Kenmore has a gross weight increase to 3190lb that my 1967 C180H is eligible for. Does anyone know what kind of performance I could expect out of a 180 with stock wing, stock engine and 88 inch two blade? Takeoff and climb performance are not terrible at 2800 lb, but I wonder how it woul perform with 400 lbs more on board.

Your wing is the same as the 1970 Skylane that I owned with a pard back in the mid 70s. Fully loaded to its authorized 2950 gross weight, it would climb out of Laramie on a cool morning, i.e., with the DA about at field elevation, at about 400 fpm. I would think that an additional 240 lbs. would deteriorate that climb rate some, but not dramatically. The 1979 TR182 that we traded the original Skylane in on would climb out with its full gross load of 3100 lbs. at about 600 fpm, but it had a slightly different wing, and of course, the turbocharger.

Cary

With increase in weight of 100 lbs decrease takeoff and climb by 10℅ with no other changes.

Something to bear in mind: Just because the LEGAL gross weight is 3190 doesn't mean the operator MUST always operate at that weight. In relatively low density altitude conditions, that weight will work fine. If it's hot and high, reduce your takeoff weight. More flexibility is a good thing.

Kenmore has operated their 180s at that weight for decades....on floats.

MTV

I always fly as light as I can, and seldom fill the tanks all the way up.

We adventured in a C170 to Alaska last July, running 50-100 lb under gross when the tanks were full. Learned a serious lesson from that one! Taking off from 1500 and 2000 foot field elevation runways (never above 6000 ft DA) on warm days It had horrible climb performance, which most of my previous experience told me that these numbers would be OK. It was that extra 100 lb that puts it over the edge. We would rotate at 800-1000 feet, but needed to accelerate and climb, and it had very little to accomplish this with.

I would guess that climb performance vs. weight is not a linear relationship. I am wondering if at 3190# the C180 will suffer a similar plight as the 170, more out of curiosity than having a strong desire to fly around at this weight.

Call Kenmore and ask about performance. They'll have numbers. I've flown them on floats at near SL density altitude, and they do fine. Kenmore is a stand up outfit...ask em for numbers.

MTV