Horsepower Plus STC Pirep

[320KPH]

Hey guys

anyone had personal experience of the Horsepower Plus STC that used the HIO360 hi-comp pistons?

It's used in the Cardinal too...

[KSMooniac]

I've heard of bad things about it, but don't have any direct experience, nor would I install it in my plane even if free.

IMO, our engines evolved from 150->160->180->200 hp variants and I think at 200 hp we're really out of headroom to squeeze more power out. Perhaps with some very judicious engine management you could run more power over a TBO run without cratering it, but who knows.

[SkyPilot]

I flew a Mooney 201 in 1987 that had a Firewall Forward/Horsepower plus decal on the tail. The owner never mentioned any issues. Mind you, I did his night rating for him so he probably wouldn't have told me if it was about to blow... I seem to remember it showing 165 kts g/s on the DME in still air. Don't know if that is good, I have an "F" model.

[DaV8or]

I think in this age with uncertainty about what's next after 100LL, going higher compression could really bite you. I would skip it until a new fuel is settled on. No experience with the mod though.

[1964-M20E]

yes if anything we may be turning the timming back to 18 degrees and or lower compression pistons to butn auto fuel. OK so then we will have 180 instead of 200HP

[garytex]

And all the difficulties of alcohol. Everyone should squeal like stuck pigs to any politician that will listen against alcohol in fuel. It's bad all the way around.

[320KPH]

This suits the 172 Cardinal as well.

There are different placards on the tach for this STC than on the "normal" J

[wiseng]

I bought the STC and regretted it from day one. Oil consumption was 1-2 qts/hr on new cylinders and that was after rehoning twice. Finally had to threaten a lawsuit and many phone calls. I finally got my money back. It was definitley not something I would do again.

[Kwixdraw]

I investigated this stc a good bit. There are some restrictions on mp that limit it's usefulness and are not very clearly explained in the marketing hype. Expensive parts and not easy to find if something needs replacement acording to the folks at Lycon. Their take is that new std cylinders and piston can be made to make as much horsepower with a good port and valve seat cleanup. Check with Lycon for details.

[320KPH]

thanks for the feedback guys, I was starting to think that there weren't any out there.

[carusoam]

Check the source of the STC, then the reviews of the source. Could be interesting...

-a-

[John Pleisse]

I inherrited the FWF/HPP conversion on my 1979 201. Flew it for about 600 hours. It required a top. The cylinders, obviously, were special order. While I have no experience as an A&P and frankly, anything can detune a crankshaft, my engine had vibration problems that just would not go away. I balanced the prop twice and had frequent timing issues. One mechanic said the vibration of the helicopter pistons could have been the culprit. I traded the core and bought a factory new stock engine.

I understand this conversion is in over 60 airplanes encompassing 201's, Cardinals and Arrows. Hardly enough to develop a robust safety and performance record. Having flown both engines, there were no appreciaable perfomance gains that I persoanlly saw in the HPP conversion. So I ask, why do it? If you are considering purchasing a bird with this conversion, it is of no greater value than a stock engine. I flew mine 600 hours and thought it to be generally safe.

Upshot? The STC says 210 HP, so I gladly had my CFI provide me my High Performance endorsement.

Again, no appreciable performance gains.

[320KPH]

I thought the cylinders were stock and it was the hi-comp pistons that were the only difference.

Did you notice better performance on climb out with the 210HP? compared to stock?

Approx how many hours on the engine when you got it?

I appreciate your feedback.

The reviews I have found were not really complimentary but I have had similar experiences here in OZ with LAMEs. (overpromising and Underdelivering and overcharging)

I do however have a wealth of experience selling cars and some of the Las Vegas references were interesting. I have to go to Vegas!

[John Pleisse]

I am sorry, I mis-wrote. I had the cyliders sent out and had them rehoned. I got the plane with 1100 on the engine and took it to 1700. It was dependable, ran great and was safe. Just never got past the vibration and relaed issues. Again, it could have been anything, but where there is smoke, there is fire. When I bought the new engine, I got a full running core allowance.

I noticed no difference in climb. But again, you are comparing a tired 1700 hour FWF conversions to factory new stock.

[wiseng]

I looked back at my log books. The pistons were replaced @ 208 hrs. If I remenber correctly there was some concern about the piston length being different and maybe a possibility of rocking withing the bore. I never had a vibration issue. Oil consumption was the problem in my case. The engine now has over 1400 hrs on it and the comp are all over 76/80 using about 1qt/7hr. I saw about a three knot increase and do not remember any temperature problems.

