Baloo, What do you have for exhaust? What's you're actual empty weight? Sounds like you have the prop set right if you a pulling 2700rpm on takeoff.

The BH I flew a little had similar performance issues but it was mostly caused by a restriction in the exhaust. That plane is still a a little slow in cruise but climb performance was about where it should be.

whee wrote:Baloo, What do you have for exhaust? What's you actual empty weight? Sounds like you have the prop set right if you a pulling 2700rpm on takeoff.

The BH I flew a little had similar performance issues but it was mostly caused by a restriction in the exhaust. Hat plane is still a a little slow in cruise but climb performance was about where it should be.

I'll snap a photo of the exhaust later on today and post it for you. I'm really not much of an engine guru so any help is appreciated. The actual empty weight is 1562lbs

P.B. wrote: Some of the responses I've read give me a question of my own. What does fuel injection have to do with it? The angle valve motor is a different animal, and I don't think the injection has anything to do with it making 200 hp. The parallel valve engine produces 180 hp, injected or carbureted. I think a myth is being perpetuated about injection. I've come across several 360 parallel valve engines over the years that have been converted to injection, and subsequently claimed to produce 200 hp. I don't think injection has anything to do with power output, other than the small marginal improvement that comes from better mixture distribution between cylinders.

In my understanding, the reason injected lycomings are often rated at higher power is primarily due to the configuration. The IO-540-C4B5 for instance is rated at 250hp but I believe it's simply because Lycoming established that combination of crank, pistons, and RPM plus injection equals 250 vs the 235 of the non injected engine.

I didn't know there was a carbureted 200hp 360 configuration from Lycoming, though anything is to be expected from an experimental engine.

Fuel injection is good for high altitude and turbos. For my little (4) it's not worth the cost and fuel concerns I face in the areas I like to fly. Seaplanes have to take what gas they can!

I have the same opinion with (6) cylinders too.

With Pilot, fuel and some gear you are over 2 grand. Pulling that off the ground in 400-600 ft with a 4 banger is not that shabby.
DENNY

Another option for a 360 Lyc is converting to a 375 or 390.
My hangar neighbor had a stroker crank installed in his 360 bumping it to a 375 and he's very pleased with it.
The 390 is a 360 with bigger-bore cylinders.
Both are more involved than just pulling cylinders & having them worked over, but might be more satisfactory in the log run.
"There's no replacement for displacement", or
"You can't beat cubic inches".

In an experimental, you can go with electronic FI which is a big jump in performance over the stock mechanical kind, also if you go with the Electronic ignition you can fine tune or map every 25 RPM to the best performance though fuel flow and timing.
With the cleaning up of the cyl's and a good exhaust should make the most for the least!

$.02

You said you have a 80 inch propeller.....I presume it's constant speed?? If not, that rpm on takeoff would explain a slow cruise speed.

That engine in a certified airplane should turn around 2400 or a bit more, not 2700, which is red line. So, if it's a fixed pitch, I'd get it pitched a bit coarser. If it's a constant speed, I'd have the pitch stops checked.

You could probably get a LITTLE more hp out of port/polish and pistons, not doubt. But it sounds to me that, as others have suggested you have propeller and probably exhaust issues. I'd consider a tuned exhaust. Larry Vetterman makes exhausts for the RV crowd and they rave about them.....

MTV

My thoughts.

The T/O distance you quoted, the weight, and the HP do not add up, to me. I doubt that engine (or maybe prop) is delivering 200hp worth of thrust.

20hp for a P&P job is a sales pitch. The quote from Mauleguy which Whee posted sounds realistic to me.

That plane is heavy, what can you remove to get it down to ~1400lbs where it should be? Or is it a heavy engine block?

Higher compressions mean shorter life - Bob Barrows explained to me that the thrust bearing isn't built to take that much HP, and you should expect a shorter TBO.

Edit to fix typo

mtv wrote:You said you have a 80 inch propeller.....I presume it's constant speed?? If not, that rpm on takeoff would explain a slow cruise speed.

That engine in a certified airplane should turn around 2400 or a bit more, not 2700, which is red line. So, if it's a fixed pitch, I'd get it pitched a bit coarser. If it's a constant speed, I'd have the pitch stops checked.

You could probably get a LITTLE more hp out of port/polish and pistons, not doubt. But it sounds to me that, as others have suggested you have propeller and probably exhaust issues. I'd consider a tuned exhaust. Larry Vetterman makes exhausts for the RV crowd and they rave about them.....

MTV

Shouldn't s CS prop let the engine turn redline rpm at takeoff power?

I agree with Battson; 200hp and those performance numbers don't add up which is why I asked about exhaust and empty weight. 1562 is kinda heavy but again like Battson I think you should be getting better performance if the engine was putting out 200hp.

One other thought - weight and HP are just different sides of the same coin. How much would it cost you to shed the easiest 100 lbs?

