COZY: Engine max rpm


Marc J. Zeitlin
 

Greg Norman wrote:

I’ve been going through the gradual break-in beginning at low rpm until hot temps then running up gradually to the upper rpm range. The last time I ran my engine it would max out at 2700 rpm. I have the Bendix F.I. with a Bendix servo. Engine runs smooth at all ranges and I checked the throttle cable for max travel. All good there. Anything on the servo I possibly missed?

Do you think you have a problem? I don't know what you're asking here, and there's nowhere near enough information to provide any advice. Here are some questions (in no particular order) to answer before anyone can give you useful feedback:

  1. Is this a ground run?
  2. A taxi run?
  3. In flight RPM?
  4. What DA?
  5. What throttle/mixture settings?
  6. What kind of ignition?
  7. What engine?
  8. What airplane?
  9. What propeller?
  10. Wheel pants?
  11. Pods?
  12. Other Airplane mods?
  13. What did you tell the prop MFG about what type of prop you wanted - cruise, climb, combination?

IIRC, you have an IO-540 on a COZY MKIV, yes (not that that should have been obvious to everyone)? If so, the redline is 2700, so at least at a first glance, assuming that this is an in-flight RPM, MAYBE you're in a reasonable place. Could go either way, depending upon the answers to the 13 questions above.

--
Marc J. Zeitlin                      marc_zeitlin@...
                                            http://www.cozybuilders.org/
Copyright © 2022                     Burnside Aerospace


Glenn Charles
 

gentlemen !!!!

it’s been 17 years but my EZ is finally ready !!!

Now the hardest part - paperwork !!!

Aauuuggghhhh !!!

I need a conditional inspection !!

Anyone in the Osh Kosh area available ?? i’m at SBM.

HELP !!!

got some registration details to clean up too.

this is a rebuild. New engine, airflow performance FI.
Klaus dual ignition.
runs great !
ready for first flight !!!

Glenn

920-946-5756


Greg Norman
 

Thank for the topic steal Glen

On Thu, May 12, 2022 at 8:16 AM Glenn Charles via groups.io <gcm2291=yahoo.com@groups.io> wrote:
gentlemen !!!!

it’s been 17 years but my EZ is finally ready !!!

Now the hardest part - paperwork !!!

Aauuuggghhhh !!!

I need a conditional inspection !!

Anyone in the Osh Kosh area available ??  i’m at SBM.

HELP !!!

got some registration details to clean up too.

this is a rebuild.  New engine, airflow performance FI.
Klaus dual ignition. 
runs great !
ready for first flight !!!

Glenn

920-946-5756






Greg Norman
 

More info:
Sorry, 2000 rpm. Not 2700. Will not run past 2000 rpm at full throttle. 
Just running sitting on the ground. I’ve not flown or taxied yet. Just getting warm here. 
Cozy MKIV, IO-540D4A5, all stock - Bendix mags. Mags and timing set up by an A&P. 
Full throttle, mixture rich. 

On Thu, May 12, 2022 at 1:45 AM Marc J. Zeitlin <marc.j.zeitlin@...> wrote:
Greg Norman wrote:

I’ve been going through the gradual break-in beginning at low rpm until hot temps then running up gradually to the upper rpm range. The last time I ran my engine it would max out at 2700 rpm. I have the Bendix F.I. with a Bendix servo. Engine runs smooth at all ranges and I checked the throttle cable for max travel. All good there. Anything on the servo I possibly missed?

Do you think you have a problem? I don't know what you're asking here, and there's nowhere near enough information to provide any advice. Here are some questions (in no particular order) to answer before anyone can give you useful feedback:

  1. Is this a ground run?
  2. A taxi run?
  3. In flight RPM?
  4. What DA?
  5. What throttle/mixture settings?
  6. What kind of ignition?
  7. What engine?
  8. What airplane?
  9. What propeller?
  10. Wheel pants?
  11. Pods?
  12. Other Airplane mods?
  13. What did you tell the prop MFG about what type of prop you wanted - cruise, climb, combination?

IIRC, you have an IO-540 on a COZY MKIV, yes (not that that should have been obvious to everyone)? If so, the redline is 2700, so at least at a first glance, assuming that this is an in-flight RPM, MAYBE you're in a reasonable place. Could go either way, depending upon the answers to the 13 questions above.

