Max RPM with aeromatic and 165 Franklin
- Thread starter dtreid
- Start date
Dan Cullman
New member
How accurate is your tach????
2550 static is pretty close, if that is what you are really turning.
What is your "N" and location.
Can you turn 2700 or better in level flight?
Dan
2550 static is pretty close, if that is what you are really turning.
What is your "N" and location.
Can you turn 2700 or better in level flight?
Dan
Dan Cullman
New member
Your propeller is set correctly. I would not change a thing.
BTW. "SPN" is here at Crest- S36, with a new "N." The original 1949 number was not available.
I think SPN spent 40 years in the Edmonton area. The son of the former owner has it now.
Dan
BTW. "SPN" is here at Crest- S36, with a new "N." The original 1949 number was not available.
I think SPN spent 40 years in the Edmonton area. The son of the former owner has it now.
Dan
dtreid said:
The 14-13 Aeromatic 165 spec for static RPM is 2500 to 2550 so your settings look good to me, but it got me digging.
Well, one of my favorite reads is the FAA's Type Cert Data Sheets. According to these relevant TCDS's, the engine is rated 2800 rpm and also 2800 rpm for the prop. However, for both the Bellanca and Stinson, this combo is required to be red lined at 2650 RPM. ???
I suppose it is an arbitrary airframe horsepower limit thing. 165 whole horsepower might pull the wings off!
BTW, did Bellanca ever sell planes with 165's? I don't remember seeing the 165 in the 14-13 tcds years ago. When was it added? The only historical sheet I could find is 1973 where the 165 paragraph is marked as modified. Maybe there is a story there.
Relevant to all this, Paul at Aero Propeller told me that Tarver is retiring and closing up. I haven't seen anything here re this.
r
Dan Cullman
New member
You can turn the Aeromatic 2800, if need be. I talked to Kent Tarver yesterday about this. And he is NOT closing up shop! The printed info on the TDCS is in error when it comes to the Bellanca. No one has bothered to get it corrected. There never has been a 2650rpm limit for the Bellanca.
No...you will not pull the wings off, nor throw a blade. In my first flight in the T14-14, years ago, the improperly set up Aeromatic allowed the engine to turn 2950 on a 2550 redline engine. The prop survives quite well.
The next year, however, the engine threw an exhaust valve through the cylinder head. huhuhuhuhu.
Dan
No...you will not pull the wings off, nor throw a blade. In my first flight in the T14-14, years ago, the improperly set up Aeromatic allowed the engine to turn 2950 on a 2550 redline engine. The prop survives quite well.
The next year, however, the engine threw an exhaust valve through the cylinder head. huhuhuhuhu.
Dan
Dan Cullman
New member
A bit better, perhaps. However, you might have to adjust the flight weights to avoid over revving in level flight. I'd leave well enough alone.
Dan
Dan
Now that I have a few more hours on my bird, I have better idea of what's going on.
Today, max static RPM I can get is 2500-2550. I should be able to adjust this to 2750rpm.
At 4500ft (field is at 4000'), in level flight, I have no problem at all overspeeding the engine.
At cruise rpm of 2600, I am only seeing 17" of manifold pressure. At 85mph in a climb at full power I see 25".
This makes me think that my prop is running too coarse at takeoff and much to fine at cruise.
Am I correct in this thinking before I start messing with the prop weights and shims?
Today, max static RPM I can get is 2500-2550. I should be able to adjust this to 2750rpm.
At 4500ft (field is at 4000'), in level flight, I have no problem at all overspeeding the engine.
At cruise rpm of 2600, I am only seeing 17" of manifold pressure. At 85mph in a climb at full power I see 25".
This makes me think that my prop is running too coarse at takeoff and much to fine at cruise.
Am I correct in this thinking before I start messing with the prop weights and shims?
Dan Cullman
New member
Read the instructions in the "Field" manual.
There are two rpm adjustments for the Aeromatic:
1. Static RPM adjustment is done through "static shims" in the center of the hub.
2. Flight RPM adjustment is done through flight weights on the counterweight arms.
READ AND USE THE INSTRUCTIONS.
I can tell that you don't have enough weights on the counterweight arms.
Read the instructions...please.
Dan
There are two rpm adjustments for the Aeromatic:
1. Static RPM adjustment is done through "static shims" in the center of the hub.
2. Flight RPM adjustment is done through flight weights on the counterweight arms.
READ AND USE THE INSTRUCTIONS.
I can tell that you don't have enough weights on the counterweight arms.
Read the instructions...please.
Dan
blimpy
New member
Dan is right - read the manual.
Also, Tarver's Website has a good long explanation of how to set up the aeromatic.
Read that too.
Altitude make a lot of difference with the Aeromatic.
They should be set up to achieve the correct Static RPM at your field elevation.
No way should the prop allow the engine to over-rev static, climb, or cruise.
Franklin Service Bulletin allows an occasional over rev of 100 rpm. All of them are on the web.
More than that and you are looking at a mandatory engine inspection.
Nothing is gained from flogging an engine.
Factoid : Prop revs decrease 20 rpm per 1000 feet.... so if you are already able to over-rev at 4500
when you go down to sea level you can over-rev another 85 rpm on top of the mis-adjustment you have now.
I am not understanding a max cruise rpm that exceedes static maximum.. except with gross misadjustment.
Not that I really know anything about props, beyond what I can read, and how mine behaves.
:roll:
Also, Tarver's Website has a good long explanation of how to set up the aeromatic.
Read that too.
Altitude make a lot of difference with the Aeromatic.
They should be set up to achieve the correct Static RPM at your field elevation.
No way should the prop allow the engine to over-rev static, climb, or cruise.
Franklin Service Bulletin allows an occasional over rev of 100 rpm. All of them are on the web.
More than that and you are looking at a mandatory engine inspection.
Nothing is gained from flogging an engine.
Factoid : Prop revs decrease 20 rpm per 1000 feet.... so if you are already able to over-rev at 4500
when you go down to sea level you can over-rev another 85 rpm on top of the mis-adjustment you have now.
I am not understanding a max cruise rpm that exceedes static maximum.. except with gross misadjustment.
Not that I really know anything about props, beyond what I can read, and how mine behaves.
:roll:
Dan Cullman
New member
Full throttle on a standard day at 5000 msl should be close to 24" MAP.
Dan
Dan
Dan Cullman
New member
I would say it is a good as it gets. Leave it as it is.
Dan
Dan