Probably Stupid Question about STC
 

I joined here for reasons other than posting this but I like to make an entrance. :E
I have a Koliber 150a and I hate my stupid lycoming O-320. It runs like a dog, it sat for 3 years in it's previous hands. So, it's corroded and sick. I invested more money than I needed to into this poor old wet dog of a motor.

Can I just put something else into it, like a Titan 180 or 167 or even just an uprated 160hp STC'd O-320 at the time of overhaul? Would I really need an STC for it? They did this in the 172s, and my plane is just a low wing STOL skyhawk that's built like a tank. There are Rallyes, same exact airframe essentially, with 180hp. If it needs STC would I be paying a million dollars?

I can't get but 400fpm out of the poor sap. I weigh less than 180lbs (small dude!) and solo, still can't get but 400 fpm.

What should I do? What should I do?
I don't wanna go fast or nothing, I just want to climb reasonably. Maybe 650 fpm, or 700. :sad:

And forgive me if I'm in the wrong posting area. I've never been on a forum besides an herbal remedies site before. I'm internet ignorant. :}

Or should I sell the whole plane and get something new... oh man. Help me. :ugh:

If you want to sell it, I might buy it off you. Drop me a pm.

I don't know the details of the aircraft, but type certified aircraft are required to have a type certified engine (and prop). That engine must be "type approved" to the airframe, and an STC is one way of that. If there is an STC you can buy, applicable to your aircraft, and desired engine, go ahead. If not, doing your own STC approval, though possible, is likely not cost effective...

I'm not aware of any existing STCs for this bird. All I'm worried about is cost, like you said... The thing almost killed me.
I like the plane itself a lot and really hope to keep it but safety is priority. I might just opt for a good overhauled o-320.
Thanks for responding!

Has it got a cruise prop?

I believe it does. Funny, I was just thinking about that...

Although I have little experience of Aero-engines, they have a great many similarities to 1930's car engines.....Are your compressions good? Camshaft timing correct? (1-tooth out can have an enormous effect) Ignition timing?
Mixture?...Prop has already been mentioned....it's a compromise,like a single-geared pedal cycle. even daft things like fairing strips to flaps, can tweak performance markedly.

Your engine may fail one or more of the checks above,you may think about an exchange engine if it's cheaper than rectifying the present one.
read the POH properly and try to contact other owners....it may be that you have bought a "slug" but wanted a "racehorse"
Friend had an Aeronca Chief...lovely stable forgiving aircraft and dead simple....but you could not be in a hurry and had to watch out if there were liable to be strong headwinds.

According to the TCDS, you have a choice of three props:



https://easa.europa.eu/system/files/...2-08012007.pdf


I'm guessing you're not getting 150hp out of the engine. According to that TCDS, the gross wt is 1874 lbs?? Gross on my 150hp C172 is 2300 lbs. It ought to climb just fine on 150hp, unless you're trailing a drogue chute? A good mechanic needs to go over everything, intake, ignition, carb, and exhaust to find the problem. I climbed at 700fpm today in 90 deg air solo.

The reduced power sounds like the usual Lycoming worn cam lobes.
Especially as you say it sat around for 3 years. All the oil drains off the camshaft in a few days and then it rusts. This is due to the wonderful idea of placing the camshaft at the top of the engine instead of underneath in the sump submerged in oil. Is a very stupid design. Can be checked by measuring valve lift. On putting a bigger engine in her the type cert may cover various engine types, so could be just a case of fitting and follow any required mods.
So I would start by reading the certification paper work.

Ok, so I set a mechanic out on it, an experienced mechanic.

He's found nothing wrong with the engine so far, except my tach was 200 low on the reading (oh bother... I've probably redlined it thinking I was being nice to it at 2550!).

Inspected the valves, no problems, clean, open. Cylinders show no issues, compression/timing/ignition all checked out (I have brand new mags and a brand new carb, too).

I agree that the cam is a relatively stupid design from an oil-related standpoint. It doesn't help (not everyone can run the thing once per week).

1874lbs gross is correct.
Well, I never wanted a FAST plane. Just some climb rate (airspeed is life, altitude is life insurance!) so I can get to a safe altitude as quick as possible. I don't like putting around my treesy area low and slow at 65-70kt in a plane of this size and weight.

I guess there is a gremlin in my tail somewhere that deploys a drogue chute every time I take off just to get under my skin.

I'll talk with sensenich after demonstrating the climb problem in flight to Mr. Mechanic.

It's true man... 150 should launch this plane at the weight I fly at! No way this thing is THAT draggy, right? Besides, when I first bought her, I got 800fpm. Once. :*

Hi you did not say if valve lift was checked. It can be difficult to check if it has hydraulic lifters.

Yes Lycoming do state their engines need to be run 40 hours a month to make TBO hours.

Engine trust line can make a big difference, is it preset by the engine mount or can it be shimmed. Have seen this make a difference when the engine is pointing down.