Matronics Email Lists :: View topic - Prop won't slow below 70%

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Prop won't slow below 70%

Matronics Email Lists Forum Index -> Yak-List

View previous topic :: View next topic

Author Message

glipaz

Joined: 11 Jan 2011
Posts: 110

Posted: Tue Mar 19, 2019 10:59 am Post subject: Prop won't slow below 70%

To the brain tank:

I have a stock M-14P motor with a stock hub, Russian v530 paddle prop, and rebuilt prop governor.



Prop is at 16 degrees per the book.  In flight I am not able to get the RPM to go below 70% even with the prop lever all the way back at the gate.  I was advised to increase the size of the spring in the prop governor but Jill suggested that with all stock setup that should not be necessary.   



Any ideas or thoughts?



Gil

richard.goode(at)russiana
Guest

Posted: Tue Mar 19, 2019 11:33 am Post subject: Prop won't slow below 70%

The standard R-2 Russian governor will generate enough oil pressure for the

Russian V-530 prop, although you do need to install higher pressure springs

for MT and Whirlwind props.



But I would suggest that you are having a blockage of oil either into or out

of the governor. There are quite narrow oil ways, and a gauze filter

underneath the governor and if anything is blocked, clearly the governor

will not work correctly.



Richard

RICHARD GOODE AEROBATICS

Rhodds Farm, Lyonshall, Hereford, HR5 3LW, UK

Tel:  +44 (0)1544 340120   Fax:  +44 (0)1544 340129

e-mail: richard.goode(at)russianaeros.com

www.russianaeros.com

WORLD LEADERS IN RUSSIAN SPORTING AIRCRAFT & ENGINES

In partnership with Aerometal Kft, Hungary.

--

wlannon(at)shaw.ca
Guest

Posted: Tue Mar 19, 2019 12:19 pm Post subject: Prop won't slow below 70%

No; Just questions;



Is this M14P on a CJ?



Which book put the fine pitch setting at 16 degs.?   That is the correct 

setting for the Chinese prop. on the Huosai engine.

The book setting for the V530 with stock blades on the M14P is 14.5 degs.



However that is a different problem than what you describe which I suspect 

is an incorrect governor set-up procedure.  Have not read it for a while but 

If I remember correctly the Russian procedure is poorly written and 

confusing while the Chinese is simple and straightforward.  Numbers of 

course are different! But the basic process is the same.



I would not buy life insurance from whomever told you to replace the 

"speeder" spring in the governor.  Jill's advice here was most certainly 

correct not to mention extremely polite.



Walt



--

dsavarese0812(at)bellsout
Guest

Posted: Tue Mar 19, 2019 1:59 pm Post subject: Prop won't slow below 70%

Have you removed and cleaned the prop governor oil screen on the right side of the nose case? 



Dennis



                  

                                                                    On Tuesday, March 19, 2019, 3:35:57 PM EDT, Richard Goode <richard.goode(at)russianaeros.com> wrote:                 

                 



                 



                 --> Yak-List message posted by: "Richard Goode" <richard.goode(at)russianaeros.com (richard.goode(at)russianaeros.com)>



The standard R-2 Russian governor will generate enough oil pressure for the



Russian V-530 prop, although you do need to install higher pressure springs



for MT and Whirlwind props.



But I would suggest that you are having a blockage of oil either into or out



of the governor. There are quite narrow oil ways, and a gauze filter



underneath the governor and if anything is blocked, clearly the governor



will not work correctly.



Richard



RICHARD GOODE AEROBATICS



Rhodds Farm, Lyonshall, Hereford, HR5 3LW, UK



Tel:  +44 (0)1544 340120   Fax:  +44 (0)1544 340129



e-mail: richard.goode(at)russianaeros.com (richard.goode(at)russianaeros.com)



www.russianaeros.com



WORLD LEADERS IN RUSSIAN SPORTING AIRCRAFT & ENGINES



In partnership with Aerometal Kft, Hungary.



--

GeorgeCoy

Joined: 02 Dec 2010
Posts: 310

Posted: Tue Mar 19, 2019 2:18 pm Post subject: Prop won't slow below 70%

The speeder spring was sold (by MT Propeller) to increase the pressure or

the Russian R2 governor for use on early MT9 propellers. Later MT design did

not require the speeder spring. Sometimes we simply added a 1/4 in washer

under the spring. 

George Coy 



--

dsavarese0812(at)bellsout
Guest

Posted: Tue Mar 19, 2019 2:19 pm Post subject: Prop won't slow below 70%

You should listen to Walt because he is right on the money.  Besides the incorrect blade angle setting, setting up the prop governor is probably where your problem is.   If you haven't set up an M14 prop governor before, it would be best to find someone who has.  Otherwise it truly is hit and miss (mostly miss to be honest with you). 



