HIO-360 Info?

[shorebird]

Any of you guy's have experience building up an HIO-360 for use in an aircraft? I'll be using basic stuff, flowed cyl's, 10:1 forged pistons, pressure carb, magneto ignition and x-over exhaust. The flat mount works well for my application but the cam seems to be the issue. I have been told that the helicopter cam is a long duration cam and not what I want for my purpose. I'm looking for the most HP for the buck like everybody else.
Any comments are welcome.

Thanks

[Mel]

Another disadvantage of the helicopter engine is that it is rated at a higher RPM, not well suited for a direct drive prop.

[mahlon_r]

As far as I know, all 4 cylinder 320,360 Lycoming two mag style engines, currently use the same cam. LW-14880 or equivalent. O's, IO's, HIO's,320's,360's, 160 hp, 150hp, 180hp, 200hp, 210 hp etc., all use the same cam.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at you own risk."

[pierre smith]

Mel, I believe the reason for the higher RPMs is simply because it's NOT connected to a prop that limits the RPMs as ours do. Formula ones turn over 4000 because of the lack of pitch, not because the engines are rated for that power, as you know.

I'm surprised by Mahlon's post that all 4 cyl Lycs use the same cam! So the increase in HP from 150 to 200 is just displacement and compression ratios? That being the case, is there not a high performance cam out there yet, or a cam that will make more horsepower at the 2700 RPM redline?

[atreff]

What crankshaft does the HIO-360 use? Counterbalanced or not?

Art

[mahlon_r]

Not.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at you own risk."

[atreff]

Mahlon,
So, the HIO uses a non c-weighted crank, same cam. My understanding is that the HIO uses a different cylinder head that has a larger exhaust valve to accomodate the heat from the higher compression. Is that correct?

I couldn't get a straight answer out of Lyc on this: is the HIO's crank, case and main bearings different to handle the higher compression? I would expect that the thrust bearing is different, since there is no thrust pulling against it.

Art in Asheville

[mahlon_r]

Depends on which HIO. The D1A model uses a different bigger intake valve then the other 200HP cylinders. The parallel valve HIO?s use the same cylinders as the O and IO-360.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at you own risk."

[shorebird]

Thanks for the responses to questions regarding HIO-360.
With further investigation I have found that the cam and the crank in my HIO-360 B1A are the same as a stock O-360. I checked the etched part numbers on both and found them to match with the O-360 parts manual. All bearings are the same as well. I then spoke with Brian at Air support Int. and he confirmed that only the D1A has some differences.
Apparently, no accommodation is made for the higher RPM rating (2900rpm), it's simply a matter of Lycoming certifying the engine to turn faster in helicopters.

[RVbySDI]

Originally Posted by shorebird

Thanks for the responses to questions regarding HIO-360.
With further investigation I have found that the cam and the crank in my HIO-360 B1A are the same as a stock O-360. I checked the etched part numbers on both and found them to match with the O-360 parts manual. All bearings are the same as well. I then spoke with Brian at Air support Int. and he confirmed that only the D1A has some differences.
Apparently, no accommodation is made for the higher RPM rating (2900rpm), it's simply a matter of Lycoming certifying the engine to turn faster in helicopters.

Hmmmmm, does this mean that an engine. . . is an engine. . . is an engine?