I'm looking for a bit of "schooling" on horsepower upgrading and the real truth.
Let's start with a basic 0-360 that's never been altered or otherwise "enhanced"; what are the possibilities worth considering that don't run the risk of negatively effecting reliability.
What can be done to the "top end", pistons, port & polish, cold induction, performance exhaust and the realities of each. How will the various options better the basic specifications; are these enhancement supported by documentation or seat of the pants assessment's. Please offer your experiences be it via STC, FA or otherwise.
Is this a Holy Grail or can real substantial gains be achieved.
HP Upgrading: The Real Truth
Sat Sep 11, 2021 4:17 pm
Sat Sep 11, 2021 5:58 pm
Re: HP Upgrading: The Real Truth
In my experience upgrading incrementally is a great way to spend money for a very modest increase in performance. While it’s easy look at take off or climb performance etc. on an upgrade I’ve tried to look at the long term incremental cost vs. performance.
I’ve found it’s better to stick with what you have and operate it efficiently vs. going “all in” unless absolutely necessary. Sometimes your situation may necessitate the power/ performance upgrade. If that’s the case then I’d go for it all in. If the upgrade is a “nice to have” then I’d run the numbers pretty closely
I’m sure you come to a very logical conclusion Maple.
MW
I’ve found it’s better to stick with what you have and operate it efficiently vs. going “all in” unless absolutely necessary. Sometimes your situation may necessitate the power/ performance upgrade. If that’s the case then I’d go for it all in. If the upgrade is a “nice to have” then I’d run the numbers pretty closely
I’m sure you come to a very logical conclusion Maple.
MW
- 185Midwest offline
- Posts: 437
- Joined: Sun Sep 30, 2018 11:58 am
- Location: Fort Wayne
- Aircraft: C-185
Sat Sep 11, 2021 8:12 pm
Re: HP Upgrading: The Real Truth
Bear in mind the old saw: “Opinions are like assholes, we all have one, and the only one that doesn’t stink is mine.”
With that out of the way, it’s impossible to answer your question accurately, because you didn’t specify what you HAVE.
Are you going to have to overhaul that engine anyway? If so, I’d definitely get it ported and polished. If not, I wouldn’t even consider it.
Do you currently have an exhaust system that will work, and in good shape? If so, I’d stick with that, but maybe gut the flame tubes to flow better.
But, if you’re going to have to buy an exhaust, I’d buy a Powerflow system.
I’d definitely use a constant speed prop…..you just give up too much power with fixed pitch. Period! No way I’d use a fixed pitch prop. And my preference is MT or “brand H” composite.
I would MAYBE consider electronic ignition, at least on one side. Save weight and hotter spark.
Other than that, I’d try to keep it light.
A Good strong O-360 with a strong prop is a beautiful thing. It really doesn’t need a lot.
MTV
With that out of the way, it’s impossible to answer your question accurately, because you didn’t specify what you HAVE.
Are you going to have to overhaul that engine anyway? If so, I’d definitely get it ported and polished. If not, I wouldn’t even consider it.
Do you currently have an exhaust system that will work, and in good shape? If so, I’d stick with that, but maybe gut the flame tubes to flow better.
But, if you’re going to have to buy an exhaust, I’d buy a Powerflow system.
I’d definitely use a constant speed prop…..you just give up too much power with fixed pitch. Period! No way I’d use a fixed pitch prop. And my preference is MT or “brand H” composite.
I would MAYBE consider electronic ignition, at least on one side. Save weight and hotter spark.
Other than that, I’d try to keep it light.
A Good strong O-360 with a strong prop is a beautiful thing. It really doesn’t need a lot.
