Engine / prop combo for the -8

I realize this will spark (hopefully) a lot of discussion, but I was wondering what people think the is very best engine / prop combo for the -8. I would like to hang a 200+HP angle valve IO-360 with CS prop, but am concerned with making the plane too nose heavy (I am 5'10" 150lbs). I've considered putting the battery in the back but would like to keep things simple and avoid the long (heavy) wire run.

Assume (for the sake of this discussion) that cost is no concern. I'd like to see what is available and what others have done.

Thomas
-8 wings (inventory...)

RV-8 engine/prop

I'd like to see what is available and what others have done.

Click to expand...

Thomas, I can tell you what I did.

I have an IO-360 C1D6 with a Whirlwind 151 CS prop on my RV8. The battery is a PC-680 on the firewall. I have several items (ELT, EFIS computer, autopilot controller and pitch servo) behind the aft baggage compartment.

My empty C of G is 78.5" aft of Datum with an empty weight (unpainted) of 1099#. I have 59# on the tailwheel empty.

I went with the angle-valve engine because it was available locally at a reasonable price, and had been built up by an engine builder I know and trust.

I still think the greatest "bang-for-the-buck" is with the parallel-valve motors if I were buying new.

James Freeman

Hi Thomas,
In my limited experience, go for the 0-360 it is cheaper, lighter and if you build nice and straight and clean will be the fastest. Out of a couple of local RV-8's I know the fastest out of the group is a plain old 0-360 w/ a hartzell. For the money and extra weight, I personally don't think it is worth going for the big engine. Spend the extra time and money building a well rigged airplane and I bet you will give the 200+hp guys a run for their money.
Again this opinion is worth what you paid.
Good Luck
Kirk RV-8 Fuse

P.S I went with a TMX-360 and a Hartzell 74" Blended airfoil prop

0-360

Put the battery in the back, Odyssey. Go with a parallel valve 360. Hartzell blended airfoil.
Money no problem? Get a composit prop.

composite?

Jay, which composite?

I am at same decision point: IO 360 angle or parallel valve (i'v about decided on parallel with robbie attaway)
and prop? hartzel but i really like the looks of whirlind 151 and mt 3 blades and what about whirlwind 200rv?

battery position

Jay (and others),

If you were going with a superior IO-360 and a catto 3 blade prop....where would you put the battery?

Tony Johnson
RV8A "badboy" N12TJ res
Orlando

battery

in the back.

tonyjohnson said:

Jay (and others),

If you were going with a superior IO-360 and a catto 3 blade prop....where would you put the battery?

Tony Johnson
RV8A "badboy" N12TJ res
Orlando

Click to expand...

I have an IO-360-A3B6D with a Catto and my battery is in the back. It is a Odyssey PC-625, and I have no problems with it in winter.

My buddy has an -8 with an O-360-A1A with a Sensenich FP prop with the battery in front (same battery), and he wishes he put the battery in back. My advice: put the battery in back regardless of your engine/prop choice.

My $0.02 (probably worth about that much too ;-)


Cheers

Two Batteries?

OK, it looks like generally people feel that with nearly any engine/prop combo, the battery should go in back. I am planning on using a Whirlwind 200RV and strongly considering an IOF-360 FADEC parallel valve engine from Mattituck. I believe that they have a second battery as a backup. I assume that both could be PC-680's. In this case, would it make sense to mount one on the firewall and one in the back?

Whats the difference in weight and fuel economy between O320 w/a Hartzell
and O360 w/a Hartzell

Anyone considering the new scimitar design from hartzell. I brought on for the 8, but never got to fly it, and the project is gone. It was supposed to be a great high speed performer. It also has no rpm restrictions with or without Electronic Ignition.

Engine/prop for skinny guys...

Tshort,

I went with the (heavier) Angle Valve IO-360 for three reasons:
1) I found a used one built by someone I trust, and I got to fly behind it before I purchased.
2) Engine was already broken in.

3) I only weigh 155 lbs. Most of the RV guys I talked to who said that a lighter engine "felt better" outweighed me by 40-60 lbs! So, I reasoned I could have my cake and eat it too because:
Even tho I'll be flying a heavier engine, if you subtract out my lighter weight, I'll get the same "feels better" handling AND better rate of climb/speed than a bigger bubba flying a lighter, lower HP engine. (kidding.........)

Oh, and I put my batt in the rear.

Art in Asheville, NC

Skyhawk said:

Whats the difference in weight and fuel economy between O320 w/a Hartzell
and O360 w/a Hartzell

Click to expand...

If you fly both aircraft at the same speed, they should burn pretty much the same amount of fuel. If you run them both at the same percentage of their rated power, the O-360 powered aircraft will have a fuel flow about 12% higher, and go about 4% faster (I'm assuming the two engines are 160 and 180 hp).

I will do it differently next time

I am using an IO360A1B, Battery in back and a WW151. This plane will fly inte next 4 months and I have already started purchasing items for my next, better 8. I used the angler for sheer unaltered HP. The battery in the back and the WW for weight/CG reasons. I will not do this again! Due to the possibility of changes in the availability of 100LL, I plan to explore the diesel market, but will probably go with a TMX 180HP, Hartzell Blended and batteries in the back. I would definitely use the premium services of porting, polisihing and balance/blueprint offered by Mattituck.

The WW is almost to beautiful to use. As the jury is still out on how Titan will support its customer base and the local availability of a Hartzell overhaul will dictate the use of the blended prop. Just have it painted with gloss epoxy and it will look like a WW.

I installed a Piper type battery plug on the bottom of the fuse, behind the battery, in the rear compartment, to make it more convenient to charge the battery. I will do this again.

One final thought on engine weight. I replaced all of my accessories with lighter weight units. I used a checz governor, no vacumn system, new starter, etc. in an effort to reduce nose weight. I will do this again.

Good Luck and have fun!

Robby Knox
95% completed, 95% left to go.

Couple of other questions:

I am pretty sure I'm going with the parallel valve IO360; Lycon in CA claims (and these seem to be substantiated) to be able to produce a 220+ HP version of this by using higher comp pistons, flow matching, electronic ignition, etc. Anyone have any experience with these engines? How should / will it affect the long term reliability of the engine (I guess I already have an idea about this, but I'm wondering just how much detrimental effect it will have)?

Also, on my very (too) short 1 day trip to OSH I saw the -8A with the new IO-390X engine at the lycoming tent. Didn't talk to those guys, but talked briefly with Aerosport power, and they said that it is actually lighter than the angle valve -360. Anyone know any more details about this setup?

Thomas
-8 wings