F

Flyrod

Well Known Member
:eek: What can Lycoming get out of their IO 360s if they are not worried about certifying it? How about 225HP at 274 lbs! I ran across this engine in a listing of Lycoming products. It is called the IMO-360-B1B. The customer was listed as a defense contractor, so Imagine they are putting it in a drone or UAV.

Anybody know about this engine? What are they doing to produce all that HP in 360 cubes? Just curious.
 
The only way to increase HP if the cubic inches remains constant is to either increase the RPM or raise the compression ratio.

So, adding a turbo or supercharger, or letting the revs go higher will get you the extra horsepower pretty easily.

We can not really use more RPM because of propeller issues, but on some drones it might be practical, say with a smaller diameter multi bladed design.

Another thing not mentioned is fuel consumption and longevity. These always suffer as HP is increased.

There is no free lunch!
 
pvansrv3 said:
The only way to increase HP if the cubic inches remains constant is to either increase the RPM or raise the compression ratio.
Click to expand...

Oh my, not to be disrespectful, but you are so far off base here.

There are many ways to increase HP other than above. Just a few----cam timing, cam profile, intake tuning, exhaust tuning, ignition system optimization, head work--valves, ports etc, chemical coatings, drag reduction, and the list goes on.

pvansrv3 said:
There is no free lunch!
Click to expand...

True. Very true. But if you are willing to pay for it, there are a lot of gourmet choices out there.

By the way, Lycon in Calif, has modified many 360 to the 240+ HP range, and these engines are still quite reliable. I have a friend who ran one in a RV 6, flew it for years with no problems.
 
LyCon uses a 10.5 to 1 piston to get that power though. Although LyCon swears by porting I've always wondered about just how much good it does. The main thing I've wondered about is this. At the RPM that our engines are turning the air velocity through the ports doesn't seem to me to be high enough to make that MUCH difference to power given back. As far as cams go they have limits on just how much good they can do. They're fine for putting the final touches on power increase but a cam wouldn't be at the top of my list of things to worry about for power. I'd be more inclined to making the compression mod. At 10-11,000 ft. you're power output is 65% at best. Any increase in power at sea level altitude becomes vanishingly small at cruise altitude.
 
Mike S You are right, theoretically, and I stand corrected.

But if you change cam designs then you might affect running at idle, tuning intakes and exhausts might help a little but only at maximum power at sea level. In a practical world,as relates to porting and polishing, as soon as you are running at altitude, the mass flow rates are reduced so the net effect is lost. Unless you fly at sea level a lot.

The simplest and easiest and cheapest way to raise HP is to cram more air and fuel through the cylinders by increasing compression ratio or rpm. That raises temps, fuel burn, costs to operate.

If there was a free lunch, why do pilots all over go buy the $200 hamburger?
 
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