for my money it would be an 0320 and a climb prop so you can get out shorter and run mogas.

Ington,

I saw your post. I was responding to hotrod's post in any case.

As to your question regarding the 150 vs 160 hp Lycomings, I guess I wouldn't worry too much about it. I've flown O 320s of a bunch of different flavors and dash numbers, both 150 and 160 hp. In my experience, I've flown 150s that were pretty strong and also 160s that weren't all that strong. In other words, it really depends on the particular engine. Note that there are literally dozens of different exhaust systems for these engines, which can make a big difference in apparent power. And, there are a number of other features that affect the actual power output, not the least of which is wear and how the engine was overhauled.

It is worthy of mention that a pretty common modification is installing the higher compression pistons from a 160 hp engine into a 150. That is the primary difference between the two. That's not a simple "owner operation", of course, but not that huge a deal either. And, there are STCs for some models of 150 hp engine to do just that to convert to 160. Something to consider.

On the topic of auto fuel, I'm not sure I'd be red hot to run auto gas at the kinds of density altitudes you're talking about in any case......but, I'm no auto gas expert either.

I'd find one with what appears to be a good strong engine, mounted to a good solid airframe, and go from there. I wouldn't be afraid to buy a high time engine, either, and have it field overhauled, with the piston mod.....

Oh, and piston part numbers are something that's pretty hard to verify on an assembled engine, if you know what I mean...

MTV

mtv wrote:Ington,
...On the topic of auto fuel, I'm not sure I'd be red hot to run auto gas at the kinds of density altitudes you're talking about in any case......but, I'm no auto gas expert either....
MTV

I am no expert by any means, but it is my understanding that at higher altitudes, detonation is actually less of an issue with lower octane fuels. Detonation can have many contributing factors, but a simple way to think about it is the following:

At a constant fuel flow rate, dense air (low altitude) and a low octane fuel (higher compressibility) result in a lean fuel mixture (compared to that of a higher octane fuel with the same atmospheric pressure) and make detonation at wide-open throttle more likely. With the same amount of fuel (constant flow rate), higher altitude will richen the air/fuel mixture due to the atmospheric pressure drop as you increase altitude. This air has less oxygen per cubic foot than air at sea level, so the air/fuel ratio will become richer and act more like a high octane fuel, reducing the chance of detonation for a given type of fuel (mogas) at higher altitudes when compared to lower altitudes.

That said, based out of KLMO at 5050 msl, the 160hp would be nice, but we have mogas that is significantly cheaper than 100LL and I'm not sure that any performance gain would be worth the engine work and need to run 100LL. I don't have a climb prop either (although it would be nice) but I routinely fly in/around/over our mountains, just not when heavy.

akavidflyer wrote:for my money it would be an 0320 and a climb prop so you can get out shorter and run mogas.

The 160 hp 0-320s can still run mogas. Just has to be 91 octane. Thats per the EAA or Peterson autogas stc. Also, like Mike says, its fairly easy to upgrade a 150 to a 160. Basically just have to to the top end. Did it on a Citabria and did not cost too much. I wouldn't be scared at all to go with a 150 and do the 160hp stc conversion. And then burn 91 octane mogas. Best if bith worlds.

David

It may be easy to upgrade, may not. A lot of 150HP Tri-Pacers have the original narrow deck O-320 and can not be upgraded to 160HP just by a piston swap, it requires new cylinder hold down plates on top of the cylinder flanges. Also if you are looking at 160HP PA-22s make sure the crank AD has been taken care of.

Any opinions on the o-290 in some of the pacers? I know HP is king, and I've read that the 290s aren't the easiest to find parts for anymore. Are they dogs compared to the 320s?

I know a guy that has one in a Pacer, he has VGs and droop tips and if W&B's are to be believed his PA20 is about 150 pounds lighter than my PA22 (I have the full heavy gyro panel, his is pretty sparse, I have the heavy nosewheel, etc.). His plane gets off a little faster because of the VGs and lighter weight, though my 150HP plane will beat him in the climb. If they are kept nice and light they are pretty capable planes. My concern with the O-290 was parts availability but can't really say for sure if that is a legitimate problem or not.

UngaWunga wrote:Any opinions on the o-290 in some of the pacers? I know HP is king, and I've read that the 290s aren't the easiest to find parts for anymore. Are they dogs compared to the 320s?

Remember, the O290 engine is an orphan. I wouldn't buy one expecting it to be a long term relationship. Don't discount a good deal on a O290 powered Pacer, but be prepared to re-power it in the future, if not purely for the performance but for the maintenance costs.

Compared to the O320, the O290 climb and takeoff will suffer, but cruise will not be that much different. Comparing the 150 hp Clipper a buddy built to the O290 powered Pacer another friend had, they were both solid 125 mph planes.

