n5lp

n5lp

fugio ergo sum
If one was overhauling a 150 HP O-320 and considering performance mods up to around 180 HP, what would people think would be the best bang-for-the-buck mods and tweaks that would retain reliability?
 
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I went with 9.5:1 pistons, roller rockers and ended up with around 177 hp. If I had it to do over, I would not go beyond 9:1. I have about 750 hrs since overhaul and still have the same oil burn and compression as just after overhaul.

8.5:1 will get you 160 hp.
 
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Years and years ago, I put an O-320 on my Yankee to replace the stock O-235 that had run out....bought a core and had it rebuilt. The overhauler asked if I wanted a 150 or a 160. I asked what the price difference was, and he said there wasn't one!

No brainer - 160 HP at least....

Paul
 
Engine

n5lp said:
If one was overhauling a 150 HP O-320 and considering performance mods up to around 180 HP, what would people think would be the best bang-for-the-buck mods and tweaks that would retain reliability?
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Larry:

Check with Barrett Performance Engines in Tulsa. Doesn't get any better.
Their shop is No. 1 in my opinion. They can get you 170-180hp out of an old narrow deck with no problems or reduced engine life.

Class act and nice folks to talk to.
 
320...

Piece of cake experimental build 320, built better than Lycoming Specs ever thought of... Got one flying. Flowed, balanced, ported, polished, cam etc... Makes for a fast, SMOOOOTH running engine available up to 190 HP to my knowledge. These engines perform at high RPM's and love it! :D

Whatcha Building???
 
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Larry,

At OSH this past summer I spoke to Bob Honig at Eagle engines and he said adding dual electronic ignition to any engine will increase your HP by 6%. (They recommend the P-mags, BTW, just to start that war again.)

He also said adding ported cylinders will get an O-320 well over the 180 mark. If you do this, mark your cylinders (#1, #2, etc.) and send in your exhaust and intake tubes and ask them to match the cylinders to them. That will keep the air flowing smoothly, in and out of the cylinders.

Remember, an engine is nothing but an air pump. The easier you can get the air to flow in and out, the more power it will make.

One other thing Bob told me, when done properly, these changes will not impact your TBO.
 
LPM article on porting

BikePilot said:
I've no personal experience with it, but this article from the April kitplanes was really interesting (its about porting)
http://www.kitplanes.com/issues/26_4/builder_spotlight/issues_builderspotlight_8623-1.phtml

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I'm to cheap to spend $7.50 to read one article out of KITPLANE. Light Plane Maintenance recently had a good article regarding port and polish work on aircraft engines. I'll happily email it to anyone who requests it. Contact me via email or private message. When responding via private message, include your email address.
Charlie Kuss
 
HOT ROD 0 320

There are some shops, I will only say in the Western part of the US, that make absurd claims about horsepower enhancements. Unless you want to fly a hand grenade, a reasonable horsepower for the 0 320 is in the 170-175 range. More than that and you won't get much time out of it. Study the REAL FACTS about Barrett and Mattituck and you will find that they generally agree with the above and do not recommend radical mods for every day use and longevity.
Barrett, as of a few years ago, did not like electronic ignition. They will tell you exactly how much they think high compression pistons will reduce TBO. The number that Monty gave me years ago was that 10-1 pistons on an acro airplane that is flown hard will go 700 hours and the bearings will be worn out.
The 0 320 H pistons are a good compromise. They will not reduce TBO significantly. They run about $120 each vs $250 plus for the 10-1. Flowing the cylinders is a huge waste of money unless you want to run 3000 r/m to race at Reno. A forward facing fuel injection vs carb will give a noticeable increase in power. Balancing does not necessarily increase power but is cost effective just to have a smoother running engine. A cam can be a very expensive experiment when you have to tear the engine down to put the stock cam back in. Barrett, as of a few years ago, did not offer special cams. Mattituck does cams only for the likes of Bohannon.
Unless you have special considerations, such as racing in a certain class, it is far more cost effective to hang a parallel valve IO 360 on the front and forget about the hand grenade. I have hopes of doing some racing so I am building an 0 320 with the H pistons, balanced and not much else.If my checking balance was something north of 500k I would do the full treatment except for the cam, but that is not going to happen. (It would be Barrett or Mattutuck, I wouldn't even consider any one else) I strongly urge you to talk to Barrett and Mattituck and treat all the other hype as you would a promise from a politician.
 
Thank you all

I appreciate the opinions expressed, both here, and via e-mail and PM.
 
