Q: Our flying club is getting ready to have our engine rebuilt and some have asked about upgrading to 180 hp using an STC on the Lycoming O-320. Have there been any issues doing this and does the engine make it to TBO?
We currently have a Ram STC and a Power Flow Tuned Exhaust on it.
A: Alan, if you do have, in fact, a Lycoming O-320-E2D, you don’t need to go any further as the answer is simple.
To my knowledge, the O-320-E2D was never bumped up to 180 horsepower (legally that I am aware of) because of the front main bearing configuration, which is the same as the Lycoming O-235 series of engines.
If there are any STCs out there, I have no knowledge of them.
However, if there is an FAA STC to make this conversion, I’d strongly recommend you contact someone who has experience with this conversion other than the original STC holder.
With regard to the engine making TBO, I wouldn’t have a clue and the actual service life of the converted engine should come from an operator who has complied with the STC. I have my doubts that this subject would be addressed in the STC.
I’m not certain there is an STC to upgrade the O-320-E2D to even a 160 hp configuration. Again, this would be because of the front main bearing. There are some models of the O-320 series engines that can be modified to increase horsepower, but not the O-320-E2D.
I’m not familiar with the RAM STC you presently have, but not knowing the particulars, you must gain some advantage from it. The Power Flow exhaust system is also an advantage to get more power out of the engine.
We must remember that this O-320-E2D is certified at 150 hp @ 2700 rpm at sea level on a standard day. Once the airframe manufacturer installs its equipment, like the exhaust system, cowling, induction system, vacuum pump, and any other engine driven accessories, these all reduce the total output power of the engine to a horsepower figure that may surprise you if you were to sit down and run the numbers.
Let me offer a suggestion. Not knowing what the RAM STC offers and the efficiency of the Power Flow exhaust system, and the total time on your engine, let’s assume you’ve lost an unknown amount of horsepower. My thinking here is just doing a fresh overhaul on your engine, bringing everything back to factory new limits. You may be surprised at the difference in power and it may improve aircraft performance without spending lots of extra money.
Everyone is always looking for more horsepower and lower fuel consumption, but when it comes right down to it, we must allow logic to creep in and save us.
This brings to mind one more thing and that is there are wants and needs, so ask yourself, do I want this increase in power and am I willing to spend the extra money to get it, or do I really need it for the type of flying I do?