--
Marc J. Zeitlin                      marc_zeitlin@...
                                            http://www.cozybuilders.org/
Copyright © 2022                     Burnside Aerospace


kent ashton
 

Tach accurate?    Getting full throw on the throttle linkage?    Butterfly(?) opening fully?

On May 13, 2022, at 9:27 PM, Greg Norman <gnorm76@...> wrote:


More info:
Sorry, 2000 rpm. Not 2700. Will not run past 2000 rpm at full throttle. 
Just running sitting on the ground. I’ve not flown or taxied yet. Just getting warm here. 
Cozy MKIV, IO-540D4A5, all stock - Bendix mags. Mags and timing set up by an A&P. 
Full throttle, mixture rich. 

On Thu, May 12, 2022 at 1:45 AM Marc J. Zeitlin <marc.j.zeitlin@...> wrote:
Greg Norman wrote:

I’ve been going through the gradual break-in beginning at low rpm until hot temps then running up gradually to the upper rpm range. The last time I ran my engine it would max out at 2700 rpm. I have the Bendix F.I. with a Bendix servo. Engine runs smooth at all ranges and I checked the throttle cable for max travel. All good there. Anything on the servo I possibly missed?

Do you think you have a problem? I don't know what you're asking here, and there's nowhere near enough information to provide any advice. Here are some questions (in no particular order) to answer before anyone can give you useful feedback:

  1. Is this a ground run?
  2. A taxi run?
  3. In flight RPM?
  4. What DA?
  5. What throttle/mixture settings?
  6. What kind of ignition?
  7. What engine?
  8. What airplane?
  9. What propeller?
  10. Wheel pants?
  11. Pods?
  12. Other Airplane mods?
  13. What did you tell the prop MFG about what type of prop you wanted - cruise, climb, combination?

IIRC, you have an IO-540 on a COZY MKIV, yes (not that that should have been obvious to everyone)? If so, the redline is 2700, so at least at a first glance, assuming that this is an in-flight RPM, MAYBE you're in a reasonable place. Could go either way, depending upon the answers to the 13 questions above.

--
Marc J. Zeitlin                      marc_zeitlin@...
                                            http://www.cozybuilders.org/
Copyright © 2022                     Burnside Aerospace


Marc J. Zeitlin
 

Greg Norman wrote:

Sorry, 2000 rpm. Not 2700. Will not run past 2000 rpm at full throttle.

So if you're only getting 2K RPM on a static runup, there may or may not be something wrong. You don't say what prop you have (question #7) nor what type of prop you asked for (question #13). It's possible that with an O-540 COZY MKIV fixed pitch prop that's designed for cruise, not climb, that the blades are pitched so high and well into the stall regime with no forward speed, and that drag (torque) is so high that 2K RPM is all that can be achieved. Knowing more about the prop would have indicated whether that's a likely scenario or not, but you leave us guessing. A high speed taxi run could give some indication - at 40 - 50 kts, if RPM increases greatly (maybe to 2200 - 2300) then this could be the issue.

Just running sitting on the ground. I’ve not flown or taxied yet. Just getting warm here. 
Cozy MKIV, IO-540D4A5, all stock - Bendix mags. Mags and timing set up by an A&P. 
Full throttle, mixture rich.

But it's also possible that you just have the WRONG prop, or that there is (as Kent asks) something actually incorrect about the way the engine is running. I'd try a short run with leaning to best RPM and see what can be achieved, and I'd start taxi testing and see what it does when you get to just under rotation speeds. I'd also give a bit more information about the prop, as requested, and maybe that would reveal something.

--
Marc J. Zeitlin                      marc_zeitlin@...
                                            http://www.cozybuilders.org/
Copyright © 2022                     Burnside Aerospace


Keith Spreuer
 

Who made your prop? If the engine is running fine then the prop mfg should be able to say what static rpm is expected. Personally I would like to 2300 or more. With a O 540 a Cozy ought to have plenty of power even if not optimal 


On Sat, May 14, 2022, 2:27 AM Greg Norman <gnorm76@...> wrote:
More info:
Sorry, 2000 rpm. Not 2700. Will not run past 2000 rpm at full throttle. 
Just running sitting on the ground. I’ve not flown or taxied yet. Just getting warm here. 
Cozy MKIV, IO-540D4A5, all stock - Bendix mags. Mags and timing set up by an A&P. 
Full throttle, mixture rich. 

