MT vs Catto vs Hartzell

I really enjoyed reading the comments about the Catto prop thread. I have a IO-360A1A constant speed on a RV-8 that I will be doing a lot of aerobatics and XC-IFR (not at the same time). I don't want to be afraid to fly in the rain and keep my speed up when traveling (so there goes the wood prop). I love the look of the 3-blades, but it seems you may give up 7 knots or so. I am concerned about the composite props after seeing John Huft's prop fly apart (RV-8) on his way home from Sun-N-Fun last year (it was a composite, but not a Catto or MT). The MT looks cool, but for over 8,000.00 it should maybe have diamonds embedded in the glass.
OK, those are my thoughts and desires (aerobatics and flying fast in the rain). Now I need some advice...go for it...and thanks for your comments ahead of time.
Steve

I'm not sure that it's mentioned on the Catto website, but when I asked about a Catto 3-blade, he did mention that he'll add a leading edge protector strip for an additional $85 that let's you fly in rain if you'll ease up on your cruise speed (but maybe not much).

I won't be ordering my engine or prop for about 6 to 8 months, and while I have chosen my engine for sure (Mattituck IO-360 w/EI), I am still wondering about the prop.
I'm leaning toward the Catto because of the cost difference, but I have to balance that against any performance loss compared to a CS (Blended Hartzell or Whirlwind 200RV).
Is there a formula to compute how to choose between a few knots and a few thousand$$$?

FP vs CS formula

The equation is:

(have lots of money) + (extra maintenance cost) = CS prop

I would've, if I could've. But, still happy enough with FP performance.
Maybe one day...

Mark Andrews N598X 0-360/Catto 3-blade

Steve,
FWIW, I ordered the 3-blade Catto for my 8. Mostly, it was for simplicity ( I gotta maintain this thing) and to save weight. The prop only weighs 17# and is alleged to be very smooth making for an enjoyable ride. ( kinda like the Harley rubber mounted vs hard mount). Although, due to less momentum, I'm told it does not idle smoothly. If you are going full IFR and think you are going to be on the heavy end of things, I think the C/S is more important. There is no argument that the C/S provides more power available during T/O, Climb and the slow end of aerobatics. Period. For me, keeping it simple, light and fun is what its all about. Thus, the Catto.

I have a lot of time in the ole Rhino, too. So, sometimes I dream about Max performance. That would be a P-51 clone or an L-39. Not a Rocket or an RV-8 with a C/S prop.

Just my thoughts... Cheers,
Chuck

Props

If it is in the budget, C/S is the only way to go. Great launch & brakes, for anything. We do formation & I hate to fly with the F/P guys. For acro it is also great for anything you do there. If not in the budget now you can at least get in the air with wood & watch for a good deal. There are some people changing over to C/S, we had two in our group this summer & they sold theirs. Could do a WTB for one if needed.

My 4 has an Blended airfoil Hartzel that I like real well. I have another A/C with the 4 blade M/T and it is turbine like smooth. I know I'm giving up performance with the 4 blade, but it looks great hanging on the nose.

Where is the proof that a 3 blade is really slower and by how much? I realize that there can be an efficiency loss with more blades but is there any real proof between the various props on these planes?

The average Sensenich fixed pitch is $1900. Average Hartzell constant speed is $5600. MT prop governor is about $1000. (All prices from Van's catalog.) I make the difference to be 5600 + 1000 - 1900 = $4700. Maybe a few hundred more for a cable and hoses. Still a chunk of change, but less than $6k. Am I missing something?

economics FP vs CS

You can do some crude economic evaluations to evaluate one position or the other. Here's some crude numbers:

$4700 price difference divided by $3.00/gallon = 1,567 gallons of gas.
For argument's sake, let's say we burn 9 gal/hr on average, so 1,567 gallons divided by 9 gal/hr = 174 hours flight time.
The CS prop will allow the engine to run more efficiently, let's be generous and say it saves 1 gal/hr. So, 1 gal/hr X $3.00/gal = $3.00/hr savings. And, $4700 divided by $3.00/hr savings = 1,567 hrs until CS prop saves enough fuel to pay for itself. Assuming flying 200 hrs/year, the payback period would be 1,567 hrs divided by 200hrs/year = 7.8 years.

But, the real reason I went FP was the initial capital outlay... just didn't have the cash on hand at that time.

The actual cost of flying: "How much ya got?"

Mark Andrews N598X

Yeah sorry I didn't look close enough.

Extra Maintenance?

I have owned several Hartzell's and maintenance consisted of once every year, about 10 minutes worth of effort, to grease the hub. Those stating it takes more maintenance, I am just guessing, that you may have never owned a constant speed prop? A hydraulic prop is a very reliable piece of equipment and should go the distance between engine overhauls. Many of the horror stories are from 60-year-old prop designs on 40-year-old planes.

Also metal blades are more impact resistant and small chips can be blended out with a file on the ramp. I am not sure but most of the high tech composite props need special repair methods. As I understand it those repairs must be preformed by the manufacture wherever they are located and require the prop removal.

Cheers George