie over silicon wrap. On 2 occasions now, performing short engine runs without the cowling on, the male pins have swung in the breeze to contact something metal and blew the 1A fuse. If the female connector were what was attached to the plane, and a male-male wire used between the plane and the cowl flap, this would not be able to happen.

Click to expand...

... I will talk to the manufacturer of the actuators and see if we can order them with this plug arrangement as you suggested. I agree, this would be an improvement. Thank you for calling this to our attention. Allan...

so what connectors do y'all recommend be used? I just received my flap (got one) and will start planning the surgery soon.

Also, wouldn't this flap also be a good on top of the cowl for post landing heat venting?

Very Interesting!

moll780 said:

so what connectors do y'all recommend be used? I just received my flap (got one) and will start planning the surgery soon.

Also, wouldn't this flap also be a good on top of the cowl for post landing heat venting?

Click to expand...

... This is a real coincidence that you posted this because I just received an e-mail about this very thing! The cowl flap can be mounted for the most part anywhere on the secondary side of the cowl that increases the differential pressure. The guy I am referring to mounted his two EZ Cool Flaps on the top of the cowl. This area in a climb, is actually a lower pressure area than the bottom, thus making the flaps performance even better. He excitedly reports that an added benefit to this location (and I don't know why?) was an actual increase in speed rather than a decrease. He said he picked up 3 kts in cruise with them open and verified this with several repeated tests. He also said he was going to do some tufting work, with video and figure out what is taking place. Can't wait for these results!
... There are a couple of other guys that are in the build or testing stage without paint, that are putting the EZ Cool Flaps on the flat sides of the lower cowl at the rear, just below the hinge part line. These should also function well in this area and allow for very easy access as well. We will post the information when it comes in. Thanks, Allan...

Is this top side installation aft of the baffling? If installed forward of the baffles then cooling air would not be forced through the cylinder fins.

Mike H said:

Is this top side installation aft of the baffling? If installed forward of the baffles then cooling air would not be forced through the cylinder fins.

Click to expand...

... Yes! This installation is behind the baffles, as far back as possible. Thanks, Allan...

on top has the added benefit of the visual confirmation. cool...

ajay

We have about 22 hrs on our RV-4 installation and 10 take offs and landing and only had one cylinder go over 400 to 405 one time. This is way better than before the installation. Very happen with results.

rvator51 said:

We have about 22 hrs on our RV-4 installation and 10 take offs and landing and only had one cylinder go over 400 to 405 one time. This is way better than before the installation. Very happen with results.

Click to expand...

...Thomas, did you install one or two EZ Cool flaps? Thanks, Allan...

Hi Allan,
I only installed one. I don't think there is room for two unless you could do a tandem configuration. But the front one might hit the airbox on the RV-4.

That would be interesting to see an RV with the vents on the upper cowl. ala Rutan's catbird and boomerang and maybe others.

Awaiting Results!

jchang10 said:

That would be interesting to see an RV with the vents on the upper cowl. ala Rutan's catbird and boomerang and maybe others.

Click to expand...

... These airplanes had updraft cooling and were pretty much a completely different animal in that regard. We are still waiting for more results on his testing of the EZ Cool flaps installed on the top and will post as soon as available. Thanks, Allan...

ASA New Product Video is up!

I bought one of the AS cowl flaps in July because I had CHT problems on #4 cyl on my O-360-A4M in my -9A. On takeoff I would routinely see 420F on #4 and 390-400F on the other 3 cyl. I could control the CHTs by pulling some power and leveling off to get 125 KTAS. I had sealed all the openings on the baffling and re-wickering the baffle seals, but nothing seem to correct high CHTs on takeoff and climbout short of leveling off and pulling some power.
I installed the AS cowl flap on the right side of the lower cowling near the aft end where the curvature is fairly level. Installation of the cowl flap was straight forward with no surprises, but the wiring was tough. That small wires and the connector was definitely not designed for use with ham-fisted pilots. Getting insulation peeled back without cutting strands of wires was a chore and the connector has no safety lock. Soldering those miniature strands of wires to the supplied switch was another adventure in funland with vulgarity added. I hoped Alan's ears were burning.
HOWEVER, the cowl flap works as advertised. I can now take off and climb without #4 cyl not getting hotter than 395F, full power ant 110 KTAS to level off altitude. At level off, power set to 2550 rpm leaned to 8.5 gph (fixed pitch) 152 KTAS, closed cowl flap, all CHTs in the 360-370F range. With cowl flap open in cruise, the cyl temps drop to 330+or - 5F and the TAS drops 3 kts. I just returned from flying to the East Coast through Albuquerque, McKinny TX, Tulsa, Tunica MS, Richmond VA, Morgantown WV, Doylestown PA (just North of Philadelphia and back. With 21 days, 39.7 hours, I would say I gave the AS cowl flap a pretty good test in August in the hottest parts of the country and it passed with flying colors. I don't think I will put a second flap on the left side, the one works good enough. Alan, fix those ittybitty tiny wires and a lockable connector and the product would be perfect. Dan

Cowl flap installed

Alan's cowl flap went in beautiful and the effects on the cylinder temperature is near 18 degrees difference. Wow, all I can say is that this is one mod that really works I had louvers but this works great


I should probably buy another just to make it look bad!!!!