MTV
Sat Sep 11, 2021 8:41 pm
Re: HP Upgrading: The Real Truth
Definitely agree with doing the head work if you are doing an overhaul. In my opinion it is the easiest, most cost effective, and reliable way of getting the most out of an engine. Back in my Robinson mechanic days, I came into a flight school that was overhauling their own aircraft and engines. The only thing out of the norm that they were doing from any other shop was having their cylinders ported and polished during the overhaul. I came from a school that did no polish work, and we probably changed the engine to transmission drive belt maybe once a year to every six months per aircraft. This new shop had us doing the belts on each machine about once a month if not more often, due to the extra power stretching the belts on auto-rotation recovery. For them it was a waste of money, but it proved to me that polishing cylinders was obviously going to pay dividends for a fixed wing setup. Other than a polish job, good baffling and a proper magneto time, I don’t know too many other options that would gain you much more on a carbureted engine without an STC modification. That being said, watching the retrofit fuel injection systems that you can buy for older cars and trucks now has me dreaming of some sort of aircraft application. Perhaps someday in the near future…
- IdahoWilly offline
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- Joined: Tue Aug 13, 2019 8:38 pm
- Location: Greenleaf
- Aircraft: Cessna 182
Sat Sep 11, 2021 11:02 pm
Re: HP Upgrading: The Real Truth
One thing to keep in mind is when you start with a basic stock motor of most any kind it was built with cost and longevity in mind. You can increase power but usually at a cost of cash or longevity. The other MOST IMPORTANT FACTOR is HP increase in not stacked with mods. If you say porting is good for a 10 percent increase, exhaust is good for another 10 percent increase, air filter good for 10 percent increase. That will not give you a 30 percent increase!! Look hard at what your plane/engine has, ask around, pick the choke point/best increase single mod and do that. Once you get even close to that first 10 percent increase the rest is better spent in FUEL. DENNY
DENNY
Sun Sep 12, 2021 8:07 am
Re: HP Upgrading: The Real Truth
I'm curious about "porting & polishing" aircraft engines, in particular certified (non-experimental) engines.
As I understand it, a certified aircraft engine must be overhauled in accordance with the mfr's overhaul manual.
Where in their OH manuals do Lycoming or Continental spell out the port & polish procedure?
Seems like an STC would be required, or maybe spell it out in a CRS's operating certificate.
As I understand it, a certified aircraft engine must be overhauled in accordance with the mfr's overhaul manual.
Where in their OH manuals do Lycoming or Continental spell out the port & polish procedure?
Seems like an STC would be required, or maybe spell it out in a CRS's operating certificate.
Cessna Skywagon -- accept no substitute!
Sun Sep 12, 2021 10:19 am
Re: HP Upgrading: The Real Truth
Horsepower makes heat so be sure your plane can cool the additional heat- oil and cylinder head temps.
Weight takes horsepower to move it. If you haven't already done so put your airplane on a diet. Lose the old radios, steam gauges, the speaker in the ceiling with the heavy magnet, firewall the battery and go lithium, utility interior, lightweight starter, lightweight alternator. Take the paint off the plane. Lightweight oil pan. Titanium axles. Are there tires and wheels that are lighter than what you have now but essentially the same size?
What do you always carry in the plane? Lighter versions? Titanium, plastic. KUIU jackets, pants, raingear, sleeping bags, tents.
How about what you wear? Heavy hiking boots? Maybe switch to Oakleys or some other lighter weight brand. How about you? Are you overweight? I certainly am and I've already lost 35 pounds in three months by eliminating sugar and wheat from my diet, another 35 to go. The SQ2 is happier. I am happier.
Grams add up to ounces, ounces add up to pounds.
Drag takes horsepower to overcome which creates heat. Put on a speed kit (EXCEPT for the flap gap seals if the flaps work better with airflow going through the gap- like Fowlers). Put on a Sportsmans STOL kit along with BLR VG's, you'll increase the wing size reducing takeoff/landing speeds without affecting cruise speed. You'll gain back a little weight but that will be cancelled out plus some by the performance of the Sportsmans/VG's. Lose the big rotating beacon atop the tail.
As MTV mentioned a constant speed prop- will add substantial weight but increase performance across the board.
Oh yea, you said horsepower.
