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Just MT Propeller

Allen Buckley said:
THEN WHERE DID THE MT RATE ? ? ?. Allen B
Click to expand...

The fixed pitch MT Propeller has the same stainless steel leading edge as the constance speed propeler blades.

The MT Propeller stainless steel leading edge is three times more resistant to rain and sand erosion than an aluminum blade.

According to some of performance information provided by the pilots flying the MT Propeller, the fixed pitch MT Propeller is equal to, or better than, the competition.

Like the MT Propeller constant speed propeller blades:
The fixed pitch MT Propeller can be overhauled.
There is no life limit on the propeller.
Up to 15% off of the blade tip can be lost in a blade strike and still be replaced by the factory during overhaul.

The MT Propeller blades and tips can be painted in any of five standard colors:
Red, Black, Grey, White and Yellow.
The back of the blade is painted Dull Black for the RV's.

Regards,
Jim Ayers
 
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I was installing my MTV-18 yesterday and noticed that one counterbore for the drive lugs was smaller than the others. This corresponded to #1 blade. Is this normal? I had asked that all holes be machined for .750 lugs. I assume this is for phasing on certain engines?

What is the recommended Crowfoot tool for torquing the prop bolts? Any corrections needed to the specified torque values?
 
Regarding the Spinner,

Anyone fine the MT spinner is not fully round? I mean I may be just picky but the edge seems to rise and fall ever so slightly as the prop is rotated. Could it be the filler plates distorting the composite shape?
 
Rick S. said:
Regarding the Spinner,

Anyone fine the MT spinner is not fully round? I mean I may be just picky but the edge seems to rise and fall ever so slightly as the prop is rotated. Could it be the filler plates distorting the composite shape?
Click to expand...

Yes, I found this too. Pretty lightweight piece.
 
MT propeller indexing

rv6ejguy said:
I was installing my MTV-18 yesterday and noticed that one counterbore for the drive lugs was smaller than the others. This corresponded to #1 blade. Is this normal? I had asked that all holes be machined for .750 lugs. I assume this is for phasing on certain engines?

What is the recommended Crowfoot tool for torquing the prop bolts? Any corrections needed to the specified torque values?
Click to expand...

The Lycoming propeller flange for a CS propeller has four threaded bushings that extend above the ring gear surface and two threaded bushings that are just below the ring gear surface.
As you indicated, this is a Lycoming engine/propeller standard for indexing any propeller to the engine.

You'll need a 3/4" crowfoot capable of taking 65 foot pounds of torque. And you might want to grind off the ends of the open end so they don't extend past the flat on the nut. This will help so the propeller hub isn't damaged as the bolt assembly is torqued.

I use a very expensive open end Snap-On digital torque wrench which is calibrated annually, so I don't have to deal with any corrections.

I believe if the crowfoot is placed even with the drive lug (at about 90 degrees), no correction is necessary.

Regards,
Jim Ayers
 
MT Spinner dome/filler plate

Rick S. said:
Regarding the Spinner,

Anyone fine the MT spinner is not fully round? I mean I may be just picky but the edge seems to rise and fall ever so slightly as the prop is rotated. Could it be the filler plates distorting the composite shape?
Click to expand...

On some MT spinner assemblies the spinner dome at the propeller blade cutout overlaps the filler plate on the rear spinner bulkhead. I believe this is the "distortion" you are seeing.

Some MT spinner assemblies have a notch in the filler plate so the corner of the spinner dome at the blade cutout is attached directly to the rear spinner bulkhead. There would be no "distortion" of the spinner dome on this installation.

I believe the difference depends on the structural requirements for the filler plate in each application.

I was once told that MT Propeller has over 800 different spinner assembly combinations. (And I still occasionally have difficulty finding the correct one for a customer.)

Regards,
Jim Ayers
 
2 degree brush angle?

MT recommends a 2 degree opening angle on the brush block in the direction of prop rotation. Purpose? Important?

BTW Jim, really appreciate you helping out us MT owners here with your fast replies and depth of knowledge. How much are spare brushes and what is the typical lifespan?
 
rv6ejguy said:
MT recommends a 2 degree opening angle on the brush block in the direction of prop rotation. Purpose? Important?

BTW Jim, really appreciate you helping out us MT owners here with your fast replies and depth of knowledge. How much are spare brushes and what is the typical lifespan?
Click to expand...

The 2 degree requirement is passed through by MT Propeller from the brush assembly manufacturer. I believe the 2 degree angle helps keep the brushes in contact with the slip ring if there are any irregularities in the slip ring surface.

The price of a brush set may have changed recently, but it was $64 for a brush set including the aluminum angle.

If the slip ring surface is protected so it has a smooth (polished) surface when installed, then the brushes should wear very little. The slip ring and brushes are taken from the electric de-ice hardware for the propeller blades. The electric controller on the 12 volt system limits the current to 3 amps. This is a fairly low current compared to the 10 to 20 amps for an electric de-ice boot on the heated blade.

My guess would be that the brushes should have about a 1000 hour life. Much less if there are any significant scratches in the slip ring surface.

