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O-290 Questions

knifeman

I'm New Here
I have an opportunity to buy an O-290 (no idea the dash number yet). I do know it has mags, no carburetor and was running at the time it was taken off the plane but has been sitting in an A&P's shop for a couple of years.

I am planning at least a partial teardown and inspection before I make a decision on the purchase. I have some idea of what to look for but am far from expert in this.

So, for those who do know...

What should I look for on this engine and are there any specific items that would make this deal a no-go?

Assuming this engine is good to go, does anyone have a guide on how to convert it for use in the RV-3? Or should I convert my money into an O-320?

Thanks in advance for the help

Chad Eyanson
Apple Valley, CA
 
The carb was one of the most difficult parts to locate when I was building up my O-290. However, you have two options, one is to use one of the throttle body injection units or a carb from a Continental O-300. I’ve heard the O-300 carb works well but haven’t tried it. My carb came from an airboat engine shop in Florida and I had it rebuilt. That carb was sold after I trashed my engine, so I can’t help you there.

To convert the engine for an RV project, check out my website. You will have to buy a new accessory case, timing gear, and plunger to drive the fuel pump.

You will also want to replace the valves with O-320 valves because the O-290 seemed to have an issue with their stock valves.

High compression helicopter pistons were a common mod.

The dash number is important because only the later models had hydraulic lifters, which is much more desirable.

Stay away from converted GPU's, typically called an O-290-G. (Mine was an O-290-D2, which had the hydraulic lifters.) The G's had mechanical lifters and a weak prop flange that was prone to failure. There was a backing plate for them but I'm not sure they are available any longer.

IIRC, the TBO on this engine is only 1800 hours.

ECi did make rings for the O-290 at one time and I have an unused set. If you need them, let me know, I'm sure we can make a deal.

In my experienced opinion, I would convert your money to an O-320!
 
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Thank you Bill for the quick response and the answer to my email. Good info.

The mechanic who owns this engine talked about the the prop flange backing plate you discussed, so I am guessing this is a -G. If I verify that I will pass on buying the engine.

I was hoping it would be good compromise between performance (O-320) and good fuel economy (O-235). Based on your recommendations it seems an O-320 and some throttle discipline may be the best way to go.

Chad
 
Thank you Bill for the quick response and the answer to my email. Good info.

The mechanic who owns this engine talked about the the prop flange backing plate you discussed, so I am guessing this is a -G. If I verify that I will pass on buying the engine.
You are welcome and Smart move!

I was hoping it would be good compromise between performance (O-320) and good fuel economy (O-235). Based on your recommendations it seems an O-320 and some throttle discipline may be the best way to go.

Chad
You are right, I REALY liked the O-290-D2 I started with in the -9. It was light and at 140 HP / 135 HP continuous it was a good compromise. (My empty weight was only 990 lbs against a 1750 GW.) The O-360 is a different animal and I've gained about 70 lbs between the engine and all the other "options" I have added because power wasn't going to be an issue.

Throttle discipline is easy for me as I typically fly everywhere at 50 to 65% power, which gives me fuel burns in the range of 6 to 8 GPH. 75% power is a between 9 and 10 GPH.

Keep looking for an O-320, they are out there. I would stay away from the "H" engine simply because of the location of the fuel pump, which is on the front. If you find a usable O-320 w/o the fuel pump fitting, grab it. Changing the accessory case is easy enough to do. (I bought my accessory case and parts from eBay.)
 
O-290G

Thank you Bill for the quick response and the answer to my email. Good info.

The mechanic who owns this engine talked about the the prop flange backing plate you discussed, so I am guessing this is a -G. If I verify that I will pass on buying the engine.

I was hoping it would be good compromise between performance (O-320) and good fuel economy (O-235). Based on your recommendations it seems an O-320 and some throttle discipline may be the best way to go.

