160 hp engine options

[delusional]

I plan on a FP 150-160hp engine that can run auto fuel if necessary. Given those parameters, why would the 160 hp io-360-l2a 2400 rpm derated engine not be the "best" choice? I am early on still so this is just brainstorming, really just want to know if I haven't thought of some major disadvantage, but my main rationale is as follows:

- the 160 hp rating would be fully supported by Vans
- small weight penalty compared to 0-320
- lower engine speed means lower tip speed, thus quieter
- fatter torque curve means better thrust at takeoff
- more popular engine makes spares easier to get

So, aside from the weight penalty, and perhaps a bigger, more expensive prop, why is this not an ideal solution?

 

[N941WR]

Why de-rate the engine? With the standard compression you can still run premium unleaded.

I would expect that if they ever release 100UL, then you will be able to run it or premium.

As for options, get your O-320 with a hallow crank and have it plugged. Then you can add a CS prop later, if you want.

You can always retard the timing a little bit, if you are really worried. This can also be don programmatically with P-mags.

The other option is to install a 150 hp O-320 and just not worry because that engine will just about run on water.

 

[delusional]

lower tip speed

Why de-rate the engine? ...

Fair question, Bill, and I know you speak with great authority when it comes to Lycoming engine options on the 9; The reasons to derate are two: less noise, and Van recommends it. I'm not against overkill regarding power, but isn't 160hp _enough_ overkill?

It hadn't occurred to me to limit the revs any way other than the usual methods of careful prop selection and a red line painted on the tach face; but the ignition method is food for thought.

I admit the nearly universal fuel compatibility of the low-compression 320 is attractive...

 

[N941WR]

Richard,

A FP RV (or any FP plane for that matter) isn't really that loud as the prop isn't going to turn at full RPM until you are up high and the plane has accelerated to max cruise speed.

I wouldn't de-rate anything but you can always do a partial power takeoff, the plane will definitely do it.

People are constantly telling me how quiet my RV is, on both take off and landings. Particularly on landing; more than once I have taxied to the ramp and the people I?m meeting were sitting outside had commented that they didn?t hear me land. As for the takeoff, the plane climbs so well, you will be up and away long before the noise bothers anyone. My -9 is the first plane I?ve flown that will allow me to exit Class Delta airspace through the top.