Jim Ayers
 
Jim I am using a MTV-12B/C183-59 propeller and a AIO-390 in my 8 the hub is only 1.250 and VAN'S states you should use a 2.250 spacer I am worried that the air filter won't work with the cowling moved aft an inch would like your thoughts

Thanks Richard
 
richardwhite said:
Jim I am using a MTV-12B/C183-59 propeller and a AIO-390 in my 8 the hub is only 1.250 and VAN'S states you should use a 2.250 spacer I am worried that the air filter won't work with the cowling moved aft an inch would like your thoughts

Thanks Richard
Click to expand...

Hi Richard,

I think what you have said is your MT propeller has a 1.25" spacing from the mounting surface of the propeller hub to the back edge of the spinner.

VAN's states a 2.25" spacing from the hub mounting surface to the back of al propeller hub where their rear bulkhead is mounted. The spinner bulkhead has a rear facing flange of about 7/8" thickness. For a 1/8" clearance between the back of the spinner and the front of the cowl, the front face of the cowl is about 1.50" forward of the hub mounting surface.

Normally, the MT Propeller for an RV has a 1.50" to 1.75" spacing from the hub mounting surface to the back of the spinner. This is customer specified when purchased from MT Propeller distributors. I don't know what VAN's does.
It would appear that you just need to mount your cowl to be about .25" behind the spinner bulkhead. Apparently about .5", or less, back from VAN's "normal" position.

I believe VAN's recommends using the propeller to mount the cowl. This is an excellent way to damage the painted propeller and spinner parts.
Create a replacement for the propeller assembly to use to mount the cowl.

BTW, the MT Propeller number you gave is not complete. It could be MTV-12-B/183-59, or MTV-12-B-C/C183-59.

Hopefully, it actually has the 183-59b blades. The -59b blade design is important for performance and the lack of RPM restrictions.

For the Lyc. 360 engine without crankshaft dampeners, the 183-59 blades, there is an RPM restriction between 2050 to 2300 RPM.
There is no RPM restriction on Lyc. 360 engines withcrankshaft dampeners.

For the Lyc. 360 engine without crankshaft dampeners, the 183-59b blades do NOT have an RPM restriction.

You show a AIO-390-???? engine. The fourth place of the model number identifies the crankshaft dampening. A three digit model number does not have crankshaft dampening.

I didn't find any information related to the 390 engine, but would expect it to be no better than the Lyc. 360 engine for impluse loading and harmonic loads introduced to the propeller. One of the fun parts of being experimental. :)

Regards,
Jim Ayers
 
Prop me up....

Over the 13 years I flew My RV4 I ran a total of seven different props,(Sterba, Bernie Warnke, Catto, Sensenich Metal, Margie Warnke, Gary Hertzler, MT) the last of which was an MT fixed pitch. After trying everything else the MT gave me both cruise and climb within 10% of the best in all the other props I tried with no RPM restrictions and aerobatic. It was almost rain-proof, a huge plus here in the SE USA. The fact that it's supported by a large company with a huge bank of test data made it an easy decision.
The performance desires for my 170HP Lycoming on my RV4 were stringent. I stipulated to the engineer via email max RPM, climb RPM and static. During the initial tests all of the numbers were within 25 rpm of those original numbers. I sold the aircraft with the MT with good results reported by the new owner. My Dad bought one for his new RV6 and during the initial test flight I found it's performance to be very similar to my RV4, again excellent. For FP applications, they are an excellent value.

Rob Ray
RV4/HR2


Post test flight on my Dad's RV6
 
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Van's Aircraft choice of MT governor

I recently received a phone call from the owner of a newly completed RV-10. His IO-540 engine and propeller were only getting 2500 RPM during a full power static run-up.

This would be a typical situation when Van?s Aircraft sells a MT governor for a new Lycoming 540 ?wide deck? engine.

(A ?wide deck? engine has hex nuts holding the base of the cylinders to the engine case. If you don?t have hex shaped nuts holding the cylinder base to the engine case, then you don?t have a ?wide deck? engine.)

Van?s Aircraft sells a single model of MT governor for the IO-540 engine. The governor model they have sold is designed for the 0.895:1 gear ratio in the ?narrow deck? Lycoming 540 engine.

New Lycoming 540 engines will have ?wide deck? cylinders and an internal governor drive gear with a gear ratio of 0.947:1.

Running the gear ratio numbers, a governor designed for 2700 RPM on a 0.895:1 gear ratio engine will limit the maximum RPM to around 2550 RPM on a 0.947:1 gear ratio engine.

Just great.
Van?s Aircraft sells only one MT governor for the Lycoming 540 engine. This governor is set up for the ?narrow deck? engine with a 0.895:1 gear ratio.
Van?s Aircraft sells new Lycoming 540 ?wide deck? engines with a 0.947:1 gear ratio.

What to do?

