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RV-9 engine selection

greight

Member
Been looking at engine choices for the RV9---What is the lightest 150HP engine? It seems that the IO/O-320 weighs practically as much as an IO/O-360. I guess it is because all of the ancillary parts and accessories are the same. I think most even use the same case. And the costs are about the same.
 
light weight engines

According to Tony Bingelis (Firewall Forward) book recommended by Van's,
the o-320 E & A series weigh 244 lbs dry (table page 33) which is the lightest
o-320 listed and happens to be rated at 150 HP.

Of course, with ONLY 150 hp, your -9 will not be capable of flight:D

Dave
-9A FWF kit (150 HP o-320E2A)
N514R
 
Engine weight

Just a thought, if you are trying to be as light as possable, Get an O-290-D2
(233 Lbs dry weight) It is factory rated at 140hp@2800rpm. Install 9/1 compression pistons and electronic ignition and you should be over 150hp. Also ECI has several lighterish options for the O/IO-320 but I dont have specific weights. Russ
A&P/IA Alaska
 
Contrary to some beliefs, these planes don't need to be light as possible. When you stick a small engine on...............that's exactly what you get.............smaller performance, and it shows bigtime !

Believe me.....

L.Adamson --- RV6A
 
Just a thought, if you are trying to be as light as possable, Get an O-290-D2
(233 Lbs dry weight) It is factory rated at 140hp@2800rpm. Install 9/1 compression pistons and electronic ignition and you should be over 150hp. Also ECI has several lighterish options for the O/IO-320 but I dont have specific weights. Russ
A&P/IA Alaska
Sounds a lot like my 990 pound O-290-D2 powered RV-9. Only that engine weighs 264 pounds dry (No oil, but all the accessories). Check out this site for engine weights.

Only one problem with that engine, after the prop strike I had last June I could not locate parts to overhaul it. Worse yet, the best quote I had for doing an overhaul was more than the cost of a new O-320 from any of the reputable engine shops. Once my insurance company heard that, they wrote me a check large enough to buy an ECi kit of my choice. Thus the O-360 that I currently have in my basement, waiting to be installed.

Contrary to some beliefs, these planes don't need to be light as possible. When you stick a small engine on...............that's exactly what you get.............smaller performance, and it shows bigtime !

Believe me.....

L.Adamson --- RV6A
Don't believe him...

I was very happy with my 135 hp O-290-D2 and dual electronic ignitions. With the climb prop I had, it would cruise at 165 mph / 140 knots and the climb rate was outstanding (1800 FPM solo). All that on ~ 7 gph. Oh, and because of the light weight, I had a 760 pound useful load without inflating the GW beyond Van's recommendation.
 
Don't believe him...

I was very happy with my 135 hp O-290-D2 and dual electronic ignitions. With the climb prop I had, it would cruise at 165 mph / 140 knots and the climb rate was outstanding (1800 FPM solo). All that on ~ 7 gph. Oh, and because of the light weight, I had a 760 pound useful load without inflating the GW beyond Van's recommendation.

Don't tell anybody.......... but his new replacement engine for the damaged 0-290 is a 180HP 0360. That's 20 HP over Van's recommendation for the RV9.

I guess... subconsciously, he really wasn't that happy afterall.. :D

L.Adamson ---- RV6A
 
Don't tell anybody.......... but his new replacement engine for the damaged 0-290 is a 180HP 0360. That's 20 HP over Van's recommendation for the RV9.

I guess... subconsciously, he really wasn't that happy afterall.. :D

L.Adamson ---- RV6A

No, not at all. When you look at the weight (12 lbs) and cost (~$500) difference between the O-320 and the O-360, I had to wonder why not put the larger engine in the plane. Besides, I'll gain that 12 pound difference back by going with a lightweight composite FIXED PITCH prop.

Had I not trashed the O-290-D2, I would have continued to be very happy with it. But since parts are not available for that engine and I couldn?t rebuild it, I had to come over to the HP dark side.
 
Carb location for a trike

FYI:

If you go with a carburated engine, some, like the O-320 B2B, has the carb too far aft which can interfere with the nose wheel strut. That is easily fixed (new sump, intake tubes, and oil pickup) but something to think about. I didn't know that before I bought my used engine.