Smilin' Jack

Good one Dan

DanH said:

http://youtu.be/S3SKXfEMSYY

Click to expand...

Just going through the thread and you got me. Right on the money too!

Any results yet on the top mount???

Anyone able to fit these in a -10 yet?

Smilin' Jack said:

Alan's cowl flap went in beautiful and the effects on the cylinder temperature is near 18 degrees difference. Wow, all I can say is that this is one mod that really works I had louvers but this works great
Smilin' Jack

Click to expand...

So, to clarify, the cowl flap plus one louver dropped temps 18 degrees from what you were running with two louvers?

Out of curiosity, how much had two louvers dropped your temps from stock cowl?

Comment on mounting a flap, above, behind the baffles.

The exits in the Catbird(?) work because forward on the cowl, particularly at higher angles of attack, is a low pressure area. Typical CFD studies show pressure aft of the plenum has recovered by that point, reducing the overall benefit.

Not knocking the product, but I saw a bird with flaps in the top of the cowl that "drooped" when parked, but closed in flight due to the dynamic pressure. The builder liked them, but I haven't tried them yet.

These passive "vents" could work aft of the upper plenum, also, but I'd check with a water manometer first.

mjb

Steve,
when I first flew the plane in October last year the reason for the louvers at that time was to help with the pressure on the cowling where it fastens to the firewall. I have the skybolt duez fasteners and would get swelling between the fasteners. I bought a louver from Aircraft Spruce and cut it in half and installed half on both sides. I did see only about a 5 degree drop on the temps with the louvers. So most of my climb outs would be at 120 to 140 mph just to keep the cyl temps below 400.

With just the one cowl flap installed. I used a 90 mph climb out to 3000 feet and then a 100 mph climb out to 5500 feet the cylinder temp never got above 390. (field elevation is 1500 feet) in fact, out of 3000 feet the temps were below 380
The temperature was 87 degrees F.

On other takeoffs during the day we climbed to traffic pattern at 85mph and saw 370 degrees as the max on the cylinder temp. I could never do this before.

I have a friend with a RV6 serial number 16 who built a manual cowl flap and he could always out climb me going some where and his temps were always low.

I believe this is a win win situation...so much I am inclined to install a second cowl flap during my condition inspection in October.

I used only proseal to hold it in. and it appears to be working well. Since the pressures on the cowl flap are from the inside..

Painted the cowl flap off the plane and taped up all the actuator and taped the flange. Removed the paint from the inside of the cowling where the flange on the cowl flap would rest.

Since I already had the louvers and built up the cowling with filler to flush the louver I had to use that spot for the cowl flap.

It is set forward 3 inches from the back edge of the cowling where it meets the firewall. Since the firewall/cowl line is square I used the junction to measure the installation..I installed it on the right side since I have a 4 pipe exhaust and a dual heat baffle on the right side, I would not need a heat shield. I installed the switch on the right side of the throttle with the LED just above it and If I do a second one I will install that switch on the left side of the throttle. Should one quit at least I will still have one cowl flap I can use until I repair the other one.

One interesting note, When the cowl flap is extended (open), The LED (YELLOW) flashes a nice remainder to close it at altitude.

I had to touch up the cowling a bit since I had to grind down the additional filler I used to blend in the the louver.

Smilin' Jack

Thanks for the detailed clarification, Jack! Much appreciated.

Pirep

I just wanted to give a quick pirep on the EZ Cool Flaps that I just finished installing. Installation was fairly straightforward and I only encountered 2 issues. First I needed to read the switch diagram more carefully. The switch has 6 connecting points and I didn?t fully appreciate that there were a total of 10 wire connections with 4 out of the 6 tabs having 2 wires connecting to each. I was also very slow to realize that there were 2 jumpers. That?s just my lack of experience reading wiring diagrams.

The other installation issue was with the LED plastic bushing/bezel. I struggled with just getting the bushing to snap into the instrument panel. It was fine without the LED in it but it just wouldn?t snap in with the LED in the bushing. It took a while before I measured the panel and then the bushing and discovered that my panel was too thick for the recess on the bushing that was for the panel thickness. Once I realized this it was easy to make a small counter sink in the panel to reduce the depth until the bushing fit. I installed the cowl flaps with nutplates and countersunk screws. I would offer the caution that care needs to be taken to not tighten the screws too much as the honeycomb sandwich that the cowl is made of is easy to compress. When I finish the install with filler and paint I will use flox to stiffen the area.

I was finally able to flight test it yesterday. It was important to properly warm up the engine before testing and this was done with the standard flight testing technique of flying to lunch I was with Sam Toy as adult supervision and one other plane. After lunch we flew for about 20 minutes to re warm up the engine. Sam, being a much better stick than I am, did the flying while I did data acquisition. We dropped down to 1000? and started a climb at 25 squared, full rich, 110kt climb speed with the cowl flaps closed. The second test was the same thing but with the flaps open. OAT at the start of the climb both times was 82F. Top of climb OATs on flaps closed test was 78F so there wasn?t much change in 3500? from 82F. Flaps open top of climb temp was 71F at 7000? so from 82 to 71F.

