IO-550

[ilya1502]

Okay, thanks. But we don't have to worry about that noisy stuff in the sim, do we? So, A2A, please, make us a 2-blade prop option!

[awash2002]

Yes A2A please do a 2 blade prop option and a IO-470 engine option

[Dogsbody55]

Yes A2A please do a 2 blade prop option and a IO-470 engine option

I have to agree. However, history suggests that this will not happen.

For some reason, and assuming I recall correctly, the IO-470 engine option was dropped during beta testing. Regular forum members may recall that the Bonanza was originally to be released with a choice of 3 engines, one of which was the IO-470.

Speaking purely for myself, I was disappointed that this engine was dropped. The difference between the IO-520 and '550 is not as discernible since I fly mostly with a light load and I think the package would have been better with the IO-470 included.



Cheers,
Mike

[AKar]

For some reason, and assuming I recall correctly, the IO-470 engine option was dropped during beta testing. Regular forum members may recall that the Bonanza was originally to be released with a choice of 3 engines, one of which was the IO-470.

I think the thing is that when V35B was chosen as the model to be simulated, the IO-470 was dropped because it is not an engine that powers it in real world. IO-520 is the baseline and IO-550 is a common replacement via an STC.

-Esa

[Dogsbody55]

For some reason, and assuming I recall correctly, the IO-470 engine option was dropped during beta testing. Regular forum members may recall that the Bonanza was originally to be released with a choice of 3 engines, one of which was the IO-470.

I think the thing is that when V35B was chosen as the model to be simulated, the IO-470 was dropped because it is not an engine that powers it in real world. IO-520 is the baseline and IO-550 is a common replacement via an STC.

-Esa

Perhaps an earlier version version, such as an N35 or P35, was in the offing??

http://a2asimulations.com/forum/viewtop ... =0#p472317


Cheers,
Mike

[AKar]

Bonanza models H35 thru P35 came with IO-470 series engines. I don't know but guess that if one of these would have been the model by that time in development, it would have made sense to have an IO-470 as a baseline.

Speaking of the engines, IO-520 and IO-550 are very similar in their configuration; in principle the IO-550 is an IO-520 with increased stroke to have slightly more displacement. They share the bore, the compression ratio and the basic layout - and usually do 2700 RPM. IO-470, on the other hand, shares the stroke with IO-520 but has slightly smaller bore. It has versions of different compression ratios; the ones used in Bonanzas were either 8.0:1 or 8.6:1. Versions of IO-470 that had higher compression ratio were reportedly somewhat notorious in that they cracked their cylinders. Different models also have different RPMs.

-Esa

[ilya1502]

Screw the IO-470, just give the freaking prop!

Esa, and can you tell how different the performance and fuel efficiency is with IO-550 in comparison to IO-520?

[AKar]

Esa, and can you tell how different the performance and fuel efficiency is with IO-550 in comparison to IO-520?

In per horsepower fuel consumption, I doubt there would be appreciable difference if compared at similar leaning approach. User technique, in particular in what comes to leaning, and differences from engine and installation to next certainly matter more. It is more about the rating (and to not trivial extent, about how the rating is defined). At given cruise altitude, with IO-550 you get a little more wide-open throttle horsepower. Therefore you may be able to lean towards better economy and retain similar cruise performance to that an IO-520 provides at higher power mixture setting.

By leaning to some common reference (say, peak EGT or whatever) and by adjusting the throttle to some given same horsepower output, I'd expect the engines do pretty much identically in terms of fuel use. Obviously, flight test results may vary from an airplane to next.

-Esa

[Jarek]

Nice comparison in presented in this article:
http://summitaviationmfg.com/wp-content ... Engine.pdf

In the engine life period (1700Hrs) fuel savings with IO-550 may reach ~30k USD (0.55 cents vs. 0.61 with 520 per nautical mile for best power setting)
550 is a new generation engine and the major improvement here is efficiency rather than performance.
However personally I'm still with 520 - due to pure nostalgia as fuel is cheap in p3d

[AKar]

550 is a new generation engine and the major improvement here is efficiency rather than performance.

In what way? It ships with little or no technological advances in comparison to IO-520 in what comes to performance/economy, though it is somewhat better engine in details. Note by the way, that in the comparison is an IO-550-R, with 310 hp, not the 300 hp -B we get with A2A Bonanza.

These comparison results are precisely from flying a higher horsepower engine at higher altitude. Swapping the engine alone would result in negligible fuel savings I'd say, without completely rethinking one's cruise profile and/or leaning profile as well. It is the latter where the savings come, whereas the new engine acts more like an enabler.

-Esa

[Jarek]

It is the latter where the savings come, whereas the new engine acts more like an enabler.

-Esa

Sure, agree. It's a key here. Displacement has changed and that's mostly it. The application used in the paper is that you want to get from A to B in a given time, so you have to use more aggressive settings on 520. But while power increase between 520 and 550 is only 5%, the economy of V35 improves by 10% (in this specific application). Similar paper could be written how A2A 550 helped me save on electricity bills due to reduced flight simming time

[AKar]

To push the point a little, their fuel consumption figures for IO-520-B are 1.5 gallons per hour higher than what is in the V35B Bonanza's charts. That's a lot, given the difference in TAS for used power settings is within one knot. To do another kind of comparison, and perhaps a little bit more fair one, consider the following.

Using A2A Bonanza's data, with IO-520-B at 7000 ft, we do 172 knots in it and burn 15.0 gph.
Using their data on the left, with IO-550-R at 6850 ft, they do 174 and burn 15.5 gph.

Put that way, they do 2 % less measured in nm/gallon. Which is much less impressive!

Using their data on the right, with IO-550-R at 7000 ft, they do 170 knots and burn 13.6 gph.

This gives a gain of 9 % in nm/gallon, which is impressive. But now with original engine we've got two knots of TAS advantage, which we perhaps could lean away like they apparently did with their original four knot advantage that was at 6850 ft, which is close enough the same, closing the gap somewhat.

Note that this is not an article per se, but a brochure for an engine STC offer, and this shows.

Again, this is not to say that there aren't significant benefits with IO-550, I know for a fact there are, but more than anything, one needs to judge the numbers critically. A good starting point is to note what the numbers actually represent. And what they perhaps do not represent, and maybe intentionally so.

-Esa

[Jarek]

I've decided to analyze data I have for my A2A V35/520. Now I have 35 flights and almost 55h counted with total consumption of 626.80 gallons.
This gives average of 11.4gph - seems to be low, but this is true value, including time for warmup, taxi and all phases of flight.
Unfortunately I did not record precise route data, so burn per nm is not available.
Virtual fuel cost was 3 320 USD with 45 gals still remaining in the tanks.