Skybolt Al

Skybolt Al

Well Known Member
I'm considering an 0-360 for my RV9A. Is there any problems with obtaining parts from Van's to do this? Do I just use an engine mount and other parts meant for an RV7? FINALLY, is it worth it?
Thanks.
 
o-360 for a -9A

I have it on good authority from some of the experts around here that the
o-360 in a -9A should be considered MINIMUM.....

I'm worried sick that my 150 HP -9A will not get off the ground:D

All kidding aside, the o-360 seems to be a popular thing to do although Van's
recommends a max of 160 HP for the 9.

The larger engine only weighs slightly more and provides increase take-off
and climb performance.

So, go for it!

Dave
-9A finish kit (#!@&* canopy!!)
 
I think it was Mahlon that originally pointed out that an o360 with a sensibly pitched to prop won't make more than 160 bhp anyway. When you look at an o320 and add a cs prop then there really is no good reason not to put a 360 in a 9.

My next 7 or 8 will prolly have a 540 just cus....:)

Frank
 
Daver said:
I have it on good authority from some of the experts around here that the
o-360 in a -9A should be considered MINIMUM.....
Click to expand...
Not so fast. I had a 135 hp O-290-D2 on my -9 and was very happy with it. With the climb prop I was seeing 1800 FPM climb and 165 mph (140 knot) cruise speed.

Had I not had the prop strike I would still be flying with that engine.

However, after looking at the numbers I can see not real reason not to go with an O-360. One thought is to have any of the engine builders work up an O-320 with EI and ported and polished cylinders. That should get close to 180 hp.
 
150 hp

Building on a budget required me to jump on the best deal I could find be it a O-235, O-290 or whatever.

I managed to get a O-320E2A (150 HP) with 450 hr SMOH. It came with all the accessories included a sump heater & oil cooler. Excellent logs, all AD's
complied with, etc.

I bore scoped it, compression tests, and I even pulled a jug to check out the
cam shaft - all clean as a whistle.

I got it to my garage for $7k.

If it woulda' been a O-360, I'd be just as happy (or happier) but I'm optimistic it'll work OK.

Dave
 
Has anyone had any troubles getting insurance when they've installed a 360? I know there was some discussion about this a while back. I know the performance difference in a Cessna 172 is huge when you put the 360 on it. I can imagine it's equally impressive in an RV.
 
9A O360

I see no problem with using the larger engine, if that is what you feel you need to do. But... They go like crazy with an O320, and you can use a certified prop combination with the metal Sensi option. And...you won't have an "issue" to overcome if you decide to sell your bird someday. Remember, Van says it's a no no, and that carries a lot of weight with potential buyers.
I remember a guy that tried to sell his beautiful RV6 that wasn't primed. He took a tremendous hit when he sold it.

I'm just sayin'...

Regards,
Chris
 
Well

apkp777 said:
Has anyone had any troubles getting insurance when they've installed a 360? I know there was some discussion about this a while back. I know the performance difference in a Cessna 172 is huge when you put the 360 on it. I can imagine it's equally impressive in an RV.
Click to expand...

Certainly not on a 7 or 8 cus thats what is the de-facto engine. i don't know if there would be an issue or not if you put one in the 9..

Haha..are you kidding me?..A 172 makes like what 700FPM..Well my 7a at sea level makes a sustained 2400FPM on a cool morning solo..I'd say its considerably more impressive in an RV...:)

Cheers

Frank
 
other considerations

I know there are many factors that go into an engine choice. I am offering up this post just as another point you may want to consider.

I have made the committment to put an ECI IO-340 in my 9A. ECI rates this engine at 185 HP while claiming a weight difference of 7 or 8 lbs more than an IO-320. I am not sure what the weight difference really is between the 320 and the 340 but I do think the 340 is going to weigh less than the 360. If ECI claims prove to hold true then at 185 HP it is 3 to 5 HP more than the 360.

I do not have any hard data to do any comparisons since I am not flying yet but I do have the engine installed on my aircraft and am currently plumbing it now. I have encountered some things that have forced me to make changes to a standard installation but the truth is they are really related to the forward facing sump, the electronic ignition, etc. rather than the difference between the 320 and the 340. The truth is, the size, location, and pretty much everything else on this engine is the same as the 320. So, even though I have had some frustrations on the installation it is not really that bad.

Drop me a note if anyone is interested in any of the details of this installation. I think the IO-340 is going to be a great fit for the 9A.
 