The correct MT governor part numbers for the "front case mounted governor" on the Lycoming 540 engine are the following:

Lycoming 540 ?narrow deck? engine ? P-860-3

Lycoming 540 ?wide deck? engine ? P-860-5

If you have a ?wide deck? Lyc. 540 engine, ask Van?s Aircraft for the correct part.

If you already have the P-860-3 MT governor set for the narrow deck engine and you have a wide deck engine, you can do the following:

There are two adjustable stops on the governor. The return spring on the governor places the governor arm against the low pitch stop.
Run the engine to full power and determine the maximum available RPM. If the maximum RPM is less than 2700 RPM, then adjust the low pitch stop so there is additional lever travel in that direction.
Do a ground run RPM check to determine the maximum achievable RPM.

It is possible that you will need to adjust the low pitch stop screw until there are no threads showing on the low pitch stop in order to get 2700 RPM. And sometimes the stop needs to be filed down slightly too get a little extra travel.

I have heard that for a new Lycoming engine: the ground run should be limited to 5 minutes maximum, the oil temperature should stay below 180 degrees F, and the cylinder head temperatures should stay below 350 degrees F. Don?t exceed any of these limits.

Regards,
Jim Ayers
 
Here is the response I recieved from MT themselves regarding Van's supplied governor and adjusting the Static RPM. Just incase anyone hasn't seen it before.


"Rick,

all P-860-( ) governors are basically the same. The - ( ) number only refers
to the control arm position and the max. rpm of the governor. To change the
control arm, loosen the 6 screws, turn the entire center portion to the
desired position, tighten the 6 screws and safety.

To change max rpm the set screw on the high rpm stop is turned
counterclockwise (out) to increase rpm and clockwise (in) to decrease rpm.
If there is not enough adjustment possible ( 1 turn = 25 rpm) the control
arm must be reset on the spline one notch at the time.

All this can be done on the plane.

To have MT Propeller USA, Inc. modify the governor max. rpm would cost
approx. $100.00, unfortunately the control arm position must be adjusted on
the plane

Best Regards,
Juergen Zahner
mt-propeller USA, Inc.
ph: 386-736-7762
fax:386-736-7696
[email protected]
www.mt-propellerusa.com"
 
Van's choice of MT Governor on Lyc. 540 engine

I counted 5 threads showing on the low pitch adjustment screw on one of the MT Governors.

By Juergen's information, that would increase the RPM by 125 of the 150 RPM needed.

I still think it would be a good idea to get the correct governer of the engine to start with. Having to fool around with a governor adjustment on a new engine and a new aircraft would be inconvient, when there are some many other items to deal with.

Regards,
Jim Ayers
 
Oil Leak

Jim,

I had an interesting experience on my way to S&F. I have a MTV-15-B/183-402, 2 blade prop on an IO360. As usual I cycled the prop at run-up before take off and everything was normal. When reaching my altitude of 8500' I pulled the prop back to 2500 rpm for cruise but it did not change pitch. After moving the lever back and forth a few times still no change. It was spinning at 2675. When I went to lean the engine the prop then kicked in. I leaned and the prop seemed fine after that. A moment later there were tiny specs of oil on the windscreen (which at the time I did not know it was oil because they were so tiny). Oil pressure and temps were normal as was everything else and other than the initial spritz of oil that did not happen again there was nothing more unusual. On landing I cycled the prop and everything was normal. The next leg the same thing happened with the same spritz of oil. I noticed upon landing in FL that there was a small amount of oil on the base of one of the propeller blades. I flew the plane back and forth a few days to Kissimmee then home and a few time since without any recurrence of this.

I have no idea if this was from the engine causing the prop not to change pitch or if it was in the propeller hub along with what appears to be a very small oil seal leak.

Thoughts? Major issue?

Thanks
 
Oil Leak

A small amount of grease from the base of the blades is common.

There should not be any oil coming out of the propeller. There should be no oil coming from the base of the hub or from the base of the blades.

My first thought is that there was a small amount of debris in the propeller hub that got between the propeller hub cylinder wall and the piston. This is what could have prevented the propeller from changing pitch. It could have also gotten between the piston oil seal and hub wall to cause a small oil leak into the propeller hub and out through the blade hub.

Since the oil leak has stopped and the pitch change seems to be working normally, it would appear that everything is back to normal.

My concern would be that the debris is still in the piston area and could be damaging the cylinder wall of the propeller hub. This would be an expensive part to replace.

Since your are in Maryland, you might consider having the closest MT Propeller FAA Repair station, or MT Propeller USA in DeLand, Florida do an internal inspection of the propeller.

Just as a side note, the governor provides 375 psi to the propeller when it is trying to move standard propeller blades to a higher pitch. I've been told that there is around 150 psi in the propeller hub when the blades are being held in position.
The governor can flow 8 quarts per minute at 375 psi. So we don't want to see any oil leaks.

Regards,
Jim Ayers
 
Prop indexing?

I took a first look at bolting the prop on today. From a first read of MT's handbook, a look at the flywheel and the prop there is no clue as to how to index it. I guess that must be related to the TDC mark on the flywheel.

