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  #21  
Old 09-20-2019, 07:14 AM
Low Pass's Avatar
Low Pass Low Pass is offline
 
Join Date: May 2006
Location: Houston
Posts: 1,959
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They work as advertised. As for them being a band aid for poor construction, etc. that's not on subject and honestly a very presumptive assessment. I fly in conditions from 20 to 105 F, airports at 10 ft MSL to 9,900-ft. The flexibility these devices offer is exactly what I needed. My engine cooling is tight and effective. I have my timing at an optimum point for power and temperature control. And last, I will not operate at >400 CHT. With these cowl flaps, I do not have to stair step my climb anywhere. They offer me 8-10 deg improvement on my hottest CHT. But you pay with a 3-4 kts of drag. For this reason, I rarely use them in cruise. But there are some scenarios where it's nice to be able to crack them open to knock off a couple of degrees CHT rather than upset the mixture with a nicely balanced LOP cruise condition.

Mine (two) have been installed 2,3 years now, in the typical location in the bottom of the cowl on each side of the exhaust. Yes, an articulated cowl exhaust augmenter arrangement would likely serve the same cooling benefits with less drag. But the ASA cowl flap option provided the benefits I needed at the time.
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Last edited by Low Pass : 09-20-2019 at 12:35 PM.
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  #22  
Old 09-20-2019, 02:32 PM
sibriggs sibriggs is online now
 
Join Date: Nov 2014
Location: Concord, NH
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Default Captain Avgas

I think your post of something for which you have no first hand knowledge is pretty lame. You make a number of assumptions that are wrong. Perhaps you might do more research and talk to folks who have flaps installed before offering an uneducated opinion.
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  #23  
Old 09-20-2019, 06:45 PM
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DanH DanH is online now
 
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Easy now gents. Blame me. Bob is probably thinking of my posts regarding the temperature sensitivity of that particular actuator, as I did detect some increasing internal freeplay when using that particular brand to operate a variable exit. My lower cowl air temperature is higher than average, but the actuator location is fully shielded from radiant heat exposure, so it's not an unreasonable concern. Allen says he has sold 5000 of them without a heat related failure. At two per airplane, that would be about 1/4 of the entire RV fleet. Interesting dichotomy, not that it matters. They seem to be reliable enough, and I think he is supplying a model one size larger than I used.

Will open cowl flaps work, as in lower CHT? Of course they will, as they increase mass flow...assuming that mass is actually flowing through the cylinder fins, not just bypassing the engine via crappy seals.

Quote:
Originally Posted by maus92 View Post
Adding a bit more detail, the FF on takeoff for the past two years varies between 14.9-15.9 GPH, which apparently is low.
No, it's not.

Best power is typically found in the BSFC range between 0.5 and 0.55 lbs per horsepower per hour. The quick math is easy. If we assume 0.5 BSFC (the bottom of the range) just compare fuel flow x 12 with expected HP for the altitude. Your signature says you have an O-360 and location says you're near sea level, so let's be generous and say you're making 180 hp. 14.9 x 12 = 178.8, while 15.9 x 12 = 191. You have plenty of fuel.

Still don't believe? Minimum fuel flow for best power, for the 390 per the Lycoming manual, is 105 lbs for 210 rated HP, or 0.5 BSFC. That's 17.5 GPH, exactly what I indicate at full throttle and 200 MSL. I then lean in the climb to keep EGT where it was at liftoff, all the way up. Lots of us do.

