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Dmadd

Well Known Member
Is anyone building with the O-235 in mind? More specifically, the O-235 and a tail wheel?
Just wondering...

Dennis
 
Dennis,

I have found several O-235 RV9s in existence.

They mostly do not post here as this site tends to be somewhat hostile to O-235 installations. The RV9 was designed for the O-235 and depending on your mission it still may be the right choice. A lot of discussions about the RV9 as a LSA has occurred. Search RV9 LSA for background. Most think the only choice for a RV9 should be an O-320.

I am close to the O-235 or O-233 decision this fall , if Lycoming ever delivers an O-233. Van's has dropped the 235 stuff from its catalog, but the O-235 engine mount and cowling is available. I still have the option for either an O-233, O-235 or O-320.
 
It's an interesting option, especially with 20 gal of gas now wiping out a Benjiman...

We briefly considered the O-235 during the construction of the RV-9, as Dad had an O-235 equipped Long EZ at the time. We briefly gave thought to "salvaging parts from the Long EZ for the RV-engine included. The Long EZ sold, so that thought went with it. We ended up with an O-320 - just 'cause that's what you were "supposed" to do.

I'm not sure you'd save much with the -235. They're about the same price (used) as the -320. I can easily pull the 0-320 back to 100 or 110 HP and burn the same 6 gph. But I still have the full 160 HP for take off, which is nice.
 
mission?

You might want to consider 2 things.
1. if doing x-country, the -9 is said to be best at altitude, so you will want Oxygen, survival gear, decent avionics, IFR, maybe an autopilot etc.
I have a simple VFR -9a and am usually at gross just with my gear, full fule, some water and a passenger.
2. if you keep it 'simple' with a fixed pitch prop, an 0-320 is not producing 150 or 160 hp on takeoff. I turn 2100 on the roll, which I think the Lyc charts show as more like 85 hp!...so this limits use of short or grass strips etc.

just some food for thought.
 
0-235

This is slightly off-topic, but I've got a tailwheel RV9 with a 120 hp WAM diesel. I've been happy with the performance. Of course, it's got a turbo, but HP is HP, and I don't feel like it's underpowered at all. My engine is just as light as a 235; overall about 100 lb lighter than most o-320 RV9's. the lighter weight makes a significant difference in performance. My AVERAGE fuel burn is in the mid to high 4 gph range (not just cruise).

Based on my experience with my 120 hp '9, I think an O-235 would work out great! If you do build one, I'd like to compare performance numbers. From what I can tell so far, and from what our (Ken Krueger and I) testing shows, the 120 diesel performance is on par with the 0-235.

Kurt
RV9 WAM 120 Diesel / Jet A, 245 hours, flying since late 2008.
 
I have to agree with Kurt.

The O-235 powered RV will work out nice. Mine started with a 135 O-290, which is a great match for this plane.

However, the issue is resale. Not many people will pay the $$$ for 115 hp when they can pay just a little more for an O-320.

The cost of the engines are very close to being the same, so if you have the choice, go with the O-320. You can always pull back the black know and get the same fuel burn as the O-235.

As for the O-233, I was recently looking at my W&B with the O-290 and was almost too tail heavy with the light engine. The 233 would probably exaggerate that problem and force you to put some weight up front. That can be done with a metal prop or steel crush plate. Either way, you might just want to start with a slightly heavier prop.

Keep the options down and you will maximize your empty weight.

Performance wise, the -9 will fly just fine with a small engine.
 
Kurt,
I've just started my testing with our 0-235 powered 9a. We have got it registered Recreation Aviation Australia, which has a MTOW of 915 lb (same as LSA). The A/C weighed in at 893 lb empty.

So far there is 9hrs on the hobbs, but I haven't done much testing yet as I have just been concentrating on breaking in the engine. The temps are just starting to stabilize, so it looks like I might be able to get into testing. I've done some testing like, stall's, turns and some climbs. But decided to put off any further testing because of the overheating.

Stalls, 38 kts clean and 35 kts with flaps.


Bob







kgood said:
This is slightly off-topic, but I've got a tailwheel RV9 with a 120 hp WAM diesel. I've been happy with the performance. Of course, it's got a turbo, but HP is HP, and I don't feel like it's underpowered at all. My engine is just as light as a 235; overall about 100 lb lighter than most o-320 RV9's. the lighter weight makes a significant difference in performance. My AVERAGE fuel burn is in the mid to high 4 gph range (not just cruise).

Based on my experience with my 120 hp '9, I think an O-235 would work out great! If you do build one, I'd like to compare performance numbers. From what I can tell so far, and from what our (Ken Krueger and I) testing shows, the 120 diesel performance is on par with the 0-235.