On Thu, May 12, 2022 at 1:45 AM Marc J. Zeitlin <marc.j.zeitlin@...> wrote:
Greg Norman wrote:

I’ve been going through the gradual break-in beginning at low rpm until hot temps then running up gradually to the upper rpm range. The last time I ran my engine it would max out at 2700 rpm. I have the Bendix F.I. with a Bendix servo. Engine runs smooth at all ranges and I checked the throttle cable for max travel. All good there. Anything on the servo I possibly missed?

Do you think you have a problem? I don't know what you're asking here, and there's nowhere near enough information to provide any advice. Here are some questions (in no particular order) to answer before anyone can give you useful feedback:

  1. Is this a ground run?
  2. A taxi run?
  3. In flight RPM?
  4. What DA?
  5. What throttle/mixture settings?
  6. What kind of ignition?
  7. What engine?
  8. What airplane?
  9. What propeller?
  10. Wheel pants?
  11. Pods?
  12. Other Airplane mods?
  13. What did you tell the prop MFG about what type of prop you wanted - cruise, climb, combination?

IIRC, you have an IO-540 on a COZY MKIV, yes (not that that should have been obvious to everyone)? If so, the redline is 2700, so at least at a first glance, assuming that this is an in-flight RPM, MAYBE you're in a reasonable place. Could go either way, depending upon the answers to the 13 questions above.

--
Marc J. Zeitlin                      marc_zeitlin@...
                                            http://www.cozybuilders.org/
Copyright © 2022                     Burnside Aerospace


Rock Braud
 

Just adding a datapoint here.

I have a Cozy with an IO-540-J4A5 with Catto three blade and Dynon EFIS (the original one, not the HDX).

Anywho when I first fired up my IO-540 I too would only get 2000 static RPM. Went round and round and worried I had the wrong prop. Ended up using an "external" optical RPM device which showed I had something like 2300 RPM static.

Turns out it was the scale factors in the Dynon which cause errors in reporting. Fixed the scale factors and the Dynon RPM matched the "external" optical RPM device.

Food for thought.

Later.


scott carter
 

Greg 
IO 540 (260hp) Catto 68x88
Static 2150-2200
Xtra EZ N 541SL

Scott Carter 


On May 14, 2022, at 3:20 AM, Keith Spreuer <kspreuer@...> wrote:


Who made your prop? If the engine is running fine then the prop mfg should be able to say what static rpm is expected. Personally I would like to 2300 or more. With a O 540 a Cozy ought to have plenty of power even if not optimal 

On Sat, May 14, 2022, 2:27 AM Greg Norman <gnorm76@...> wrote:
More info:
Sorry, 2000 rpm. Not 2700. Will not run past 2000 rpm at full throttle. 
Just running sitting on the ground. I’ve not flown or taxied yet. Just getting warm here. 
Cozy MKIV, IO-540D4A5, all stock - Bendix mags. Mags and timing set up by an A&P. 
Full throttle, mixture rich. 

On Thu, May 12, 2022 at 1:45 AM Marc J. Zeitlin <marc.j.zeitlin@...> wrote:
Greg Norman wrote:

I’ve been going through the gradual break-in beginning at low rpm until hot temps then running up gradually to the upper rpm range. The last time I ran my engine it would max out at 2700 rpm. I have the Bendix F.I. with a Bendix servo. Engine runs smooth at all ranges and I checked the throttle cable for max travel. All good there. Anything on the servo I possibly missed?

Do you think you have a problem? I don't know what you're asking here, and there's nowhere near enough information to provide any advice. Here are some questions (in no particular order) to answer before anyone can give you useful feedback:

  1. Is this a ground run?
  2. A taxi run?
  3. In flight RPM?
  4. What DA?
  5. What throttle/mixture settings?
  6. What kind of ignition?
  7. What engine?
  8. What airplane?
  9. What propeller?
  10. Wheel pants?
  11. Pods?
  12. Other Airplane mods?
  13. What did you tell the prop MFG about what type of prop you wanted - cruise, climb, combination?

IIRC, you have an IO-540 on a COZY MKIV, yes (not that that should have been obvious to everyone)? If so, the redline is 2700, so at least at a first glance, assuming that this is an in-flight RPM, MAYBE you're in a reasonable place. Could go either way, depending upon the answers to the 13 questions above.

--
Marc J. Zeitlin                      marc_zeitlin@...
                                            http://www.cozybuilders.org/
Copyright © 2022                     Burnside Aerospace