Originally Posted by NorthernRV4
I've really been trying NOT to think much about the engine I will use for my -4 because it's a ways off before I need it. I've had an idea of what I will likely use but still open to options. This morning I came across an ad on Barnstormers for an engine/CS prop very close to home and it seems like a potentially good buy. Looking for some opinions/direct experience from the community on this.
Lycoming IO-320 E1A
Hartzell prop HC-C2YL-4BF
both from a Decathlon. Condition aside, I have a few questions about the suitability for my -4
Fuel Injected: a plus since I plan to build it for inverted flight.
Dynafocal 1 mount
Induction: I'm told it's Horizontal induction, I know this affects the lower cowl/intake and FAB setup. Any potential problems here?
No idea on the suitability of the prop, wondering if there's any issues due to differences in speed range of a Decathlon compared to a -4... Being CS does the blade profile make a big difference for an RV application? Any advice here?
I built my RV4 25 years ago when there was much more FWF Experimentation
taking place than now. I've seen numerous plug and play
FWF from certified airplanes that worked well and saved money.
Your engine prop combo has been literally bolted onto an RV4 with no mods by a friend of mine and it worked very well. The Citabria/Decathlon lower cowling utilizes a forward facing induction with the foam filter element mounted in the lower cowling. It's internally plumbed with a 3" SCAT connecting it from the cowling to the Bendix Fuel Injector Induction Servo mounted on the lower sump. Van's sells a FAB option just for that setup. Make sure the seller includes the full Christen inverted system
, boost pump and assorted hardware. As far as the prop, the blade shape on that model is optimized for the Decathlon's lower entry aerobatic speed range, but will still provide excellent top end speed. Get as many parts from the Decathlon as you can, every thing you include saves $$$ and could be potentially sold to fund your project.
I think the Decathlon FWF would be a great option.
PS:Many builders have also retrofitted the Engine/Prop of the Mooney M20 series as well as the Twin Comanche's IO-320B1E with the unique Type-1 Dynafocal mount. Van's sells both type 1 and 2 mounts for that very reason.
My current RV6'X" sports an 0-360J2A salvaged from a Robinson R22 that is light, powerful and saved $$$.
My RV4's early 0-320A (Dash Nothing) came from an Apache I salvaged. I sold the props to fund my project and utilizing a Sterba wood prop saved weight and cost. Selling the Apache's feathering Hartzell props paid for my panel and finishing kit. The engine gave me 1000 hours with just minor maintenance required.