Darrel Starr
Registered User
Plymouth, MN
I don't have a written explanation of the bump but as I understand the graph, that is the enriching coming into play at full throttle.
150 HP vs 180 HP
- Thread starter Charlie Longley
- Start date
Gordon Misch
MEMBER
Toledo, Wa (KTDO)
I think I figured it out. The table attachment you provided has a notation that Lycoming does not recommend leaning above 75% power. So it appears that the graph transitions from "best economy" to full-rich operation, presumably independent of the carb's auto-rich feature. I presume that because I know that it's possible to fuel-starve the engine at high power settings by over-leaning with the mixture control. So I suspect that the lower power portion of the graph could be linearly extrapolated into the higher power domain, but that it is not recommended.
bob turner
Registered User
So: we have decided we are talking about fuel flow at cruise. One poster says that he compares gallons consumed with the hour meter.
Since I do neither of those things, no wonder I burn more fuel than others do. My fuel burn computations are takeoff to touchdown wrist watch times, compared to gallons added next stop. I get 4.5 in the 85 HP J-3 and 9 GPH in the 180 Decathlon and 10 in the 200 Mooney.
Since I do neither of those things, no wonder I burn more fuel than others do. My fuel burn computations are takeoff to touchdown wrist watch times, compared to gallons added next stop. I get 4.5 in the 85 HP J-3 and 9 GPH in the 180 Decathlon and 10 in the 200 Mooney.
bob that seems like a more "real world" way to measure. Every flight is going to have a full power take off, full power climb and power off (or low) descent. Having said that , your averages would vary widely from flight to flight ie: a flight on the bald a#* prairie where you star a a low DA and climb to maybe 1500' AGL vs a flight in the mountains where you may take off at a 4000' DA and have to climb 6 or 7000' to clear that next ridge line. If all of your flights are from the same take off, cruise and landing elevatiosn tho you should get a good average
skywagon8a
MEMBER
SE Mass MA6
Darrel,
What was the source for this chart Power Setting & Fuel Consumption.pdf ? Was this a chart which you developed? It appears to be very useful. I would like to find a similar chart for a IO-360-B. Thanks.
What was the source for this chart Power Setting & Fuel Consumption.pdf ? Was this a chart which you developed? It appears to be very useful. I would like to find a similar chart for a IO-360-B. Thanks.
spinner2
MEMBER
Montana
My gph figures come from gallons indicated on the gas pump and hours on the hour meter (not tach time). For me that would include taxi time but for me that is just several minutes coming and going to the hangar.
Things like aggressive leaning at sub 75% power settings, fuel flow gauges, temperature probes on all cylinders and electronic ignition that changes timing and creates a hotter spark combine to produce economical operations.
Darrel Starr
Registered User
Plymouth, MN
Skywagen8a,
i save these charts & tables when I come across them in documents - mostly on-line in Lycoming documents. I will see if I can relocate it on line again.
i save these charts & tables when I come across them in documents - mostly on-line in Lycoming documents. I will see if I can relocate it on line again.
185 Bushbird
Registered User
Surfside SPB-Minneapolis, MN
Charlie, just get a 320, either 150 or 160, you can burn auto fuel in any of them but save the extra $ for time building. I have had 9 cubs on floats J3, PA12& 7 PA18's in my float training business, stick with a 150 or 160hp. It will cost less and be easier to sell when done with it. Many will look to deep into fuel burn, performance #'s, etc? but the 320 will do your friend just fine. If he wants to build hours this winter, he would spend less renting my 150 hp in Florida vs buying one and paying insurance, sales tax, maintenance, hanger- storage, etc. in 100 hours of float flying.
If you friend just wants time he should go get a pacer. I have a 160 cub and fly with a 180 cub a lot. I can't keep up with him and his fuel burn is the same as mine when I run 2400 rpm. If your friend plans to keep the cub AND MOVE TO ALASKA than he should buy a 180. The real cost is in the conversion and prop. He should not buy a 150 with the plan to upgrade!!! It will cost more in the long run. Now the big question is should he get stock or long wings if he is on floats!!! So what he may really want is a big wing cub with a 180:lol:
DENNY
DENNY
skywagon8a
MEMBER
SE Mass MA6
It is the pilot's responsibility to load the airplane within the proper CG range. A properly loaded 180 long wing Cub is a dream to fly, as is a 150 stock short wing Cub.
cubpilot2
SPONSOR
Anchorage Alaska
I totally agree.
