Considering a 0-320 E2A for a RV-9A

[rblackley]

I am considering the purchase of a 0-320 E2A. I understand this to be a 150 hp @ 2700 rpm and 140 @ 2450. It has a 7.00/1 C.R. uses a dynafocal 1 mount. It has a straight riser in the oil sump and -32 carb. The guide shows 3/8" attaching bolts. I assume it has 2 mags.

I have a few questions.

Why would there be 2 seperate hp and rpm ratings on an engine? How are the rpm's limited in the 140 hp application? (prop pitch?)
This engine uses 3/8" prop attaching bolts my finish kit is set up for 7/16" I have read that the bushings can be replaced with a puller. Is this a simple fix? I would assume minimal cost. This engine was overhauled in 2000 and it appears to have been sitting. What measures should be taken to preserve an engine that is going to be sitting for a long time? Has anyone installed this engine? If so I would appreciate your opinion on the suitability of this engine in a rv9a application. Planning a fp metal sensatech prop.

Thanks


Ryan
[email protected]

 

[rvator51]

Should work fine

Lots of E2As flying in RVs. We have one but we changed the pistons to get 160 hp. I also changed the bushings from 3/8 to 7/16 for our Sensenich prop with a homemade puller.

 

[rblackley]

Thanks for the information and PM' s

Ryan

 

[rv9aviator]

The bushings are a no brainer to change. You can use a socket as a puller and push them right out. They are very expensive but you may be able to trade yours for some 7/16 at an engine rebuilder. That is what I did. The fellow that rebuilt my E3D swapped mine.

 

[N941WR]

Ryan,

I flew my -9 with a 135 hp O-290-D2 for 250 hours before my infamous prop strike. That engine will have plenty of power to lift you and all your stuff.

Like your engine, the O-290-D2 had two HP ratings, 140 hp at 2800 RPM w/ a 5 minute max limit and 135 hp at 2600 RPM continuous. I suspect, but don't know because I never dynoned the engine, that the dual electronic ignition increased that HP significantly.

At the time your engine came out, Piper was selling the PA28-140 and PA28-160. The RPM restriction may have been more marketing than anything else.

As for the prop bolt bushings, you will need a prop extension (Call Sam at Saber Mfg. for that.) so order your extension with the 3/8" bolts on the hub side and 7/16" on the prop side. Or, as you mentioned, you can spend the extra money and change your bushings. If it were, I would just do the conversion in the prop extension.

 

[Neal@F14]

My Cherokee has the O-320-E2A. It's a rock solid, utterly reliable juggernaut of an engine. You can easily and economically turn it into 160hp simply by changing the pistons from 7.0:1 compression ratio to 8.5:1 and it will still run fine on 91 octane premium unleaded auto gas. The two hp ratings are just only numbers on the data plate, it just means that when you throttle back to 2450 rpm it's only putting out 140hp. This was to satisfy Piper & FAA paperwork for the early models of the Cherokee 140 to further distinguish it from the Cherokee 150 model (which was actually a heavier-built airframe more closely matching the Cherokee 160 & 180). There's no limit imposed on how long you can run the -E2A at full power 2700 rpm like you might find on other certain kinds of de-rated high performance engines.