Hot Rod 0-320

Re: the poster who takes issue with "claims" of hot rod engine builders in the Western US. I assume you are talking about Ly-Con in Visalia, CA. I have one of their mild IO-320's in a T-18. It has 10:1 pistons etc. and it drives a Blended Airfoil, 200 hp prop. I'm not sure if you have been watching the Red Bull races or following Reno Air Races or know who many of the aerobatic air show guys like Sean Tucker use, but it is Ly-Con. You might find it interesting that Ly-Con has seen no economic slow down and there is a long waiting list to get an engine from them. With a 25 year reputation, they are not new in getting a little more out of a Lycoming or a Continental engine, and they are an FAA certified shop and as the article in Kit Planes pointed out, they have invested heavily in computer controlled milling of case joint "O" rings among other things.

Lastly,there are many RV's flying with Lycon built engines for many years. That is how I first learned about them.

Tom Hunter
 
More info please

Tom Hunter said:
snipped With a 25 year reputation, they are not new in getting a little more out of a Lycoming or a Continental engine, and they are an FAA certified shop and as the article in Kit Planes pointed out, they have invested heavily in computer controlled milling of case joint "O" rings among other things.
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Tom Hunter
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Tom,
I was unaware of the case joint O-rings you mention. Could you please tell us more about them? Tell me about some of the other mods that LyCon offers.
Charlie Kuss
 
HOT ROD O 320

I am familiar with Lycon and their excellent reputation. For Shawn Tucker or the top Reno racers Lycon is probably the best shop. I simply do not believe any claims of anything near 200 hp from a 320 that will run for more than 500 hours. The 10-1 pistons in your 320 do not constitute a "mild" engine by my standards. What are your expectations for engine life? My experience with the 10-1 pistons is that they generate a lot more heat and require a lot more fuel at high power settings.
 
Your mission?

First define your mission: a go fast,aerobatic, climbing airplane that you fly locally for thrills using expensive gas, or the other extreme, cross country cruise , sightseeing, at anemic fuel flows. There are tradeoffs. I had a cassutt with "modified 0-320" but only flew local and 45 min at a time. (16 gals fuel didn't last long.) Now, older and more "tender" :cool:, I put a 150 hp 0-320 in an RV-9 for longer x-country and ability to burn any auto gas,ie cheap flying. Personally, any mods would be in the ignition first, then balancing, and if affordable, fuel injection. The 320 stock is almost bullet proof and after all these years , proven. I agree with previous post, cheapest power upgrade is to install a "stripped 0-360" Light starter, alt, and electronic ign of some sort. 'course all depends on how deep your wallet is------------:D♠
 
your mission?

Excellent post. If your mission is being in the top three at Reno, you need a grenade engine. If your mission is flying over the Rockies or the Everglades, you need a reliable engine. I am using the H pistons, just over 9-1, balancing, and perhaps later electronic ignition and fuel injection. One point I failed to address is that if you are running a fixed pitch prop way beyond rated r/m, you will make a lot more power even with a stock engine.Just look at the Lycoming power curves. They don't drop off that much until the valves start to float, and that is usually past where the prop goes supersonic. I ran my 0 360A4A Pitts 3500 r/m for 300 hours and then with a different prop 3300 r/m for 700 more hours. The engine was balanced and showed no signs of weakness at 1000 hours. Oil pressure, which is a good indicator, was the same at 1000 hours as when new. Cross country was at 2800 much of the time. The acro time was probably 75%, cross country 25%.
 
0-320 tuning

...and if your mission is to get more out of your engine without sacrificing reliability then the way you operate your engine is critical.

First, with higher compression pistons, you do NOT want to fool around with LOP.

Lycon recommends 125 ROP.

Second, you do not want to run the engine real hard at lower altitudes. Not only will you burn a lot of expensive gas, but you'll be in the yellow arc on your airframe.

Third, you need a prop that will make use of the additonal power. A CS will be very useful.

4th, you want to limit the max RPM. I have my prop governor set to a little less than 2,700

5th Fuel injection is needed.

OK..so what do you get for your money...and I'll agree it isn't cheap for a Ly-Con engine:

The ability to climb fast to altitude (it burns about 14 gph during climb) and then settle down and cruise at a reasonable fuel burn.

Once at altitude, you can throttle back and lean and get a reasonable fuel flow. E.G., in comparison to a friend in a 0-360 CS RV-6 I can fly at his best cruise speed on less fuel. Since his engine runs hot on climb, he is limited to a shallow climb angle. He's tried all the tricks in the book to get his CHT's down and the engine just runs HOT. When I went from a regular IO-320 to a Ly-Con IO-320 I expected it to run hot. In fact it did not. It runs as cool as the regular compression engine. CHT's are never over 300. Oil temps are just in the green during the winter and in the middle in the summer...and that is with half the oil cooler blocked off. I'll admit, I was very surprised at this.

