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O-320 HP increase options and prop questions

R

roxiedog13

Registered User
Just overhauling my O-320 now with new factory cylinders, Lycon is doing a port & polish and flow match, I'm told this will get me in the 180HP range with stock 8.5:1 pistons . I'm considering the 9.5:1 or 10:1 pistons as an option to add even more HP as I understand 10-15HP additional . The problem, I am told, is that once I go beyond 8.5:1 pistons I have to use AVgas , possibly get away with a 50/50 mix at 9.5:1 , definetely 100% AVgas for 10:1 option.

Who has done this ? Are the claims accurate for HP and is that HP realized at the prop? What prop recommended for each level of HP .

I have the Borer 1A200 now it is pitched 82X45, with the 160 and additional powerflow exhaust my static was around 2350-2400. My thought was to re-pitch this prop to 47 if I go with the 9.5:1 pistons since it will be in 190HP territory .

I'm adding one Pmag to the build now, may go with the second one at this point . I have been running Autogas all along with fuel additive for lubrication, 500 hours in no issues. AVgas is going to double my cost per hour for fuel
trying to decide if I should keep the stock pistons at 180 HP contiue to use auto fuel or use the 9.5 or 10:1 pistons and run AVgas . Cylinders are in the shop now and I have to make this decision now, any feedback will be appreciated.

BTW, I'm new , this is my first post and :p I don't have a cub. I own a 172 owner maintenance with many mods that make it a fantastic 4 place spam can performer . ;-) I've been off the water in 130ft on floats, not your typical 172 .
 
Your horsepower expectations are a little.... generous.

What mods make it a fantastic performer? I have fond memories of my Hawk XP (Isham 210hp) on PeeKays.
 
If you are on floats I recommend that you keep the Comp ratio such that you can use auto/boat gas. Often that may be your only option. I too agree that the Hp claims may be somewhat optimistic. I would not re pitch the prop until you see what your new engine runs at. I was under the impression that Pmags were experimental only. You have an experimental 172? Again, upping the comp ratio in a certified airplane? You should be able to go 9 to 1 and still use auto gas, though I would still recommend a little bit of a mix.

Best of luck

Bill
 
I feel you should wait on re-pitch. I went the direction you are considering, 10:1 pistons with Sutton Exhaust...I do not think I get 180hp...I think more realistic at 165-170....I run 50-50 Av Gas/91 Auto gas from time to time with no noticeable issues...
 
stewartb, we have a Hawk XP that is that is somewhat highly modded. Sportsman stol, vg's, glas air nose fork, 10 in wheels with 29" air hawks. We fly it off of average type grass strips here on the ranch and use it mainly for going places, she's not very fast but very functional for what we do. Now to my question, we've been thinking about the Isham but haven't done it. Do you think it would get us airborne a little quicker and any other advantages you may think of ?
 
Your engine was de-rated from 210 to 195hp. Adjusting fuel flow and turning up the prop to 2800 makes it 210hp. The STC also includes a new fuel flow gauge with revised markings. It's a simple STC and yes, worth doing. Maybe pull the FAA CD on 758JY (my old plane) or 736SK (a buddy's old plane) and poach on the field approvals to install an 80" seaplane prop with wheels. With the added power that prop really works well.
 
Bill Rusk said:
If you are on floats I recommend that you keep the Comp ratio such that you can use auto/boat gas. Often that may be your only option. I too agree that the Hp claims may be somewhat optimistic. I would not re pitch the prop until you see what your new engine runs at. I was under the impression that Pmags were experimental only. You have an experimental 172? Again, upping the comp ratio in a certified airplane? You should be able to go 9 to 1 and still use auto gas, though I would still recommend a little bit of a mix.

Best of luck

Bill
Click to expand...

Appreciate the feedback . The 172 is in owner maintenance in Canada , I am legal to do the mods I am considering including Catto prop, the Pmags, non TSO'd instruments, etc. It's not quite experimental or home-built but very close.

For those that think the HP claims are "generous" , and I'm not saying you are wrong, however , LYCON claim a stockO-320 with ported/polished and flow matched cylinders will make 180+ HP , here's the video : go to o-320 videos
it shows 184HP at 2680RPM , 360 ftlb torque. Adding 9.5:1 and 10.5:1 adds 10 and 15 hp respectively, according to them .