CHTs at the beginning of both climbs were very similar with both hottest cylinders starting at 332F. They were very cool from the descent to the test point altitude.

Results: Flaps closed test we stopped at 4500? because the hottest CHT was rapidly climbing through 415F. On the flaps open test as we went through 4500? the hottest CHT was 395 so I was very pleased to have a 20 degree improvement!

Even more surprising though was that on the first test the rate of temp increase was attention-getting but on the second test the rate of increase was very slow and slowed to the point of negligible increase by 5000?. From 5000 to 7000? the hottest cylinder stayed at 398 and there was no increase on the other cylinders. This is a great comfort. I have never been able to keep climb power in and keep climb airspeed the same and not see CHTs continue to increase until I either remove power or push the nose over.

Other items: it looked to us as the airspeed difference at 7000? between open and closed was around 7kts with a slight but noticeable pitch down with closing. There was a slight change in sound between open and closed with a very slight rumble associated with them being open. Strangely, in cruise, CHTs were practically the same with the flaps open or closed. This may require more testing for validation.

All in all I am VERY pleased. I had been hoping for around 15 degrees and have gotten 20. What I hadn?t fully appreciated was the cessation of CHT increase while still climbing with full climb power.

Thanks Jeremy. Good report. Congrats! It sounds like by using the plural, that you installed 2 sets, one on each side. Correct? Did you run them to one single switch that controls both at the same time?

Yes, 2 flaps, one on each side of the exit area with the exhausts, one switch. I bought a larger switch to match the others in the panel.

A word about wiring: I was a bit uncomfortable with the wire from the servos being both very small and non-aircraft grade but I understand why it is the way it is. I covered the existing wire from the servo and the servo itself in aluminized fiberglass strips with a sticky back like what is sold as heat shielding and covered the exposed edges with simple aluminum tape. I taped them to the sides of the cowl and used 2 position molex mini jr connectors and aircraft grade wire to bring them to the center of the engine mount. I then used a 4 position molex mini jr connector with jumpers and aircraft wire to bring only 2 wires through the firewall then everything as shown on the schematic that comes with the cowl flaps.

Right now it's a bit of a reach to get at the connectors to take the cowl off so I plan to extend the existing wires from the servo so I can put the connectors right next to the vertical hinge pins for the lower cowl.

Wiring Diagram

I'd like to run some wiring for two of these units before I close the front skin. Is there a wiring diagram available? All I've found on the website is a video.

Mark Dickens said:

I'd like to run some wiring for two of these units before I close the front skin. Is there a wiring diagram available? All I've found on the website is a video.

Click to expand...

...Try this! If you need more just let us know. Thanks, Allan...
.

one other aspect to report...

I flew to lunch yesterday and OAT was around 80F. I left the cowl flaps open while parked, ate, returned and fired up the engine. Normally I don't have terrible problems hot starting but it frequently takes once of hitting the start button, advancing the mixture, catching and then dying and then doing it again and then it keeps running on the second time. It also then has the typical injected rough idle due to fuel still boiling in the injector lines.

Well yesterday's hot start was on the first time after only a very few blades and it idled very nicely thank you very much Now this is admittedly a sample size of ONE but I do believe that leaving the cowl flaps open on a short turn around might help to purge the hot air and reduce the hot engine rough idle problem.

Cowl Flap

Im looking to install cowl flaps in an RV6 ,but not for CHT which run very cool. I would like to know how much an affect they have on oil temp when you install and report to us RV drivers your results.
Thanks Bob

RV-8 Install?

Has anyone installed these on a -8? I measured and I don't think there is enough room without getting into the curve of the cowling. Any thoughts from -8 installers?

effect on oil temp

I have a friend at Livermore who installed 2 cowl flaps to help with his oil temps. He doesn't seem as happy as I am, but that's hardly scientific

I will try to press him for more objective data but I think it will require significantly more patience to test it as oil temps take a lot longer to stabilize. I should say at this point that when I initially tested my plane I was very oil temp limited until I bit the bullet and installed a MUCH BIGGER oil cooler. That solved the oil temp problem, but I still had CHT problems until I installed the cowl flaps.

Mark Dickens said:

Has anyone installed these on a -8? I measured and I don't think there is enough room without getting into the curve of the cowling. Any thoughts from -8 installers?

Click to expand...

I dont have an -8 but I did install one on the RV-4 in the center rear section of the bottom cowling instead of on the sides.

rvator51 said:

I dont have an -8 but I did install one on the RV-4 in the center rear section of the bottom cowling instead of on the sides.

Click to expand...

I thought about that, but what a hot, brutal environment right by the exhaust. Do have any pics of the installation?

For my RV-4, its actually the best spot as far as distance from the 4 exhaust pipes.

See post #95.

rvator51 said:

For my RV-4, its actually the best spot as far as distance from the 4 exhaust pipes.

See post #95.

Click to expand...

... If possible I would like to see some photos as well. I don't have access to a RV4 so I have very little information when asked. Thanks much, Allan...