I saw a 9 for sale with a 140 hp Lyc. o-290 D2. According to some research, the o-290’s seem to be good and fairly lightweight engines, but unsurprisingly, it’s one of those engines that’s hard (and expensive) to find parts for. The recommendation seems to be to fly the aircraft until it’s time to overhaul, and then replace it with an o-320. Is this relatively simple? Do both engines use the same mount? Or is it just better to keep looking for a 9 that’s already equipped with an o-320 (as with o-235 powered RVs)?
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RV 9 with Lycoming o-290
- Thread starter Duncannon
- Start date
PilotjohnS
Well Known Member
My opinion
I believe the engine mount and firewall forward will need to be redone when going from O290 to 320.
But the 9a airframes are rare to be for sale. In looking at the performance numbers, the 290 and 320 arent much different. If i was looking for a 9a, i would not hesitate with an 0290 if the airframe is good. JMHO
I would also switch to the new nose gear at the time of engine change.
I believe the engine mount and firewall forward will need to be redone when going from O290 to 320.
But the 9a airframes are rare to be for sale. In looking at the performance numbers, the 290 and 320 arent much different. If i was looking for a 9a, i would not hesitate with an 0290 if the airframe is good. JMHO
I would also switch to the new nose gear at the time of engine change.
There was never a special mount made for fitting an O-290.
If switching to an O-320 it should fit fine but would likely have to be a conical mount engine ( I don’t think O-290’s were ever made in a dynafocal version, but I could be wrong).
If switching to an O-320 it should fit fine but would likely have to be a conical mount engine ( I don’t think O-290’s were ever made in a dynafocal version, but I could be wrong).
Phyrcooler
Well Known Member
I’m in the market for a 9A, and briefly considered the same or similar plane. But based on discussion on other forums with someone who actually had one with an O-290 and later had to swap out, the O-320/360 mount 2” closer to firewall necessitating a different mount than original AND a shortened cowling. I’m not sure what mount was used originally. So definitely more work than just swapping out the motor according to someone who did it. The well documented lack of parts discussed across lots of forums made me concerned about being stuck with no alternative but to replace the motor when something fails. If I were younger, I might consider what could end up being a project plane. It’s definitely attractive, and if your circumstances are different and you are ok with a potential project someday, I’d try to negotiate on it. As previously noted, it would give the opportunity to swap out the nose gear.
Over the years there is occasional discussion regarding using non-standard motors and their impact on resale. I recently watched a very clean O-235 equipped 9A sit for sale for quite a while and that motor has ready parts availability. I don’t know what they eventually got for it but they were asking $90k and it had a digital panel. The planes with Subies really sit and you see prices drop.
Just the opinion of someone studying Barnstormers and Trade-a-plane multiple times a day!
Over the years there is occasional discussion regarding using non-standard motors and their impact on resale. I recently watched a very clean O-235 equipped 9A sit for sale for quite a while and that motor has ready parts availability. I don’t know what they eventually got for it but they were asking $90k and it had a digital panel. The planes with Subies really sit and you see prices drop.
Just the opinion of someone studying Barnstormers and Trade-a-plane multiple times a day!
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The RV-9, RV-7 and RV-6 use the exact same engine mounts.
There was a special mount produced (may be still is, I’m not sure) that was slightly longer for use when and 0–320 was installed on an RV-7. it was necessary, because that airplane was specifically designed for a heavier engine.
The RV nine was designed for the 0–320. The standard length engine mount was used on that airplane for that engine. There is not a very big difference in weight between and 0–290 and Dan 0–320 so I don’t know why Bill originally used the extended length engine mount. I don’t think it was necessary.
So I guess it is possible that there is another RV-9 that was built using and extended engine mount so that would be something to confirm but I wouldn’t assume it to automatically be the case because it shouldn’t have been necessary.
An RV-9 built with and 0–235L2C is a different situation, and it did require a special engine mount because the engine weight is significantly different enough, but I didn’t mention it because this conversation was about the O-290, and it is an engine mount that is specific to that model of engine only. The other engine models will not mount up to it.
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Phyrcooler
Well Known Member
Good information and appreciated. I guess best advice for OP if they’re concerned is to verify which mount was used.