I know the result I want which is so that is stops in the normal position for swinging. About 10 to 5 I guess. I presume that is appropriate?

It looks as though any position is possible since (I think) all the bolts are the same.

Its a two blade MTV11. Anybody been here recently, or know the answers, so I can take a short cut? I would rather only do the job once.

Thanks, Steve.
 
MT propeller indexing

Steve Sampson said:
I took a first look at bolting the prop on today. From a first read of MT's handbook, a look at the flywheel and the prop there is no clue as to how to index it. I guess that must be related to the TDC mark on the flywheel.

I know the result I want which is so that is stops in the normal position for swinging. About 10 to 5 I guess. I presume that is appropriate?

It looks as though any position is possible since (I think) all the bolts are the same.

Its a two blade MTV11. Anybody been here recently, or know the answers, so I can take a short cut? I would rather only do the job once.

Thanks, Steve.
Click to expand...

For the Lycoming SAE2 propeller flange, the MT propeller hub has five (5) counterbored bolt holes and one biolt hole that is NOT counterbored. This hole is usually behind blade number one. (Blade number one has the data sticker.)

The Lycoming SAE2 propeller flange should have four bushings protruding through the ring gear and two bushings that are flush with (or slightly below) the ring gear surface. These two bushings are opposite each other across the center of the propeler flange.

The bolt that is in the propeller hub without the counterbored hole should be installed into one of these flush bushing. (Two possible positions of the propeller.)

The ring gear and propeller hub alignment should be marked (Sharpie?) if the engine/propeller combination have been dynamically balanced.

I have been told that dynamic balancing to 0.04 IPS or less floats the crankshaft journal on the oil and keeps the crankshaft from contacting the bearings.

Regards,
Jim Ayers
 
MT for me...

Ah, Memories...
Jim, does MT make a 2 blade for the Rocket with IO-540?

Smokey


El Bandito...

Confucious Say:FP MT props don't leak:)
 
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RVjim said:
For the Lycoming SAE2 propeller flange, the MT propeller hub has five (5) counterbored bolt holes and one biolt hole that is NOT counterbored. This hole is usually behind blade number one. (Blade number one has the data sticker.)

The Lycoming SAE2 propeller flange should have four bushings protruding through the ring gear and two bushings that are flush with (or slightly below) the ring gear surface. These two bushings are opposite each other across the center of the propeler flange.

The bolt that is in the propeller hub without the counterbored hole should be installed into one of these flush bushing. (Two possible positions of the propeller.)

...............

Regards,
Jim Ayers
Click to expand...

Jim, thanks, in fact I bolted it on before I saw your reply. I ended up bolting it on so it will stop in the classic 11 - 5 position. I figured MT does not care which of the 6 possible positions you use since they say nothing.

The flywheel certainly can only be installed in one of two positions for the reasons you state (4 plus 2 bushings), but I am a bit puzzled about the 5 counterbored holes (above) since while I was expecting to find something like this and saw only symmetry. My prop by the way, an MTV-11, has that irritating system where you are turning nuts linked to a screwed thread with a cotter pin rather than bolts. (I really dont want to take it back off just to look.)

Since it all bolted on fine I guess the only possible error is that it is 180 deg out. Does this matter?

Thanks, Steve.
 
Propeller indexing

Steve Sampson said:
Jim, thanks, in fact I bolted it on before I saw your reply. I ended up bolting it on so it will stop in the classic 11 - 5 position. I figured MT does not care which of the 6 possible positions you use since they say nothing.

The flywheel certainly can only be installed in one of two positions for the reasons you state (4 plus 2 bushings), but I am a bit puzzled about the 5 counterbored holes (above) since while I was expecting to find something like this and saw only symmetry. My prop by the way, an MTV-11, has that irritating system where you are turning nuts linked to a screwed thread with a cotter pin rather than bolts. (I really dont want to take it back off just to look.)

Since it all bolted on fine I guess the only possible error is that it is 180 deg out. Does this matter?

Thanks, Steve.
Click to expand...

Hi Steve,

Check the track of the blade tips. If they are within tolerance, you should be good to go.

I believe you are referring to the irritating system for bolting any CS propeller hub to the Lycoming propeller flange.

Just hold the propeller up to the propeller flange to get the threads started on some of the bolts. (Four, then two more.) Turn each bolt about two turns. Then go back and turn each bolt two more turns, making certain the the propeller hub is staying parallel to the propeller flange. Sure is fun. :)

Regards,
Jim Ayers
 
Number of blades?

smokyray said:
Ah, Memories...
Jim, does MT make a 2 blade for the Rocket with IO-540?

Smokey
Click to expand...

Hi Smokey,

The simple answer is no.

MT Propeller says the Rocket with the Lycoming IO-540 engine has too much horsepower to be efficient with a two blade propeller. Now if you want a 2 blade propeller for ground display purposes on a Rocket, that would be a different matter.

It seems you might have asked a simple question with a controversial answer.

The most efficient number of blades is determined by the engine horsepower and the aircraft altitude.

The higher the horsepower and altitude, the greater the number of blades.

