EZ Cool Flaps

There's a growing install base and body of favourable comments on EZ Cool Flaps; lower oil temps, lower CHTs (particularly in climb-out) & faster cruise speed (anecdotal only!). Any empirical, repeatable data?

From the pix available, a two flap configs appear to be the norm.

What's the consensus for the RV-10 (or, other model)? One flap or two?

Typical location of flap(s)? Lower, upper (after baffling)

PerfTech's video is an excellent install guide. What's the actual installation (in cowl & electrical) timing been? Hours to days? What's the elapsed time?

Any surprises? Like special tools? Awkward install? Attach/ detach lower cowl (assuming that's the final location)?

Honestly, I have never had cooling issues with my setup, but I think its because I've done other easy things to improve cooling. Efficiency is the key! I've NEVER had oil cooling issues - in fact, I have to close up the vent sometimes to get temps up. Even with the most agressive climb on 100 degree days, my oil never gets too hot.

1) EVERY leak in the baffles is sealed with RTV. That means even the gaps around sparkplug wires running through the baffles, around heads, engine mount, you name it. Use a flashlight and spot them! There are gaps around the fuel line running through the lower plenum from the servo the spider that is easy to fix. SEAL SEAL SEAL

2) Speaking of sealing, I have sealed EVERY gap in my oil cooler - that includes the firewall mount, the gaps between the oil cooler and the mount. It all gets sealed.

3) My upper cowl ramps are glass in and sealed to prevent air front moving forward behind the ramps.

4) I use a file and removed all the excess flashing from the cylinder head fins. The stock setup has a surprising amount of casting flash that blocks these cooling paths.

5) All puckering in baffle fabric was removed to ensure the fabric is sitting flat on the upper cowl. Checking for wear/black marks is an easy way to see where the fabric is fitting properly and where it is allowing air to escape.

6) I only climb at Vx for the first 1000 feet - to get the heck out of the way of hard stuff that wants to hit my plane. But Vx has very little visibility, so I go into a cruise climb of 120 knots, this is still generally 1500 FPM.

Can you overheat? Sure, climb Vx on a 100 degree day to 8,000 feet, you'll see some high temps.

Let's be careful not to presume that heating issues are due to either build errors/sloppiness or pilot error/sloppiness.

There are many meticulous builders and pilots who have for a number of perfectly valid reasons been either oil temperature or CHT limited to the point of it needing to be addressed by modifications after having address all your points and more. I had to increase the size of my oil cooler and will be adding the cowl flaps. Yes, I have SEALED, SEALED, SEALED, verified no flashing in the engine casting, checked and glassed the ramps, inspected the engine compartment in the dark with a flashlight and mirror for any hint of leaking baffles or oil cooler mounts, redid the cowling glasswork after it was flying to add a bit more exit area and had many other builders look at my install, including 2 that have engines that run too cool. They found no area that I had overlooked. I took any and all suggestions and tried the various solutions out.

Finally I installed a much bigger oil cooler and that has successfully address the oil temperature issues. I still find that on a hot day, I must climb out above 120kts or the CHTs will easily get to 420F and when coming to Sun Valley, ID from Livermore, CA a week ago the airplane was at gross, I wasn't paying close enough attention to CHT and on the climb to 11,500ft at 120-130 kts my hot cylinder got to 430.

Some installations run hotter than others. Some people are making more power/heat than others. Running electronic ignition? Higher compression ratio pistons? Constant Speed prop that produces full power from initial throttle up on the take-off roll? There is even some anecdotal evidence that suggests that ECI engines might generally run a bit hotter than the Lycomings. Perhaps more power? Who knows.

I just order the cowl flaps from Anti-Splat. I don't think I'm a lame builder or pilot. Honestly.

Jeremy,
Is it one particular cylinder that gets hotter than others? I had an issue with #5 which I rectified with a little modification to the baffles

Bill what did you do special with your #5 cylinder

Geoff

I slit the rear baffle and created an 1/8" gap behind #5 cylinder. I filled the slit with silicone to create a wall to fill the opening. I have a new baffle that I am reworking now that I have a final solution that will have an aluminum side wall to seal the gap created by the additional spacing. I lowered the temp by 20-25 degrees. Now all the cylinders are about the same temps. As part of the CHT balancing I also cut the right forward air dam to about 1/3rd and completely removed the left air dam. While I still can't climb at full power to altitude in the summer, I can climb at 25/2500 at 120kts and keep the CHTs well under 400.

Before and After:

Question for RV10 drivers

Do you think the ASA cowl flap can replace the bottom louvers as per Vans plans?
(I have seen RV10's with a second set of louvers installed on the sides of the bottom cowl. Not sure if this was done due to inadequate cooling or installed from the onset.)
Thanks.
Johan

jjconstant said:

Let's be careful not to presume that heating issues are due to either build errors/sloppiness or pilot error/sloppiness.

Click to expand...

I wasn't making a commentary about any builder or pilot. I was just expressing that there are things that can be done prior to buying expensive components and adding a lot of new parts. If you have already done these things - great. I for one didn't know that these were things that would make a difference until someone told me about them.

Dorfie said:

Do you think the ASA cowl flap can replace the bottom louvers as per Vans plans?
(I have seen RV10's with a second set of louvers installed on the sides of the bottom cowl. Not sure if this was done due to inadequate cooling or installed from the onset.)
Thanks.
Johan

Click to expand...

I don't THINK the ASA cowl flaps will fit where the bottom louvers go per plans. The exhaust pipes/mufflers go directly over that area with not much clearance.

Don't cut the holes for the ASA cowl flaps without checking that there will be clearance. (I have not seen the cowl flaps except in pictures, so it might be possible, but there is very little space in that area.)

Bill.Peyton said:

I slit the rear baffle and created an 1/8" gap behind #5 cylinder. I filled the slit with silicone to create a wall to fill the opening. I have a new baffle that I am reworking now that I have a final solution that will have an aluminum side wall to seal the gap created by the additional spacing. I lowered the temp by 20-25 degrees. Now all the cylinders are about the same temps. As part of the CHT balancing I also cut the right forward air dam to about 1/3rd and completely removed the left air dam. While I still can't climb at full power to altitude in the summer, I can climb at 25/2500 at 120kts and keep the CHTs well under 400.

Before and After:

Click to expand...

Can we see a pic of this please?

I thought I had taken more photos, but apparently not. Dan Horton explains why this works and shows his mod in this http://www.vansairforce.com/communit...ad.php?t=37835
thread. The principle is the same. I extended the cuts in the rear baffle up to the top bend. Removed most of the top bend to create additional space between the #5 cylinder and the baffle. Filled the gap created with high temp RTV. I have a new baffle and plan on making a more permanent solution when the plane is down for annual.

jjconstant said:

I don't think I'm a lame builder or pilot. Honestly.

Click to expand...

We don't either
Been through those same exercises...