Example, my take-off roll at at 1700 lbs (basically as light as I can fly) is 100ft at 100% throttle.

If I close the throttle to 75% (195hp) power I would use 300ft T/O roll.
If I add weight up to 2300 lbs I would use about 300ft T/O roll.

So with the power of assumptions, I guess -100lbs is very roughly the same at +10hp...?
The accuracy isn't important - even if my guess is 50% wrong, you still get the same principle. I know you could calculate it exactly, but ain't nobody got time fo' dat!

I paid $4300 for 15 more hp (100-115 jump). So the same percentage you are talking about! And it was worth it (considering there was no cheaper way to do it). A

I bought larger cnc cylinders w/ forged higher compression pistons for my Rotax and installed them in about a day. I'm at 6600ft elevation, my climb went from 700-750fpm to 11-1200fpm (some other tweaking has been required, and still working at extracting all there is)... anyway... HP in planes isn't cheap.. for an honest 200-230hp jump that is well worth it.

To be more scientific about this, you have to give up speaking in takeoff distance and climb rate. There are too many variables in technique. What I personally would do, like Mauleguy was quoted as saying above, is strap that tail to an immovable object with some sort of pull force gauge and get a static pull reading. You might have to get the help of an A&P who has access to the equipment. Then see about adjusting that prop to get a better pull. I would bet a chicken burrito that your engine is doing fine and it's the prop.

Every 200/180 HP aircraft engine I have flown had more than enough power for the certificate's GW. 200 is a lot of ponies.

My gig; 180HP, MT propeller, floats(A), GW @ sea level my little ship does at least 700FP @ 85 KTS (~Vy). She is heavy, draggy but, never seemed to cross my mind building a new engine?

Be introspective first before tearing down the engine. Then move accordingly.

To the OP, my guess is that you're going to be disappointed that your $2500 didn't buy you more performance. If indeed you could get 30 more hp for $2500, that would be nice, but don't count on it. You might get enough to be able to feel it, but you can't expect miracles. Porting and polishing and balancing and higher compression are all good things, but not necessarily that good. It's like when we used to put dual glasspacks and a high flow air filter on our cars--they'd make more noise, their performance would improve a little, but we couldn't move up to the higher performance class at the drag strip.

I'd love it if my 180hp Lycoming would get me the figures you've quoted. But at my normal flying elevations, it ain'ta gonna happen. My engine is already ported and polished and balanced, and I have a pretty efficient dual exhaust system on it, so I'm probably at the limits of my engine's performance now. When I pull out of somewhere with a 9-10,000' density altitude and climb at the gosh awful rate of 150-200 fpm, for sure I wish I had more hp, but would 25 more make that much difference? Might feel it, but it wouldn't be much.

Of course, if I didn't haul everything and the kitchen sink on my camping trips, it would help a lot. I think that's the real key in your situation (mine, too). Find out what you can leave at home. Don't tanker so much gas. If you can knock off 100-150#, good guess that your airplane will perform noticeably better.

Cary

It would be interesting to see real dyno tests on aircraft engines that might show the effects of porting and polishing. On automotive engines, porting and polishing rarely yields anything close to a 5% gain on a wide range of engines, and the gains diminish quickly away from WOT.

2% seems to be around what people expect from a reasonable amount of whittling and polishing.

In addition, most stock aircraft engines will output somewhat over rated HP early in life, and claims of remarkable gains on remanned engines seem sketchy to me without some other expensive mods after that is taken into consideration. A rebuilder in Colorado dynos stock O-470's in at 5-8 hp over nominal going out the door, and I'm told the incoming exchanges rarely dyno below rated HP when accounting for the atmospheric conditions.

What is so different about aircraft engines that makes this attractive? Does anyone have data that does more than merely show rated HP vs dyno with the mods?

I had a 150 HP Grumman Traveler that we upgraded to high-compression pistons. That change converted it to 160 HP, although the STC limited the max RPM to 2650 to keep the new HP within 5% of the original - but that's beside the point.

The top speed didn't change, because of the fixed-pitch prop, although I found I had to be careful not to exceed the max RPM limits. Where the change really hit was in takeoff and climb performance. The higher-compression engine turned a higher static RPM, thus developing more thrust sooner in the takeoff roll. And when airborne, the extra 5% power made a huge difference in the rate of climb. On hot days in Texas (105F) I would typically see about 480-500 fpm ROC before the upgrade. Afterwards, I was consistently seeing 650+ fpm on those hot days, and almost 1000 fpm on cool days (winter).

The "gravy" with this was that the high-compression pistons made the engine a good bit more fuel efficient. For the 18 months I owned the plane after the HC upgrade, my average fuel burn dropped by almost a gallon (actually 0.8 gph) over the average for the preceding 18 months.

For $2500, even if you don't get all 25-30 additional HP, I would definitely go for both the HC pistons and the Lycon port job. It's the closest thing to "free power" you can get, with zero impact on reliability.