REFLECTOR:Engines

[reflector@tvbf.org]

At 07:54 AM 4/22/04 -0400, you wrote:
All the same arguments we used when we went from the 360 to the 540 on the 
Berkut.  Let me throw in a couple more.

1) 540's aren't significantly more expensive on the used market than 
360's.  Cores can be less.  Rebuilds, of course, are more, but not that 
much more.

2) I *think* that the CG change will be the same solo or dual.  Add weight 
to the nose either in useful equipment or lead pushed forward to counteract 
the 80-100 lb engine difference, after that the CG shift with load will be 
just like a 360.  I think.

3) It's an easy engine to hotrod.  We get 300 hp out of them with nothing 
but porting and 9.5:1 pistons.  The 235 hp engines are exactly the same as 
the 260 hp, the rating is just done at a different RPM.

4) Smooooooth.

5) There's no replacement for cubic inches.

6) like you said, fly on a cruise prop, climb performance is as good or 
better than a 360 with a climb prop.

7) NO LOSS OF FUEL EFFICIENCY.  The fuel specific stays the same.  If 
you're in formation with an identical airframe but with a 360 engine, 
you'll have almost the same fuel burn - yours will be just a touch higher 
because you're hauling the extra 80 lbs.

The CG is the key.

>I am considering engine options for my 173 Elite RG.
>
>Option 1.  Does anyone know of a used Franklin 220 available.  My current 
>preference is a Franklin 220 with an IVO In-flight adjustable prop, but 
>don't know if I can find a Franklin.
>
>Option 2.  Has anyone heard of installing an O-540 (250 Hp version) in a 
>173 RG.  Here is my thinking (shoot holes in the theory as required)  I do 
>not want to pay the high price of an MT (a real budget buster.)  The 
>majority of my flying will be long cross countries so a fixed pitch prop 
>optimized for cruise would be preferred.  With that prop I realize the 
>trade off is longer takeoff distance and reduce climb performance.  So in 
>comes the O-540, the additional horsepower will compensate for the lower 
>climb performance prop.  (Lower climb fuel economy is OK.)  Other 
>disadvantages: modifying the cowling (its only time),  increased empty 
>weight (81 pound, I can live with that), more front ballast required when 
>flying solo (can live with that too.)  Possible advantages: increased 
>engine life (will be running slower than normal operating limits, lower 
>CHT etc.), high density altitude or short strip - will have a little extra 
>HP available.
>
>I welcome anyone's opinions or comments on #2.
>
>Thanks,
>Joe