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O320 E2A Convert to CS Prop?

Dale007

I'm New Here
I have an RV7A with a fixed pitch prop. My engine is an O320 E2A. Can this engine be modified for a CS prop? If so will I have to modify the cowl as well? Any other gotchas to consider?
 
If it's a true -E2A you will need a new crank too...

One option would be the electric MT CS prop.
 
0 320

Engines evolved as follows:
I have heard of 0 320's with no dash number/letter but they are not listed in Lyc directory
0 320A1A-very first 0 320, Tri Pacer engine, configured for "controllable prop"(really constant speed)
0 320 A3A same except prop bolts, used in Piper Apache, constant speed prop
0 320 A3B same except oil sump
0 320 E1A same except type I dynafocal mount
0 320 E2A same except fixed pitch prop, prop bolts and alternative power rating of 140 hp(Cherokee 140)
The E2A COULD HAVE lightening holes in the crank flange which would be undesirable for aerobatics. Otherwise I don't know why you would need a new crankshaft.
 
The standard crank for an O320-E2A is solid, and has 3/8" prop bolts but some -E2As came from the factory with a hollow crank that was plugged, and theoretically could be converted. My old Cherokee 140 was one of those. The -E2A does have the beefier front main bearing which would definitely be desirable for a CS prop, but I'd guess the 3/8" bolts are probably not appropriate for a heavy CS prop... you'd surely want the bigger 7/16" prop bolts for that.
 
The E2A is definitely constant speedable internally and with the addition of the appropriate Constant speed parts like the gov. drive, plumbing and rear crankshaft plug, you will have a constant speed capable engine without any major disassembly. You may have to change the prop dowels in the crank flange depending on if the prop you intend to use has 3/8 bolts or 7/16 bolts. The E2A should have 3/8 prop bolt bushings as the default.
Good Luck,
Mahlon
?The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."
 
O-320 D3G convert to CS prop

Same question about converting to CS prop... in my case it is the O320-D3G in my RV-6. I long ago installed 7/16" prop dowels in the prop flange and I know that the front section of the crank is hollow as I long ago inspected the interior of the front section per a Lycoming SB to check for corrosion (it was ok). It looks like I could follow Lycoming Service Instruction No. 1435 to convert to constant speed by adding an expansion plug in the aft part of the front section of the crank, replacing the accessory case with one that has the machined surface for the governor, etc. The Lyc. SI lists the O-320-D1G, but not my D3G. Anyone done this? Any other "gotchas"?
 
When I converted the O-320 on my RV-9A to constant speed, the engine was not a problem -- the original builder had not installed the plug normally used for fixed pitch.

I did run into a cowling issue, however. For whatever reason, even with the (presumably) normal spacer for the metal fixed pitch prop, the constant speed prop would not fit with the existing cowling. I bought a new cowling (more on that later), but later found a 2 1/4" spacer for the constant speed prop. That made things fit with the existing cowling, the only problem being a rather large gap between spinner and cowling. HOWEVER, that large gap makes it oh so easy to take the cowling on and off. I no longer look with envy on planes with really tight clearances, rather, I feel sorry for them.

Back to the cowling -- it's brand new from Van's, latest model (includes the extra exhaust fins), and fits the -7 and -9 series aircraft. I'll sell it to you at Van's price and pay the shipping -- will save you about $200. Or if you know anybody driving past Savannah, GA...

Ed
 
if you do need a crank, i have a std size ready to drop in, SB complied with and was ready to drop in. i will sell. it is plugged for FP, but that is easily fixed.

bob burns
RV-4 N82RB
 
I realize this is a slightly older
Thread but just wondering what the weight of the needed parts plus CS parts would be compared the fixed pitch metal sensenich or a composite.

Anyone whose done the conversion have a ballpark price on parts for converting?
 
Prop Weights

I did a little research on prop weights for my -9A. If I recall:
CS Hartzell with governor and plumbing- 64 lb.
Aluminum FP Sensenich- 32 lb.
Catto two blade composite- 12 lb.

I had to add a 10 lb. crush plate in front of my Catto prop to keep within the CG range in the most aft condition.

No info on cost comparisons. Hope this helps.
 
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