Dennis



                  

                                                                    On Tuesday, March 19, 2019, 4:21:18 PM EDT, Walter Lannon <wlannon(at)shaw.ca> wrote:                 

                 



                 



                 --> Yak-List message posted by: "Walter Lannon" <wlannon(at)shaw.ca (wlannon(at)shaw.ca)>



No; Just questions;



Is this M14P on a CJ?



Which book put the fine pitch setting at 16 degs.?   That is the correct 



setting for the Chinese prop. on the Huosai engine.



The book setting for the V530 with stock blades on the M14P is 14.5 degs.



However that is a different problem than what you describe which I suspect 



is an incorrect governor set-up procedure.  Have not read it for a while but 



If I remember correctly the Russian procedure is poorly written and 



confusing while the Chinese is simple and straightforward.  Numbers of 



course are different! But the basic process is the same.



I would not buy life insurance from whomever told you to replace the 



"speeder" spring in the governor.  Jill's advice here was most certainly 



correct not to mention extremely polite.



Walt



--

wlannon(at)shaw.ca
Guest

Posted: Tue Mar 19, 2019 7:12 pm Post subject: Prop won't slow below 70%

--

glipaz

Joined: 11 Jan 2011
Posts: 110

Posted: Sat Apr 20, 2019 6:23 pm Post subject: Re: Prop won't slow below 70%

Gents:

Thank you for your comments.  My prop is set to 14.5 degrees, not 16.  

The prop cycles properly on the ground using the proper runup procedure quoted below.  It attains 99% RPM at full power and, after pulling throttle to 70%, then cycling prop to minimum, the RPM drops to 53%.  



From Task Card 204:

"NOTE: The adjustment is regarded to be completed, if with throttle fully open and the governor control lever set to the low pitch stop, the engine gains a speed of 99 % (2900 r/min) and when the lever is shifted to the high pitch from nominal rating II 70 % (2050 r/min), the speed of rotation drops drastically to 53 %."



In cruise flight, with MP at 6.4, the RPM does not drop below 70% even with the prop lever back at the stop.

wlannon(at)shaw.ca
Guest

Posted: Sat Apr 20, 2019 7:12 pm Post subject: Prop won't slow below 70%

Hi Gil;



Question 1;  In cruise at 640 mm/hg what happens when you push the nose 

down?  Does the RPM remain at 2030 or increase?



Question 2:  Have you by any chance replaced the pitch change piston assy. 

with a Chinese one?



Walt



--

glipaz

Joined: 11 Jan 2011
Posts: 110

Posted: Sat Apr 20, 2019 7:24 pm Post subject: Re: Prop won't slow below 70%

Hi Walt.  Pitching forward causes RPM to increase.  

Re pitch change piston, I assume you mean the piston in the hub.  I bought it with the hub and assume it is standard Russian.

yakman285(at)gmail.com
Guest

Posted: Sun Apr 21, 2019 2:18 am Post subject: Prop won't slow below 70%

I have seen differences in " dome pistons" used in V530 hubs (and Chinese). The main thing to check is the amount of angular motion allowed by the assembly. There is a "ring" on the base of the piston that is held in place with cotter pins. The Thickness of that ring controls the amount of linear piston movement, hence total angular movement in the blades. Also check depth of the dome being used.



I have seen different ring thicknesses and by mixing Chinese and Russian parts in my Yak-Chang or Nan-Yak, I could get 2900 RPM fine pitch and as low as 1680 RPM at low MAP settings in coarse pitch. Once managed 520 NM on 46 gallons. With an aux tank of course!

Craig Payne

rickkelleyfly(at)gmail.co
Guest

Posted: Sun Apr 21, 2019 6:14 am Post subject: Prop won't slow below 70%

Donâ€™t know that one. 210-787-0327



Sent from my iPhone



 	  Quote: 	
		   On Apr 21, 2019, at 3:17 AM, Craig Payne <yakman285(at)gmail.com> wrote:

 

 I have seen differences in " dome pistons" used in V530 hubs (and Chinese). The main thing to check is the amount of angular motion allowed by the assembly. There is a "ring" on the base of the piston that is held in place with cotter pins. The Thickness of that ring controls the amount of linear piston movement, hence total angular movement in the blades. Also check depth of the dome being used.