It used to be pretty simple with GA aircraft rarely being flown above 10,000' with their lower horsepower engines. The 2 blade propeller is king.

Then the RV's came along and portable oxygen was added. From a sea level airport, it takes about the same time for an RV to reach 17,500' as the GA aircraft takes to reach 7,500'.

Just as a rough rule of thumb, with 180 horsepower, or more, the 3 blade propeller becomes more efficient than the 2 blade propeller as the aircraft is flown above about 8,000'.

And with 260 horsepower, or more, the 4 blade propeller becomes more efficient than the 3 blade propeller as the aircraft is flown above 15,000'.

Bottom line. How the owner expects to operate the aircraft determines which propeller best suits their needs.

Regards,
Jim Ayers
 
Jim,

I had A & P visitor tell me the other night I needed to use .41 safety wire on my prop attach bolts, I used .032. I swear the Mt instructions said .32...can you confirm? I know, look at the manual but I was thinking maybe there might be a metric vs. inches conflict.
 
My FAA inspector questioned this as well. I got out the Operation and Installation Manual. As soon as I showed him the MT manual where it says to "Safety wire flange bolts in pairs with .032 stainless steel wire" (page 18-1 in my manual), he was fine.
 
Propeller Bolt Safety wire

Hi Rick,

Bob Brown is correct. 0.032" diameter SST safety is what MT Propeller calls out for the 1/2" diameter bolts on the Lycoming engine.

Regards,
Jim Ayers
 
MT for me...

Thanks Jim,
I am flying the large two blade Hartzell "Paddle" on my Rocket with mixed feelings. I loved the MT fixed pitch on my RV4, a quality product. As much as I love aerobatics, a lighter nose on the HR2 would be awesome given that the Hartzell has a big hub plus extension (78lbs)and is noticeably heavy. 90% of my Cross Country is above 8000', therefore...which MT do you recommend for the HR2 with a 300HP IO540?

Smokey
 
3 blade or 4?

smokyray said:
Thanks Jim,
I am flying the large two blade Hartzell "Paddle" on my Rocket with mixed feelings. I loved the MT fixed pitch on my RV4, a quality product. As much as I love aerobatics, a lighter nose on the HR2 would be awesome given that the Hartzell has a big hub plus extension (78lbs)and is noticeably heavy. 90% of my Cross Country is above 8000', therefore...which MT do you recommend for the HR2 with a 300HP IO540?

Smokey
Click to expand...

Cruising at 8,000', the 3 blade MT works best. 54 pounds for the standard 3 blade propeller and spinner assembly.

If you fine yourself more often cruising around 15,000', then the 4 blade MT comes into its own. Again, about 54 pounds for the standard 4 blade propeller and spinner assembly.

I have a counterweighted 4 blade MT for my oxygen equipted HR2. This weighs about 70 pounds, because the counterweights weigh 4 pounds on each blade.

Regards,
Jim Ayers
 
MT Governor adjustment & overspeeds.

My prop is getting slight, 30rpm, overspeeds, so to 2730rpm. If I remember correctly this is adjusted via the governor stop? Problem is I cant find my governor docs.. Anyone know how much 1 turn of the stop screw on the governor should bring the rpm back?

The prop docs are on the web site. Are the governor docs there also? A link wouldf be a great help.

Thanks.
 
MT governor adjustments

Steve Sampson said:
My prop is getting slight, 30rpm, overspeeds, so to 2730rpm. If I remember correctly this is adjusted via the governor stop? Problem is I cant find my governor docs.. Anyone know how much 1 turn of the stop screw on the governor should bring the rpm back?

The prop docs are on the web site. Are the governor docs there also? A link wouldf be a great help.

Thanks.
Click to expand...

http://mt-propeller.com/en/entw/operation.htm

This will get you to the governor installation and operation manual.

Or look for the E-1048 document to the "operation and installation manual" page of the "Service Documents" page of the "Production" page of www.mt-propeller.com.

From 5.4.b on page 10:
One turn should equal 25 RPM.
Clockwise to decrease RPM.
Counterclockwise to increase RPM.

Also, Paragraph 5.3 "Perform Static Run-Up" and Paragraph 5.5 "General" "Static Run-Up" have some intersting comments will worth reading and understanding.

Jim Ayers
 
rv8ch said:
Hi Jim,

I've got an electric MT Prop that I purchased from Eggenfellner, but since I doubt I'm going to use the engine, do you know if this prop has any value? Can I change it to become a model that will work with a lycoming?

http://www.rv8.ch/article.php?story=20050604180346524

Thanks!
Click to expand...

The full propeller number is needed. MTV-7-( )/( )-( )

I suggest you offer the propeller in Doug Reeves Classified ads. MT Propellers are custom designed to the engine. Someone with a RV and an Eggenfellner Subaru engine is very likely to want your propeller assembly.

