Just MT Propeller

[smokyray]

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

[RVjim]

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

[Rick S.]

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
Juergen.Zahner@mt-propellerusa.com
www.mt-propellerusa.com"

[RVjim]

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

[Capflyer]

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

[RVjim]

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

[Steve Sampson]

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.

[RVjim]

Originally Posted by Steve Sampson

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.

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

[smokyray]

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

[Steve Sampson]

Originally Posted by RVjim

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

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.