Van's Air Force
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O-290 G
- Thread starter jany77
- Start date
RJDickensheets
Member
Worth it, I think.
I can't address the install issue, but the first RV4 I ever flew had one mated to a wood prop. Terrific match for the airframe - light and nimble. I actually preferred it over the O-320 metal prop combo.
rd
I can't address the install issue, but the first RV4 I ever flew had one mated to a wood prop. Terrific match for the airframe - light and nimble. I actually preferred it over the O-320 metal prop combo.
rd
I had a biplane with a converted O 290-GPU and a wooden prop. No starter or other accessories but it ran great.
I didn't actually do the conversion on the engine, but if I remember correctly it included removing some mounting lugs from the case and adding backing plates to the crankshaft flange. Also, you need to add an appropriate harness, if it doesn't already have an shielded aircraft harness. This may not be true for every O-290-GPU model. The following site sells a manual to do the conversion and I think that EAA also can provide some assistance in that area if you ask them.
http://www.esscoaircraft.com/product_p/7002.htm
I didn't actually do the conversion on the engine, but if I remember correctly it included removing some mounting lugs from the case and adding backing plates to the crankshaft flange. Also, you need to add an appropriate harness, if it doesn't already have an shielded aircraft harness. This may not be true for every O-290-GPU model. The following site sells a manual to do the conversion and I think that EAA also can provide some assistance in that area if you ask them.
http://www.esscoaircraft.com/product_p/7002.htm
N941WR
Legacy Member
I recently accompanied a friend as we went to pick up an unmodified O-290 GPU and here is my observation:
The flange everyone talks about is a big round thing up by the prop hub. It is there so they could be bolted up to a dynamo (generator). They can be cut off w/o a problem, IMHO.
The prop flange is about the same but you will need the bolt bushings.
The accessory case had two openings for mags and "I think" both drive gears where in there. If not, I have a spare gear from my O-290-D2 that I can sell you.
They accessory case had the opening for a fuel pump, which my O-290-D2 did not and has since been replaced. The unit we picked up had a cover over the opening so I don't know if the proper gear and push pin were in there or not. I suspect not. Again, you can pick these items up on eBay.
The sump needs to be replaced as the GPU used an down draft carb, not an updraft.
For ignition I plan on using duel Pmags. The price isn't much more than slicks and I can use auto plugs, get a hotter spark, have electronic ignition, etc.
Parts can be found for the engine but they do require some searching. It seems to me that the engine is about 40% O-235, 40% O-320, and 20% O-290.
The most difficult part to find is the Marvel-Schebler MA 3SPA (10-3565-1) Part #: 62830 carburetor. Aircraft Spruce lists them but it turns out they neither have the core nor will they rebuild one if you have a core. Long story but they can be rebuilt. Contact me, if you find one and I'll give you the name of the FAA repair station that yellow tagged mine.
I bought my carb core from an airboat builder in FL that had a fresh overhaul. Don't believe them, it still had the composite float in it which was replaced when it was yellow tagged.
The other carb option is to use one from a Continental O-300 Marvel-Schebler MA 3SPA (10-4895) TCM Part #: 633029. I have heard they actually work better than the carb spec'ed out by Lycoming. The difference seems to be jetting, venture size, and maybe a few other small parts.
There are some pictures of my engine on my web site listed below.
Good luck!
The flange everyone talks about is a big round thing up by the prop hub. It is there so they could be bolted up to a dynamo (generator). They can be cut off w/o a problem, IMHO.
The prop flange is about the same but you will need the bolt bushings.
The accessory case had two openings for mags and "I think" both drive gears where in there. If not, I have a spare gear from my O-290-D2 that I can sell you.
They accessory case had the opening for a fuel pump, which my O-290-D2 did not and has since been replaced. The unit we picked up had a cover over the opening so I don't know if the proper gear and push pin were in there or not. I suspect not. Again, you can pick these items up on eBay.
The sump needs to be replaced as the GPU used an down draft carb, not an updraft.
For ignition I plan on using duel Pmags. The price isn't much more than slicks and I can use auto plugs, get a hotter spark, have electronic ignition, etc.
Parts can be found for the engine but they do require some searching. It seems to me that the engine is about 40% O-235, 40% O-320, and 20% O-290.
The most difficult part to find is the Marvel-Schebler MA 3SPA (10-3565-1) Part #: 62830 carburetor. Aircraft Spruce lists them but it turns out they neither have the core nor will they rebuild one if you have a core. Long story but they can be rebuilt. Contact me, if you find one and I'll give you the name of the FAA repair station that yellow tagged mine.
I bought my carb core from an airboat builder in FL that had a fresh overhaul. Don't believe them, it still had the composite float in it which was replaced when it was yellow tagged.
The other carb option is to use one from a Continental O-300 Marvel-Schebler MA 3SPA (10-4895) TCM Part #: 633029. I have heard they actually work better than the carb spec'ed out by Lycoming. The difference seems to be jetting, venture size, and maybe a few other small parts.
There are some pictures of my engine on my web site listed below.
Good luck!
o290g
thanks bill the reason why im asking about conversation is i know about one engine for sale which was not used at all and its cheap of course im on budget and dont want go for loan i dont see any reason why spend that much money for new engine when this one can do same think maybe little bit more
thanks bill the reason why im asking about conversation is i know about one engine for sale which was not used at all and its cheap of course im on budget and dont want go for loan i dont see any reason why spend that much money for new engine when this one can do same think maybe little bit more
N941WR
Legacy Member
Engine prices are the reason I went with the -9 over a -7 or -8. I figure 175 mph on 6.5 GPH isn't so bad.
As for the carb issue, before I found my carb I did look into two other options that might be more desirable for you since you are building a -3.
The Ellison Throttle Body and the Aero-Carb Throttle Body. Back when I looked into the Ellison the cost was crazy expensive, around $3,000, if I remember right. The Aero-Carb was around $400.
I connected with a guy who built an O-290-D2 powered rag and tube plane who used the ACV-C05 (38mm) Aero-Carb and had very good things to say about it. A lot of people had a good amount of second hand garbage to share regarding the aero-carb which was completely discounted by one person's first hand knowledge/experience.
One thing to keep in mind with either throttle body, you will need a fuel return line. The guy I exchanged emails with just ran the return line back into the cockpit and tied it back in just after the fuel valve. (Email me off list and I'll give you his contact info along with a guy in CA who specialized in building up O-290's for experimental use.)
As for the carb issue, before I found my carb I did look into two other options that might be more desirable for you since you are building a -3.
The Ellison Throttle Body and the Aero-Carb Throttle Body. Back when I looked into the Ellison the cost was crazy expensive, around $3,000, if I remember right. The Aero-Carb was around $400.
I connected with a guy who built an O-290-D2 powered rag and tube plane who used the ACV-C05 (38mm) Aero-Carb and had very good things to say about it. A lot of people had a good amount of second hand garbage to share regarding the aero-carb which was completely discounted by one person's first hand knowledge/experience.
One thing to keep in mind with either throttle body, you will need a fuel return line. The guy I exchanged emails with just ran the return line back into the cockpit and tied it back in just after the fuel valve. (Email me off list and I'll give you his contact info along with a guy in CA who specialized in building up O-290's for experimental use.)