If you are building a taildragger, it makes no difference.
 
160 HP Hartzell CS

I have close to 500 hours on my 9. I have a 160 HP O-320 with a Hartzell constant speed prop. Weight and balance is right on and the plane performs wonderfully all the way to 17,500 ft. There is a huge difference between a 150HP and a 160HP and a HUGE difference in climb performance and comfort when cruising when using a CS prop. Also 1 gph less fuel consumption with a constant speed prop when in cruise. Don?t worry about being light. If you can carry more because you have a little engine and composite prop you have no performance to carry the extra weight. My 2 cents.
 
I have close to 500 hours on my 9. I have a 160 HP O-320 with a Hartzell constant speed prop. Weight and balance is right on and the plane performs wonderfully all the way to 17,500 ft. There is a huge difference between a 150HP and a 160HP and a HUGE difference in climb performance and comfort when cruising when using a CS prop. Also 1 gph less fuel consumption with a constant speed prop when in cruise. Don?t worry about being light. If you can carry more because you have a little engine and composite prop you have no performance to carry the extra weight. My 2 cents.

Around here, we're constant speed prop fans too. We do live in mountain country with airport elevations beginning around 4000' msl. The constant speed allows for a brisker takeoff, quieter cruise flight, and excellent braking effect when getting back to the pattern. Lot's of RV's around here (including 9's), and C/S props are by far the majority.

L.Adamson --- RV6A/ Hartzell CS
 
There is a reason...

Don't tell anybody.......... but his new replacement engine for the damaged 0-290 is a 180HP 0360. That's 20 HP over Van's recommendation for the RV9.
One time ... On Barnstormers ... There was a guy selling a 9 ... with a 200hp IO-360 ... would cruise at 225 mph ... Beyond Vne.

The folks at Van's design some really nice airplanes, and certainly had a good reason to restrict the 9 to 160HP.

Before you decide to beef up the engine ... Probably should read this "Why can't I use a larger engine?"

JMHO...
 
One time ... On Barnstormers ... There was a guy selling a 9 ... with a 200hp IO-360 ... would cruise at 225 mph ... Beyond Vne.

The folks at Van's design some really nice airplanes, and certainly had a good reason to restrict the 9 to 160HP.

Before you decide to beef up the engine ... Probably should read this "Why can't I use a larger engine?"

JMHO...

While you are certainly correct to be concerned about top speeds, flutter margins, and Vne in any aircraft, this is a PILOT problem, not an EQUIPMENT problem. It is the pilots primary duty to manipulate ALL controls in the aircraft (which includes power) to keep the aircraft within its flight envelope. If the pilot is incapable of acting as a pilot, then I still say he (or she) should stay on the ground, rather than trying to idiot-proof the airplane.

Know your limitations, and act within them.
 
Super-9 ??

I may get in trouble with the more conservative folks, but I would install an ECI IOX-340S (185hp and lightweight) and whirlwind 151 constant speed. I wouldnt even rule out raising the compression to 10/1 with electronic ignition:D. Just an observation but compairing VNE on the RV-4 vs. routine airspeeds from the HRII crowd it seems the safety margins for VNE are well.. generous. Russ
 
Just an observation but compairing VNE on the RV-4 vs. routine airspeeds from the HRII crowd it seems the safety margins for VNE are well.. generous. Russ

Also remember that the RV-4 was designed as an aerobatic aircraft. The RV-9 was NOT!
IMHO, the RV-9 and -10 were most likely not designed with limits as conservative as the aerobatic steeds.
 
I may get in trouble with the more conservative folks, but I would install an ECI IOX-340S (185hp and lightweight) and whirlwind 151 constant speed. I wouldnt even rule out raising the compression to 10/1 with electronic ignition:D. ...
Russ,

I looked at the IO-340 when picking the O-360 to replace the O-290-D2 in my -9. It turns out the O-360 puts out more HP, costs less, and only comes in a few pounds more. In fact, with a composite CS prop (Whirl Wind) it is still lighter than an O-320 w/ a FP metal prop.

Also remember that the RV-4 was designed as an aerobatic aircraft. The RV-9 was NOT!
IMHO, the RV-9 and -10 were most likely not designed with limits as conservative as the aerobatic steeds.
I couldn't agree with you more Mel.
 
Russ,

I looked at the IO-340 when picking the O-360 to replace the O-290-D2 in my -9. It turns out the O-360 puts out more HP, costs less, and only comes in a few pounds more. In fact, with a composite CS prop (Whirl Wind) it is still lighter than an O-320 w/ a FP metal prop.


Yep. My primary reason for choosing an IO360 vs the IO340S was that I want to be able to run Mogas, which means lower compression pistons, which rules out the 340. Current plan is an ECI IO360 with Whirlwind CS prop.
 
Just had this random thought someone may be able to answer.
The RV-9 can float excessively in the flare if the speed is a bit high or if the idle is set too high. Would the bigger 180 HP engine with its bigger FP prop be likely to increase the length of the flare all other things being equal? The bigger engine/prop would produce more thrust at idle rpm, but possibly offsetting this the bigger prop would present a larger surface area to the airstream and therefore give a bigger engine/prop braking effect.

Fin
9A
 
Just had this random thought someone may be able to answer.
The RV-9 can float excessively in the flare if the speed is a bit high or if the idle is set too high. Would the bigger 180 HP engine with its bigger FP prop be likely to increase the length of the flare all other things being equal? The bigger engine/prop would produce more thrust at idle rpm, but possibly offsetting this the bigger prop would present a larger surface area to the airstream and therefore give a bigger engine/prop braking effect.

The larger engine with a fixed pitch prop on the 9, just won't help with any braking effect. The C/S will, and a 9 will actually fall through a flare.......just like my 6A, if you don't watch the airspeed. You wouldn't think a 9's wing would act like a heavier sink rate 6, but it does.....when combined with a C/S that can slow the plane down so fast.

L.Adamson ---- RV6A
 
Just had this random thought someone may be able to answer.
The RV-9 can float excessively in the flare if the speed is a bit high or if the idle is set too high. Would the bigger 180 HP engine with its bigger FP prop be likely to increase the length of the flare all other things being equal? The bigger engine/prop would produce more thrust at idle rpm, but possibly offsetting this the bigger prop would present a larger surface area to the airstream and therefore give a bigger engine/prop braking effect.

Fin
9A
Maybe but I doubt you will notice it. I'll let you know in a few months if your theory works or not.

Don't forget, that with the large engine, weight also goes up, thus increasing your stall speed. These two things may balance themselves out. I don't really know.
 
Interesting question Finley!

It seems to me that the pilot,, with some experience, automatically adjusts the nose up trim to compensate.

For example if the hypothetical 9a with a 320 and a fp Catto uses 65 kts indicated airspeed for their final approach then an equivalent 9a, but with a 360 and a Catto (pitched for the greater hp) might require a slightly higher angle of attack to maintain the same final approach speed which results in similar landing performance. The 9a airframe/wing likes a particular approach speed and the pilot cancels out the extra residual thrust from the bigger engine/prop with up trim to get to that magic number.

I have experienced relatively long landing distances on my 360/9a due to too high an idle setting and due to too high an approach speed. However, as Larry mentions, the 9 can also drop out from under you, similar to a 6 or a 7 (don't ask how I know) if you let the speed bleed off too much. With a constant speed prop the deceleration is quicker and therefore the potential drop out could occur even faster to a distracted pilot.

Cheers,

db
 
Engine mount

Resurrecting an old thread, sorry about that.

I am planning on using a catto 2 blade on my RV 9. So this lends itself to using the weight savings for a bigger engine. I am curious if the RV9 O 360 has to use a custom engine mount, baffles and such. Or does Vans have Firewall Forward kit that is good for this combo?
 
Lots of 360s out there in RV9/9As. Uses same mount, baffles etc. as RV7 that you can order direct from Vans. Just let them know when you order the FWF kit what you want.

With the Catto, you may still be light on the nose. Difference between the Catto and aluminum Sensenich is about 30 pounds. But still within CG if you are careful how you set things up. Weight difference between 360 and 320 is only about 10 pounds (again depending on how they are set up).
 
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I've got an RV-9 QB on order that will arrive someday. Thinking ahead I've read various threads on using a 360 vs 320 and decided I'd like the IO-360. I fly my IO-360 RV-6 most of the time at 40% power or less so I'm more interested in economy and takeoff performance than speed.

I would like to use a horizontal draft. I haven't seen where anyone has done this before but Vans offers the horizontal draft IO-360 for RV-6 and RV-7, so i thought it ought to fit in the RV-9 too. I've got probably a couple of years to decide.
 
I have an IO320 in my 9A. I also have a BRS chute. MY W&B is still good but could but I should have gone with a 360 just to bring some more weight forward and have given myself more margin.
 
I friend and experience RV pilot/builder points out the problem with horizontal draft is there is little room left over for the heat muffs. All that space where the pipes cross over is filled with an air filter and there are few lengths of tangent pipe. He has flown 9's with IO-360's and his opinion the IO-320 with a constant speed is the sweet spot. Good and abundant heat is important at my latitude.
 
I installed the IO 360 M1B on my 9A and followed OP-33 for the cabin heat. Everything turned out just fine.
 

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Thanks for sharing. So it can be done. Do you have any close up pics of the install? Were you able to install two heat muffs? Any issues or gotchas? I'm planning a 9 so that ought to free up some space up front.
 
Check out the IO340

Ok, so I have around 750 hours now on my ECI IO-340 (stroked 320) putting out 180 hp and weighing 8 lbs more than an IO-320, 8 lbs less than an IO-360. Of course ECI was bought out by Continental. They do still sell that engine. It is a fantastic engine for the RV9A.

So, some details on my setup (oh, and if you do a search for IO340, or just on my username, you can find quite a few of my posts on this engine):
I used the RV7 IO360 cowl and the IO360 snorkel which meant some fabrication work on the pilot side intake to accept the air filter.
I have forward facing cold air induction so crossover exhaust doesn’t work. I have Vetterman four straight pipes.

Other than these changes most everything else on the firewall forward is pretty much the same as a standard IO-320.
 
One heat muff. I have an RV 10 firewall mounted oil cooler. The engine is a Thunderbolt that has piston squirts installed. These are not normally on a parallel valve engine, but should result in lower CHT's. The snorkel is a pain in the neck, but doable. I deviated from the plans a little on this. I have to remove the entire snorkel to remove the filter. I think the end result looks good.
 

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Thanks for posting your closeups. I'm still about a year away from an engine but given lead times I need to start sorting out my options now. My fuselage has a crating estimate early September.

One heat muff. I have an RV 10 firewall mounted oil cooler. The engine is a Thunderbolt that has piston squirts installed. These are not normally on a parallel valve engine, but should result in lower CHT's. The snorkel is a pain in the neck, but doable. I deviated from the plans a little on this. I have to remove the entire snorkel to remove the filter. I think the end result looks good.
 
What's your mission?

Ted, please help us out by filling out your profile. That way you don't look like a poser just throwing out a controversial question to see the fray.

Assuming you are building - - the engine selection is one parameter to meet your goals for budget, and what you want to do. Coast to coast, short trips, cost per mile, climb, take off distance, IFR, etc all drive the equation. Just like you want it.

The IO360 CS prop would allow you to use discretion in throttle and speed selection to keep it in the envelope, but to allow some high altitude cruise with low fuel burn at lower RPM and leaner fuel settings for a 9's maximum economy.

Scott Card (& Tanya) has a lot of experience in cross country in their 9 and excellent advice. Bill has been through this is depth and experience behind his information.

Sitting at 14k in cruise going across vast distances consider what its like leaving 15 KTAS on the table when the chasing the sundown . . . . if that is your mission.
 
YIO-320 non-certified vs Thunderbolt?

My RV-9 fuselage has a late September crate date and I want to pull the pin on an engine. I'm looking at the YIO-320 from Vans. $41.6k for a non-certified Lycoming with P-Mags and $47K for a Thunderbolt engine with dual E-Mags and AFP FI. The non-certified engine does not offer a FI option.

I would like to hear thoughts on choosing the Thunderbolt vs non-certified given the $5.4K premium for a Thunderbolt beyond the balanced parts, chrome rocker covers, and color choice. The nomenclature is confusing; both engines are non-certified. P-Mag vs E-Mag? What FI comes with the non-certified engine?

I will follow up with Vans to track down answers.

I like the idea of the horizontal induction but I wonder if I have the skills to pursue that choice.
 
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