UngaWunga wrote:Any opinions on the o-290 in some of the pacers? I know HP is king, and I've read that the 290s aren't the easiest to find parts for anymore. Are they dogs compared to the 320s?

Horsepower is not king. Lift is king. You are trying to get off the ground, at high DA, and climb to a higher DA. For this you need lift. The horsepower (thrust actually) is only what drags the wing through the air to make the lift. If you want to fly on power alone, go talk to the jet-pack and flying car guys... and lock your wallet in a safe somewhere else.

To make a lot of lift, you can have a big wing and not a lot of power (Taylorcraft, J-3) or you can have a lot of power and a smaller wing (Pitts Special, F-104).

Which airplane do you think will perform better high altitude STOL at EQUAL weight... a 150HP Tri-Pacer or a 150 HP Super Cub? What's the main difference between these two airplanes that use so many of the same parts and shapes?

Of course, more power is always better than less power, but do not forget or minimize the effect that the wing airfoil, area, aspect ratio, and lift coefficient has on the equation.

For example, with decent pilot technique an 85 HP Taylorcraft will operate safely out of a 7500 foot density altitude runway. So will an 85 HP Cub. The reason for this is more about lift, not power.

EZFlap wrote:

UngaWunga wrote:Any opinions on the o-290 in some of the pacers? I know HP is king, and I've read that the 290s aren't the easiest to find parts for anymore. Are they dogs compared to the 320s?

Horsepower is not king. Lift is king. You are trying to get off the ground, at high DA, and climb to a higher DA. For this you need lift. The horsepower (thrust actually) is only what drags the wing through the air to make the lift.

Thrust lifts weight too, if it's got an upward component. Ask some of those crazy aerobatic guys who hang it off the prop!

All other things being anywhere close to equal, the plane with more power almost always: climbs faster, lifts more weight overall, takes off shorter, lifts more weight out of smaller places, etc etc.

Between the 150 wing and the Pacer wing, the hp will likely be the deciding factor. The 180hp Pacer and the stock 150/150TD are very different machines.

Battson wrote:
Thrust lifts weight too, if it's got an upward component. Ask some of those crazy aerobatic guys who hang it off the prop!

All other things being anywhere close to equal, the plane with more power almost always: climbs faster, lifts more weight overall, takes off shorter, lifts more weight out of smaller places, etc etc.

Between the 150 wing and the Pacer wing, the hp will likely be the deciding factor. The 180hp Pacer and the stock 150/150TD are very different machines.

The difference between a Pacer wing and a Cessna wing means that all other things are not equal. With two identical airplanes, of course power makes all the difference. But 180 HP on a high lift Pacer wing and 150HP on a low pitching moment (lower lift) Cessna wing is apples and oranges.

Of course you always want as much power as you can get, or as much as you can afford to run gas through. Of course. But power doesn't always solve the problem of a smaller wing on a short runway. Yes it accelerates faster. But lift is always what gets a conventional airplane off the ground, and although power is a tool for doing that, it's not a substitute for wing area when you are talking about STOL flying. If power was enough to solve everything, the Antonov AN-2 would be a monoplane, and the winning Cubs at Valdez would have clipped short wings to save weight.

Yes, understood. I was asking in the scope of the Pacer, for a comparison of the 125/135hp and 150hp engines. The fuel savings are nice, and I don't plan on flying around at gross or at high density altitudes often. My local field is 93' MSL.
Then there's the solid lifters vs hydraulic lifters on the o-290? I think I have some reading to do on the short wing site.

But, the third leg of that performance equation is weight. Wing span and chord are limited by structural considerations, power is limited by fuel you can carry, and by the weight of engine and prop.

The ideal is the BEST wing design, with a moderately sized engine, kept as light as is practical.

MTV

Stewart tips and vg's should help. Plus cruise prop. Think that will make an ok performer out of any 150 or 160.

kevbot wrote:22/20-150. I learned to fly in it, based out of KLMO and routinely fly in the teens

kevbot, if you don't mind me asking; was the plane privately owned? or is it available for rent/instruction from an FBO or Flight Club on the field?

KLMO is the closest field to my house and I'm giving serious consideration to buying a Tripacer. My flying experience is 90% 172s. I have a few hours in Tomahawks and Warriors/Cherokees and a handful in the 182. Those are all extremely forgiving and easy to fly aircraft (just don't spin the Tomahawk), and I'm a bit nervous to buy a Tripacer without getting some time in one first.

I want to own vs. rent because I'd like the option of having the plane for an extended period of time as well as be able to fly into some grass/gravel strips (I've yet to see a flight school or FBO the explicitly allowed it). I'm mostly interested in doing cross countries to remote places in WY or SD for camping for my short term goal with the aircraft vs renting and boring holes in the sky along the front range. I'm not yet at the skill level to fly into the true back country and do true airport landings but would like to get there "some day". 150hrs of flying in Florida doesn't quite prepare you for flying into the mountains.