Kurt
RV9 WAM 120 Diesel / Jet A, 245 hours, flying since late 2008.
Click to expand...
 
fuel

Reading some of the Long Ez stuff out there, those guys get the O-235 down to 3 or four gallons per hour. My O-320 won't go that low. :)
Somewhere I read that 3-4 GPH on an RV-9 is about 120-130 mph true. (can't find that data anymore) :-/
I'm just wondering what kind of endurance /range one could end up with by using that engine.
Might be a fun trainer for tail wheel endorsements and RV transition training... Cheap too...

Thoughts?

DM
 
117kt on 4.2

Here you go. 117ktas on 4.2 gph - I can get it down to 3.6 but it ain't much fun. At this speed - Over 1000 NM range with no wind - it would be even better up high.

RV-9A Kinda heavy, sorta straight....O-320/carb/hartzell/dE-Mag/P-Mag setup

IMG_2247.JPG


Dmadd said:
Reading some of the Long Ez stuff out there, those guys get the O-235 down to 3 or four gallons per hour. My O-320 won't go that low. :)
Somewhere I read that 3-4 GPH on an RV-9 is about 120-130 mph true. (can't find that data anymore) :-/
I'm just wondering what kind of endurance /range one could end up with by using that engine.
Might be a fun trainer for tail wheel endorsements and RV transition training... Cheap too...

Thoughts?

DM
Click to expand...
 
Wow!
Thanks Pete. Thats awesome!Good data point.
Thanks

Dennis


petehowell said:
Here you go. 117ktas on 4.2 gph - I can get it down to 3.6 but it ain't much fun. At this speed - Over 1000 NM range with no wind - it would be even better up high.

RV-9A Kinda heavy, sorta straight....O-320/carb/hartzell/dE-Mag/P-Mag setup

IMG_2247.JPG
Click to expand...
 
Watch your numbers

Just a note of caution, the "heavy" O-320 and "light" O-235 are not. The listed dry weight for the 160hp O-320-B1A thru B3C is 250lbs. The listed dry weight for the 118hp O-235-L2A is 252lbs. Basicly the same weight and a lot less power for the O-235 series. The old 135/140hp O-290-D2 at a svelt 233lbs was a superior light weight engine. Good luck, Russ
 
AK4x4 said:
Just a note of caution, the "heavy" O-320 and "light" O-235 are not. The listed dry weight for the 160hp O-320-B1A thru B3C is 250lbs. The listed dry weight for the 118hp O-235-L2A is 252lbs. Basicly the same weight and a lot less power for the O-235 series. The old 135/140hp O-290-D2 at a svelt 233lbs was a superior light weight engine. Good luck, Russ
Click to expand...

I'm not so sure about these weights. The O-290-D2 was 264 pounds.

Check out this link for weights.

I suspect the difference in weight is the 233 lbs vs. 264 lbs numbers doesn't include the carb, mags, starter, & generator (not alternator). Those early starters and generators were HEAVY!
 
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Lycoming lists the O-233 engine weight as 213lbs dry. This includes alt, starter, ignition but, without a engine driven fuel pump.

Engine weights are tough, unless you have a list of the specific alternater, starter, carb or injection, oil filter, fuel pump and so on. Most engine weights seem to be buried in the aircraft empty weight.
 
N941WR said:
I'm not so sure about these weights. The O-290-D2 was 264 pounds.

Check out this link for weights.

I suspect the difference in weight is the 233 lbs vs. 264 lbs numbers doesn't include the carb, mags, starter, & generator (not alternator). Those early starters and generators were HEAVY!
Click to expand...


I have to agree with Bill on this. I did a lot of research on the weights of the lycomings before choosing our engine. There is about 15 lb difference between the lightest and the heaviest of the different models, The engine we finished up choosing, was the 0-235 C2C (241 lbs). After stripping, rebuilding the engine and bolting on all the light-weight bolt on gear, in place of the heavier gear, it weighed 223 lb.

Bob
 
I think the 0-235 is a great choice for a 9A. I was skeptical until I saw the performance of one built in Tea, SD. The plane was built very light. What I saw was two FAA sized pilots and 10 gallons of fuel climb out at 700 FPM and do several T&G's. Then load up with 20 gallons of fuel, and fly it home to weastern Iowa. The cost of the engine was very reasonable and made the project profitable for the builder.
 
Built one, flew it, and loved it

N942WG has the O-235, 118 hp engine and it flies great. Matched it up with a Catto prop and enjoyed it immensely. I would not hesitate to do this again as it sipped fuel while still giving very respectable performance. In fact, it was right on the money with Van's performance numbers posted for the O-235. Unfortunately, my job changed and I sold in order to move to Houston.
Pat Garboden
Katy, TX

N942PT RV9A under construction
 
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