Performance of MT prop with 183-59B blades?

There are many reports of poor cruise speed performance with 3 bladed MT props with 183-59 blades. Supposedly, the newer 183-59B blades are more efficient. I've read one report on this forum from a Canadian flight test engineer who tested a prop with the 183-59B blades and found it had performance equal or better to the Hartzell blended airfoil prop (more info). But, his tests were not on an RV.

I'd love to hear from any guys with 183-59B blades on RVs. Do you have any sense of how your performance compares to other RVs, or against Van's specs? Even better would be to hear from someone who has flown a Hartzell and an MT with 183-59B blades on the same aircraft/engine, with no other changes.

Kevin, jamie Painter and myself actually swapped props a couple of weeks ago.. We took my 3 blade MT off of my Rv-7A and put his hartzell blended airfoil on it. We are going to publish the numbers soon, but I saw about 2-3 knots less speed on the MT than the Hartzell, and it was pretty consistent. So, not much difference here, for all of the noise we've heard.
In a nutshell, we ran at 7500' DA, WOT, leaned 50-100 ROP, and only changed the prop from 2700 to 2200 RPM at 100 rpm intervals. The MT is much smoother at all rpms on MY airplane. I noticed an uncomfortable buzz in the Hartzell at 2700 and 2200. The Hartzell did seem smoother at higher airspeeds, above 160 knots IAS.
So, we eliminated everything except the prop by swapping them. Now, due to time and weather constraints, Jamie ran his 2nd flight test on day 2, and saw about 7 knots difference. He is going to rerun them, as they didn't seem quite right. Because, when we flew side by side with the props swapped, we were almost even--- perhaps 2-3 knots difference, but it was hard to tell, as we mostly stayed with each other during the timed runs.
We left the power set for 3 minutes at each rpm, then wrote down the IAS, TAS, and GPS speed. I was able to repeat my readings when I put my prop back on, so while we aren't certified Civilian Test pilots, I think the data gives us a pretty good understanding of the slight differences.


Vic

vic syracuse said:

Kevin, jamie Painter and myself actually swapped props a couple of weeks ago.. We took my 3 blade MT off of my Rv-7A and put his hartzell blended airfoil on it. We are going to publish the numbers soon, but I saw about 2-3 knots less speed on the MT than the Hartzell, and it was pretty consistent. So, not much difference here, for all of the noise we've heard.

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Thanks Vic - That is encouraging. I'm hoping an MT with the 183-59B blades would be at least as fast as my now trashed Hartzell with the 7666A blades (i.e. the Hartzell that was commonly used before the blended airfoil prop came out). Your data suggests that I would probably be happy with this MT.

Hartzell vs. MT vs. Whirlwind

Hi Kevin,

Just curious - what is making you consider the MT? Weight? Looks? Something else?

I'm considering the MT as well, since overhauls will be a bit easier for me since they flying distance from where I'm based, but there is still a pretty substantial price difference between them.

Van's is showing this:

• MT 2 blade
  O-360, 72", 2 Blade, hydraulic pitch change
  Part Number = PROP MTV15B/183-50
  Price = $8440.00
  
• MT 3 blade
  O-360, 72", 3 Blade, hydraulic pitch change
  Part Number = PROP MTV12B/183-59B
  Price = $9160.00
  
• Hartzell 3 blade
  Compact hub Constant-speed prop for (I)O-360 (180/200hp) 72"
  Part Number = PROP C2YR-1BFP/F74972
  Price = $6330.00

2000 USD will get the Hartzell prop back to the US at least once, possibly twice.

I was really impressed with the electric MT that I had for my Eggenfellner engine. Very high quality, and the pre-built spinner was very well made.

Have you rejected the Whirlwind 200RV? It looks very nice as well.

rv8ch said:

Just curious - what is making you consider the MT? Weight? Looks? Something else?

....

Have you rejected the Whirlwind 200RV? It looks very nice as well.

Click to expand...

I bought a Hartzell with 7666A blades using Van's discount back before the new blended airfoil Hartzells were available. Now that prop is scrap, due to my recent overspeed event. I've decided to go with an "aerobatic" prop with counterweighted blades, as I don't want to spend this much cash and time if I ever have a similar event again. I can afford this once, but twice would be a bit much.

The prices that Van quotes represent a significant discount on the list prices, but the discount is only available once per RV. I already used my discount, so I need to look at list prices, or a used prop.

The counterweights on an "aerobatic" Hartzell prop will not fit inside Van's spinner. The spinner that Hartzell sells for that prop costs $2200, but it has a larger diameter than Van's spinner, which means that it won't mate up to my cowling without major and time consuming fibreglas work. I hate fibreglas work.

The MT "aerobatic" prop comes with a spinner, and they will custom fit the spinner to your dimensions, so in theory it should mate right up with my cowling. And, the cost of the MT prop (including spinner, and shipping from Germany) is less than the list price of the Hartzell "aerobatic" prop + spinner (which would still need a lot of work to fit my cowl).

So, for me, with my current "requirements", the MT prop is cheaper and an easier fit than the Hartzell. And, the "aerobatic" Hartzell prop is not available with the blended airfoil blades. It has the same 7666A blades as my current prop. So, there is a reasonable chance that the MT prop will be a better performer too. So, it is looking like I will order an MT prop.

As far as the Whirlwind prop - I wanted a prop from a larger company, so I had more comfort that the company would be around to support the prop for as long as I have the aircraft. Also, the 200 RV prop does not appear to be available with counterweights.