1940 bl65

[jack clifton]

I have about 4 hours on my tcraft now since major. I note it is a lycoming bl65. It has the open cowl like the j3 , and a wood prop. I am getting about 75mph cruise at recomended rpm of 2500, this is with trimming it out to dive first, then letting it come back to level flight after each trim adjustment. Is this about right for cruise, or is it a liittle slow. I static about 2350 rpm, we are at 4000 ft. elevation at our airport. I have checked it both directions, it seems to be about that speed 75.
let me know, my friend's bc65, continental powered, metal prop gets about 95 mph at 2300, knowing that the continental gets it's horspower with more cubic inches, and less rpm. I think I should cruise faster than that. I may have a climb prop, as I can get the full 2650 red line rpm in cruise, but it sure climbs o.k., Jack

[fearofpavement]

Re: 1940 bl65

My first solo was in a BL-65. A 1941 model. That was back in 1977 and I still remember it well.

Anyway, enough nostalgia, two things I would suggest. One is to check your tachometer for accuracy. There are a variety of different means to do that but probably someone you know has a tach checker they would loan you. If your tach is accurate, the climb prop theory is most likely. If you like the performance as is leave it be, otherwise you could have the pitch increased a bit. It's always a trade off with a fixed pitch prop. You can't have it all

OK, forget the pitch change thing, I just re-read your post and missed the wood prop part. Those are hard to re-pitch...

Do you use the aircraft to go places or just go up and fly? If you're not going A to B it doesn't really matter how fast you go does it? OK, dumb question, everyone wants to go faster. My guess is that most of the people on this forum either could or do have an aircraft that is faster than their T-Craft but enjoy the T for what it is. My neighbor used to get back from an MD-11 trip and fly his Cub which is way slow just because it's fun!

[flylo]

Re: 1940 bl65

Jack,my '38 with an open cowl & wheel pants cruises 90 @ 2400 & 85 @ 2000 RPM. I'm about 800'AGL. I learned to fly in a '40 with a closed cowl & it was close to the same. Which prop do you have? How much does it weigh? I've collected alot of parte & engines,if you need anything let me know.The redline should be 2550.

[Howard Wilson]

Re: 1940 bl65

I get about 81 mph @ 2300. Open cowl.That was without bungee covers, and landing gear to fuselage fairings. No wheel pants. Metal prop. Will check pitch info......

[Bob Waldron]

Re: 1940 bl65

Jack,

I get 88 and better at 2400 with my 1939 BL-65 with the open cowl. I found that bungee covers and landing gear fairings amounted to about 10 miles per hour increase. I use a climb prop, and would hate to give up any of the climb rate that I have.

[jack clifton]

Re: 1940 bl65

Thanks guys, I am happy just flying her, but I think the bungee covers would help as well as knowing the pitch, and the tach accuracy. I will check, and would anyone have a set of bungee covers for sale, I have not been able to find any. Forrest said that there are some fglass ones out there, but I don't know, Jack

[barnstmr]

Re: 1940 bl65

I fly my father-in-law's BC65 a lot. He has a Cont. A75 with a 7442 prop. Therefore it will not turn up any faster than an A65, so it is effectively an A65. (The A75 has the same power curve as A65, except it continues to go higher horsepower at higher RPMs than the A65.)

Anyway, we routinely indicate 90 mph to 95 mph (on "step"). Perhaps your airspeed indicator is not plumbed properly. Where does it source the static air? If it has an open port on the back of the gauge for static air, check your cruise with windows open vs. with windows closed. The change in air pressure affects the gauge if it is static sourced inside the cockpit. Ideally, you want a source of true static air. I have seen various airplanes with this having a big effect on the airspeed gauge.

[barnstmr]

Re: 1940 bl65

You can also check the actual airspeed by comparing to GPS groundspeed while flying reciprocal headings at 90 degrees to prevailing wind. (The reciprocal headings are to cancel out any headwind/tailwind). Take the average groundspeed of the two and compare to what you were indicating. Be sure the power setting/RPM is the same both directions.

[VictorBravo]

Re: 1940 bl65

After having fooled around with the pitot-static system on my 1940 BL(C)- 65, I might suggest that you disregard about 20% of what the airspeed indicator reads either way. It appears that some of the Taylorcrafts had external static ports next to the pitot tube, some had cockpit vent static, some had the static line stuck 2 ribs into the wing root, etc. Not exactly a NACA scientific setup!

I went so far as to buy a German calibrated pitot-static probe for high performance sailplane use, and still could not get a reading that matched the GPS making test runs in all four directions.

My advice, like what has or will be mentioned in this thread, is to go fly a square pattern, N, S, E and W on a known calm day at low altitude, with the ball centered, and average out the GPS numbers at two or three RPM settings. That will be your cruise number

[NY86]

Re: 1940 bl65

Fly 3 headings 90 degrees apart and record your GPS speed. Go here and compute your airspeed.