McCauley to Hartzell for my Ovation

[N81FM]

Hi All,

I intend to change my McCauley three blades for an Hartzell.

I'm sure you already discussed this but didn't found information in the forum. Can you tell me what should be the new performance ( climbing i know, seems to be 1250 fpm at max weight ) but what about speed. Actually 145 KIAS at 8000 ft.

Thanks a lot

Jean-Claude

[Jeff_S]

Hi Jean-Claude,

 

I haven't seen much on the difference between the old McCauley 3-blade and the Hartzell.  One thing you've got going for you, if you choose, is that you can actually install the Hartzell that was designed for the Acclaim S.  They have now been certified for all Ovation installations. I'm not sure of the differences between that and the normal Hartzell blended-airfoil that's been on the Ovation 2s and 3s for a while...I believe it's lighter, and may have some slight differences that improve speed.  But I think it costs more than the standard 3-blade. Your best bet is to call Hartzell and talk to someone knowledgeable.

[Robert C.]

From my reading on the topic there will be very little difference in speed. The principal advantage will be climb rate and take-off roll reduction.

Have you considered the 4 bladed MT prop instead? Less weight and another improvement in t/o distance and climb rate.

Robert

PS: welcome on board

[Hank]

Have you considered the 4 bladed MT prop instead? Less weight and another improvement in t/o distance and climb rate.

Maybe Erik will eventually tell us how well the 4-blade performs on his Green Rocket.

[carusoam]

The top prop comes in three variations.

Thin, thick and composite.

I went with thin. The cost is the number of times that the blades can be re-cut for OHs.

The composite is ultra light and gives some owners fear of low inertia or no flywheel effect.

I am unable to compare the hartzell to the original Mac because it was mounted at the same time the 310hp STC was done on my machine.

Sure there is some speed/efficiency increase... Cruise numbers for the top prop are given at 2550 rpm.

Cruise numbers for the O1 end at a 2500 rpm red line.

Where the 310hp top prop combo really shines is T/O performance and climb rate. It's memorable and measurable...

Does that help?

Best regards,

-a-

[N81FM]

An idea of the cost of this 4 bladed MT prop ?

[Robert C.]

An idea of the cost of this 4 bladed MT prop ?

Give them a call?

http://www.mt-propellerusa.com/en/mtusa/stcs/mooney_8.htm

[Guest]

I have a 3 blade MT on my IO720 powered Comanche. The only issue is poor idle when the engine is really hot other than that it's a great prop, it weighs 38 pounds less than my Hartzell. Being in France an MT from right next door in Germany would make good sense for you.

Clarence

[carusoam]

Clarence,

How does the IO720 handle the light prop during start up and shutdown?

The Cirri have the immediate / instantaneous stop. It looks like something broke.

It stops. It doesn't shut down.

As for starting..have you seen anything like kick-back related issues? It looks as if following procedure may be more critical with a light prop.

Best regards,

-a-

[Guest]

On cold starts no troubles at all with normal idle. Hot is a different story, the lack of weight does limit the fly wheel affect and it seems to need a little more RPM to be steady. Shut down is rather quick, the same as my E model when it had the MT.

The only real concern I have is if I were to need a blade repair, but then I've had really poor service from Hartzell on their composite blades as well.

Clarence

[StevenL757]

From my reading on the topic there will be very little difference in speed. The principal advantage will be climb rate and take-off roll reduction.

Have you considered the 4 bladed MT prop instead? Less weight and another improvement in t/o distance and climb rate.

Robert

PS: welcome on board

One of Bob Minnis' sales points for the 7498 (Acclain Type-S, "thin") prop (based on hundreds of hours of flight testing) is that it gives a ~ 10 knot increase over the McCauley 3-blade, and about 7 knots over the Hartzell F7693 /DF-2 (the "thick" Hartzell). Both of these metal Hartzells are the same price. The composite Hartzell runs ~ $22,500 and although much lighter than both metal variants, is outperformed by the 7498. Mine was $15.7k through Bob with the TKS accessories. Without TKS, expect about $12k. The 7693 weighs 80 pounds, versus 73 pounds for the 7498. Agree with the climb rate and takeoff performance, but the 7498 also outperforms the 7693 in cruise as well, making it an overall well-rounded choice. Anthony above makes these points as well, and I'm sure can attest to the dramatic performance increase over its predecessor.

[StevenL757]

Hi Jean-Claude,

 

I haven't seen much on the difference between the old McCauley 3-blade and the Hartzell.  One thing you've got going for you, if you choose, is that you can actually install the Hartzell that was designed for the Acclaim S.  They have now been certified for all Ovation installations. I'm not sure of the differences between that and the normal Hartzell blended-airfoil that's been on the Ovation 2s and 3s for a while...I believe it's lighter, and may have some slight differences that improve speed.  But I think it costs more than the standard 3-blade. Your best bet is to call Hartzell and talk to someone knowledgeable.

The differences are huge. Mike Trudeau, VP of the Top Prop division, enjoys discussing the performance differences, and welcomes phone calls re: same. He and Bob Minnis were the reasons I opted to go with the Acclaim Type-S prop when I installed my IO550N 310HP engine. Mike can be reached at 937-778-4212.

[Jeff_S]

That's interesting.  It seems like maybe installing the lighter prop would help me recover some of the knots lost due to having the A/C. It would move my COG even further aft, but at seven pounds difference maybe not so much. I may have to give this some thought.

[carusoam]

The weight differences of the three TopProp options (thick, thin and composite) is eye opening.

N vs G saves a couple of pounds also...

Getting the scoop directly from Mike T. And Bob M. is enlightening.

Best regards,

-a-

[Jeff_S]

So I talked to Mike Trudeau at Hartzell yesterday. It was a great conversation and he is a stand-up guy, real low key, very open about all the possibilities. He told me they had purchased the STC from Bob Minnis to ensure that this option was available to Mooney pilots for as long as possible. Hartnell wanted to control the STC since it is their prop, after all.

 

But as for performance improvements, he said there are no absolutes (which I always knew) and that much of it would depend on the starting point. Clearly, even their first Top Prop was a dynamic improvement from the 2 and 3-blade McCauleys that it replaced. He said the take-off roll was reduced by 60% (!!) compared to those props, which was as much a testament to how poorly those props were matched to the airplane than how special the Hartzell is. But compared to a plane that already has the 310hp and the older Top Prop, he felt the performance improvements would be more modest, ~3 knots in cruise for a normally aspirated engine at 6-10,000'.  His honest opinion was that it wouldn't make sense to replace an almost new prop like mine, but if for some reason mine got dinged, or if somebody really wanted to buy my prop, then maybe it would be worth upgrading.  I appreciated his honest assessment...he clearly isn't in it just to move aluminum parts.

 

So, anybody wanna' buy a nearly-new Hartzell Top Prop with only 68 hours on it?

 

[Flymu2]

So, anybody wanna' buy a nearly-new Hartzell Top Prop with only 68 hours on it?

 

 

Jeff,

 

I may be interested in your prop. PM me.

 

Thanks,

 

Dennis Wolf