0-360 build, what kind of horsepower will it end up with

I?m in the process of rebuilding my 0-360 and made a few improvements along the way. I installed new Superior cylinders, had them port and polished, and put in 9.5 to 1 pistons. I was already running 1 emag but stepped up to running dual pmags. Any guesses on what kind of horsepower I?ll be seeing?

Randy
8A

Hard to tell.

Based on this thread, 9:1 in an O-360 puts out 185 hp. you might get close to 190 with 9.5:1, if the timing on the P-mags are set properly. Less if you have too much or too little advance.

Porting your cylinders does make a difference but you will get more efficiency out those cylinders if you have them port matched to your exhaust and intake runners.

FWIW, ECI lists my O-360 with 8.5:1 compression at 188 hp and when Craig Catto cut my props, he said it was closer to 200 than 180. It took him three props to get it close and even now, I can spin this prop at over 2800 RPM at 8,000 feet, which I only did once for testing.

Good luck, I hope you get the results you are dreaming of!

I pure guess, but I had a IO360 with 10:1 pistons and had 200 HP.
I am not sure if the fuel injection adds HP.

I suspect with porting and polishing might give more.