I wanted to go that same route, but decided against the ECI IO340 due to the high compression ratio pistons as the only option. I want to run pumpgas, which means I need the 8.5:1 pistons, which locks me into the IO360 if I want more than 160 hp. I'm planning on running forward induction with a cold air sump, AFP injection, one mag and Lightspeed II, with a C/S prop.
 
Insurance???

apkp777 said:
Has anyone had any troubles getting insurance when they've installed a 360? I know there was some discussion about this a while back. I know the performance difference in a Cessna 172 is huge when you put the 360 on it. I can imagine it's equally impressive in an RV.
Click to expand...

Having had my 9A with an O-360 for two insurance cycles, I haven't had the first issue with getting insurance. I get my insurance from SkySmith.
 
frankh said:
Haha..are you kidding me?..A 172 makes like what 700FPM..Well my 7a at sea level makes a sustained 2400FPM on a cool morning solo..I'd say its considerably more impressive in an RV...:)

Cheers

Frank
Click to expand...


I think he was referring to the difference switching from an 0-320 to an 0-360 makes, as opposed to comparing a 172 and RV. Sort of an "it makes a big difference in the 172, should also make a big difference in the RV" type thing.

That being said, put whatever you like (within reason). This is the great part of experimental aviation. Some people like light airplanes, some people like more power. It's all good!
 
No insurance problems here at all.

As far as the extra HP goes, it's all about power management. When you get in your car you don't use all 200 HP to back out of the drive way. Be reasonable, and use the power when you need it and you'll be fine. The performance at altitude is where you separate the 0-320s from the 0-360s.
 
Geico266 said:
No insurance problems here at all.

As far as the extra HP goes, it's all about power management. When you get in your car you don't use all 200 HP to back out of the drive way. Be reasonable, and use the power when you need it and you'll be fine. The performance at altitude is where you separate the 0-320s from the 0-360s.
Click to expand...

I (mostly)agree with Larry...

The problem is related to people not being educated enough to make proper judgments in managing the power.

Theses forums are proof of that considering the heated debate that is in the archives on such subjects as "Is VNE based on true airspeed or indicated airspeed?". It is important to fully understand this (and other subjects) when you make the decision to equip an airplane with more power than the designer recommends.

Recommended reading...http://www.vansaircraft.com/pdf/hp_limts.pdf
 
I was originally going to go with a -360 as the price difference was only a few hundred, as I recall. But, Van's had a great Sun n Fun deal on a experimental Lycoming IO-320 that made the difference several thousand, so I jumped on it.

A problem has been that Van's has only recently started supporting an IO-320 in an RV-9 and the drawings for an IO engine installation are all for an IO-360. The differences are not that difficult to work around, but the installation of an IO-360 would have been a bit simpler. Now, if you are talking about a regular O-320/360, you might have the opposite problem.

Van's will support you if you choose a -360. But, if you can get a IO-360 for not much more than the price of a IO-320, I would recommend you go for it.
 
Jim F

In the discussion of the larger engines are you forgetting that the reason the factory recomends nothing larger than a 320 is because IT WILL GO TOO FAST. ie; max cruise will exceed the Vne of the airframe. The other RV's are an aerobatic airframe with a much higher Vne and maneuvering speed. The engineers caution about exceeding the speed limitations of the 9. I remember when I was building my empenage at Synergy Air, how much different (and thinner) my tail components were than the friends who were building a 7 or an 8.

Also, there is the issue of fuel consumption. I am happy with my 0-320/CS match.
 
Jim F said:
Also, there is the issue of fuel consumption. I am happy with my 0-320/CS match.
Click to expand...

My 0360/CS is beating or at least equal with some 0320/CS's when we both throttle back. At least it proves the point that an 0360 can also use less fuel if that's what you want, while offering better performance on the top end.

L.Adamson --- RV6A
 
Jim F said:
In the discussion of the larger engines are you forgetting that the reason the factory recomends nothing larger than a 320 is because IT WILL GO TOO FAST. ie; max cruise will exceed the Vne of the airframe. The other RV's are an aerobatic airframe with a much higher Vne and maneuvering speed. The engineers caution about exceeding the speed limitations of the 9. I remember when I was building my empenage at Synergy Air, how much different (and thinner) my tail components were than the friends who were building a 7 or an 8.

Also, there is the issue of fuel consumption. I am happy with my 0-320/CS match.
Click to expand...
Jim,

Not a problem, The Vne for the -9 is 210 mph and most people are in the low 190's with the O-360.
 