 

 I have seen different ring thicknesses and by mixing Chinese and Russian parts in my Yak-Chang or Nan-Yak, I could get 2900 RPM fine pitch and as low as 1680 RPM at low MAP settings in coarse pitch. Once managed 520 NM on 46 gallons. With an aux tank of course!

 

 Craig Payne

wlannon(at)shaw.ca
Guest

Posted: Sun Apr 21, 2019 9:59 am Post subject: Prop won't slow below 70%

Hi Gill;



If you were removing the prop. the first operation would remove the skull 

cap then the safety wire, screw and lock plate that keeps the pitch change 

cylinder in place on the hub.

Rotate and remove the cylinder complete with the piston from the hub. 

Remove the piston from the cylinder for inspection.



This assembly is absolutely identical and interchangeable whether Chinese, 

Russian or Polish with one important difference.



Looking at the piston you will see there is a ring on the fwd. side that is 

held in place by 2 cotter pins.  This is the coarse pitch stop ring that 

contacts the inner fwd. surface of the cylinder and determines the coarse 

pitch blade angle and therefor the pitch range of the prop.  This is 

adjustable by varying the ring thickness.



If the ring thickness is approx. 4 mm (5/32") it is Russian for a coarse 

blade angle of approx. 35 deg.  If approx. 8 mm it is Chinese (or Polish) 

for a coarse angle of approx. 31 deg.



Let me know what you find,



Walt



--

wlannon(at)shaw.ca
Guest

Posted: Sun Apr 21, 2019 11:00 am Post subject: Prop won't slow below 70%

Gill;



In describing the piston/cylinder function I should have written "---------  

and determines the maximum coarse pitch blade angle ---------".



Walt



--

glipaz

Joined: 11 Jan 2011
Posts: 110

Posted: Sun Apr 21, 2019 8:42 pm Post subject: Re: Prop won't slow below 70%

Walt, thank you.  I had not heard/known about this difference in piston ring size and will look to see.  If I open it and find that the ring is the Chinese 8mm size, can I replace it or mill it down to 4mm or do I need a replacement piston?  I assume the cylinder does not need to be replaced.

Gil

wlannon(at)shaw.ca
Guest

Posted: Mon Apr 22, 2019 9:21 am Post subject: Prop won't slow below 70%

Yes, it can be replaced or removed and milled down.  It is a simple alum. 

alloy spacer ring designed to accommodate different requirements for coarse 

pitch blade angle.  Yes, the cylinder is fine.  I can't be certain this is 

your problem but it sure fits the symptoms.



Walt

--

dsavarese0812(at)bellsout
Guest

Posted: Mon Apr 22, 2019 9:55 am Post subject: Prop won't slow below 70%

I have a question.  

If during pre takeoff run up the prop will cycle down to 53% and up to 99%, why would the ring have anything to do with the problem heâ€™s having?

Dennis



Sent from my iPhone



[quote] On Apr 22, 2019, at 1:20 PM, Walter Lannon <wlannon(at)shaw.ca> wrote:

 

 

 

 Yes, it can be replaced or removed and milled down.  It is a simple alum. alloy spacer ring designed to accommodate different requirements for coarse pitch blade angle.  Yes, the cylinder is fine.  I can't be certain this is your problem but it sure fits the symptoms.

 

 Walt

 

 

 --

glipaz

Joined: 11 Jan 2011
Posts: 110

Posted: Mon Apr 22, 2019 4:49 pm Post subject: Re: Prop won't slow below 70%

Gents:

I measured the ring.  While the ring itself is 12mm thick, the part that extends beyond the piston is 5mm.  See attached pic. I do not foresee that this is the problem but Iâ€™m here for your advice.  

Gil

63779D3E-9380-4D6C-AFB0-3566BAF90050.jpeg

Description:

Filesize:

1.91 MB

Viewed:

9098 Time(s)

77E5FE4F-7773-4B9F-B19F-A043BDFE8D0A.jpeg

Description:

Filesize:

1.82 MB

Viewed:

9098 Time(s)

wlannon(at)shaw.ca
Guest

Posted: Mon Apr 22, 2019 6:12 pm Post subject: Prop won't slow below 70%

That is a stock M14 ring.  The course pitch will be approx. 35 deg. so back 

to the drawing board.



Sorry!

Walt

--

wlannon(at)shaw.ca
Guest

Posted: Mon Apr 22, 2019 6:24 pm Post subject: Prop won't slow below 70%

It has nothing to do with the high RPM (99%) adjustment.

The 53% setting could, I believe, be obtained with adjustment of the 

governor low RPM screw even with a higher coarse pitch setting in the prop.

Walt



--

Display posts from previous:

	Matronics Email Lists Forum Index -> Yak-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum