Problems with installing O320-B2A in an RV-6A?

Badger · #1 05-02-2015, 01:28 PM

I'm engine shopping for my RV6A under construction now. Does anyone on VAF have experience with installation of an O-320 B2A in an RV-6A? Need to know if there are interference problems with the nose gear mount or similar. Or will it fit Vans standard nose dragger mount (conical) for RV6A, without requiring modifications? This B2A engine is equipped with the vertical updraft sump and plugged hollow crankshaft. From photos, it looks like the prop governor pad is on the front bottom of the engine case.

Also, the B2A uses 3/8ths inch prop bolts/bushings. Can the bushings in the crankshaft flange be changed to 7/16th bushing/bolts, to allow use of various props (including Cato) that use the 7/16ths mounting bolts? Or does a crankshaft with a larger diameter flange have to be installed to accommodate the 7/16ths prop bolts?

jrs14855 · #2 05-02-2015, 02:16 PM

Probably a Piper Tri Pacer engine, high compression version of O 320A. Prop bushings are easily changed, some threaded rod and nuts, stack of washers and/or some sockets that the threaded rod will pass thru. IIRC you only have to draw the bushings part way out of the flange. Prop bushjings are quite expensive.
This engine is likely a narrow deck engine, some parts are hard to find and only available used. It most likely has lightening holes in the crank flange and possibly a thinner crank flange. It would be best to use a wood prop with this.
Never saw a prop governor pad on the bottom, they were either on the accessory case or on the left front side of the crankcase.

az_gila · #3 05-02-2015, 02:17 PM

This Lycoming document will help you with any prop bushing swaps...

http://www.lycoming.com/Portals/0/te...20Location.pdf

Badger · #4 05-02-2015, 02:52 PM

Found a picture of one showing front bottom of B2A. What is that bottom case mount, just behind the prop flange for???

Badger · #5 05-02-2015, 03:02 PM

jrs,
The pic I posted shows the forward bottom 'mounting pad' on the B2A. If not for the prop governor, then... what? Also, the prop flange is solid, no lightening holes. I haven't committed to either fixed pitch or controllable pitch props yet, but would like to have the option to start flying with a fixed pitch and move to CP prop later.

William · #6 05-02-2015, 03:04 PM

Quote:

Originally Posted by Badger

Found a picture of one showing front bottom of B2A. What is that bottom case mount, just behind the prop flange for???

That is where the starter mounts.

BR,
Bill

Badger · #7 05-02-2015, 03:05 PM

AZ___Gila,
Thanks for the bushing info! Any thoughts/knowledge to share on O-320 B2A install in RV-6A?

William · #8 05-02-2015, 03:05 PM

I've got a O320-b2a on my RV6A. No problems with the install.

Badger · #9 05-02-2015, 03:20 PM

William,
Thanks for the reply! Did you use Vans standard conical engine mount for your B2A RV6A??

Can you share pics of your engine install? I'm about 85% complete on wings. Tail feathers need fairings yet. Fuselage is at the 'big canoe' stage, rotisseried on a streeeeetch model Harbor Freight 'engine' stand.

William · #10 05-02-2015, 03:28 PM

Quote:

Originally Posted by Badger

William,
Thanks for the reply! Did you use Vans standard conical engine mount for your B2A RV6A??

Can you share pics of your engine install? I'm about 85% complete on wings. Tail feathers need fairings yet. Fuselage is at the 'big canoe' stage, rotisseried on a streeeeetch model Harbor Freight 'engine' stand.

Yes, stock conical mount from Vans. I won't be at the hangar till Wednesday. I'll take some firewall forward pics this Wednesday if you still need them.

Best regards
Bill