Jim F said:
In the discussion of the larger engines are you forgetting that the reason the factory recomends nothing larger than a 320 is because IT WILL GO TOO FAST. ie; max cruise will exceed the Vne of the airframe.
Click to expand...

I know quite a few people who have put a -360 in a 9, and I haven't talked to one yet that was able to exceed the 210mph Vne in cruise, or at least in reasonable cruise conditions. Who have you talked to that is able to do that?

In any case, this still comes down to simple power management. The throttle is nothing more than another control on the aircraft that can be manipulated throughout its full range to get the airplane to do what you want it to. You don't always use full rudder, elevator or aileron, and it's not likely you will use full throttle constantly either. You can exceed Vne with an O-235 in a 9A also, even at idle power - just point the nose at the ground and hang on. The pilot has to be a PILOT, not a spectator. Use ALL the controls in the aircraft to maintain safe flight, at all times. If the pilot is not capable of judging the limitations of the aircraft, then he needs a spamcan.
 
I'd read and understand this (http://vansaircraft.com/pdf/hp_limts.pdf ) before installing a bigger engine.

While the Vne for the 7 & 9 are near the same, the other characteristics of the wing are not. the 9 has a longer span and I believe a higher coefficeient of lift. Its lower stall speed creates a lower Va. These will likely make it behave different that its short and fat winged brothers.
 
From Van's document:

Vne can be established based on a number of factors. One consideration is the speed at which the airframe design limit will not be exceeded when encountering a sharp edge vertical gust of 25 fps. Another is the maximum safe speed at which the airplane can be flown without encountering aerodynamic flutter. The RV -9A Vne was set based on flutter considerations. But in cruising flight, gust loads are the limiting factor. If an engine capable of producing 75% power speeds of over 180 mph is used, design strength could be exceeded.
Click to expand...

In other words there's two considerations:

First there's Vne. Van's set this as 210 mph TAS (not in the above document - but in the manual). As Bill mentioned, the -360's are getting into the low to mid 190 mph TAS WOT, well short of the 210 mph limit.

My IO-360 with 3-blade Catto will see about 195 kts TAS at 8000' DA when WOT (2770 rpm). My normal cruise will be 150-160 kts TAS, turning around 2450-2600 rpm.

Next there's Vc - max structural cruise speed. Van's set this at 180 mph IAS. Depending on altitude and temp, the low to mid-190 mph TAS in most cases gives an IAS of less than 180 mph. And again, this is generally at WOT (and well above 75% power).

If you were to use a -360 with a CS prop, or a FP prop that was pitched for a really fast cruise, perhaps you'd run into issues. But with the pitch recommended by Craig for this combo it just isn't an issue. If you read the last line in Van's paragraph above, I'm pretty sure I'm well below both limits at 75% power.
 
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-9a horsepower?

I wouldn't shy away from a -9a with an 0-360. ..especially if it lets you stay low compression, and use pump gas in needed in the future.
Mine is ok with the 0-320, but if you control the weight with a lite starter and electronic ignition, so that you don't increase the weight on the nose too much, ok.
You really don't want much more weight on the nose wheel, do you?
 
flyboy1963 said:
I wouldn't shy away from a -9a with an 0-360. ..especially if it lets you stay low compression, and use pump gas in needed in the future.
Mine is ok with the 0-320, but if you control the weight with a lite starter and electronic ignition, so that you don't increase the weight on the nose too much, ok.
You really don't want much more weight on the nose wheel, do you?
Click to expand...

There is a real mis-conception here. That weight on the nosewheel is only there until the pilot climbs aboard. A lot of the pilot's weight is behind the main wheels, which does in fact take weight off the nosewheel. In fact, sometimes it's an advantage to have more nose weight. It allows a better balancing act with the CG when flying with passengers and baggage. Some RV side by sides even have to add weight up front to allow more baggage as the fuel burns off.

I have.... what would be termed a heavy nose wheel weight in comparison to some other RV's. Yet when I'm flying it, it's very easy to keep weight off the nose while on the runway.

L.Adamson ---- RV6A
 
I modified my weight and balance spreadsheet to calculate the weight on the nosewheel. The purple line on the chart shows the limit based on various c.g. locations. Obviously the further forward the c.g., the higher the nose wheel loading. As you can see, as the fuel burns off the weight on the nose wheel lowers.

Weight_Balance.JPG
 
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