s10sakota

s10sakota

Well Known Member
Has anyone ever installed and flown with a 160 hp O-320 and then wished they went with the O-360?

Did you swap? Was it worth it? Performance difference?

Thanks!
 
I think the quest should be, "Has anyone installed an O-360 and wished they had installed an O-320?"
 
N941WR said:
I think the quest should be, "Has anyone installed an O-360 and wished they had installed an O-320?"
Click to expand...

The answer would probably be no. ;) More power when you need it, and throttle back to get the same fuel economy.

I do know lot's of 0320 owners who wanted 0360's. they were mostly in 6's..........at the time.

L.Adamson --- 6 with an 0360
 
Let me back up a bit.

When I first built my RV-9 I installed a 135 hp O-290-D2 in it. It was a great engine and a great match for the -9. I could cruise it at 140 knots / 165 mph all day long at 65% power and still climb it at 1600 FPM with full fuel, full seats, and baggage while burning around 7 GPH.

It really did very well with the small engine.

However, when I trashed that engine I found the cost of an O-360 ECi kit was only $500 more than an O-320 kit AND the 360 was only 20 lbs heavier. Thus, I installed the larger engine.

As for performance, I can easily pull the throttle back and match the speeds and fuel burn of the O-290 only I can now climb faster and cruise faster, if I want to.

My typical 65% cruise speeds are around 154 knots and I can run lean of peak due to my dual electronic ignition and burn 6.5 GPH.

The next thing to take into account is resale value. The 180 hp (I)O-360 is the "standard" engine for the -7 (and -8) and anything less can really impact the value.

Regardless of the engine, make sure it has the hallow crank so you can run either a FP or CS prop. Heck, you can even start with a FP and change it to a CS prop as your budget allows.
 
As a RV wannabe I would be currious to hear from some -4 owners on this subject. Doing my reasearch when I was in the marked came up with the 320 owners really liked it because of handling reasons. For handling the 320/fp wins, for speed and maybe W/B if you carry a heavy passenger the 360/vs wins. In an RV-4 of course.

Do I have this right?

Mark
 
Thanks for the replies so far guys! I do know one thing, I will never install a cs prop. Yes they are awesome, my goal for this RV-7A is lightness and simplicity!

The reason I ask is because I may be able to get an O-320-ED2 for free....but it has a cracked case.

First my buddy has to make sure I can get the engine, but if I can, I'm trying to decide if it's worth it to fix this one with a new case and the 160 hp pistons, or just go with the 360. I may regret not having the power later!
 
s10sakota said:
...The reason I ask is because I may be able to get an O-320-ED2 for free....but it has a cracked case...
Click to expand...
I have a "free" bulldog, the dang thing is the most expensive dog I have ever owned!

A friend bought an O-320 core for his -9 project at a great price, $500, IIRC.

After sending all the parts off, having the case converted to dynofocal mount, replacing the parts that needed replacing, he could have bought a O-320 ECi kit engine for just a few grand more and EVERY thing would have been zero time. He is happy that he has learned a lot but not happy that he could have had a new engine for about the same $$$.
 
Bill,

That's the kind of info I need! Thanks. I have no idea what it would cost to have this engine rebuilt but like you said it may turn out to be no deal at all.

It just may be better to look at something like the ECI kit.
 
s10sakota said:
Thanks for the replies so far guys! I do know one thing, I will never install a cs prop. Yes they are awesome, my goal for this RV-7A is lightness and simplicity!
Click to expand...

Just something to keep in mind, and especially at airports that are quite a bit higher than sea-level. You'll be thinking the "lighter" aircraft is going to be the performance king. And then you'll fly with someone who has a C/S, and wonder why yours seems like a "slug" on the takeoff roll in comparison. RV's really aren't slugs............but you'd notice the difference quite easily! MY take, is that I never want an RV without a C/S.

L.Adamson

P.S. --- the only time a C/S is not the one to have.........is if you prop strike it... :(
 
Good choice on the FP prop thing.

Remember, despite LA's rants about CS props (here is mine for FP props), while a CS prop RV will outperform a FP prop on take off, even at sea level, your RV will still out run any factory plane out there.

I would not be afraid to take my RV, with its cruise prop in or out of any field a CS prop guy might go into.

Just like the engine choice, remember, the 150 HP O-320 is a great engine for a FOUR place airplane and you are going to stick one in a light two place craft, it will go like stink. The problem us RV guys forget is that we only tend to compare RV's to other RV's and RV's have unreal performance. If you compare a heavy 150 hp RV-6 with FP prop to a F33, the RV will hold its own, except for the two missing seat thing.
 
I love my 150hp O320 and I like my wood fixed pitch prop (but would love a Catto with nickel edges).

My -8 climbs at 1800+ at sea level. Sure it will be less at 9000' in Colorado but I'm still climbing at 800fpm at 10,000 and climbing and climbing.