Chad

I restored a 3A with an O-290"G", over an 18 month period to include complete engine tear and reassembly. I flew it about 50 hrs over a one year period and in that time was happy with the power, economy, etc. of the engine when married up to a light "3" airframe. Cruising around at 140-143 mph at 2300 rpm yielded a fuel burn of 4.9 to 5.1 gph. My engine only had 145 hrs. on since O.H., so I didn't have to consider replacing jugs, etc. but I read that an O-290 case could be machined open a bit, to allow O-320 jugs to be installed. If I kept that engine long enough, I would have considered that option when I top overhaul became necessary. One last thing: All the manuals on modifying a "G", do not recommend aerobatics due to the lightness of the front bearing, even with the prop flange adapter. I had to have my crankshaft turned down about .003 to make it round again; and since it only had 140 hrs on it; I had to speculate that aerobatics might have been the cause since the original builder owner stated in the logbook here and there: "...pulled 6 G's today...", etc. Doug
 
Carb available

Should you decide you need a carb, I have an MA4SPA I didn't use. Need to confirm part numbers for your app if you think it fits your mission.
 
The other Lycoming....

I have an opportunity to buy an O-290 (no idea the dash number yet). I do know it has mags, no carburetor and was running at the time it was taken off the plane but has been sitting in an A&P's shop for a couple of years.

I am planning at least a partial teardown and inspection before I make a decision on the purchase. I have some idea of what to look for but am far from expert in this.

So, for those who do know...

What should I look for on this engine and are there any specific items that would make this deal a no-go?

Assuming this engine is good to go, does anyone have a guide on how to convert it for use in the RV-3? Or should I convert my money into an O-320?

Thanks in advance for the help

Chad Eyanson
Apple Valley, CA

Hi Chad!
Excellent info above. I will add that the 0-290D series (and G's) had choked cylinder barrels originally. This caused piston ring flexing and higher oil consumption/ ring failure. Retrofitting aftermarket cylinders and Pistons solved the problem. However, the 0-290 like many great engines of the past is an orphan. Parts are more difficult to find especially cases. You may spend more than if you rebuilt a more available model...

Another option is "my favorite orphan" the 0-320A narrow deck. I've installed one in both of my RV's (initially from the same salvaged Apache) and the 9A I am delivering this week. GREAT engine. Plentiful parts, straight (conical) mount, only a few pounds heavier than the 0-290 and CS prop capable if you desire. Carbs are numerous as are all the other parts. Check them out on barnstormers, they're great, light high power to weight engines.

V/R
Smokey
 
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I agree with Smokey and the others. I have a T-18 with an O-290-G, it's great. But it was on the plane when I bought it. I have no intention of changing it. If I keep the plane long enough, I'll bore the case for O-320 cylinders because I'm a hot rodder.
But when looking for an engine to install in a project plane, I think I would pass it by. For my RV-8, when I lost the desire to continue with my turbo rotary engine, I found an IVO-360A1A from a Brantley Helicopter for $5500, 167 SMOH.
It is a conical mount O-360 that needed a new sump, one gear and an aircraft accessory drive case to convert it. I had the case, and bought the gear and Superior cold air sump.
Conical mount engines use a lighter mount, but it is a special order from VANs, which takes a few weeks for delivery.
You can find a suitable O-320 for reasonable cost. Just keep checking the ads and asking around at the airport and your EAA chapter.
Smokey also found a helicopter engine for one of his. They are the same lycoming core, but often cheaper. You need to price out the special parts required to adapt it to RV service.
 
Hi Chad!


Another option is "my favorite orphan" the 0-320A narrow deck. I've installed one in both of my RV's (initially from the same salvaged Apache) and the 9A I am delivering this week. GREAT engine. Plentiful parts, straight (conical) mount, only a few pounds heavier than the 0-290 and CS prop capable if you desire. Carbs are numerous as are all the other parts. Check them out on barnstormers, they're great, light high power to weight engines.

V/R
Smokey

I have an O-320-A narrow deck with about 500 hrs smoh. It's been in dry storage since the late 70's, so I will have to sell it as a core. Partially torn down. Cyls removed case not split. Cam, lifters and crank look good. It appears in great shape.

A friend is selling for me. Asking $4000 OBO. You can call him:
Tracy Martin AP/IA
Cell: 706-982-9016
Home: 706-782-9707
 
O-290

Thanks to all for the info.

The engine in question is in fact a -G so I will be passing it up. I plan on doing aerobatics and the thin prop flange on the engine makes that inadvisable at best. Prices I have been reading about for a rebuild are also excessive so that was another reason to pass.

I will be keeping my eyes open for an O-320 or an O-235 for this project.

Thanks again for all the info

Chad
 
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