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MT 3 Blade on an RV14

mike newall

Well Known Member
Sponsor
Raising the question again -

Any reasons why not an MT prop on a standard IO-390 install on a 14 ?
 
Make sure the prop/engine are a certified combination and that your engine is certified. (no experimental ignition or fuel systems, etc.) MT does not warranty props that are installed on non-certified engines.
 
Errrrrrr -

We have an MT on our RV7. Titan ECI IO-360 with dual P-Mags and MT were completely happy with that.

I am enquiring from a weight and balance point of view because I understand that 14's are coming out tail heavy.

The MT is an exceptionally smooth prop, accelerates and decelerates way better than the Hartzell - may not be as fast, but we are not concerned with the last 5 knots.

:D
 
Mike,
You might check with Norris Brown "norrisair" here on VAF, he has a 14A with an MT 3 blade prop although he is running the XP-400 engine.

Not sure what you mean by 14s coming out tail heavy, the numbers I have seen that have been shared by others don't really point to a problem even with lightweight props. With 5 gallons of remaining fuel (gulp), 415lbs pilot/passenger, and 100lbs baggage my CG would be right at the rear CG limit and I am running a lightweight 2 blade composite prop (Whirlwind). So I wouldn't be too concerned with coming out tail heavy.

Raising the question again -

Any reasons why not an MT prop on a standard IO-390 install on a 14 ?
 
Great info thanks. The early indications I read were that it may have issues with a light prop, but I guess as they are coming to completion, actual figures are becoming available.
 
Raising the question again -

Any reasons why not an MT prop on a standard IO-390 install on a 14 ?

From a mntc perspective, hard to get the lower cowl on/off with a 3 blade, plus no where to turn the prop where the blades aren't always trying to jab you in the leg or eye.
 
I don?t have a horse in this race, but recommend you do a value equation on the various prop options. No prop has proven better performace than the two blade Hartzell BA, and many props degrade performance. Considering the standard Hartzell prop is one of the lower cost options I?d need a lot of convincing on why I?d spend twice as much money on a prop that may or may not provide the same performance.

I?ve been trying to convince one RV-14A owner to dump his very expensive, high end composite CS prop for the Hartzell. He has never gotten anywhere close to Van?s performance numbers.

Carl
 
From a mntc perspective, hard to get the lower cowl on/off with a 3 blade, plus no where to turn the prop where the blades aren't always trying to jab you in the leg or eye.

It's just a jump to the left

And then a step to the right

With your hands on your hips

You bring your knees in tight

But it's the pelvic thrust

That really drives you insane

The cowling comes off just the same ;-)
 
I don?t have a horse in this race, but recommend you do a value equation on the various prop options. No prop has proven better performace than the two blade Hartzell BA, and many props degrade performance. Considering the standard Hartzell prop is one of the lower cost options I?d need a lot of convincing on why I?d spend twice as much money on a prop that may or may not provide the same performance.

I?ve been trying to convince one RV-14A owner to dump his very expensive, high end composite CS prop for the Hartzell. He has never gotten anywhere close to Van?s performance numbers.

Carl

Value....

Performance...

We have some unique opportunities when it comes to value, however the advantages of the MT are super smoothness, unrivalled acceleration and deceleration. If I sacrifice a few knots in the cruise.... so be it.

Having flown behind both - there is no decision - the Germs win hands down ;)

Oh and as they say.... Ramp Presence - they look super cool !
 
I was at Race for Rhinos in Botswana earlier this year and ended up racing very close to a 2-blade RV-10. The speed difference was about half a knot........

As Mike says, the ramp presence is huge. Also, my AP looks after 6 RV-10s - all the others have 2-blade Hartzells. He tells me my 3-blade MT is by far the smoothest and best sounding. It weighs less and doesn't have any resonance issues.

It's a minor hassle getting the bottom cowl off but easy enough once you've done it a few times. To me, it's a no brainer.......
 
Errrrrrr -

We have an MT on our RV7. Titan ECI IO-360 with dual P-Mags and MT were completely happy with that.

I am enquiring from a weight and balance point of view because I understand that 14's are coming out tail heavy.

The MT is an exceptionally smooth prop, accelerates and decelerates way better than the Hartzell - may not be as fast, but we are not concerned with the last 5 knots.

:D
I've had an MT on my RV-10 with an IO-540-C4B5 for ten years. I have one mag and one Lightspeed ignition. I live about 20 minutes from MT USA in Deland, FL. They've been great to work with over the years, including an overhaul I had done a couple of years ago. They've told me repeatedly that, even though the engine and prop are a certified combo, since I have a non certified electronic ignition, there is no warranty.
 
Jake, no - 3 blade MT is a constant speed prop.


Carl - Pah !

Dave - I know the boys at Deland...... they like sippin' whisky :D I will PM you as our season starts, I get to MCO twice a month with work ( Thomas Cook A330)
 
Whirlwind

I?m almost to the point of picking my prop for my 14. I?m probably going to go with a 3 blade. Yes I understand the downside but the sound and look are a positive. 2 questions

1) MT is referenced here, any positives or negatives over a Whirlwind ?
2) Anyone have a picture of a 14 with a 3 blade ? I?ve seen tons of 10?s but not a 14.

I?m using a Lycoming 390 if that makes a difference.

Thanks and happy holidays and save flying !!
 
I will vouch for the MT as being extremely smooth, even before balancing. I do not find any greater difficulty with cowling R&I. A nice feature of the MT is there is no required maintenance between overhauls, other than visual inspection. No grease gun required. Liberal field repair is also allowed using a good quality epoxy.
Performance wise, I run neck and neck with an O-360 RV8 with a 2 blade CS Hartzell. Prop IS pricey, but well worth the money.
 
Heres a pic of a -14A with a MT 3 blade

2u61lc6.jpg
 
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