Personally the 150/152 is out of the question for me even if it had a 150hp engine because they are just too cramped. I've flown with my buddy in one years ago; because believe it or not his boss would let him fly it for free; and flying someone else's plane for free beats not flying at all. Even when I had the option to rent one at a lower cost than a 172 I always opted to pay more for the 172.

Rogue_Ryder wrote:

kevbot wrote:22/20-150. I learned to fly in it, based out of KLMO and routinely fly in the teens

kevbot, if you don't mind me asking; was the plane privately owned? or is it available for rent/instruction from an FBO or Flight Club on the field?

KLMO is the closest field to my house and I'm giving serious consideration to buying a Tripacer. My flying experience is 90% 172s. I have a few hours in Tomahawks and Warriors/Cherokees and a handful in the 182. Those are all extremely forgiving and easy to fly aircraft (just don't spin the Tomahawk), and I'm a bit nervous to buy a Tripacer without getting some time in one first.

I want to own vs. rent because I'd like the option of having the plane for an extended period of time as well as be able to fly into some grass/gravel strips (I've yet to see a flight school or FBO the explicitly allowed it). I'm mostly interested in doing cross countries to remote places in WY or SD for camping for my short term goal with the aircraft vs renting and boring holes in the sky along the front range. I'm not yet at the skill level to fly into the true back country and do true airport landings but would like to get there "some day". 150hrs of flying in Florida doesn't quite prepare you for flying into the mountains.

Personally the 150/152 is out of the question for me even if it had a 150hp engine because they are just too cramped. I've flown with my buddy in one years ago; because believe it or not his boss would let him fly it for free; and flying someone else's plane for free beats not flying at all. Even when I had the option to rent one at a lower cost than a 172 I always opted to pay more for the 172.

Reviving a thread from the dead!

The plane was privately owned. I'd offer to let you come look/go on a flight, but I brought it out to CA a while back after I graduated from college. Sounds like a Pacer would be a great plane for what you want and they're nothing to be afraid of. Pacers have very docile flight characteristics and the [taildragger] ground handling also won't bite you, it'll just do what it's told. I've never flown a Tripacer, but there used to be a couple actively flying around the front range area that you may be able to meet up with. I'd definitely recommend flying a variety of a/c before purchasing anything. There's plenty of a/c that'll fit your mission so don't get too fixated on a particular example or type.

The -135 Pacer is a pokey Pacer. Still very capable. Just not at gross weight.

The -135 Pacer requires about 60% of rated power to maintain altitude at gross weight at 12k'. That's around 80hp. The power produced at 12k is around 70% of rated at 12k. That means the climb power is around 14 hp. That means the plane can climb at roughly 230 fpm theoretically at gross at 12,000' density altitude, a pretty accurate calculation compared to reality (I always figured 200 fpm max up at 12k').

The -150 Pacer has the same performance needs, but that ~15 extra rated hp becomes about 11 extra horsepower at 12k, which puts the expected climb rate at 12k at about 400+ fpm, again very close to actual experience.

The difference makes the climb gradient on takeoff at any altitude pretty striking...perhaps 20-30 percent more altitude per mile, pretty important when the trees are getting larger.

Thanks for the inputs! I will not get hung up on 1 make/model of A/C, the Tri-P is appealing because it seems like it's got a better load carry capability than a 172 and since the only 172 that'd even be close to my price range at this point would be an O-300 powered one the Tripacer would be cheaper to overhaul as it has 2 less cylinders.

With the pretty large amount of EAA activity out at KLMO I may go down the EAB route, but I don't have time to build myself at the moment (It's taken me almost a year to build an engine for my muscle car and I still don't have it in the car yet), so the likelihood of me finishing an aircraft in a reasonable amount of time is pretty low.

Keep in mind, Pacer wing area (small) and higher altitude. Wing area comes into play more at higher altitude.

You say this 150/150 has “high gross weight”, what is that gross weight? What is the legal useful load with this exact airplane?

MTV brings up excellent points but if like you say the airplane you are interested has a higher legal gross weight and depending on how much then the 150/150 may be a consideration.

Kurt

I found 150 hp Tri-Pacers to be the best mountains flying trainers at Gallup New Mexico. The tailwheels were mostly 135 hp then and more expensive. The CAP 172 and pipeline 172s and 150 hp 152s didn't do as well, but adequate.Colts and 135 hp Tri-Pacers worked fine with two people. My students took all of them off airport.

Is Shelly's Cottages still in business in Lyons? I lived there building Boulder CC and Fairway Livings in 1963 and soloed the Kensair 90 hp SuperCub at Jeffco that had been ground looped and rebuilt seven times.