My cub has the squared off wings and 180 hp. I flew it for 18 years with the 150 up until 3 years ago when I did the conversion. I still find myself grinning from the performance change.
The only thing perhaps out of the ordinary is the thrust line modification which I think is very important. The Penn Yan mount comes with -6 deg pitch vs. the original engine having -4 deg. The Thrust Line lugs bring it up to -2. I am sure that this has contributed to a lot of the negative reviews on the conversion; like "nose heavy....pig". With -6 degrees the engine is trying to pull the nose down.
.
I rarely touch the trim. It is not "nose heavy" on approach. I would say that there is little to no change in the way it handles.
I do agree that it does fly better when loaded towards the aft limits, but it was also that way with the 150hp.
Other then a slight vibration increase, (which is still less then running the old short original props) and a bit more fuel burn...(@2350, the same speed as when @2550 on the 150 and 1/2 gal per hour more ) I love it!
We all talk about trick performance mods and such, but I tell you what; the way this thing now drags me, the old lady, and sometimes the dog, out over the trees (on floats), is a huge jump in "performance".
Performance with skis.... I typically can see 1700 fpm at 65 - 70 mph IAS. (No passengers) Never came close to that before.
DW
Registered User
pacific northwest
Everyone talks about nose heavy with the 180hp conversion but by the time you put on the light weight accessories, exhaust,the lighter props you can get the weight down to a stock 150/160hp....yea yea you can lighten up the 150/160 and you would have a great flying cub. Now the squared off wing I agree you do lose some roll rate and I do like the look of the round tip wing I think if your not hauling heavy loads or on floats most of the time I would stay with round tip. And you can't fly one configuration on one plane and say there all pigs.
DW
DW
nanook
MEMBER
northern alaska
You'll (almost) never find an owner willing to state that spending tens of thousands of dollars of testosterone induced mods on his cub was a mistake. I've flown quite a few differant versions of these cubs on steroids. I'm talking about working cubs not stripped down for Valdez versions. From a working cub view of things, or do you want to spend all day flying this cub for a living. The heavy-extended-wing, 180hp cub would be my last choice. Keep telling yourself how great it is, someone may believe you....
Bill Rusk
BENEFACTOR
Sandpoint, Idaho
I will piggy back on what skywagon8a is saying above. The CG plays a HUGE part in all this. Most of the 180 cubs are probably tending to be a little nose heavy so they are heavy on the controls, require a lot of trim, and just don't fly all that good. If you load em up to get the CG a little further aft, that is great but then they are 200 pounds heavier. The best cubs were the 90 hp versions because they had the furthest aft CG, then the 150 came along and with the heavier engine they were much higher performance but they were heavier on the stick because of the more further forward CG.
Build a light 180 hp cub, put a little lead in the tail to get the CG back, and I'll bet it would be awesome (at least I sure hope so because that is what I'm trying to build)
More opinion only
Bill
Build a light 180 hp cub, put a little lead in the tail to get the CG back, and I'll bet it would be awesome (at least I sure hope so because that is what I'm trying to build)
More opinion only
Bill
get your papers out and do a real weight & balance check next time you fly solo... bet you are out the forward limit or real close. be sure to use the seaplane graph not the landplane
and ya... 150/160 is good.... as one of my old instructors used to say, the extra power just gets you that much higher in the next tree
and ya... 150/160 is good.... as one of my old instructors used to say, the extra power just gets you that much higher in the next tree
L18C-95
FRIEND
Oxford UK
I have to agree, even if I am biased. The 150 HP I operate comes in around 250 lbs heavier than the -95, so no useful load advantage, and feels much less sprightlier while using 70-80 % more gas. It also feels more nose heavy. It does come with 'essential' comforts such as gyros, electric system, landing/nav lights and metal flying controls.
it was ferried across the North Atlantic so I grant some of the equipment was pretty useful once.
