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Which engine for my RV-8?

usafmd

I'm New Here
Hi all,

It's time to order an engine and I've already come across several opinions, mostly aiming at 200-215HP (though 180HP is certainly not out of the question). Names that have come up include Superior, Titan, Aerosport, and Barrett Performance. I see that the first three have options to build or watch someone build the engine ( extra cost $500-1,000) and I would appreciate any opinions on this as well (? worth it to pay an extra $1,000 to build your own).

I'm sure there's not one right answer, but I certainly would appreciate gaining from your expertise and experience.

Thanks.

Michael Lewis
Astoria, OR
 
From what has been said over the years on this site, you can't go wrong with any of the 4 you named. I have a Superior io360 on my RV8 with 9:1 pistons rated at 185HP turning a Catto 3 blade. I am very happy with the performance. More power is always good.
 
It's a very competitive market.

FWIW, the 2018 Kitplanes Engine Buyers Guide will be mailing shortly.
 
It's a very competitive market.

FWIW, the 2018 Kitplanes Engine Buyers Guide will be mailing shortly.

Duly noted, since I am creeping up on closing in on maybe needing to possibly start thinking about engine choice.
 
We had both a IO-360 and an IO-390 in our RV-8, for about a 1000 hours each. There is no question the 390 is hands down the winner. Our 360 was built and dyno'd around 210. But that was downhill with the wind at your back and it was working. The 390 stock dyno'd at something like 217. At it's rated HP it'll run all day every day. Flying it the engine is real stump puller, with a ton of torque. Weight was more less the same, accessories the same, and it pretty much dropped into the same hole. I have no clue on cost (Dad's toy and I never asked).

Building a safe, reliable engine isn't hard. There isn't much too them, and once you have all the parts there and ready to go you can assemble one in a day or two. I think it's fun! At a minimum it is definitely educational.

That being said the difference between a good engine and a great engine is in all the tiny little extra details the high end shops and engine gurus incorporate. Perfect balance of all the internals for that turbine smoothness....super precision ring fits for minimal oil consumption....etc... While not always necessary to make a safe, reliable engine, the difference is noticeable. Whether or not it's worth the extra price is up to you.

Whatever you do, I'd pay the money watch/help assemble the engine. If you haven't done it before, it's to good of an educational opportunity to pass up!

DEM
 
Off plan, or not?

Do you know how each of these options will bolt up to the standard firewall forward kit and/or what deviations and fiberglass work might be needed to make it work?

....Can?t go wrong with the standard Vans / Lycoming offering of a YIO360M1B and smooth bottom cowling. Or any variation of the same.
 
quote..."Can?t go wrong with the standard Vans / Lycoming offering of a YIO360M1B and smooth bottom cowling. Or any variation of the same."

I agree and add their Hartzell C/S prop special ($1000 off when bought together) and it is hard to beat.

Allen
Very Slow Build 7a
 
How about a UL Power?

I recently sold my angle valve IO360-A1B6 in favour of a UL Power 520iS. I haven't purchased it yet, but I have committed to the install. I am going to marry a Airmaster (NZ) 3-blade constant speed prop to it (they use the Whirlwind blades).
Basically, I am working with Experimental, so I thought I would run hard with modern technology.
My 2 cents worth.
 
I prefer the parallel valve 180hp with fuel injection. Add a Hartzell blended airfoil prop and you can’t go wrong. Maybe send off the cylinders to Lycon or someone to hop them up if you want some of xtra hp.
You won’t be the fastest in a race and you won’t out climb everyone, but you will always be close. Plus you won’t need to reinvent anything.
Whatever you do, stay with what VANs recommends. It will save you time and money during the build. If you use after market or different components than what VANs supports you can add a lot of hours, and I mean a lot, to your build doing modifications to make everything work.
Just my two cents
Good luck
 
Comparing engines

I have a lot of time behind a 180hp IO-360 RV-8A, and recent time flying a fire breathing 220hp RV-8.