Can you make it run cooler by dumping more fuel in it? Yep. I have dyno charts which say you can run it out to around 0.6 and drop CHT as much as 35F. Power is down, and it's dirty, and it's expensive, but it will work.
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  #24  
Old 09-21-2019, 12:45 PM
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PerfTech PerfTech is offline
 
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Quote:
Originally Posted by DanH View Post
Easy now gents. Blame me. Bob is probably thinking of my posts regarding the temperature sensitivity of that particular actuator, as I did detect some increasing internal freeplay when using that particular brand to operate a variable exit. My lower cowl air temperature is higher than average, but the actuator location is fully shielded from radiant heat exposure, so it's not an unreasonable concern. Allen says he has sold 5000 of them without a heat related failure. At two per airplane, that would be about 1/4 of the entire RV fleet. Interesting dichotomy, not that it matters. They seem to be reliable enough, and I think he is supplying a model one size larger than I used.
.
……..Thanks Dan for the comments, and it looks like I need to clarify the over 5K
units in use. We sell a lot of the Easy Cool Flaps to all experimental aircraft
via Spruce, as well as many to the automotive industry for under hood use.
The "over 5K includes all actuators we have purchased from that supplier".
Sorry for the confusion guys. Thanks, Allan
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  #25  
Old 09-21-2019, 08:44 PM
Captain Avgas Captain Avgas is offline
 
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Location: Melbourne, Australia
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Quote:
Originally Posted by DanH View Post
Easy now gents. Blame me. Bob is probably thinking of my posts regarding the temperature sensitivity of that particular actuator, as I did detect some increasing internal freeplay when using that particular brand to operate a variable exit.
Quite correct Dan. I recall that you ultimately ditched your Firgelli L12 Actuator after only about 10 to 15 hours of operation at temperatures of 160 - 200 F due to excessive play in the mechanism. You stated at the time that you considered that your incowl temps could in fact reach 230 F. In fact the Firgelli L12 spec sheet calls for a max operating temp of only 122 F. You also stated at the time that the Ray Allen actuators have a “sorta maximum rating of 180 F”. The Ray Allen actuator spec sheet does not have a max operating temperature but you probably got that information from their FAQ page which states that the nylon components are likely to deteriorate above 180 F. As far as the Ray Allen actuator is concerned the following statement from Ray Allen is relevant: “We know of our servos that are used successfully inside cowlings, but we are hesitant to recommend it. Try to keep the servos in a ventilated location under the cowl away from exhaust pipes, or better yet, behind the firewall”.

I don’t think it would come as any surprise to anyone who had actually done any real research on this matter that these cheap actuators with relatively low operating temperatures are not going to like being in the elevated temperatures adjacent to exhaust pipes.

But hey, this is the Experimental Category so builders can do whatever they want. I’m just raising the matter so people can be a little bit more informed about the potential pitfall of locating electrical devices with specified low operating temperatures in high temperature locations, particularly when those locations may be subject to the accumulation of flammable liquids.
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  #26  
Old 09-21-2019, 09:35 PM
bkc3921 bkc3921 is offline
 
Join Date: Jul 2007
Location: DuBois,Il
Posts: 130
Default My experience with the Antisplat Cowl Flap install and results

I just finished my install, and have been using it for about 2 weeks. I'm used to a 400 degree Vy step climb on a 90 degree Midwestern day, and now its comfortably around 380..so I am very pleased with the result...Now to the install.

I had an issue with the LED indicator emitting more heat than I though was normal. I spoke to Allan a couple of times, and as always he is quick to respond. Through more troubleshooting than you would care to know, we never did really come to a conclusion. I simply began to realize that the amount of heat the LED gave off was apparently "normal"..It has not been an issue to date.

I truly support Allan and his company...I believe many of his products are useful, and everyone is free to use them if they so desire...if I have any (minor) complaints, it is something Allan said on his install video. He said you could probably do this "in a couple of hours".... Yeah, right. If my grandma had wheels, she would be a wagon. (Sorry, Allan!) Just wiring that 6-lug mini switch takes longer than that. Choosing the correct flap location, making sure that the flap doesn't interfere with existing structures, routing wires, mounting the switch to the panel AND a power source, installing an in-line 0.5 fuse, CAREFULLY cutting and sanding the mounting hole for the flap, epoxy and cowl curvature shimming work, and any necessary painting takes FAR, FAR longer than "a couple of hours".....

Having said that, I'm still glad I did the install, and I'm enjoying the lower temperatures. Thanks Allan!...
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Last edited by bkc3921 : 09-21-2019 at 11:05 PM. Reason: typo
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