Crash
GONE WEST
Nikiski Alaska
The problem with a certified 180 hp PA-18 is the choice of "good" legal props. THERE ARE NONE!!!!!!! end of story!
Experimental is another story. An O-360 might be an option using a Catto prop or Whirlwind, but for a certified PA-18, I always recommend an O-320. This is after 10 years owning/flying a stock wing O-360 Cub.
Take care,
Crash
Experimental is another story. An O-360 might be an option using a Catto prop or Whirlwind, but for a certified PA-18, I always recommend an O-320. This is after 10 years owning/flying a stock wing O-360 Cub.
Take care,
Crash
listened to my Dad rant for years about airplanes being nose heavy from bigger engines...
as I studied, learned, and flew more and different airplanes (with those words ringing in my ears), I finally figured it out. you can trim it to hold, the nose up. but sooner or later you're gonna run out of elevator. largely displaced trim tabs reduce control authority. a balance weight, to counter a c.g. problem increases the moment (weight x arm = moment) and now your trying to horse around all that extra moment. that makes it SLUGGISH !!! AH HA !!! THATS WHAT HE MEANT.
Don't think nose heavy, think pitch DULL. I love my 18-135 cause its balanced so well. the best it ever flew was w/out that heavy generator, a light weight starter, 8.50x 6's, and that skinny AM prop. I have compromised some of that for gains in other areas. but that's the compromises we make.
as I studied, learned, and flew more and different airplanes (with those words ringing in my ears), I finally figured it out. you can trim it to hold, the nose up. but sooner or later you're gonna run out of elevator. largely displaced trim tabs reduce control authority. a balance weight, to counter a c.g. problem increases the moment (weight x arm = moment) and now your trying to horse around all that extra moment. that makes it SLUGGISH !!! AH HA !!! THATS WHAT HE MEANT.
Don't think nose heavy, think pitch DULL. I love my 18-135 cause its balanced so well. the best it ever flew was w/out that heavy generator, a light weight starter, 8.50x 6's, and that skinny AM prop. I have compromised some of that for gains in other areas. but that's the compromises we make.
bob turner
Registered User
I get confused between the ancient parts of this thread and the recent parts. Just punched the button on Bill Rusk's post of a year ago.
I am fortunate to instruct in J-3s, PA-18s with little motors, and lately 160 and 180 HP versions. The 180 I am most familiar with came out of CC at about 1200#. There is nothing exceptional about it that makes it heavy - it has the standard CC Stits cover, and no extras except the normal stuff - VGs and blimp tires. Yes, it goes straight up, but it takes a bit more runway to launch than does a J-3. And yes, I would characterize it as a piglet otherwise - controls are not harmonious and well balanced. It is fun to go straight up! The Carbon Cub is way more fun, and outperforms it.
I am fortunate to instruct in J-3s, PA-18s with little motors, and lately 160 and 180 HP versions. The 180 I am most familiar with came out of CC at about 1200#. There is nothing exceptional about it that makes it heavy - it has the standard CC Stits cover, and no extras except the normal stuff - VGs and blimp tires. Yes, it goes straight up, but it takes a bit more runway to launch than does a J-3. And yes, I would characterize it as a piglet otherwise - controls are not harmonious and well balanced. It is fun to go straight up! The Carbon Cub is way more fun, and outperforms it.
I think a lot of people never feel the difference. sometimes u just don't know till u fly something that has exceptional balance, and is short coupled. when you do, it's a real awakening. then, you start picking apart everything else you get to fly.:???: cubs are a good step ahead of some others we fly.
the working class boys, out in the bush need the extra weight all the performance mods bring w/ them, in the name of getting it done, (safely). and they out there to work, not just for the quality flying experience some of us get to enjoy
the working class boys, out in the bush need the extra weight all the performance mods bring w/ them, in the name of getting it done, (safely). and they out there to work, not just for the quality flying experience some of us get to enjoy
