280hp V 310hp

[NewMoon]

So I owned an Ovation with 310hp but never flown a 280hp version. For those of you who have, is there a significant difference in performance so makes it  not worth looking at non-STC planes?

[rickseeman]

I've never flown the 310 hp version but I'm happy with 280. More climb is always good in any airplane I guess but shorter takeoff wouldn't mean anything to me. The 280 will takeoff anywhere you need to take off from. If it took off in 500 less feet would that really matter? They say you can use 2550 in cruise instead of 2500 but I don't think that would be any help to me. Unless I'm in a big hurry I turn back the rpms just to make it quieter and save gas anyway. So I guess all it would give me is climb. Sounds good but not gigantic to me. I get to 10,000 pretty quick.

[LANCECASPER]

56 minutes ago, NewMoon said:

So I owned an Ovation with 310hp but never flown a 280hp version. For those of you who have, is there a significant difference in performance so makes it  not worth looking at non-STC planes?

The only difference I noticed worth mentioning was the take-off and initial climb performance.

I did the conversion on a 2000 Ovation2 that I owned. As soon as I was past 1000 feet AGL I brought power back to what the POH recommended for the 280hp climb. It's a great, but costly, addition for short field performance. However 2700 rpm is way too loud for any length of time. If you operate out of a good length runway I wouldn't see the need for it. 

[NewMoon]

Good input guys,  appreciate your feedback. 

[William Munney]

For you 280hp owners.  The cost of the STC, change in the governor and the new propeller required makes it about 30K for 30HP…….and no increase in cruise speed.  It was a hard NO for me when i considered it during new engine time.

[Ragsf15e]

Depending on exactly what you get with the stc, it may be worth it… when you upgrade an Eagle to 310, isn’t that the stc that also gives you ~150lbs of gross weight increase?  Maybe the Ovation already has that at 280hp? 

[exM20K]

For my acclaim, it was a no-brainer to do it.  LL10 is short, so the extra power gets the plane off the ground significantly faster. Full power climb is simply astonishing for a piston single. Acclaim Type S prop didn’t need to be changed, so the all-in cost was more like 5 AMU’s.

I probably wouldn’t do it if a non-run-out prop needed to be tossed.  
 

my 90% trip is 750 NM typically flown at 16 and 17,000, so the time-to-climb difference is significant.

If you operate off a short strip it adds a margin of safety, and I can out-climb my engine-out descent rate by a lot, which potential energy becomes my second engine should #1 fail.

But if operating off long runways with no excursions into the teens, It may not be worthwhile. If looking at two candidate aircraft, one with the STC, all other things being equal, I’d take the 310 as it’s a free option. You can always fly it per the original POH, and you’ll be glad to have the extra 10% power one day when departing  high, heavy, and/or short.

-dan

[PT20J]

30 hp = 990000 ft-lb/min

At a takeoff weight of 3300 lb, that’s an initial climb rate increase of 300 fpm.

[dkkim73]

On 8/3/2024 at 7:47 PM, PT20J said:

30 hp = 990000 ft-lb/min

At a takeoff weight of 3300 lb, that’s an initial climb rate increase of 300 fpm.

Dimensional analysis for the win! 

[dkkim73]

@exM20K Dan, do you climb at 2700 rpm all the way to cruise at, say, 17k?

I'd always thought the main impetus for this STC was safety with short runways or airports with few ditching options. Didn't think about the climb aspect...

Cruising in the high teens puts an Acclaim smile on my face and makes the commute quick. 

 

[Niko182]

If i'm going high, I'll usually climb at the full 2700rpm. Above 15000ft I'm usually running between 2600 to 2700rpm anyway since the lack of power up there for us non turbo'd folks.

[exM20K]

25 minutes ago, dkkim73 said:

@exM20K Dan, do you climb at 2700 rpm all the way to cruise at, say, 17k?

I'd always thought the main impetus for this STC was safety with short runways or airports with few ditching options. Didn't think about the climb aspect...

Cruising in the high teens puts an Acclaim smile on my face and makes the commute quick. 

 

Yup.  Roughly 1200FPM @ 130 KIAS, or 1500FPM @ 120 KIAS. Puts a grin on my face every time.

-dan