I had to remove the URL , sorry, the site would not allow the post . If you want to see the video, go to lycon find the videos under other then media .

They only have piston options for 9.5:1 and 10:1 not 9:1, 9.1:1 available from others, progressive air I do believe. There are a couple of different opinions regarding the use of auto , AVgas or a mix. All pretty much agree that aty 10:1 AVgas is the only choice. One user has been running a 50:50 mix with 9.5:1 without issues, with stock pistons , auto fuel is approved , I have the STC for mine.
 
J5Ron said:
I feel you should wait on re-pitch. I went the direction you are considering, 10:1 pistons with Sutton Exhaust...I do not think I get 180hp...I think more realistic at 165-170....I run 50-50 Av Gas/91 Auto gas from time to time with no noticeable issues...
Click to expand...

I will also have port&polish with flow balancing on all four cylinders. Did you have that done in addition to the pistons ? The porting/polishing and balance is supposed to be the most bang for the buck, they claim 20HP over stock with that alone. I have a powerflow exhaust as well , that is supposed to be good for 10-15 HP. When I added this to the stock O-320 160HP my static RPM went up 100 RPM with the same propeller .

I know that stacking all these mods is not cumulative BUT most together should be good for a major bump. I was hoping to hit others that have done all of the same , see what results they have will ALL the same mods.
 
Bill Rusk said:
If you are on floats I recommend that you keep the Comp ratio such that you can use auto/boat gas. Often that may be your only option. I too agree that the Hp claims may be somewhat optimistic. I would not re pitch the prop until you see what your new engine runs at. I was under the impression that Pmags were experimental only. You have an experimental 172? Again, upping the comp ratio in a certified airplane? You should be able to go 9 to 1 and still use auto gas, though I would still recommend a little bit of a mix.

Best of luck

Bill
Click to expand...

This is the part I'm trying to determine. If I don't see major increases in performance with the 9.5:1 pistons, might as well stick with the stock compression port and polish only . Combined with the powerflow I'll still be in 180HP teritory can use 25% mix of AVgas or straight auto with lubricant when stuck. Places I fly there is no AVgas for hundreds of miles . Doesn't help that Avgas is double the price, all has to be factored in to my decision .
 
For comparison, Titan exp engines list hp for a 9.0-1 0-320 at 165hp. A 9.0-1 0-340 rates at 180hp. Titan cylinders are flow optimized and flow matched from the factory.
 
stewartb said:
Your horsepower expectations are a little.... generous.

What mods make it a fantastic performer? I have fond memories of my Hawk XP (Isham 210hp) on PeeKays.
Click to expand...

Floats are EDO 2000 made by peck aero ,actual displacement now is 2300 with work done to the bottoms, boosters etc. Sportsman STOL & tips, gap seals, Vg's , 1967 model year was the lightest ever made , also has smaller tanks. Light weight alternator and starter, rear seat removed replaced with fold-able bush seats . Added powerflow exhaust , Pmags , Borer prop 1A200 . I'm currently removing the entire vaccume pump, related instruments and plumbing , all older steam gauges, radios etc., install a single glass EFIS and Garmin 796 . Adding the wing-X extensions next winter if all goes well .
 
roxiedog13 said:
I will also have port&polish with flow balancing on all four cylinders. Did you have that done in addition to the pistons ? The porting/polishing and balance is supposed to be the most bang for the buck, they claim 20HP over stock with that alone. I have a powerflow exhaust as well , that is supposed to be good for 10-15 HP. When I added this to the stock O-320 160HP my static RPM went up 100 RPM with the same propeller .

I know that stacking all these mods is not cumulative BUT most together should be good for a major bump. I was hoping to hit others that have done all of the same , see what results they have will ALL the same mods.
Click to expand...

Yes...on that... I think after talking to a few guys I should maybe had my case shaved a bit...heard this will help in the results colum.
 
J5Ron said:
Yes...on that... I think after talking to a few guys I should maybe had my case shaved a bit...heard this will help in the results colum.
Click to expand...

Yes on that meaning you did have your cylinders ported, polished and flow matched? Having the case halves shaved is what many have done to increase compression with stock pistons. It is the same as putting in higher compression pistons, I don't think you would do both, then again, maybe it is .
 