If and when I get a new engine it will probably be a lycoming reman just for the roller cam. If money is not an issue I would have someone like Lycon flow match the heads and check the balance etc. Wonder what something like that would cost?

[anAscendancy]

This Stc is just allowing us Hot Rodders or us Mooney owners to go faster. The Stc is a gift from God. How many of you truing out at 160 k have said in the back of your mind "Would be nice to go just a bit faster." This Stc is meant to squeeze 5 more k out of your A3B6 at altitude never mind more power on take off and climb.. There is no mp restriction on take off. I wanted it for my E though it is a A1A and wouldnt work because of the lack of a counter weighted crank. People run these pistons all the time in the experimental world and besides lycoming in there io360 helicopter engine. I doubt lycoming would install them in one of their helicopter engines if they felt they were an issue. I mean if they run flawless in their io360 helicopter engine then it might make sense that they should be able to work on a their fixed wing version. Im purchasing the Stc for my J and will post the performance increase once established. The new firewall forward went out of there way to offer us io360 owners who want it, more power and the option if we so choose. We all know the options us certified aircraft owners have.

[320KPH]

Wiseng, sounds like the pistons were at issue rather than the STC.

AnA , good points. Let me know when you get the STC.

Moonpie, was tha the FWF compared to the reman?

[N601RX]

You might want to google firewall forward before you buy anything from them. There are plenty of post about them on other websites. I sent my camshaft to them for the centrilub mod. IT was susposed to be returned the next day. It took over 3 months and threats to get it back. They will not return phone calls.

[wiseng]

Anascendancy. Good Luck You are going to need it. Talk to Lycoming about the differences between the IO-360 and the HIO-360..

[anAscendancy]

No need for luck. I know there are differences between and aircraft engine and a helicopter engine. However, they are fundamentally the same. The new firewall forward might have communication issues as they did a centralube cam for me and were difficult to contact. I figured they were in the back working. In this day and age who can always afford someone to answer their phone. They are still providing a service that otherwise would be unavailable. What ever shortcomings they might have I believe is overcome by the service they provide, and I'm not talking about bedside manner. I'm talking about giving us better STCs. Lycon runs hi comp pistons in there race motors with no or very little issue be it heat related. Lycon told me as long as I didnt use chrome cylinders Id be ok. They related a story to me about a guy who ran 10:1 pistons in an M20E A1A. There was someone at the fisdo that was going to field approve it for him. He had great success with them, he just bought a K before he got around to gerting it approved and put it back to stock. The moral of the story is if you want Hi Compression pistons in your Mooney there is a option and it works if done right.

I wonder what a io360 would do with a roller cam, port flowed jugs, hi comp pistons and a powerflow? All STCs available to use certified aircraft owners. I believe that would blow the io390 out if the water for the dollar spent. Perhaps 240 hp in a four banger, could you imagine a certified M20J with that without all the weight of a Continental. We have the octane at the moment, I believe we should use it.

[carusoam]

Sounds like risk vs. reward...

You take on some risk, if it works you are rewarded with higher output.

If it doesn't work, can you go back? If yes, at what cost?

There are a couple of TN systems that have proven results in Mooneys. How does that sound?

There are Missiles with proven results.

Do they advertise this STC anywhere?

I have 10:1 cylinders in my 1992 automobile with cross current fluid cooling and electronic ignition. Unfortunately continuous output is pretty low in that application. Going longer than 10 seconds full throttle will have you lose your license...

Keep us abreast of your decisions...

Best regards,

-a-

[anAscendancy]

Ly Con charges 250 per head for porting so 1000 plus tax if your in California. They will port any worthy jug new or used.

[anAscendancy]

Ly Con charges 250 per head for porting so 1000 plus tax if your in California. They will port any worthy jug new or used.

[anAscendancy]

STCs are advertised however not all.

Ly Con roller cam Stc isn't advertised. You need a newer style case. I found one for my E, it had some damage repaired it and also port flowed my jugs with powerflow. Only thing missing is hi comp pistons. Can't have them in a A1A. Hoping to make some More than stock hp.

For my J I'm going to do all that with the firewall forward hi comp Stc. Really you just need to gap the rings correctly and do there special cylinder break in procedure not like stock break in and your golden.

[wiseng]

Did all that as far as break in and ring posistion etc. I really tried to make the thing work. Find someone who is happy with the STC and the performance of the provider. I have been unable to find any one.