Q: I have an O-320-E2A engine that is rated at 140 horses. What is required to add an additional 10 horses to that engine? I heard that all I need to do is change the cylinders and pistons. Please provide guidance.
Bob Agledor Sr.
A: Bob, you may be in luck when it comes to increasing the horsepower on your engine to 150 from 140 horsepower.
The interesting thing about your specific engine model was that it was actually certified at 150 horsepower at 2700 RPM with an alternate rating of 140 horsepower at 2450 RPM.
That seems to say that if you increase the RPM to 2700 on your engine, you’ll get the 150 hp that you were looking for at no additional expense for cylinders and pistons that you had mentioned.
However, you’ve heard the old saying “there is no such thing as a free lunch.”
Even though there doesn’t appear to be any cost to upgrade the engine to 150 hp, you may end up having to install a different prop, so please keep that in mind.
Both the 140 hp and 150 hp engines were installed in the Piper PA-28-140 and the Piper PA-28-150, so there’s another clue that it can be done.
In your case, even though the engine is certified for a dual hp rating, the question remains is your aircraft certified for a 150 hp engine?
I suggest you do a little research with your local FAA office, which should be able to tell you if your aircraft is approved for that horsepower.