Here are my thoughts:
- Both engines have a Hartzell CS prop. The engine choice is secondary to the decision to install the Hartzell BA CS prop. I?ve flown the same RV-8A with a FP and then changed out to the Hartzell - there is no comparison in performance.
- The 180HP IO-360 is more than enough power and provides for 170kt cruise at 7.5 - 8.0 gph - and climbs at 2000+ fpm. This makes for a superb cross country plane.
- The 220hp RV-8 jumps off the runway - I was amazed at how short a run it took compared to the 180hp RV-8A (which is no slouch itself).
- The 220hp RV-8 cruises at 180 kts (2400 rpm at 23? MP or so) at 9 gph (there is no free lunch - go faster, use more fuel).
- The 220hp RV-8 is of course heavier. I?d give the nod to the 180hp RV-8A for the best handling - but they are close.

For the new RV-8 project I got the Van?s show special (IO-360-M1B and Hartzell CS BA prop). This is, in my opinion, the absolute best value option out there.

Decide what you want the plane to do and how thick a wallet you have. Then get what you want.

Carl
 
To long a list.

As has been said above, you will do well with most of the top four or five you listed. We roll our own, that is to say we buy from a spec. list to get what we want. Most owner-builders will not try to put their engines together, but I feel that it is a good idea for someone that is going to be flying their bag of parts to know as much as they can about those items. It makes it much better to put your mind at ease when you start servicing and trying to figure out problems later on after you start flying. Most of the parts that go into a Lycon are made and supplied by companies that send those parts to the people or company's you have listed. If you have the time and money to go and help put your power plant together, I think you will benefit a lot from that. As to the choice of what engine configuration you need, that one is up to what kind of flying you do and what you want out of your flying. This is just us for this aircraft and no other, but what we did was select an IO-360 with a good no counter weights or "dampers" if you wish. Add all the oil spray nozzles, the EX-ECI cylinders with the high air-flow seats and guides, then add 9:1 pistons. This gave us along with some intake and exhaust port work some 195 or so B.Hp. but kept the weight of the engine as low as we could.
After a good build with a good Prince prop it gave us an aircraft that came in at 1008 Lbs. with a Hp. that was just at are slightly below the "Max." 200 Hp. that Van's had recommended for that airframe. This with a moving of some weight after we weighed it for the first time gave us an aircraft that can carry 792 Lbs. by the book, but more important to us was to be able to load the front baggage compartment to it's full limit, take on full fuel, two 200 Lbs. people and put the 75 Lbs. in the rear baggage compartment and still be under gross weigh by the recommendations from Van's.
It's just all in what you want out of you flying, you can build or have built an engine that weights a little and gives you a lot or you can get one that weighs a bit more and has more pull also. The 8 is a very good platform if you keep it light and well balanced, but you might like more speed dam the torpedoes. Hope this helps, Yours, R.E.A. III # 80888
 
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375

I have a 180hp PV O-360, but when it comes time to replace it, I think I would go with the IO-375 PV 200hp. Light weight, PV, and 200 hp. Sounds like a winner to me.
 
Aero Sport advertises a IO-382 which sounds intriguing. I figure if a 375 is good a 382 must be better :D Not much info on their site about it though, they have been saying its a "new engine" for years nows.... Anyone know if they actually sell?
 
Aero Sport advertises a IO-382 which sounds intriguing. I figure if a 375 is good a 382 must be better :D Not much info on their site about it though, they have been saying its a "new engine" for years nows.... Anyone know if they actually sell?

Basically a 360 case with a 400 crank and rods, parallel valve cylinders, and roller tappets, all from Superior. ASP includes balancing, porting (with flow bench docs), a cold air intake, dual P-mags, custom paint, two cases of break-in oil, and two filters. Last OSH special was $37,450.

The 382 is Aero Sport's signature product, but actually any good engine shop can build one. Aero Sport and Barrett are Superior's two largest shop outlets.
 
