The problem is not just the engine reliability, it’s the whole system reliability.

If you ran lower compression pistons or turbo normalized it, then okay maybe 200hp is reliable.

But what prop and PSRU combo are you going to trust at those power levels?

Remember, with auto conversions (or sleds) it’s rarely the engine the fails, it’s everything else. PSRU, pumps, fuel system issues, cooling system issues, electrical system issues.

I used to have a 190hp 1000cc big bore arctic cat. The engine had case porting, transfer port porting, aftermarket custom head, pinned and welded crank, rifle bored carbs, pipes, no oil injection, exhaust valves pinned open (not like they did much after the overbore), more timing.

The engine ran good and it was silly fast, the reliability issues were short clutch life, and the flipper on the right side would explode a belt if you weren’t thinking about what you are doing.

Now I have a 150HP stocker. I hold it to the bar all day long and for the most part don’t need to worry about anything blowing up.

I contend that 150 in that airplane is a lot, and not thinking about when your PSRU is going to explode will add some enjoyment to flying.

Schu

Groppo Trail?

Nobody ever seems to mention, when talking about more horsepower being more "stolworthy" that the extra weight sure as heck doesn't help when LANDING, especially when landing with MORE FUEL, needed to keep that bigger engine running for more then a couple hours.

courierguy wrote:Nobody ever seems to mention, when talking about more horsepower being more "stolworthy" that the extra weight sure as heck doesn't help when LANDING, especially when landing with MORE FUEL, needed to keep that bigger engine running for more then a couple hours.

To be fair, that's not always an issue.

I can set my IO-540 to cruise at the same airspeed and power settings as an O-320, for almost exactly the same fuel burn. Like a Cub, 28 L/hr and 95 knots is easily done in the Bearhawk.

I am sure the same rule applies to smaller motors (without FADEC). Easy to pull back the throttle a bit further.

not meaning to get this thread too far off topic...but do you plan on insuring this 'dream plane'? If you do or are required to by the state you live in, you might want to make sure you can even find an insurer that will insure the plane with a 'non-aviation' engine. There are insurers out there that will insure you, but the cost may give you a bit of sticker shock.

Ok, back to engine talk with Click and Clack!!