At 8,500 foot altitude I run it at 2400 and 22 inches and 125 ROP and fuel flows are about 9 gph and 195mph still air cruise. If you want to get better fuel flow, you can either slow down or go higher. I've tried slowing down, but 160 feels too slow, even though fuel flow was a shade over 5 gph. Ok...you got me...I did lean it a bit thinking that with the throttle that far out, I couldn't hurt it, but I still stayed ROP.

Since I can cruise climb at 160- 170 with rpm less than 2600 and all temps in a comfortable region, I frankly can't see how I am over stressing this engine. It currently has about 200 hours on it, uses no oil to speak of, purrs....well..you know...I gotta believe it will last a good long time. Kenny at Lycon said it would make it to Lycoming recommended TBO.

I'm not sure what the definition of a grenade engine is, but if it is what I have on my plane, I'd say it's pretty trick.

Tom Hunter
 
Tom,

Not to argue but 1-5 are BS. Lycon is a good company! IIMHO, don't agree with the rest. F/P props will do fine, LOP works great at cruise, Altitude makes no difference running the engine hard... we can run 2970 RPM's and the engine loves it at 500AGL ... not my first rodeo. Fuel injection... Blah Blah... the old carb has never failed me. To each there own...

My 2 cents worth...





Tom Hunter said:
...and if your mission is to get more out of your engine without sacrificing reliability then the way you operate your engine is critical.

First, with higher compression pistons, you do NOT want to fool around with LOP.

Lycon recommends 125 ROP.

Second, you do not want to run the engine real hard at lower altitudes. Not only will you burn a lot of expensive gas, but you'll be in the yellow arc on your airframe.

Third, you need a prop that will make use of the additonal power. A CS will be very useful.

4th, you want to limit the max RPM. I have my prop governor set to a little less than 2,700

5th Fuel injection is needed.

OK..so what do you get for your money...and I'll agree it isn't cheap for a Ly-Con engine:

The ability to climb fast to altitude (it burns about 14 gph during climb) and then settle down and cruise at a reasonable fuel burn.

Once at altitude, you can throttle back and lean and get a reasonable fuel flow. E.G., in comparison to a friend in a 0-360 CS RV-6 I can fly at his best cruise speed on less fuel. Since his engine runs hot on climb, he is limited to a shallow climb angle. He's tried all the tricks in the book to get his CHT's down and the engine just runs HOT. When I went from a regular IO-320 to a Ly-Con IO-320 I expected it to run hot. In fact it did not. It runs as cool as the regular compression engine. CHT's are never over 300. Oil temps are just in the green during the winter and in the middle in the summer...and that is with half the oil cooler blocked off. I'll admit, I was very surprised at this.

At 8,500 foot altitude I run it at 2400 and 22 inches and 125 ROP and fuel flows are about 9 gph and 195mph still air cruise. If you want to get better fuel flow, you can either slow down or go higher. I've tried slowing down, but 160 feels too slow, even though fuel flow was a shade over 5 gph. Ok...you got me...I did lean it a bit thinking that with the throttle that far out, I couldn't hurt it, but I still stayed ROP.

Since I can cruise climb at 160- 170 with rpm less than 2600 and all temps in a comfortable region, I frankly can't see how I am over stressing this engine. It currently has about 200 hours on it, uses no oil to speak of, purrs....well..you know...I gotta believe it will last a good long time. Kenny at Lycon said it would make it to Lycoming recommended TBO.

I'm not sure what the definition of a grenade engine is, but if it is what I have on my plane, I'd say it's pretty trick.

Tom Hunter
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0-320 tuning

If you want reliabilty and good fuel economy on a hot rod engine, you limit the time it is running at a high rpm, and take advantage of the opportunity it gives you to climb faster. Only a CS prop gives you both. The recommendation of LY-CON is don't run LOP due to the potential of detonation when running 10:1. If you want to run a lower compression Lycoming at 2800 or higher on a carb and a fixed pitch prop 500 feet above the ground that's your business. In my case in my plane I would not do that since I would be at the red line of the airframe...and to me that makes no sense. The reason for
FI on a tuned engine is to be more efficient in fuel flow and to take advantage of the efforts in porting and polishing. A carb is fine but FI with balanced injectors are more efficient.

Tom
 
Lots of stuff you CAN do. I'd do 9.5:1, weight balance the rotating mass, roller cam (no real power), and add balanced fuel injection and EI.

If you plan on REALLY getting some power out of it, spinning it up to 2800 and using O-480 Cylinders (Angle valves) will get you some top-end flow. Lycoming sells those cylinders kits new still. This is a little extreme for 180hp, and you'd have to make new baffles, and perhaps some cowl work depending on how tight your cowl is.
 
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