eye lids on a Cruisaire.

G

Gary Brink

New member
A guy stopped by today to see the progress on my 47' Cruisaire. He used to own one but when he looked at the nose and saw the "eye lids", he asked why I had them. I frankly was at a loss for an answer but I'm pretty sure they were standard on my bird. Were they unique to a few Cruisaires or a few years? I have a picture of a Cruisaire hanging there and when I looked at it, there was no eye lids. :shock:
Thanks,
Gary Brink
 
My ser. is 1077, among the 1st dozen or so and is has the eyelids. (could have been an early retrofit for all I know) Since I am more an experimenter than a preservationist, I faired mine in with micro balloon. Looks a little Cessna-like compared to the original.
The eyelids were probably some bib-overalls engineering in the late stages of testing to get better cooling at slow climb speeds. But the sharp edges are guaranteed to produce separated flow and unnecessary drag.
BTW, cooling inlet efficiency is fairly easy to test, and that will be part of my fun if I ever get it in the air.

r
 
I am a little disappointed as the panel had some significant scratches in it and had "fish eyes" around the rivets. I took it to my buddy's body shop to have him paint it as I have my plane in the paint shop and another guy is waiting to get his bird in the same paint shop. It will be done in a couple of days and I'll send you a picture.
Gary
 
Umm, two sailors go into a bar. The first one says to Guiseppe ................ whoops wrong forum!

Faired Cruisair eyelids.



My thing.
r
 
In all seriousness, The "eyebrows," as August Bellanca called them, were an attempt to increase the amount of cooling airflow at low, relatively high angle of attack airspeeds, while limiting the increased airflow at higher speeds. The 14-13 was not the first to use them. The pre-war 14-12F3 had them, as well.
Years ago, I did a cooling study on my 14-13. I found the best compromise on climb airspeed vs. oil temperature was 110-115 IAS. at moderate altitudes. Climb any slower and watch the oil temp rise. Climb any faster and watch the VSI decrease below 300-500 FPM.
Dan
 
Thanks for your input, Dan. I try to always read your posts and I usually learn something. I have told a number of people how you described leaning
a Cruisaire with a Franklin by going to one mag.
Gary
 
... interesting point about the high speed drag reduction, Dan. Didn't know that.

Speed merchants like Lopresti concentrate a lot of thier attention on
"cooling drag".

Clearly, Guiseppe spent his whole lifetime working on it.

Witness the cruisaire.
 
I believe the club has a reprint available of the Raspet/Lambros Mississippi State aerodynamics study on the Cruisair in 1954. It was pointed out that cooling drag was large percentage of total drag on this airplane.
Dan
 
that report would make anybody want to saw the wings off thier airplane and take up
knitting.

I think anybody can have a "concept" and write a report.

( I'm living proof).

But I take his methodology and conclusions with a great deal of salt...
esp. regarding airspeed.

Cooling drag is a huge % of drag on any gasoline airplane.
Necessary evil.

I know some guys with " the worlds fastest C-152"... they built a fiberglass cowl ala lopresti with cooling inlets
a rat couldn 't get into, put 5 inch wheels on it, taped aluminum foil inside the windows for an antenna and etc.

Now it cruises at the Still Air Max speed.. but got so heavy you cant carry two people and a sandwich,
have to stoop to get into it, and I gather it is generous in it's overheating .

1 mph per horsepower is good
you want 2 mph.. get a mooney mite.
 
I know that Bellanca advertised them to get 1 mph per horsepower but is anyone actually getting that in true ground speed? People that I have talked to say their bird doesn't actually get the advertised speed.
Gary
 
Well Gary, groundspeed discussion is up to the atmosphere, so to speak. What info we are after is Indicated airspeed corrected for the atmosphere in which we are flying and installation error, Calibrated, you might say.
When these airplanes were new, clean, light and a fresh engine, I'll bet they would do darn close to 150mph TAS. at 2500 RPM. Age, time and weight takes a toll on any piece of equipment. A basic 14-13 with wood prop and minimal radio had what was called a "basic weight" of 1250 lbs. How many of your Cruisairs weigh that little? As a matter of fact how many of you have actually done a real weight and balance on your airplane, let alone weighed it. I'll bet darned few. The calculations you have on your 337s and logs are based on someone's crude attempts 50 years ago. Believe me I've seen it many times that owners are surprised to find their airplane weighs 100-150 lbs more than they thought.
Dan
 
PS. I have flown a couple Mooney Mites and they will get 2mph/hp....but you're only flying one person. A Cruisair can fly four.....
Dan
 
I'm sure you are right, Dan. My battery had been moved into the engine compartment so when I had it down to the bare frame, I removed the "platform" under the cargo box that once held both the battery and the ELT. I probably took off eight to ten pounds. I also got rid of the old BIG DG which saves a few pounds. However, I added 1419 axels and Cleveland brakes plus wing tip strobes so I know that I will be adding weight. We will weight it and do a weight and balance when I am done but I am sure that I will have a CG issue and will need to add weight in the tail section. I'll let you know how much it actually weighs when I'm done.
Gary
 
My turn...
Raspet was actually right on the money. Most 150 hp Cruisairs do ~125-135 mph. That is what he showed was the TAS (in mph) when the airspeed indicator showed 150. There was (is?) significant error in the pitot system in our planes.
And Dan, you are right about the weights. I have weighed my plane, and it weighs 1409 lbs empty. If anyone wants to weigh there Bellanca, come to Creswell, and I will weigh your plane.(NO CHARGE).
Larry
 
Gary,
Axles and strobes won't add much. Over the years, owners keep adding dozens of gadgets, appliances, AN gyros meant for a B-17, Electronics of ancient age,Venturi tubes, heavy upholstry and a bunch of crap in the luggage box and back seat that they never use. Let's put a forest of antenna on the top of the fuselage a couple old beater rotating beacons like my Cruisemaster has .....and now we're talkin' turkey. A two place Bellanca that does 125mph...maybe.
Being light starts at the rebuild/restoration stage and takes real planning and execution. None of the 14 series Bellancas need heavy fabric. Medium is plenty strong and takes less material to finish. Lightweight starters, alternators, batteries will help the nose heaviness in the airplane.
I once replaced an industrial battery in the T-14 that weighed 35 POUNDS with a Concord RG battery that is more powerful and weighs 21 pounds....replaced the starter with a Skytek and saved 8 pounds...now that is a good start. Pretty soon, I'll just float away.....
Dan
 
The eyelids on the Cruisaire were done at the factory. During certification tests it was found that the Franklin didn't get enough cooling air during climbout, so Bellanca added the eyebrows on the prototype. They worked well and a cowling redesign was too expensive, so they were put on all Cruisaires. They look like an after thought and they were just that.

Gene deRuelle
 
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