The International Cessna 170 Association

Well had 10 mins to my self and started thinking[??? ??] what was the weight difference between the continental powered and the Lycoming powered aircraft that I have [170A] . So a search back through all the old paper work and a eye opener was had with the Lycoming powered aircraft is 10.5 kgs or 23 lbs heavier. I can't believe it as it has the light weight starter and a light weight alternator fitted. Even the voltage regulator is lightweight [solid state]. I believe the sensenich prop is lighter. So where is the weight increase with 4 cylinders instead of 6. I still love the 4 banger for its grunt. However the fuel consumption for the same trips have dramatically decreased with the Lycoming But I have fitted GPS also . Another point is that I get to altitude a lot quicker also . {please note . The aircraft was weighed with the same calibrated scales. ]

I have the Avcon conversion, and if I recall correctly most of the weight increase is in the constant speed prop. And since it's all up front, it has a much larger affect on the CG.

DEM

I fitted a Sensenich fixed pitch prop [60 in pitch] due to concerns it being nose heavy. However it has turned out a good choice BUT that new MT prop is looking very good. Also a Mc Cauley has a new composite prop [fixed pitch] also . There is a story getting around about the Mc Cauley prop having a extra 100 lbs of thrust and no rev limitations .

I wouldn't trade my constant speed prop for anything. It more than offsets the small weight change, and I can address the CG by carrying all the crap I always carry (tie down kit, quart of oil, spare headset, etc....) in the baggage area.

DEM

The constant speed prop was considered but a C OF G calculation put it on the very edge of being too nose heavy. Putting the battery down in the tail was a no no as they get hammered by vibration and bouncing around on rough landing surfaces.
So the battery was put on the fire wall and light weight starters and alternators were used . I used to carry a heap of junk in the back [spares that might come in handy one day] but had a big clean out . Having junk in the back cost fuel and load carrying capacity plus performance of the aircraft . Some clown - I do not like this person] suggested that I bolt on 15 lbs of lead weight to the tail wheel spring and not have any issues with C OF G . I will not go on what I thought about this . So using the Sensenich prop I am with in the manufactures specifications . however those new composite fixed pitch props that cost a arm and a leg are very attractive .

When making the choice to do the engine upgrade thing, I checked "book" weight differences & found the weight between the Cont O300 & the Lyc IO 360B1E was within 3lbs of each other. Pretty much even money. Time will tell when we step on the scale.