IO360 (mechanical injection) in place of the O360 will give you a good HP increase and let you cruise LOP. Cold air intake also if it isn't part of the IO. And a low restriction, tuned exhaust system. A low restriction air filter element.
Call Lycon and talk with them about port and polish benefits. High compression pistons are going to bring heat and probably restrict you to Avgas.
Hope this helps. Let us know what you do and whether you think it was worth it.
Weight takes horsepower to move it. If you haven't already done so put your airplane on a diet. Lose the old radios, steam gauges, the speaker in the ceiling with the heavy magnet, firewall the battery and go lithium, utility interior, lightweight starter, lightweight alternator. Take the paint off the plane. Lightweight oil pan. Titanium axles. Are there tires and wheels that are lighter than what you have now but essentially the same size?
What do you always carry in the plane? Lighter versions? Titanium, plastic. KUIU jackets, pants, raingear, sleeping bags, tents.
How about what you wear? Heavy hiking boots? Maybe switch to Oakleys or some other lighter weight brand. How about you? Are you overweight? I certainly am and I've already lost 35 pounds in three months by eliminating sugar and wheat from my diet, another 35 to go. The SQ2 is happier. I am happier.
Grams add up to ounces, ounces add up to pounds.
Drag takes horsepower to overcome which creates heat. Put on a speed kit (EXCEPT for the flap gap seals if the flaps work better with airflow going through the gap- like Fowlers). Put on a Sportsmans STOL kit along with BLR VG's, you'll increase the wing size reducing takeoff/landing speeds without affecting cruise speed. You'll gain back a little weight but that will be cancelled out plus some by the performance of the Sportsmans/VG's. Lose the big rotating beacon atop the tail.
As MTV mentioned a constant speed prop- will add substantial weight but increase performance across the board.
Oh yea, you said horsepower.
IO360 (mechanical injection) in place of the O360 will give you a good HP increase and let you cruise LOP. Cold air intake also if it isn't part of the IO. And a low restriction, tuned exhaust system. A low restriction air filter element.
Call Lycon and talk with them about port and polish benefits. High compression pistons are going to bring heat and probably restrict you to Avgas.
Hope this helps. Let us know what you do and whether you think it was worth it.
- Barnstormer offline
- Posts: 2700
- Joined: Sun Oct 14, 2012 7:42 am
- Location: Alaska
- Aircraft: C185
Sun Sep 12, 2021 11:33 am
Re: HP Upgrading: The Real Truth
Barnstormer wrote:Horsepower makes heat so be sure your plane can cool the additional heat- oil and cylinder head temps.
Weight takes horsepower to move it. If you haven't already done so put your airplane on a diet. Lose the old radios, steam gauges, the speaker in the ceiling with the heavy magnet, firewall the battery and go lithium, utility interior, lightweight starter, lightweight alternator. Take the paint off the plane. Lightweight oil pan. Titanium axles. Are there tires and wheels that are lighter than what you have now but essentially the same size?
What do you always carry in the plane? Lighter versions? Titanium, plastic. KUIU jackets, pants, raingear, sleeping bags, tents.
How about what you wear? Heavy hiking boots? Maybe switch to Oakleys or some other lighter weight brand. How about you? Are you overweight? I certainly am and I've already lost 35 pounds in three months by eliminating sugar and wheat from my diet, another 35 to go. The SQ2 is happier. I am happier.
Grams add up to ounces, ounces add up to pounds.
Drag takes horsepower to overcome which creates heat. Put on a speed kit (EXCEPT for the flap gap seals if the flaps work better with airflow going through the gap- like Fowlers). Put on a Sportsmans STOL kit along with BLR VG's, you'll increase the wing size reducing takeoff/landing speeds without affecting cruise speed. You'll gain back a little weight but that will be cancelled out plus some by the performance of the Sportsmans/VG's. Lose the big rotating beacon atop the tail.
As MTV mentioned a constant speed prop- will add substantial weight but increase performance across the board.