Regards,
Jim Ayers
 
Prop Problem

Back in April on my way to Sun-n-Fun I experienced a strange situation where upon reaching altitude the prop would not back down to where I wanted it and had a grease leakage. It only happened twice on the way down with the prop not reducing immediately until the mixture was played with. When I came home I brought my prop to an MT shop in PA and they agreed that there was excessive leakage of grease and resealed the blades. Since then everything has been fine until yesterday.

As usual I had reached cruise at 2500' and everything adjusted fine. Flew like this for about 20min then started a climb to 4500'. When I reached altitude and leveled off the prop went from 2650 to 2750 and would not back down pulling back the prop control, throttle, or mixture. I played with it and when pulling the throttle back to around 12" the prop pulled down to 2600 and the prop control still didn't work. Between juggling the throttle then pulling my mixture to around 60 deg ROP and the prop control back to way below where it would usually be for around 2400-2500 for about 30 sec the prop just kicked in and dropped in rpm. I adjusted everything for cruise then everything went back to normal. Upon returning I had a similar incident. It seems that the 4 times this has happened (two back in April) were after a climb where the prop rpm was increased for the climbout from about 2450 to 2600.

I'm no expert and very confused as to why pulling power and/or mixtures (which definitely changes my engine performance going ROP) along with moving the prop control had no effect and allowed the prop to overspeed. It never oversped for more than a few seconds where my alarm caught it.

Here's my set-up: I/O360 180hp with dual Lightspeed Plasma II+ ignitions. Prop is an MTV15B/183-402 and a P-860-18 governor. Everything was new and yesterday rounded the 100hr tach mark on the plane.

Any thoughts on what this could be? Bad governor? Oil line problem? I know it is not a cabling problem because all the controls worked normal except for these few moments.

One other note is that since getting my prop back from its resealing I notice that it has trouble every once in a while holding a constant rpm and can vary in any situation around 50rpm.

Thanks
 
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Prop Problem??

As I understand it, the most common cause of propeller surge is air being trapped in the propeller hub/crankshaft. Cycling the propeller on the ground is normally done to remove this air.

"As part of the MAG check before each flight, the CS propeller is cycled until there is at least a 350 RPM drop." Statement from my flight instructor in a Cherokee Arrow. (Since this is a Lycoming IO-360 180 hp engine with Hartzell CS 2 blade propeller, it seems like it would be applicable to the engines used in the RV's.)

In my opinion, RV's are notorious for not having full travel at the governor. They are typically set to the high RPM stop, but don't reach the low RPM stop.
Without full travel to the low RPM stop on the governor, it makes it very difficult to properly cycle the CS propeller.

The engine may need to be run at 2000 to 2100 RPM to get the propeller to cycle after the propeller is first installed.

Since the Rocket shares the same RV heritage, it frequently has limited travel in the engine control cables, also. Add to this a limited RPM for the MAG check, and being able to properly cycle the propeller becomes even more difficult. (Rocket with new MT propeller experienced propeller surge shortly after take off. Reducing RPM control surge. Propeller never cycled on the ground due to concern about propeller strike on new propeller.)

I don't know if this is related to your problem. However, it is a starting point in eliminating possibilities.

Regards,
Jim Ayers
 
Mike. first of all I am no expert, but have been asking questions to more fully understand the prop. Only Jim has come forward so I will share my thoughts.
(Jim are you a representative of MT, or just an interested party?)

The way the system works is this as I understand it.

By moving the prop control you are altering the pressure in the pipe that runs from the governor to the prop. The governor is basically an oil pump. If you ask for coarse pitch the pressure rises, less it falls. The pressure is well above the pressure the rest of the engine is running at. (I think 3 or 4 times but am not sure. It may say in the manual.) There is a good little diagram showing how the pressure is controlled in there also.

At the prop end, as best I understand i, and by looking at MT's drawings, it is just the pressure of this oil acting against springs in the hub. Since there is almost no flow, the pressure is instantaneous, hence the quick response.

So, assuming my understanding is correct, what can we say?

1. The mixture control has no relevance.
2. You say that you pulled the prop back to 12" and the speed dropped to 2600. Well, once the engine is not developing enough power to turn the prop at the requested speed, it just slows down 'til it can. At low power it just behaves like any fixed pitch prop, changing with engine speed.

From here on it is surmise on my part:

Either the prop is not responding to the pressure, or the pressure is not being controlled by the governor. Everything to my mind points to the later. I have never seen the inside of the governor mechanism, but the way the handbook shows the pressure being controlled there must be small orifices. My money would be on a partial blockage.

Clearly gentle exercising of the prop prior to take off makes sense but I don't believe this is the problem...apologies Jim... unless it is VERY cold where you fly. The only other issue would be if you regularly did not bother to exercise it might have to start governing with no/little lubrication, so over time might become damaged.....? I doubt this though.

The fact we get nowhere near the slow stop is a red herring also. Yesterday, in the circuit, I pulled my prop back to 1800rpm at 18". I had not run out of travel or even close. I think the low stop is a place you would not want to operate your engine in practice.

These are just my thoughts, and I would love someone who knows the details to correct me. Good luck!
 