I am curious about how much Lycon charges to port, polish, etc. an engine as you describe in order to obtain the promised results.

I've had long discussions with Lycoming OEM engine representatives about both the porting/polishing process Lycon offers and the legality of increasing the horsepower of their engines. It has been my experience that if you really want honest answers to your questions you can best rely upon advice from people who aren't trying to sell you their product/service.

Moreover, we all like to boast about how powerful/great our own setup is: you know, we all have an O-320 that produces 210hp and 1000 lbs. thrust at 5000' on an 850 lb. SC, not to mention we all have 12" dicks. Of course none of us have the yardsticks handy to easily measure our claims, so they're hard to prove/disprove. Really; how many of us have never exaggerated their own airplane's performance? Hyperbole is, I think, one of our common denominators, so we can't be trusted either.

Shaving weight from your aircraft will likely increase its performance far more than any pie in the sky engine tuning promise, for a lot less money. IMHO, of course.
 
3 years ago it was $250/cylinder, on lycon's dyno and real world on my airplane it made a difference that was well worth the extra $1,000.
 
Paul Heinrich said:
I am curious about how much Lycon charges to port, polish, etc. an engine as you describe in order to obtain the promised results.

I've had long discussions with Lycoming OEM engine representatives about both the porting/polishing process Lycon offers and the legality of increasing the horsepower of their engines. It has been my experience that if you really want honest answers to your questions you can best rely upon advice from people who aren't trying to sell you their product/service.

Moreover, we all like to boast about how powerful/great our own setup is: you know, we all have an O-320 that produces 210hp and 1000 lbs. thrust at 5000' on an 850 lb. SC, not to mention we all have 12" dicks. Of course none of us have the yardsticks handy to easily measure our claims, so they're hard to prove/disprove. Really; how many of us have never exaggerated their own airplane's performance? Hyperbole is, I think, one of our common denominators, so we can't be trusted either.

Shaving weight from your aircraft will likely increase its performance far more than any pie in the sky engine tuning promise, for a lot less money. IMHO, of course.
Click to expand...

They charge $300 per cylinder, the high compression pistons are $200 each, also having anodyne treatment to the head for better heat dissipation .


I don't disagree that claims are often exaggerated especially if made by the company selling . This is exactly why I am hear asking for real world feedback. And yes, even us members have been known to tell
the odd fish story that may have a few inches tagged on. I've been around the patch long enough to know how and where to follow up manufacturers claims and also know how to interpret . Personally I look
at any claim and pretty much consider 50% a good target, I then listen to all the feedback and try to get the majority from common denominators, eliminate the highs and the lows.

The biggest bang for the buck is port , polish and flow balancing . The high compression pistons second. Overall however, it does appear as though their claims are reasonable, many owners have already shared their
experiences for increase in power and reliability .

I have already shaved the majority of weight I can from this aircraft , and I chose this particular model year because it is known to be almost 100lb lighter from the factory . Bush seats, light weight alternator and starter
vacuum pump system and all the heavy gauges including radios and nav aids are gone. I'd loose weight too but I'm already running 16% body fat . I'm 200 lb though, could loose a little muscle mass I suppose. :)
 
pa11driver said:
3 years ago it was $250/cylinder, on lycon's dyno and real world on my airplane it made a difference that was well worth the extra $1,000.
Click to expand...

Honest question. Does Ly-Con provide you the dyno report with temperatures, torque, MP, fuel flow, EGT, etc at different RPMs? The only dyno report I've seen is my own from Superior. I know other guys with Ly-Con engines but have never heard what they were given for paperwork about the test runs.
 
stewartb said:
Honest question. Does Ly-Con provide you the dyno report with temperatures, torque, MP, fuel flow, EGT, etc at different RPMs? The only dyno report I've seen is my own from Superior. I know other guys with Ly-Con engines but have never heard what they were given for paperwork about the test runs.
Click to expand...

Yes
 
If I divide my HP by fuel flow I get 11 HP per GPH at wide open throttle. How does that compare to yours? I'm wondering if there's a (relatively) consistent ratio between fuel flow and power output in 4 cylinder engines. My Cessna makes approx 12.5 hp per gallon of flow with lower compression cylinders. That's what sparked my curiosity.