Oh yea, you said horsepower.
IO360 (mechanical injection) in place of the O360 will give you a good HP increase and let you cruise LOP. Cold air intake also if it isn't part of the IO. And a low restriction, tuned exhaust system. A low restriction air filter element.
Call Lycon and talk with them about port and polish benefits. High compression pistons are going to bring heat and probably restrict you to Avgas.
Hope this helps. Let us know what you do and whether you think it was worth it.
Actually, there are two versions of the O/IO-360: Parallel Valve and Angle Valve. The Parallel Valve IO 360 is still rated at 180, in stock Lycoming version. The Angle Valve IO-360 is a very different engine, and is rated at 200 hp in Lycoming trim. Granted, both these engines can be bumped in HP with mods, and there are LOTS of HP mods for the Parallel Valve 360s, IF you're overhauling them.....
MTV
Sun Sep 12, 2021 12:19 pm
Re: HP Upgrading: The Real Truth
Thanks for the clarification Mike.mtv wrote:...The Angle Valve IO-360 is a very different engine, and is rated at 200 hp in Lycoming trim. Granted, both these engines can be bumped in HP with mods, and there are LOTS of HP mods for the Parallel Valve 360s, IF you're overhauling them.....
- Barnstormer offline
- Posts: 2700
- Joined: Sun Oct 14, 2012 7:42 am
- Location: Alaska
- Aircraft: C185
Sun Sep 12, 2021 2:26 pm
Re: HP Upgrading: The Real Truth
As requested by some here are a few more details, I'm starting with a Lycoming 0-360 A1A @ 180 hp. I'm planning a performance exhaust, make and model yet to be determined. Due to regulatory constraints a CS prop isn't an option however I can go lighter by way of a fixed pitch carbon fiber, currently planning for a Catto. The engine has less than 500 on it since a full shop overhaul so at the first top overhaul pistons, port & polish are on the list. A solid state ignition system sounds interesting along with cold air induction.
As to weight at present I've removed just over 150 lbs from the airframe, I have added some weight in the form of a STOL cuff with VG's. A quick back of the napkin W & B indicates I'll be inside 1400 lbs to be confirmed by a full and proper W & B in due time.
Still under consideration are WingX extension and an aux fuel system of some nature.
A lighter landing gear assemblies isn't on the menu primarily because I run floats all Summer and penetration wheel skis thru the winter so hard to justify titanium. Titanium is cool but if I'm being honest with myself it's just to expensive for the limit seasonal use.
Thank for all the insight, the BCP community holds a wealth of knowledge and experience.
As to weight at present I've removed just over 150 lbs from the airframe, I have added some weight in the form of a STOL cuff with VG's. A quick back of the napkin W & B indicates I'll be inside 1400 lbs to be confirmed by a full and proper W & B in due time.
Still under consideration are WingX extension and an aux fuel system of some nature.
A lighter landing gear assemblies isn't on the menu primarily because I run floats all Summer and penetration wheel skis thru the winter so hard to justify titanium. Titanium is cool but if I'm being honest with myself it's just to expensive for the limit seasonal use.
Thank for all the insight, the BCP community holds a wealth of knowledge and experience.
Sun Sep 12, 2021 2:51 pm
Re: HP Upgrading: The Real Truth
Does your owner maintenance program permit a ground adjustable prop? If so, I’d be looking hard at the new ground adjustable from (I think) McCauley.
Does the Wing X in Canada permit an upgross? I know one of the wing extensions permits upgross in CA but not US.
On floats, I’d look at 172 or 175 tanks. Del Zaire will convert your tanks, or you could find a set of 175 tanks and install them, but with two outlets per tank. That will give you 50 gallons.
MTV
Does the Wing X in Canada permit an upgross? I know one of the wing extensions permits upgross in CA but not US.
On floats, I’d look at 172 or 175 tanks. Del Zaire will convert your tanks, or you could find a set of 175 tanks and install them, but with two outlets per tank. That will give you 50 gallons.
