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There are some excellent reasons to go for the fuel injected engine but

probably the most salient is the lack of susceptability to carb ice.

Doesn't mean you can forget about providing an alternate air source, if

your main air inlet solidly ices up, you need a way to keep your engine

breathing or the silence will be deafening! One way the certificated

machines handle the task is to provide a spring-loaded door somewhere in

the intake plenum that automatically gets sucked in by the resulting

vacuum that ensues when the normal inlet stops up. Making it automatic

might be a little fussy to get rigged but it's worth it.



As with anything good, there are tradeoffs. Fuel injection is more

complex than carburation meaning there are more things to fail. For

one thing, the injection pump (hi-pressure fuel pump) has to run to get

fuel to the cylinders. Of course, this is being done by the thousands of

hours, probably every day so this may not be too much of a consideration.

Further, injectors are somewhat more prone to being affected by a bit of

debris - happens infrequently, but happens. It may not shut your engine

down. However, a cylinder could be damaged by a plugged injector because

it could go way lean, inducing detonation.



The one other thing I've observed with injected engines on a couple of

friend's airplanes is the infamous "hot-start" problem. This may not be

a fuel injection problem but may only be a "people problem".



One other thing: if you've got an engine producing 200 HP, it matters

not whether it's being produced by normal aspiration or by injection -

the airplane doesn't fly a whit different - 200 HP is 200 HP and air

density (and therefore, power) falls off exactly the same for both

engines as you climb. Are you maybe thinking of turbocharging?

If you can get that same 200 HP continuously as you climb into less

dense air, then your airplane WILL climb faster and probably fly faster

at altitude since you'll be able to maintain the 200 HP (or whatever)

up to high altitude.



I'm sure there are many more things to consider in addition. These are just

the few that come to mind.



Cheers,



Dan Schaefer

N235SP