Engines 360 vs 320

[Sam Buchanan]

Originally Posted by 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.

I too purchased a mid-time engine from Wentworth. Here is something for you to think about:

http://thervjournal.com/overhaul.htm

The only way you can be assured of what you are buying is to buy a new engine. In the long run, engine cost will be about the same.

[SeanB]

I think the choice boils down to your mission. I live in Colorado and the field elevation is 6874 ft msl, where it is commonly above 10K DA. After takeoff and heading west, there are these rather large piles of rock and dirt to consider. No way I would hang a 320 instead of a 360 in this case.

Also, I hope to get in and out of remote airstrips from time to time.

What if I fly to OSH or Cabella's and buy a bunch of things? If I'm getting closer to full gross, sure won't hurt to have the extra umph.

The RV-7 is aerobatic. A little extra horsepower could be good.

As already pointed out, on a cross-country the 360 can be tuned in for economy.

The 360 wins in all cases in my application, but the 320 would be fine for certain missions. How will you fly??? That makes the decision for you.

[Subwaybob]

Originally Posted by 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.

Mel, did you get that here in Dallas (Lancaster)?

[GEM930]

Originally Posted by Vlad

When I am flying with somebody I wish I had 360. When alone on a loooong trip I wish I had 235 Your choice it IS a primer war

What he said!

I'm one of those guys that pulled his 320 and is in the process of installing a 360. My problem was there are 3 other (almost 4) RVs at my field. When I was flying by myself I was satisfied with the performance. When I flew with other RVs... I wanted MORE POWER!!! The kicker for me was a trip from California to OSH in my buddy's 360 RV-7. I was in charger of fuel calculations and burn was always within about .2 gph of what my 320 would have been for the same speed. My 320 was a great engine and ran like a top, but I'm just a sucker for "keeping up with the Jones" I guess.
I can't comment yet on the actual difference as I'm still in the process of the install and I opted for a constant speed propeller as well, so it would not be an apples to apples comparison anyway. I do believe that if resale value is of any importance to you the 360 RVs seem to sell for more.
Good luck! I'm sure you will be happy with what ever choice you make.

[roee]

Originally Posted by LifeofReiley

Build with an O-320 as Van himself would... bullet proof, economy, light... it is all you need.

The parallel valve 360 is just as bullet proof, economical, and light as the 320.

All things being equal, choosing the 320 over the 360 is like leaving money (horsepower) on the table. The only good reason mentioned so far for choosing a 320 is if you happen to get a really great deal on one. Otherwise, the 360 is clearly the better choice.

And Van is a very practical thinker. I think he'd agree.

BTW, I think it's funny how people invoke Van's name that way. "What Would Van Do?"

Originally Posted by LifeofReiley

I guess the O-360 guys wished they had the IO-408ac now.

Nope. For a serious racer with an unlimited budget, the 408 may be a good choice. For the rest of us, balancing all considerations (performance, weight, reliability, economy, flexibility in fuel types, etc.), the parallel valve 360 is still the best choice out there.

[rockwoodrv9]

Im convinced - I will be going with a O360 for the -9 I am building. The Aspen airport is 7815 and Rifle about 6000. On a nice, warm day, with a full load, I think I will appreciate the 20 extra hp.

[Mel]

Originally Posted by Subwaybob

Mel, did you get that here in Dallas (Lancaster)?

Air Salvage of Dallas.
Lucky is the best guy in the world you would want to do business with.

[LifeofReiley]

Originally Posted by roee

The parallel valve 360 is just as bullet proof, economical, and light as the 320.

Yes... my good friends Aerosport O-360 went totally south (trashed) at 480 hrs just a couple of months ago... bearings, crankshaft, all trashed. When you run 'em hard, I'll stick with the 320 @ 178 hp.

[roee]

Originally Posted by LifeofReiley

Yes... my good friends Aerosport O-360 went totally south (trashed) at 480 hrs just a couple of months ago... bearings, crankshaft, all trashed. When you run 'em hard, I'll stick with the 320 @ 178 hp.

Interesting. I'd like to know more about your engine (its exact configuration), what caused it to fail, and under what operating conditions, etc. And I'm especially curious if there's a good reason to your belief that a 320 would not have suffered the same fate. Please share more info about your incident (start a different thread for that).

In any case, I have to point out that both the 320 and 360 have well established service records in the field over many decades and millions of flight hours, and both have proven highly reliable. That doesn't mean they never fail. But very rarely fail if built, installed, maintained, and operated properly. I don't know what happened to your particular engine and why, whether it was the result of defect, error, or if you were just one of the few unlucky ones. But in any case, remember that one incident does not negate the broader service record.

[Sam Buchanan]

Originally Posted by rockwoodrv9

Im convinced - I will be going with a O360 for the -9 I am building. The Aspen airport is 7815 and Rifle about 6000. On a nice, warm day, with a full load, I think I will appreciate the 20 extra hp.

That long -9 wing will climb like a charm on 160hp....at any USA field elevation. Choose the 180 if you wish but don't consider it essential for excellent performance from a RV-9A.