MTV
Sun Sep 12, 2021 3:01 pm
Re: HP Upgrading: The Real Truth
mtv wrote:Does your owner maintenance program permit a ground adjustable prop? If so, I’d be looking hard at the new ground adjustable from (I think) McCauley.
That's is a grey area but in all honesty given the nature of my flying when would I ever need to change the pitch I'm either on floats or ski and both prefer a fine pitch in my experience
Does the Wing X in Canada permit an upgross? I know one of the wing extensions permits upgross in CA but not US.
Yes it does, 150 lbs I believe.
On floats, I’d look at 172 or 175 tanks. Del Zaire will convert your tanks, or you could find a set of 175 tanks and install them, but with two outlets per tank. That will give you 50 gallons.
I like this idea, 175 tanks in a 170B wing I'll be researching this one a bit further.
Thank Mike
MTV
Sun Sep 12, 2021 5:06 pm
Re: HP Upgrading: The Real Truth
That was John Allsworth’s take years ago at AK Aircraft Engines too. Been awhile maybe things have changed.hotrod180 wrote:I'm curious about "porting & polishing" aircraft engines, in particular certified (non-experimental) engines.
As I understand it, a certified aircraft engine must be overhauled in accordance with the mfr's overhaul manual.
Where in their OH manuals do Lycoming or Continental spell out the port & polish procedure?
Seems like an STC would be required, or maybe spell it out in a CRS's operating certificate.
Sun Sep 12, 2021 8:49 pm
Re: HP Upgrading: The Real Truth
Owner maintenance does allow a ground adjustable prop. Really no grey area. The rule states that there is "no in flight adjustable props allowed". Ground adjustable is perfectly legal. Didn't know McCauley had a GA prop, perhaps you are thinking of the new Sensenich GA prop. They are very nice and perform quite well, along with be quite easy to adjust compared to other GA props.mtv wrote:Does your owner maintenance program permit a ground adjustable prop? If so, I’d be looking hard at the new ground adjustable from (I think) McCauley.
Does the Wing X in Canada permit an upgross? I know one of the wing extensions permits upgross in CA but not US.
On floats, I’d look at 172 or 175 tanks. Del Zaire will convert your tanks, or you could find a set of 175 tanks and install them, but with two outlets per tank. That will give you 50 gallons.
MTV
Mon Sep 13, 2021 6:25 am
Re: HP Upgrading: The Real Truth
A1Skinner wrote:Owner maintenance does allow a ground adjustable prop. Really no grey area. The rule states that there is "no in flight adjustable props allowed". Ground adjustable is perfectly legal. Didn't know McCauley had a GA prop, perhaps you are thinking of the new Sensenich GA prop. They are very nice and perform quite well, along with be quite easy to adjust compared to other GA props.mtv wrote:Does your owner maintenance program permit a ground adjustable prop? If so, I’d be looking hard at the new ground adjustable from (I think) McCauley.
Does the Wing X in Canada permit an upgross? I know one of the wing extensions permits upgross in CA but not US.
On floats, I’d look at 172 or 175 tanks. Del Zaire will convert your tanks, or you could find a set of 175 tanks and install them, but with two outlets per tank. That will give you 50 gallons.
MTV
Yes, Sorry, I was referring to Sensenich.
Depending on what you do, I could see a G/A prop being handy at times, and that ones composite, so light.
MTV
Mon Sep 13, 2021 11:46 am
Re: HP Upgrading: The Real Truth
A1Skinner wrote:Owner maintenance does allow a ground adjustable prop. Really no grey area. The rule states that there is "no in flight adjustable props allowed". Ground adjustable is perfectly legal. Didn't know McCauley had a GA prop, perhaps you are thinking of the new Sensenich GA prop. They are very nice and perform quite well, along with be quite easy to adjust compared to other GA props.mtv wrote:Does your owner maintenance program permit a ground adjustable prop? If so, I’d be looking hard at the new ground adjustable from (I think) McCauley.
