Engine smoothness question ?

Larry DeCamp · #1 11-09-2015, 04:43 PM

RV-3 with 0320parrallel mount w/carb,dual Pmag and Catto 2 blade 😞
Would a dynamical 3 blade be worth the effort to upgrade ?????

vic syracuse · #2 11-09-2015, 04:45 PM

I just balanced my MT 3 blade down to .02 IPS.

Vic

Russ McCutcheon · #3 11-09-2015, 05:04 PM

I think he?s asking if it would be worth upgrading from 2 blade to 3 blade. I don?t know what a ?dynamical 3 blade? is.

2 blades or 3, they both work well, if you like your 2 blade I would keep it, if you want a 3 blade get a 3 blade.

vic syracuse · #4 11-09-2015, 05:14 PM

Missed that. But yes, my experience has been that the 3 blades can be a little smoother. Not to start a war. I said CAN be.

Larry DeCamp · #5 11-09-2015, 05:19 PM

OK, Craig says a 3 blade might be smoother, and of course, balancing can only be worth 0 to plus X? My real unknown is the value of dynafocal. That would require a new mount, new engine and probably a cowl.

Mark Albery · #6 11-09-2015, 06:35 PM

There is a conical mount upgrade that works better than the standard Lycoming part.

It is Lord mount part J1552. About 5 times the price, but they do make a difference.

Neal@F14 · #7 11-09-2015, 06:48 PM

Quote:

Originally Posted by Russ McCutcheon

I don?t know what a ?dynamical 3 blade? is

Must be something like a "jellicle" cat

Yeah I know that a 3 blade prop is smoother and lots more sexy looking than a 2 blade, but a 2 blade is slightly more efficient than a 3 blade and a whole lot cheaper to buy.

David Paule · #8 11-09-2015, 08:25 PM

A dynamic prop balance is a lot cheaper than a new prop and has, on mine, made a big difference and that's with a 2-bladed prop. Of course if the dynamic balance wasn't enough and then you got that new prop afterwards, that would be money wasted, I think.

How is the mixture? Any smoothing when you lean or enrichen it?

Dave

David Paule · #9 11-10-2015, 08:58 AM

Larry, the only other thing I wondered about, given the snug RV-3 cowl, is whether the engine is bumping into something.

Dave

Ironflight · #10 11-10-2015, 10:17 AM

Ownign both two and three-blade props, I know that they can both be made as smooth as silk with a good dynamic balance. You have several unknowns that, unless you throw money at them, you really don't know how they affect the overall result. Going Dynafocal should help, but it would be a big deal to change. A new prop? Always fun, but unless you have other reasons to change the prop, I think I'd go for a dynamic balance first, and see if that helps.