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IO-550 versions

Posted: 20 Sep 2021, 17:16
by awash2002
I'm thinking of upgrading to the IO-550 what is the difference between the two versions the 300HP and the 310HP it's the same engine right?

Re: IO-550 versions

Posted: 22 Sep 2021, 10:24
by Scott - A2A
My understanding is it's the same engine with just more power which probably comes partly from higher compression ratios. Don't quote me on this though.

Scott.

Re: IO-550 versions

Posted: 22 Sep 2021, 12:35
by AKar
It appears that the 300 hp rated G-model has a different induction system layout to the basic model. I'd throw a guess that is for reasons in what comes to some specific installation. And, as it apparently provided that much more power, I guess more or less consistently in service, it was simply re-rated for higher hp to push the book figures accordingly in the 310 hp N-model, which is physically exactly the same, including the compression ratio of 8,5.

This is simply from the TCDS data, I'd have to find a moment to look up the history if this gain of 10 hp was indeed just accidental. And there may be slight differences here and there, but the principal specs are the same except for the power.

-Esa

Re: IO-550 versions

Posted: 22 Sep 2021, 15:24
by Scott - A2A
My response was a call for Esa to come in and give a knowledgable and detailed answer. I really should know more about the Continentals and will soon (hint hint) :)

Scott

Re: IO-550 versions

Posted: 22 Sep 2021, 16:54
by AviationAtWar
670? :)

Re: IO-550 versions

Posted: 23 Sep 2021, 01:59
by AKar
Haha, I don't think I've got any familiarity with the IO-550 series aside being involved in procuring just one STC, changing I think remembering an O-470 into an IO-550. :)

I misread the TCDS[*] and didn't notice that the G-model the 310 hp N-model is similar to is, in fact, only rated for 280 hp @ 2500 rpm (the base models are 300 hp @ 2700 rpm).

So, the "certification-level" alterations go like the G-model is similar to the base models, "except for the top-mounted induction system and the 8-quart oil sump." For reason or another, as mentioned, it is also rated for only 280 hp @ 2500 rpm. My guess is, again, that it was originally created to some specific installation, and spec'ed accordingly. The N-model, in turn, is "similar to the IO-550-G except for the increased power rating" (310 hp @ 2700 rpm).

Hence, my complete guess is that they simply returned the original rpm rating of 2700 to the G-model with its "top-mounted induction system", thus creating the N-model. And while validating, benched it at 310 hp, thus rating it a bit higher than the original 2700 rpm models.

[*] I originally posted that I misread the "STC". What I misread was the TCDS when posting! - obviously, misreading the STC, as written in the original, would have had me some trouble back then! :mrgreen:

-Esa

Re: IO-550 versions

Posted: 23 Sep 2021, 16:36
by awash2002
For now I'm sticking with the IO-520 until TBO then I will be fully switched to my Reno Race Engine a IO-550K 330HP modified

Re: IO-550 versions

Posted: 23 Sep 2021, 21:33
by Paughco
Whenever I anticipate a situation where that 300-hp IO-550 under the hood of my Bonanza won't do the job, I don't mess around trying to wheedle more ponies out of the poor thing. I leave it in the hangar and roll out my P-40. Or, maybe even the P-51.

Seeya
ATB