Does the Wing X in Canada permit an upgross? I know one of the wing extensions permits upgross in CA but not US.
On floats, I’d look at 172 or 175 tanks. Del Zaire will convert your tanks, or you could find a set of 175 tanks and install them, but with two outlets per tank. That will give you 50 gallons.
MTV
I'm happy to be wrong on this point and I'm sure it's a feature that some would want. However given that I need/want a fine pitch for at least 90% of the take off I do; float & wheel skis, a ground adjustable prop isn't a feature I'd shell out money for.
Mon Sep 13, 2021 9:41 pm
Re: HP Upgrading: The Real Truth
A turbo would do the trick, if owner maintenance category allowed it. 
But maybe not, you’re so close to sea level already.
You’re rev limited by the tip speed of your prop. What prop diameter are you contemplating and what RPM do you think optimizes takeoff performance for that prop?
You need as much volume of air as you can get the engine to pump, at the coolest temperature, and the perfect amount of fuel, optimum compression ratio, lit at the perfect time to get the most thrust from the available displacement. Any Ram air effect you can capture, low restriction air cleaner, an air box that will flow, a big enough carb, induction runners that are as restriction free as possible, porting, valve size and correct grind, cam grind profile, and exhaust tuning.
Law of diminishing returns applies. No replacement for displacement.
Honestly, you should be able to get 200 Hp out of your 360. If that’s not enough, you need a Skywagon.
But maybe not, you’re so close to sea level already.
You’re rev limited by the tip speed of your prop. What prop diameter are you contemplating and what RPM do you think optimizes takeoff performance for that prop?
You need as much volume of air as you can get the engine to pump, at the coolest temperature, and the perfect amount of fuel, optimum compression ratio, lit at the perfect time to get the most thrust from the available displacement. Any Ram air effect you can capture, low restriction air cleaner, an air box that will flow, a big enough carb, induction runners that are as restriction free as possible, porting, valve size and correct grind, cam grind profile, and exhaust tuning.
Law of diminishing returns applies. No replacement for displacement.
Honestly, you should be able to get 200 Hp out of your 360. If that’s not enough, you need a Skywagon.
Tue Sep 14, 2021 4:15 am
Re: HP Upgrading: The Real Truth
The goal is 200 HP, which is also the HP limit allowed within the Owner Maintenance regulations as well. I'd consider a Skywagon if they had an available Round Tail STC. Round tails are sexy; lets be honest we are all friends here, who doesn't like a smoooooth round tail. A bigger tail isn't always better. 
Tue Sep 14, 2021 1:33 pm
Re: HP Upgrading: The Real Truth
Mapleflt wrote:The goal is 200 HP, which is also the HP limit allowed within the Owner Maintenance regulations as well. I'd consider a Skywagon if they had an available Round Tail STC. Round tails are sexy; lets be honest we are all friends here, who doesn't like a smoooooth round tail. A bigger tail isn't always better.
I think it depends on how the tail performs more so than looks, but that is just me
Tue Sep 14, 2021 2:08 pm
Re: HP Upgrading: The Real Truth
I put a set of custom forged pistons with a sorta modern rising pack in my Continental. Based on static rpm, climb rates and cruise speed I’m reasonably confident my little 360 was producing 230hp. That’s that too surprising since Lycon claims their conti 360 rebuilds dyno at 235hp without any of their cylinder head magic.
Unfortunately the pistons didn’t last long so now I’m back to stock. 150rpm at static lost along with some climb and cruise speed.
If I were going down this road again I’d be looking at exhaust and intake then maybe some port/polish work. That’s as far as I’d go. If I wanted more power I’d add some boost.
Unfortunately the pistons didn’t last long so now I’m back to stock. 150rpm at static lost along with some climb and cruise speed.
If I were going down this road again I’d be looking at exhaust and intake then maybe some port/polish work. That’s as far as I’d go. If I wanted more power I’d add some boost.
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