Engine choices

[osxuser]

I already know what the weight/handling answer to the heavier engine prop combo.

I'm probably putting together a -4 here in the next year or so, I've got access to two engines.

1. O-360 A1A with Hartzell 2-blade off a Mooney

2. O-320 E2D with 3-blade wood American Prop

Pretty much opposite ends of the spectrum for the -4. I really would prefer a IO-320 with a CS Hartzell, but lacking that option, and RESALE value being a big factor, what would you do?

I DON'T care personally how much better it handles with the lighter engine/prop, I care how much the airplane will be worth when I go to sell it.

Both engines would be field overhauls, I am considering turning the O-320 into an IO-340 with ECI's stroker kit, but I don't know how THAT would affect resale...

What is your opinion.

 

[gmcjetpilot]

We are all boys

Mooo Horse Power +
Mooo prop =
Mooo money (resale)

If resale is your thing than put the 360/cs setup in. Even with gas cost, one can throttle back and fly a 360 with the same fuel burn as a 320 but most pilots don't have the discipline to not shove the throttle fwd at least for takeoff and climb (including me). Besides if you are going to takeoff and climb at reduced power why have 180hp? More powers does allow you to climb to altitude faster and have a higher service or operational ceilings. So most pilots look for more HP and cs props. Of couse it cost more to build with a constant speed prop.

If you are disciplined and keep it light everywhere else you can make a nice 180hp RV4 with usable weight, even two up aerobatics (but its not easy to stay under Vans lower gross/acro limits, which I recommend). I recall its 1600lbs gross and 1375lbs (?) acro. Do the math if over 1000lbs BOW you don't have much room to play with. The extra 30-50lbs of engine+prop makes a difference. Many ignore vans recommendations, which I don't agree with.

You have already said it, a 320/wood prop (light two blade) is pure magic handling. Nothing like a super light RV. However when it comes to pure get-up-n-go the extra 20-30 hp and cs prop does matter.

RV4's can handle a 360. It puts the CG near the fwd end solo (may just past if not careful). The fwd CG actually pays dividends with passenger and bags. Back in the day where 320's/wood props and RV4's where more common, many had to go to harmonic balancer weights to get the CG fwd enough to have a passenger with some bags.

Cheers

 

[smokyray]

Mo is better...

Having owned a lightweight 0-320/wood prop RV4 and flown my neighbors 0-360 C/S RV4 daily, I can safely say...I like both! For doing aerobatics and sheer fun, the 0-320/woodie is a hoot. George is right though, the 0-360 can slow down and fly alongside the 0-320 all day at the same fuel burn, has a higher resale and is more utilitarian. Just make sure you have .020 tail feathers, the 0-360 will crack them. (The RV4 builders manual even warns of this) Go with an Odessey battery to save some weight and a single paint color with a decent panel and you should sell it quickly.

After flying it though, you may reconsider selling...

Rob Ray
HR2

 

[osxuser]

I'd fly for awhile, but the -4 will have to go to pay for the -7 kit . Anybody put the ECI IO-340 in a -4? Seems like the best of both worlds. Lightweight and 185ish HP.