I have a 182M with a Air Plains IO-550 conversion was looking for advice on replacing the heavy 3 Blade McCauley prop with a MT prop and if there are any big advantages on sticking with the 3 Blade MT over the weight savings of the 2 blade other than speed.

Thanks in advance

I don't know if its different on the IO-550, but when I talked to MT about 3-blade vs 2-blade on my Pponk, they said the 2 blade was a little faster at cruise.

Flight Resource has some comparative data on the 2 versus 3 blade propellers on their website.

I have the data from Flight Res. and have talked to them Larry he said its about 50/50 and a personnel preference. The three blade preforms a tad better but I like the extra weight loss off the nose with the 2 blade model. Just hoping maybe someone out there has some real world experience with them.

I have never flown behind a 2 blade MT on a large continental. I have a 3 blade on my IO-520 and really like it. My Husky has a 2 blade MT, but that's not really helpful for this conversation.

KSMN182 wrote:I have the data from Flight Res. and have talked to them Larry he said its about 50/50 and a personnel preference. The three blade preforms a tad better but I like the extra weight loss off the nose with the 2 blade model. Just hoping maybe someone out there has some real world experience with them.

Weight loss up front will make a 182 feel that the nose is a lot lighter, for me that was the deciding factor

motoadve

Do you run a 2 Blade on a large Cont.?

See if you can get ahold of Rob on this forum, he has a 1953 180 with a pponk 520 and has had both 2 blade and 3 blade MTs on it so he knows first hand the differences.

I’d have bought a two blade. Flight Resource would have supported that choice if it were a land-plane only. They talked me into a three blade. I’m sure they were right. Call them up and take whatever advice they give you. They have your satisfaction at the front of their objectives.

IO-550 equipped.

KSMN182 wrote:motoadve

Do you run a 2 Blade on a large Cont.?

Yes 2 blade on my Pponked 182.

Did you switch to the two blade at the same time you did the engine upgrade or have you ran your plane with a heavier 3 blade. My 182 preforms great now just really looking to lighten the nose for W/B. Either the 2 or the 3 blade help with that mission but the two blade looks to out preform my current Mac 3 blade combo.
Thanks for offering your experiences

When I Pponk'd my 180, Flight Resources was pretty adamant about running a 2 blade (MTV-15) on anything under 300 hp. I wish people would quit using HP numbers without Torque numbers... but I digress

I ran a 2 blade on the Pponk (because I had one) for a few hundred hours. The weight loss up front does make it fly nice (and I am a stickler for having a nice CG without use of ballast to achieve it). But it was very evident to me that this was not enough prop for the engine. Speed difference was negligible as in almost nil.

I bought a 3 Blade (MTV-9) also from Flight Resources, before I had a home for the 2 blade, so I was able to do back to back tests flights, less than 30 minutes apart, to compare these props on my airplane. At this point t I could have kept either, both, or none. I'm not a fan boy, and know exactly how a Mac (C-66) performed on the same airplane, so it really didn't matter to me which I kept, if either, I just wanted the best all around compromise (because it's all a compromise) for my mission / airplane.

The take off difference between the two was a complete joke. I won't post numbers, because someone will call BS, but I would have been several thousand dollars ahead in keeping the 2 blade if it had any merit at all. Landing, the flight characteristics of the 2 blade may have made a difference in a STOL contest where +/- two feet would make a difference. Landing on my cross strip ~350', it makes none, I don't do STOL, and that is as tight as I ever will find a need to get my 180 in barring an emergency.

Flying with absolutely nothing in the baggage, and no rear seats, the 2 blade flies nicer. Anything at all in the baggage (as little as a couple wrenches and a qt of oil) and the difference is completely (do the math) gone.

In my way of thinking, there is really only one legitimate reason to upsize an engine on an airplane, and that is to turn an upsized prop. Installing a larger engine, and then governing it with an under pitched, or in the case of CS props under sized prop, makes no sense to me?

In the end it all comes down to mission. Total weight, as well as real world CG are most certainly factors a guy oughta consider, so I guess if your airplane or mission are out of 'normal' balance enough to require a minimalistic approach to prop selection you're probably going to be hard pressed to find something lighter that pulls as well as a 2 blade MT. On the other hand, a 3 blade MT weighs in at almost the exact weight of a 2 blade Mac, with thrust almost as good as a 3 blade Mac, and in some regimes better. There is a 6lb difference between the two MT's, and either is going to be much much lighter than your current prop.

Again, do the math. Look at the arm on the prop, and the arm on your baggage, it is a 6lb difference.... That doesn't amount to much baggage .

Take care, Rob

Thanks Rob you answered my fear of going to a 2 blade only to save a few pounds and where both props get me back into the heart of my CG envelope I think a 3 blade is in my near future. I had ran new W/B on both as you suggested and your right a couple pounds in the baggage area and they are almost identical.
Thanks again for responding / helping