Steve & Jim,

Thanks for the responses. I did a lot of internet research along with a call to my local MT repair shop and an email to MT.

I always cycle my prop two times for a 400-500 rpm drop at runup. All my linkages work fine and I have full travel on my governor. Everything works perfectly when it works.

From my research it brought me to the conclusion that I have a bad governor. My guess from my conversation with the owner at the propeller shop is that in the climb the oil is getting hot enough even though within specs that it is too thin to allow the governor to work properly and that is why after 30sec-1min the prop begins to work again as the oil cools. The overspeeding is caused by the windmilling of the prop when leveling out and yes at this point the prop is now at the low pitch stop and cannot give enough resistance to keep from spinning faster, basically turning into a fixed pitch prop where my throttle now controls the speed.

I sent a message to MT with all the details of what happend and my engine/prop setup with serial numbers and the response was quick that they were sending me a new governor. No explanation given but it must be an issue they have seen before. They were really good about sending it express and I expect it here Friday so I have a week to put it on and test before traveling to Oshkosh.
 
Capflyer said:
Steve & Jim,

Thanks for the responses. I did a lot of internet research along with a call to my local MT repair shop and an email to MT.

I always cycle my prop two times for a 400-500 rpm drop at runup. All my linkages work fine and I have full travel on my governor. Everything works perfectly when it works.
(Stuff Cut).
Click to expand...

I appreciate your mentioning the full travel on the governor arm and cycling the propeller. Both are very important.
For the projects I have visited as an EAA Technical Counselor, reduced governor arm travel has been common.

Besides being a control device, the governor is a high pressure oil pump. It is capable of pumping oil at the rate of 120 gallons per hour (gph) at 375 pounds per square inch (psi).
There is always a bypass oil flow through the governor. For a new governor, it is around 8 gph. For an overhauled governor, it can be around 11 gph.
The governor is normally operating at around 150 psi to hold the blades in position.
In order for the governor to operate properly, it requires an inlet oil pressure of 15 psi.

This information is on the EASA Form 1 that comes with the MT governor, except I converted the oil flows to gph.

Regards,
Jim Ayers
Less Drag Products, Inc.
FAA Repair Station # LDSR535X for MT Propeller only.
RV-3 sn 50 (Builder) - LOM engine with electric CS 3 blade MT Propeller.
RV-6A (Purchased to gather flight test data) ? Lyc. 360 engine with Aluminum 2 blade MT propeller.
RV-4/HR2/Less Drag Special (almost ready to paint) ? Lyc. 540 engine with counterweighted 4 blade MT Propeller designed for my aircraft requirements.
I really like RV's (started 34 years ago). And I REALLY like MT Propellers.
This is why my sales offices are called Custom Aircraft Propeller.
Sales offices located in California (805-795-5377) and in Florida (321-441-3544).
 
rv8ch said:
Hi Jim,

I've got an electric MT Prop that I purchased from Eggenfellner, but since I doubt I'm going to use the engine, do you know if this prop has any value? Can I change it to become a model that will work with a lycoming?

http://www.rv8.ch/article.php?story=20050604180346524

Thanks!
Click to expand...

Mickey,

The MT-7-C/183-51 is not suitable for a Lycoming as per this response from MT.

David,

sorry, this prop is not designed to be used with Lycoming engines. Use a hydraulic prop if possible, like the MTV-12-( )

Best Regards,
Juergen Zahner
mt-propeller usa, inc.
ph: 386-736-7762
fax:386-736-7696
[email protected]
www.mt-propeller.com <http://www.mt-propeller.com>

However a slightly different version of the MT7 (MTV-7-F/170-09) was certified with the 0235 Lycoming on a C-152 in Germany in 1992. :)

Maybe there's someone out there with a -9 and the 0235 who like to have a bit more performance on take off....
 
Eggenfellner MTV-7 propeller

The MTV-7 propeller for the Eggenfellner engine has the slip ring mounted on the rear spinner bulkhead.
The MTV-7 propeller for the Lyc. engines normally has the slip ring mounted on the back of the ring gear.

Better to sell your propeller to a Eggenfellner engine owner.

Is your propeller the MTV-7-C/183-51? With the different Eggenfellner engine packages, there have been different MTV-7 propellers used.
For example, a MTV-7-C/187-129 propeller has been used on the RV's with the Eggenfellner engine.

Regards,
Jim Ayers
 
RVjim said:
The MTV-7 propeller for the Eggenfellner engine has the slip ring mounted on the rear spinner bulkhead.
The MTV-7 propeller for the Lyc. engines normally has the slip ring mounted on the back of the ring gear.

Better to sell your propeller to a Eggenfellner engine owner.

Is your propeller the MTV-7-C/183-51? With the different Eggenfellner engine packages, there have been different MTV-7 propellers used.
For example, a MTV-7-C/187-129 propeller has been used on the RV's with the Eggenfellner engine.

Regards,
Jim Ayers
Click to expand...

Mine is the 183-51 and I believe it was one of a batch of 50 units that the EGG factory bought in 2003-4.
 
