Lycoming O-320-E2G Identification and C/S Conversion

[MidwestMan]

I have some sort of O-320 and I'm not sure which one. It's a wide deck dynafocal. The sump that came on the engine is a different style from the ones we use on RVs. The intake tubes come out of the sump at a different angle which interferes with the standard Vans engine mounts. This engine came off a Long-EZ project which requires the funny style sump. If this is the original sump and data plate for the engine, then it's an O-320-E2G. But I don't have any good way of knowing that for sure. The project it came from was a hack job with lots weird stuff and no logs, so it's entirely possible that this is not the correct data plate for the engine.

So, 2 questions:

1. How might I confirm without cracking open the engine that this thing is actually an E2G? Is there maybe a spot on the crankcase with a part number in the casting which can be referenced to a parts list?

2. I want to run a C/S prop. If this is an E2G, from my googling and forum searching it looks like it does have a hollow crank, but it has O-235 style main bearings which don't work with C/S. Apparently converting between bearing types is possible, but does anyone know exactly what it takes? Is it as simple as just putting in different bearings when the case is split, or is there some sort of machining that would be required from a place like Divco?

Thanks!

 

[Ralph Inkster]

The E2G variant came with the carb mounted farther back on the oil pan compared to the A & other variant O320's. Which probably account for the mount interference issues you see. The E2G also had the same intake tubes as used on the O235 & O290 engines. You could swap the oil pan off a different model such as a A, B, etc to move the carb to the center of the oil pan, you would also need the accompanying intake tubes as well.
You might check the carb model on your engine to be sure it is a MA4-SPA which would be proper for a 320 engine - if your's is a MA3-SPA than the prior owner may have swapped a O235 or O290 oil pan/tubes/carb onto the engine.
E2G is a 150 hp engine, you could upgrade this to a 160 hp, talk this out with your engine builder as to change out the dual front bearings to the wide single (C/S) bearing involves tear down equivalent to doing a total rebuild/overhaul.
Good luck

 

[71459]

I'm running a "true" E2G. My thinking is.. leave the engine alone, put a nice fixed pitch prop on it and go have fun. Think of all the money you will save for more fuel. More fuel equates to more flying. It's simpler, lighter, and pretty much maintenance-free. The lighter weight means better handling. When it comes to these little homebuilt airplanes, the simpler, the better.

 

[Ralph Inkster]

I'm running a "true" E2G. My thinking is.. leave the engine alone, put a nice fixed pitch prop on it and go have fun. Think of all the money you will save for more fuel. More fuel equates to more flying. It's simpler, lighter, and pretty much maintenance-free. The lighter weight means better handling. When it comes to these little homebuilt airplanes, the simpler, the better.

I couldn't agree more.

Just thought of another point - E2G rear carb placement may give you grief if you are building a nose gear plane. If it's a tail dragger, the advice above is still golden.

 

[MidwestMan]

Just thought of another point - E2G rear carb placement may give you grief if you are building a nose gear plane. If it's a tail dragger, the advice above is still golden.

The carb placement appears to be an issue on tail dragger RVs as well, definitely doesn't fit on the RV-4 that's in the hangar where I've been working. In case someone is searching for info on this: It might fit on the side by side tail draggers where there could be more width on the engine mount. I don't have an easy way to check. I already solved this by swapping on a sump from a D series engine.

Still no one appears to know if there's an easy way to verify if the engine I have is actually an E2G or not. I have no way of knowing if it's the original sump. This engine was flying on a long-ez, and the funny carb placement is standard. Someone could have swapped an E2G sump onto this engine as easily as I swapped it off.

 

[Canadian_JOY]

According to several engine builders with whom I have spoken, the E2G is one of the better of the O-320 variants. I've had very positive experience with them in their native installation in the Grumman AA5 airplanes.

 

[jrs14855]

E series

There is a Lycoming publication that addresses many of the different configurations. At the top aft crankcase is a stamped number ending in a -xx.
One dash number is -36 which is very common 320 case. Lycoming should be able to tell you what configuration your dash number applies to.