Does anyone have any real wolrd experience with the small gill vents that can be added to the lower cowling of a 180 or 182? Did anyone actually have them installed and have before and after results? Is it worth doing?
I have a 1953 180 with the original O-470A engine. It runs excellent but I have to keep the airspeed up to keep it cool on climbout. It has been this way since 1953 and the engine has gone to TBO 3 times and is close to half way again.

Will the gills help lower cylinder head temps?

Sounds like you're in the "if it ain't broke, don't fix it" situation, but maybe not.

There's a fellow living at Erie, CO, Jim (wife Vicki, can't recall their last name--maybe somebody here recalls) with a gorgeous older 182 straight-back that has the gills, which he had added because of high CHTs on the back cylinders. I was visiting with him at one of the Marble fly-ins a few years back, complementing him on his airplane. I don't recall what other mods on his airplane other than it has VGs, but I seem to recall it was a stock O-470--could be wrong on that.

Anyhow, he said the gills made a big difference in the CHTs, bringing down all of them, not just the back cylinders. I recall that he also said something about it not being an approved mod for his year 182, so it had to be field approved.

Cary

I seem to remember that the 180/185 club had them available. Maybe that will be my winter mod for the 56 182

Tim

I just completed my second flight after adding the gills (and a bunch of other stuff). The louvers definitely made a difference in CHT's. For the price and ease of install it's well worth it and besides, they look cool!

Most installs average 10 degree reduction in CHT.

My plane came with them, so not sure the difference in warmer air. However, I tape over them in winter and see 10-15f CHT temp increase.

My hangar neighbor has a gorgeous '54 180, and he said the gills lowered his temperatures noticeably.

The cowl louvers will also allow cooler air through the floor fresh air vents.
I made winter covers.

Mudwagon, that is slick! I like the nutplates in there that allow the cover plate to be added.

My Bearhawk will have the louvers to aid in cooling a 540.

Thanks everyone, I'll add that to the list of things to buy.

For what it's worth... They were on my 1953 180 I purchased it. I still overheat, and have to keep the speed up during climb. I don't know what it was like before they were put on, but they didn't eliminate the overheat during climb problem.

DEGJR

How about oil temps. Thats always been my issue. Of course I live in AZ.

Wayne

I learned to fly in a 55 180 with a J engine from the age of 12, My Dad always taught me to Climb, Cruise, and decend by cylinder head temp instead of air speed. All his engines made it past TBO while flying skydivers. ( except a go-480 on a Twin Bonanza)
I can easily keep everything in the green with my "A" engine, but my climb performance does suffer. The cowl baffel seals are all new and everything is tight to the cowl on the inside. I believe more airflow from the gill vents will help.
Oil temps haven't been an issue because I have to fly at such a high speed to keep the CHT's down. Depending on the outside air temp, I have to climb at 100 to 110mph. I actually don't know the exact airspeed because I pay so much attention to the CHT's . Fully loaded I'm only getting 500 fpm to keep the cht's in the green. I can live with it until this engine needs replaced but it doesn't perform like my old 182's with the L engine.

So what's "overheat" on climb out? 450F? Using a spark plug gasket thermocouple or a bayonet?

Our Pponk sees 400F using a bayonet on takeoff. 1955 no gills. I'll have to look at the cowl flap linkage, but can you open them up more?

Dan

Aquaman has gills.

Cessnas have louvers.

PPonk 180 here.

10 degree reduction in CHT as well.

Also, I adjusted the cowl flaps to a more open position; there's quite a bit of adjustment capability there. When fully closed, you can see about an inch of cowl flap now.

If I'm not carefu,l I can see 450 degrees by the time I'm clearing the departure end of my 2800' runway. I usually put the nose down a little as soon as I get off the ground, sort of in ground affect and let the airspeed build and watch the CHT, I try to keep it at 400. Am I being overly cautious? What CHT's do you guys see on climb out. I do tend to baby the engine in my old age.

Zzzz on your BH, make the side gills significantly oversize, and put a moveable "cowl flap" kinda thing in there to increase or decrease the airflow through the gills. Or make the gills into moveable louvers that you can adjust with a push-pull control cable from the cockpit. Have excess cooling capacity for hot weather, that you can "throttle" for colder weather. I guarantee you will thank me later if you do this while you have the chance now.

The side gill location is where all of the air should be coming out of the cowl in the first place. The bottom of the cowl in front of the firewall is absolutely the worst place to do this, but it is the place where the 1940's automotive styling people and sales people wanted them to be... from an aesthetic-sales-styling point of view.

More than one "traditional" (bottom of the cowl) cooling system actually reverses the flow when the airplane is in a steep climb, with the air being sucked out the upper front cowl opening.

Look at the latest Cubs coming out of Yakima. Look at the Grumman Bearcat and Hawker Sea Fury, and FW-190, and the Arnold AR-5. That is the right direction to go.

cliff wrote:If I'm not carefu,l I can see 450 degrees by the time I'm clearing the departure end of my 2800' runway. I usually put the nose down a little as soon as I get off the ground, sort of in ground affect and let the airspeed build and watch the CHT, I try to keep it at 400. Am I being overly cautious? What CHT's do you guys see on climb out. I do tend to baby the engine in my old age.

Different engine, but I've only seen 409 degrees on a single cylinder a couple times in my life, and never any higher. It's very rare for my hottest cylinder to get above 385 degrees, and 350 is more common if I'm not hauling a heavy load.

It's hard for me to believe what you're seeing are normal temperatures. Maybe the measurement is inaccurate?

Hammer, "A" model engines are known to run hot but, my gauge could be out of calibration. It's cruise temp is around 325-350. I think I'll have the gauge checked.