I may be looking for a new prop for my Egg Subby!

I have a quinti prop with warp drive blades that thus far (only 3.5 hr one my RV-6A) are not performing well. I may be able to get better performance after some tweeking but I doubt it. Is this prop for sale? How much?
 
MT Fixed Pitch results and a few ??

I just changed from a Sterba 68x78 prop to a MT 72x68 prop. On the day of the swap, we did a complete set of thrust and flight test evaluations of both on the same plane, same day, at MGW.

Here are the findings:
......................................Sterba..........MT
Static thrust:...................360 lbs 2400...422 lbs 2350 rpm
Climb Perf (1500msl to 7000')..799 fpm.......776 fpm overall average
Cruise: 3000 msl...................177 TAS.......199!! TAS
..........6000 msl...................188 TAS......191 TAS
...........8000 msl..................181 TAS........179 TAS

Vibration is no difference...smooth on both.
The MT runs WOT at 2650 and is very resistant to overspeed. The Sterba ran 2700+ and you had to watch for over-speed.

I can not believe the increased IAS at low altitudes with the MT!!. It is easy to run in the yellow arc of airspeed with RPM never going over 2650.

The MT is much finer, more professional construction with a stainless steel leading edge and PU strip near the blade roots. Price of the MT is a bit less than a Sensenich.

Now for the questions:
My plane is a 1994 RV-6 with 160HP Lyc O-320. Viscous dampner is installed in front of flywheel.
1. Is there a 'preferred' index position reletive to TDC Cyl #1 on the flange?
2. Does anyone want to make me an offer for my Sterba 68x78 prop?

Thank you.
John Nielsen
e-mail: Nielsen(at)Bloomer.net
 
New blade tip color available

MT Propeller has a new propeller blade tip color available. The blade tip can be ordered with a Red, White and Blue striped blade tip at the standard price.
On a Gloss White blade, the blade tip would consist of the standard 4? wide red strip, the 3/8? wide white strip and a 3/8? wide blue strip.

This new blade tip color has been added at the request of a F-1 Rocket builder in the USA. I thought it might be of interest to someone else in the USA.

MT Propeller has five standard colors available for the blades and spinner:
White, Red, Black, Yellow and Grey.

Typical combinations of these colors that work very well consist of the following:

White blade with Red tips. Pretty much a MT Propeller standard blade color.

Dull Grey blades with Gloss White tips. Recommended blade colors for aircraft planning to fly IFR. Rain will erode the Dull Grey top coat of paint over time. This exposes the Dull Grey primer color underneath. It?s an appearance thing.

Gloss Black blades with Gloss Yellow tips. This is the old CAA required blade color for all propeller blades for visibility of the propeller when it is turning.

Again, there is no extra cost to the customer when choosing from these standard colors.

Regards,
Jim Ayers
Less Drag Products, Inc. - Located in California (805) 795-5377
Custom Aircraft Propeller - Located in Florida (321) 441-3544
 
momentary oil pressure loss

If you even think you are going to be doing any aerobatics in your RV, give some serious consideration to getting a counterweighted blade propeller.

I say this because I really don't like selling counterweighted blade propellers to new customers after they have over-sped the existing propeller due to a momentary loss of engine oil pressure.

Over-speeding the engine and propeller is very expensive. It normally scraps the propeller and requires an engine tear down inspection.
For the engine tear down inspection and new propeller, we're talking about something like $20,000 on top of what was already spent for the original engine/propeller installation.

The extra expense of the counterweighted blade propeller is like buying an insurance policy that is always working for you.

The counterweighted blade propeller goes to course pitch when oil pressure is lost, so the engine RPM decreases. This is how the counterweighted blade propeller protects the engine and propeller in the event of oil pressure loss.

In the event of an engine failure with no oil pressure, the counterweighted blade propeller automatically goes to the course pitch. This reduces propeller drag by about 63% and increases the gliding distance of a CS propeller RV significantly.

Regards,
Jim Ayers
 
fast 3 blade MT propeller and a Lyc. 180 hp engine.




This aircraft had an aluminum counterweighted 2 blade CS propeller.

The owner had one basic requirement for a new propeller.
His Lyc. 180 hp. powered aircraft was just a little faster than his sons Harmon Rocket 2. He wanted a new propeller, but he still had to be a little faster than his sons HR2.

The conventional opinion is that a 2 blade propeller is faster than a 3 blade propeller. But I proposed a 3 blade propeller because the customer had mentioned a concern about vibration at 2500 RPM and below.

There is no market for this particular 3 blade propeller. There is only one of these aircraft in existance. However, this is exactly why I named the sales office of Less Drag Products, Inc. - Custom Aircraft Propeller.

This propeller was sold at the standard list price for this type of propeller. Even though it was has custom designed blades.

The bottom line. This aircraft with the 3 blade MT Propeller is still a little bit faster than his sons HR2.

The aircraft. Pirahna.
A one of a kind prototype COIN fighter from the late 1960's.
So it's not an RV. Stall speed around 120 mph.

Regards,
Jim Ayers
 
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