Just for my knowledge, does the nose gear upgrade require any cowl mods? Without digging it up, I thought there was some lower cowl opening trimming needed? Overall, if an O-290 to 320 swap can be done without having to swap mounts and redo the cowling (and paint…) this makes it a more viable idea assuming price can be negotiated.
The upgraded nose gear does require a slightly wider slot in the bottom of the cowl. That can be easily dealt with.
There is a potential issue that would require much more effort to resolve though.
The prop spinner is a long ways forward of the engine mount. This means that a very small variation in the physical dimensions and alignment of the new engine mount can result in a spinner that is no longer centered on the front of the cowling. I have even seen instances where just removing an engine, and installing a different one resulted in a different spinner alignment, because of the tolerance variations from one engine case to another.
So in simple terms, there is always the possibility of alignment issues. If any part on the front of the airplane is changed.
Alignment
With the conical mount engines shims between the mount and the mount rubbers an be used to correct slight misalignment of the spinner.
A very modest amount of shimming can also be done on the dynafocal mounts. This would typically be done to correct "sagging" engine with the softer mount rubber.
The 0 235 dynafocal mount engines were used on the Cessna 152 and Piper Tomahawk. There are at least two different dash numbers for those engines.
With the conical mount engines shims between the mount and the mount rubbers an be used to correct slight misalignment of the spinner.
A very modest amount of shimming can also be done on the dynafocal mounts. This would typically be done to correct "sagging" engine with the softer mount rubber.
The 0 235 dynafocal mount engines were used on the Cessna 152 and Piper Tomahawk. There are at least two different dash numbers for those engines.
David Paule
Well Known Member
The OP mentioned an RV-9, which is a taildragger, and thus would not need the revised nose gear.
Dave
Dave
You’re right, if he was actually talking about a tail dragger, but people use the model designations very generically a lot of the time. So who knows whether it is actually a tail dragger or tricycle gear.
Jim is correct.
I have used shims to adjust engine alignment on dynafocal and conical mount engines.
I just didn’t want anyone to think that just because the engine mount style wasn’t being changed that there wouldn’t be alignment issues that would have to be dealt with
Phyrcooler
Well Known Member
Yes. I just assumed that he was referring to a 9A since I’m aware of one for sale with a O-290. Not many around with this motor. But I shouldn’t assume.
Was it all white colored? I think I saw that one.
Yes a 9a nosewheel.
https://www.facebook.com/commerce/listing/1417157569014558/?media_id=0&ref=share_attachment
Here’s a rather good looking 9a (inside & out) with an o-290 with only 314 smoh. This is what motivated me to post this topic.
Edit: I’m not the seller, I’m not trying to advertise, just filling everyone in on why it’s so tempting.
I have a 9a that I have been flying for the last 7 years or so. It has an o290d2. Overall I am very happy with how it flys. I have never done any accurate measuring of speed but on a cool day it will indicate 140kts at 2-3k feet. The only time I wish for more performance is on hot humid days.
As I recall the cowling and the engine mount were both marked as o-235 parts when I got the finishing kit. It was nesc to fabricate the firewall forward parts such as baffling and mounting for oil cooler and filter.
I bought the engine used and built a standard kit with a basic panel. The result of which I ended up with an empty weight of 990 lbs and a 43kt stall. My total cost was under 40k. When I built the plane I had family obligations and I built the plane I could afford and after several hundred hours of flying Im still happy with it.
The biggest negative I see is the lack of cylinder parts available for the o-290. There is a company making pistons for a reasonable cost but the rings are ludicrously expensive.
As I recall the cowling and the engine mount were both marked as o-235 parts when I got the finishing kit. It was nesc to fabricate the firewall forward parts such as baffling and mounting for oil cooler and filter.
I bought the engine used and built a standard kit with a basic panel. The result of which I ended up with an empty weight of 990 lbs and a 43kt stall. My total cost was under 40k. When I built the plane I had family obligations and I built the plane I could afford and after several hundred hours of flying Im still happy with it.
The biggest negative I see is the lack of cylinder parts available for the o-290. There is a company making pistons for a reasonable cost but the rings are ludicrously expensive.