Here's an interesting article about fuel flow and power output. http://www.hyperflite.co.uk/fuel-consumption.html
 
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A 320 with 8.5:1 and a port/polish job will probably produce about 170 hp @ 2700, maybe a touch over. Going beyond that you're probably going to be fighting CHT issues, especially in a plane that's working hard at modest airspeeds. As to the prop, I'd leave it alone until you try it. I think 82x45 is plenty of prop, especially if you want it to jump off the water.
 
Another good comparison: Awhile back got some video of a couple of us taking off on a beach in Prince William Sound. Both of us were loaded similar with fuel, tools and such.

My Buddy’s cub, 0-360, Catto 86”x38” prop...took off in about 150’. Took 5 seconds to get airborne.

My Cub, Exp Widebody, 0-320, 10:1, ported Sutton Exhaust 84”x37” Catto... also took off in about 150’ but took about 6 seconds to break ground...

His gets there faster...

I think I have good power for certain, however the true torque of the 180hp, O-360 is definitely different. Neither of us were trying to horse it off, just letting the plane do it thing.
 
pa11driver said:
3 years ago it was $250/cylinder, on lycon's dyno and real world on my airplane it made a difference that was well worth the extra $1,000.
Click to expand...

Seriously, What empirical evidence do you have that supports your conclusion? What was done to your engine besides port/polish? Was it overhauled with new cylinders or anything or did you just take the engine in and have it ported/polished and then reinstalled?

Isn't everyone delighted with their engine's performance after a standard, no frills overhaul?
 
Paul Heinrich said:
Seriously, What empirical evidence do you have that supports your conclusion? What was done to your engine besides port/polish? Was it overhauled with new cylinders or anything or did you just take the engine in and have it ported/polished and then reinstalled?

Isn't everyone delighted with their engine's performance after a standard, no frills overhaul?
Click to expand...

Paul, my report is worth exactly what you paid for it and it is probably biased by the extremely large sum of money I paid to have the work done, so take it or leave it. I never claimed to have empirical evidence, other than the dyno from lycon. I also couldn't tell you how delighted everyone else is with their overhauls...


My engine was a complete overhaul, so yes, I probably gained something from that. I've also flown a number of airplanes before and after just the port/polish and before after 10:1 pistons, so I have a pretty good feel for what those mods do to an engine.

My engine was overhauled because it was old year-wise, not because it was run out. I've also worked this airplane pretty hard before and after this particular overhaul. I do mean worked, not going for $100 hamburgers and buzzing around gravel bar hoping (Nothing against those guys, that's great fun). What matters to me is what I can do with it now vs before is notably different. Bigger loads off shorter LZ's with a higher safety margin.

Also notable: The same prop with 2'' of pitch added into it static's a higher RPM than before.
 
stewartb said:
A dyno report is a piece of evidence. Anecdotes are nothing but stories. Big difference!
Click to expand...

When we buy a new factory engine do we get a dyno report ? We see the brochures and claims but how many have actually dynoed their new factory engine to see if it makes that 160HP and the torque at a given RPM ?

Lycon does provide the validated load cell numbers if they overhaul the entire engine, for many like myself, we only send in cylinders, obviously they cannot dyno those . Anecdotes are pretty much all we have from the general community overall the feedback is very consistent . A 0-320 with all the mods can operate very close to a O-360 in performance though from what I have read the O-360 usually is a notch ahead . The O-360 engine has more torque in the sweet even if HP is matched the larger cylinder volume and cam profile obviously a little better . Compared to a stock O-320 however the port, polish and flow matching of cylinders improves
the engine considerably , for a small price a lot of additional power is available . My price certainly not cheap as I had to buy 4 new cylinders , BUT compared to the cost, weight and complexity of installing a new O-360 this was a very affordable option .
 
Did you advance timing on crank gear?
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Fact; I had an O-320 E2D built by Lycon. It came with the test run results. 10 to 1's, polished and flow balanced. 209.9 H.P. at 2700 RPMs. Unless they are faking the numbers that is what it made. I have it on the plane now and it is the smoothest, hardest pulling O-320 I've ever sat behind. I don't brag about it, I just enjoy it.
 
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