Jab 2200 ground running

[Old Koreelah]

Can anyone suggest what revs a healthy Jab 2.2 will reach if tethered and ground run with throttle wide open? This might tell me if I have everything set up correctly.

 

Regards,

 

Lyle

 

 

[biggles]

I think you will find that it depends very much on the diameter and pitch of the prop . With a Jabiru prop you should get around 2800 RPM with a 60x42 and around 2700 RPM with a 60x44 , for other props I suggest you ring Jabiru .

 

Regards

 

Bob

 

 

[slartibartfast]

I believe the aim should be 2800 - 3000.

 

 

[BigPete]

My old bus (J160c) climbs out at 2900 RPM at 70 - 75 knots. (60 x 42)

 

regards

 

 

[brilin_air]

Our 160 does 600 ftpm 90 knots at 2900.

 

Ground running 2800, with a 60x44 prop.

 

-Linda

 

 

[Old Koreelah]

Thanks for the replies, people. I forgot to specify my prop, which is 60 X 42.

 

Regards,

 

Lyle

 

 

[facthunter]

Power Check.

 

Considering part of your original question, it also has ongoing relevence. The RPM figure, (if you determine what it is, and you are doing that), WILL give a good indication of delivered power.(Fixed pitch props ONLY)

 

This is something that is not mentioned very much with our aircraft, but you should have in your mind when you open the throttle, an RPM figure which would be acceptable. Obviously anything below that would mean rejecting the take-off. You might find that the carb. heat is on or something else is wrong.

 

Dont take a known problem up into the air with you. There are enough Unknown problems there already. Nev

 

 

[Guest Qwerty]

Dont take a known problem up into the air with you. There are enough Unknown problems there already.

Nev

Brilliant, thanks for that one.

 

 

[pudestcon]

Well said Nev,

 

I'm going to use your 'Known, unknown' quote quite a lot - especially to myself!! ;)

 

Pud

 

 

[facthunter]

Saying.

 

Thanks fella's

 

I first thought of it as a good philosophy in 1966 when I was doing a check ride. I informed the Captain that there was a clip missing from one of the rear doors. He said "well here's a chance for you to show initiative. What would YOU do?" I responded with what I thought was an appropriate response. Ie the quote above. and a LAME was brought out and the missing part fabricated. We were delayed some hours as it was the middle of the night.

 

I only found out many years later when I got access to my files that he had written me up as "failing to show initiative". SO I must warn you that it doesn't work. (But I still use it)...Nev

 

 

[Yenn]

If you get a chance try writing up his file as failing to show responsibility.

 

 

[facthunter]

Fix.

 

In the absence of the Wrath of God, I tell myself that "Time wounds all Heels". Nev

 

 

[Guest check-in]

Back to the prop question. I recently bought a beautiful ground adjustable composite prop from Rob Patroney. He told me to set the initial blade angle at 14 degrees and take it to full throttle in the cruise. He said it would be optimum if it made 3300 rpm. Which is exactly what it achieved first go. Now goes like a cut cat whereas with the old wooden prop it was a bit slow even though it would make the 3300 rpm. I think the old prop had too much pitch and not enough diameter (it was only 54 inch dia whereas the new one is 60 inches).

 

Although I have never tried tethering it and flogging the engine in a static condition, the Sonex book says 2750 rpm static is the target. On takeoff I look for about 3000 as it accelerates through 50 knots but by then it's all happening a bit fast, so it's a very quick look.

 

Aircraft is Sonex with Jab 2200.