I dontvthink you will go wrong with the O320 or the O360. If I were building, I'd be shopping around and what I found would likely make my decision for me.

edit: as for being liht on the nose, "yes". My plane has a significant weight ring on the hub. If I change props, I just change the weight ring and break even.
 
Last edited:
N941WR said:
AND the 360 was only 20 lbs heavier.
Click to expand...

Well it depends, 20 lb is significant for any two seat aircraft and may be an issue depending on the type of aircraft and prop in particular.

The 7 and 8 have a generous max gross weight and were designed for the bigger engine. Put the smaller engine in and there could be c of g issues.

The 6/6A has a Vans gross of only 1600/1650 lb so 20 lb cuts significantly into the load.

Put the bigger engine in a 9A and you can start to run into fwd. cg and too much weight on the nose wheel issues especially combined with a heavy prop.

s10sakota said:
Has anyone ever installed and flown with a 160 hp O-320 and then wished they went with the O-360?
Click to expand...

I fly with an 0-320 and a Hartzell C/S prop on my 9A and at one stage I did wish I had the 0-360. However once I got over the macho thing I realised that the 0-320 was the best engine for my aircraft/ prop combination and with an 0-360 I would simply be carting around an extra 20+ lb of largely unused hp. Might be a different story if I had a light weight FP prop and definitely if I had a 7, which was designed for the heavier engine.

Fin
9A
 
Last edited:
I thought VAN's makes a longer engine mount for 7's that use a 320 to compensate for lighter nose for the W&B.
 
RV-4 O-320 150hp FP

Mark,

I fly an RV-4 O320 150hp with a Prince FP wood/carbon fiber. Balance is fabulous, performance suites my needs fine.

I do formation with two RV-4's w/O360's CS and greatly notice the performance dif above 7,500 - especially maneuvering.

Nothing but Great things to say about the Prince prop/O320 combo. Very good match! Thinking about the Stroker 340 at overhaul.
 
Last edited:
Finley Atherton said:
The 6/6A has a Vans gross of only 1600/1650 lb so 20 lb cuts significantly into the load.
Click to expand...

On the other hand, there are a lot of 6's with gross weights set at 1750-1850, by the builder. Is this bad? Doesn't appear to be, since we've been doing it for 20 years or so. Van was quite conservative regarding weight, in those days. No wings have fell off or 6's. The 6 spar is a beast, when it comes to strength. I'm sure they'll be a few, who will argue this point. There always is.

FWIW, my 6, with GW at 1850 is livelier in response, climbs faster, and outruns...........the 9's with an 0320. It can also be just as miserly on fuel.

L.Adamson --- 0360/Hartzell C/S
 
It really seems that a 360 would be best for my 7A. Plus, like Bill alluded to, this 'free' engine could be a nightmare! If the case is cracked, what else is wrong with it?? Maybe the crank is bent!

The more I think about it, the more I don't want this 'free' engine!
 
Last edited:
Engine mount s longer for a 320

Hello Don

Yes, the enginemount is 2" longer on a 320 enginemount for a RV-7. This to help against tailheavy W&B.

Dominik

RV-7A, IO-320
finishing
 
Free engine

Depending where the case is cracked, it very possibly is repairable. Divco and the like repair cases every day.

If the engine is available free, get it, tear it down and send the case and steel part for inspection. What have you got to lose? It shouldn't cost much to have the parts inspected.
 
I wouldn't want a cracked spar repair on my plane, wouldn't have a cracked engine case repair either. JMO! listen to Repucci, it could cost more to get that engine airworthy than it would to build a new ECI kit. Besides, while a o-320 is the correct choice for a -9, you will be sorry on a -7. Again JMO and a prod for Bill!;)
 
Pretty much correct. A 360 with a composite constant speed would be ideal for everything but money and maybe solo handling.

The -4 solo with a 320 and light prop will make anyone smile though.


RV Wannabe said:
As a RV wannabe I would be currious to hear from some -4 owners on this subject. Doing my reasearch when I was in the marked came up with the 320 owners really liked it because of handling reasons. For handling the 320/fp wins, for speed and maybe W/B if you carry a heavy passenger the 360/vs wins. In an RV-4 of course.

Do I have this right?

Mark
Click to expand...
 
free 0320 core

I just broke down an 0320 e2d. sent out the case and all the steel parts. (waiting on the outcome) I put it on a vertical stand and broke it all down in a day. I bought the core with no log and a rumor it was a low time engine. I hired an AP to help me catalog the parts and measure up the crank before i sent it out and plan to have him reassemble with me. He agreed with the rumor that it was a low time engine from his 30 year experience of doing this. I completely value this experience and knowledge that I have gained from this.
You will pay aprox. 1,200 to analyze everything and get an estimate for any additional work. Its a chance you take,but it could be a perfectly fine engine.
Lets say everything is a mess and the crank is still good. You could always sell the crank to recoup your cost (and more) and will have gained a lot of knowledge. The case company may be able to repair it.
 
You must log in or register to reply here.