Io-540

[belchfire]

Any particular reason they had to break the whole system instead of just designating it with a suffix?

I am not certain (never been around them) but
there are some of the 540's that have the
intake and exhaust on opposite sides of the
cylender and can use upward
cooling air flow rather than downward...again
not sure but these may be the "541" engines.
If this is the case, using the 541 designation
is reasonable because of the change in
basic cylender design. Most oppossed engines
have the intake and exhaust on the same
(bottom) side of the cylender.

Case changes are usually indicated in the
suffix, like the O-320-H2AD that was used
in 172's, most of which have been replaced
by O-320-A series engines.

 

[bocefus]

Yep, one would be the TI0-541, but your supposition does not hold true. These engines are known as "upstack" and "downstack" Mostly used in ground power units.

 

[crash-proof]

H= Helicopter

Actually, it's "V" as in Vertical, for choppers
Ex: VO-540

 

[bocefus]

Er, no, actually it is V, or H. both for helicopters.
Ex: HO-360, HIO-540, TVO-435 and so on

 

[TrafficInSight]

V is for vertically mounted, and I believe all H means is that it's equipped with a cooling fan for helicopter use and possibly a different type of flange to mate with the belt pullies, may be wrong on that but it's been the only thing I've noticed different so far. So you can have a VIO-540 or an HIO-540, the V usually implies H but it doesn't have to.

 

[bocefus]

According the Lycoming Model Codes for reciprocating engines, the "V" and The "H" always indicate helicopter applications.

 

[TrafficInSight]

According the Lycoming Model Codes for reciprocating engines, the "V" and The "H" always indicate helicopter applications.

Well I've never seen a vertically mounted engine in anything but a helicopter so by virtue of that it's true... but I suppose you could vertically mount one in something and it would be a V engine. Same with an H engine.

 

[bocefus]

Well I've never seen a vertically mounted engine in anything but a helicopter so by virtue of that it's true... but I suppose you could vertically mount one in something and it would be a V engine. Same with an H engine.

I think you are misunderstanding the Lycoming Model Codes, H and V in the engine ID always indicate a helicopter application. On the other hand, there are certificated helicopters having Lycoming engines installed that do not carrry a H or V designation. Example, 0-320 and 0-540

 

[crash-proof]

and is that because they aren't mounted upright?

 

[bocefus]

No, it's because the airframe manufacturer chose to use an engine designed for a fixed wing aircraft rather than one specifically designed for a helicopter. (H)

 

[TrafficInSight]

I think you are misunderstanding the Lycoming Model Codes, H and V in the engine ID always indicate a helicopter application. On the other hand, there are certificated helicopters having Lycoming engines installed that do not carrry a H or V designation. Example, 0-320 and 0-540

No I do understand them. What I'm saying is that an HIO-360 on the engine stand looks pretty much the same as an IO-360 The difference is in the installation, but that doesn't stop me from taking an HIO-360 and using it in a GPU... when I order parts I'm still ordering them for an HIO-360. So equating H to mean Helicopter is okay as a rule of thumb but the H in the designation doesn't necessarily mean helicopter. What I've found that it means is that it is installed in a certain way. So a VO-520 in a GPU is still a VO-520.

 

[bocefus]

It appears that you do misunderstand, and what you have found is contrary to what Lycoming publishes.I didn't make this up, it it all spelled out very clear in the Lycoming "Key Reprints" publication. As far as the engine designation goes, "H" always indicates that Lycoming designed that engine to be installed horizontally in a Helicopter. "V" means that Lycoming designed that engine to be installed vertically in a Helicopter. If you want to put one of these engines in your boat, GPU, power saw, etc, then it is outside of the Lycoming design criteria. Again, regardless of what you have found, Lycoming states that "H" and 'V" engines are allways helicopter applications.

 

[TrafficInSight]

It appears that you do misunderstand, and what you have found is contrary to what Lycoming publishes.I didn't make this up, it it all spelled out very clear in the Lycoming "Key Reprints" publication. As far as the engine designation goes, "H" always indicates that Lycoming designed that engine to be installed horizontally in a Helicopter. "V" means that Lycoming designed that engine to be installed vertically in a Helicopter. If you want to put one of these engines in your boat, GPU, power saw, etc, then it is outside of the Lycoming design criteria. Again, regardless of what you have found, Lycoming states that "H" and 'V" engines are allways helicopter applications.

However, I know of at least one helicopter powered by a Lycoming O-435-4. Not an HO-435, just an O-435. And as I said before, an HIO-360 on an engine stand looks basically the same as an IO-360 the only difference is the installation. An HIO-360 runs at 2900 RPM that makes it a "helicopter" engine I guess.

 

[bocefus]

Again, you misunderstand. You will see from a previous post of mine that I said some helicopters are powered by engines other than H or V. The debate was whether 'H" or "V" designated engines are used in any aircraft application other than helicopter. The answer is no. You will not find an 'H" or "V" designation on an engine installed in a production fixed wing aircraft, but you can find Lycoming engines powering helicopters without an "H" or "V" designation. Examples, O-320, O-540. See the difference?

 

[TrafficInSight]

Again, you misunderstand. You will see from a previous post of mine that I said some helicopters are powered by engines other than H or V. The debate was whether 'H" or "V" designated engines are used in any aircraft application other than helicopter. The answer is no. You will not find an 'H" or "V" designation on an engine installed in a production fixed wing aircraft, but you can find Lycoming engines powering helicopters without an "H" or "V" designation. Examples, O-320, O-540. See the difference?

No, I understand perfectly but I think I'm just confusing you with poor examples. Yes the lycoming model codes say that H stands for Helicopter, but when you get down to the nuts and bolts the H means certain things that set an H engine apart from a plain old O, and those things would follow the engine wherever it ended up, even in a fixed wing aircraft should you decide to use it in one. I was trying to show that the model codes translate into more than just installation. That's all that's it.