Engines 360 vs 320

[CODon]

I have a parallel O-360 and am not looking back. Bought a run out engine that turned out to be quite sound. Flew it off and pulled it last week for a rebuild during the winter months. Probably not the best way to go but it fit the timeline and budget. There are a lot of options, but think it is just best to get the decision behind you and keep on building.

[wirejock]

Originally Posted by CODon

I have a parallel O-360 and am not looking back. Bought a run out engine that turned out to be quite sound. Flew it off and pulled it last week for a rebuild during the winter months. Probably not the best way to go but it fit the timeline and budget. There are a lot of options, but think it is just best to get the decision behind you and keep on building.

CODon
Not to hijack the thread, but I was interested in the runout/rebuild experience. I am on a tight budget and am considering a mid time.
Would you do it again? Was there any saving vs installing a new engine? Did the runout make the first hours easier not having to break in a new engine while flying the bugs out of a new airplane? Thoughts?

[dealfair]

Originally Posted by wirejock

CODon
Not to hijack the thread, but I was interested in the runout/rebuild experience. I am on a tight budget and am considering a mid time.
Would you do it again? Was there any saving vs installing a new engine? Did the runout make the first hours easier not having to break in a new engine while flying the bugs out of a new airplane? Thoughts?

Larry,
My old mentor used to fly the 7th Fleet Commander & SEATO VIPs all over the Pacific in a 4 engined C-118 (DC-6) back in the 1960s. He told me they NEVER allowed an engine with less than 500 hours to be installed on it. They had to have tested proven engines on that aircraft. Only grunt carriers & cargo planes flew with new low time engines. That should tell us something. MORAL: don't reject a good mid term engine out of hand. 1,000 hrs in a RV covers a gob of miles.

Good luck & Cheers,

[Ron Lee]

Go with the O-360. How many people remove an engine to install one of lesser horsepower versus the other way around?

My opinion is such that I tell people who want to buy an RV is to get one with an O-360 (not all RV models).

If you are buying a new engine, getting an (I)O-320 instead of an (I)O-360 would be a mistake in my not so humble opinion. I am not suggesting an angle valve 360 engine.

[dealfair]

Ditto what Ron Lee says. I have an O-320 in my -4 because it was available, good price, quick, etc., etc., like Sam described. It performs well; but I want an O-360. I've never met an RV owner, yet, with an O-360 who wished for an O-320.

[AlanNZ]

Firstly to clarify I'm talking about a 180hp 360 vs a 160hp 320. The thing I find strange is that I used to own a pa28 161 and fly with 2 friends (one in a 172 and the other in a pa28 also) they Both had a fuel burn of about 40 to 45 litres but I guess that depends on how hard you push them, after all more fule = more HP as a rule of thumb.

In New Zealand the 320, 160hp is far more common than the 360. From my perspective I'm most likely going to be using a mid time engine and the 320's are more available (and the difference is price is substantial).

I think you have all raised very good points for the parallel valve 360 and therefor will be on the lookout for one. I'm thinking of importing from Wentworth from the USA.

With thanks.

[LifeofReiley]

Build with an O-320 as Van himself would... bullet proof, economy, light... it is all you need. I guess the O-360 guys wished they had the IO-408ac now.

[humptybump]

One of the most common compliments I get about having a simple 150hp RV-8 is "Van would love this plane". I hope so i love it.

I don't recommend others hang the lower compression O320 on their project. It's all a personal choice. That said, every time I talk to the builder of my plane (we talk regularly and have become good friends thru the plane, RV's have that affect on people) I end up telling him, "you built the plane I've always wanted!"

Build what you want. Be happy with what you build.

[Captain Avgas]

Originally Posted by AlanNZ

The thing I find strange is that I used to own a pa28 161 and fly with 2 friends (one in a 172 and the other in a pa28 also) they Both had a fuel burn of about 40 to 45 litres but I guess that depends on how hard you push them, after all more fule = more HP as a rule of thumb.

Alan, the reality is that the Brake Specific Fuel Consumption (BSFC) of both the Lycoming 320 and 360 (parallel valve) is identical at .43 lb/Hp-hr. In other words they will both consume .43 lbs of fuel to generate 1 horsepower for one hour.

This means that both engines will burn the same amount of fuel at the same horsepower. The only difference being that you can call on more horsepower from the 360 if you need it (at a higher fuel burn of course)
.
Or put another way, if you travel cross country with a 320 producing 120 HP (75% power) you will have the same speed and fuel burn as with a 360 producing 120 HP (67% power). However you will be running the 360 engine at a lower percentage of power which should provide for superior engine longevity (all other factors being equal).

Some of those mountains in Kiwiland are pretty big so a few extra horses from a 360 may come in handy when you need them. At other times just throttle back and get the same fuel efficiency and speed as with a 320.

[Mel]

I installed an O-320 with 2500 hrs. when I built my -6. The engine had a good run sheet and history, and was bought from a very reputable Air Salvage co. I flew the engine for 3 years before rebuilding it. And even at that time, everything met all tolerances.
I would do it again in a heartbeat!

Everything else being equal (seldom is) I would chose the O-360. But I certainly wouldn't let that be a big deciding factor. Horse power has little to do with speed. It has more to do with take-off and climb, which the RV does great even with the lower compression O-320.