Local chap had an RV8 with an IO-320 in it. Tuned exhaust, dyno said around 170hp.

Now - because it was light, it performed well and the balance - 1 up was spot on.

More isn't necessarily better as you need to consider overall weight and whether it will run nose heavy with all that stuff up front.

Dan H has good words - look at newer iterations of older motors which have lightness and power with economy.
 
missing ponies?

I have a 180hp PV O-360, but when it comes time to replace it, I think I would go with the IO-375 PV 200hp. Light weight, PV, and 200 hp. Sounds like a winner to me.
Just curious - do you have times where you feel like that missing 20-30 hp would make a big difference?
 
Actually, I rarely recommend any specific choice. I think the key is to think hard about intended mission, then factor in the strengths and weaknesses of the various choices, and tailor to that mission.

Not much question, a RV-8 with a light nose is the more pleasant sport flyer. A heavy nose puts the CG against the forward limit when solo. Most run out of nose up trim when slowed for final, flaps fully extended. Maneuvers like a simple 3.5 G loop entry are better done two-handed, as the required stick force is high, which feeds a one-handed tendency to pull in a little right roll. A heavy metal prop boosts gyro forces, noticeable in rapid maneuvers or simply picking up the tail on takeoff, and it's hard on the crank at high pitch or yaw rates.

Downsides? Rear seat and baggage capability is reduced. An RV-8 loaded to the rear limit has very little pitch stability when slowed, and little stick force gradient with G increase. It's not difficult to fly, or unsafe for the aware, but it isn't pleasant.

Power: Angle valve 360's, 390's, and 400's with a constant speed pull like draft horses. Do a formation takeoff behind a parallel valve 360 fixed pitch, and you find yourself at partial throttle, wondering what is wrong with that guy's airplane. Build tip; an angle valve motor just barely fits in the standard RV-8 cowl.

Ahh, so pick a hot-rodded lightweight engine? Let's get real. It's not hard to get more power out of a Lycoming, but nobody installs upgraded parts. In addition, a pumped up parallel valve can be a challenge to cool; limited fin area, and you can't use the power if CHT is too high. I usually suggest against mods strictly for increased HP, and besides, most of the HP claims heard on the FBO porch are BS anyway. I'm not sayin' mods are bad. Things like porting for flow balance and electronic ignition make the engine a pleasure to use; any little power boost is gravy.

So, back to mission. If the airplane is going to spend most of it hours solo, mixing it up with the other local lunatics, giving rides with zero baggage, etc, I'd look at a composite constant speed and a parallel IO-360-M1B. Build it light, and you're talking Big Fun.

If the mission focus is cross country with wife and baggage, an angle valve with a metal Hartzell is the better hauler. In a pinch, either choice can do either mission.

My own is a 390 with a metal Hartzell. The mission was hauling Ms. Patti, complete with, ahhh, stuff, or a buddy and an heap of camping gear, or a few cases of Spotted Cow. The fastback increases rear baggage volume. I don't fly aggressive acro, and rarely G past 3, so the required stick force for pitch isn't a big deal. It can be hot where I live; the 390/CS combination bullets up to altitude quickly, at gross. Light, solo, cold air? No such thing as too much power, here made with displacement, not high cylinder pressure.

It fits my mission. Think about yours.
 
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Actually, I rarely recommend any specific choice. I think the key is to think hard about intended mission, then factor in the strengths and weaknesses of the various choices, and tailor to that mission.

Not much question, a RV-8 with a light nose is the more pleasant sport flyer. A heavy nose puts the CG against the forward limit when solo. Most run out of nose up trim when slowed for final, flaps fully extended. Maneuvers like a simple 3.5 G loop entry are better done two-handed, as the required stick force is high, which feeds a one-handed tendency to pull in a little right roll. A heavy metal prop boosts gyro forces, noticeable in rapid maneuvers or simply picking up the tail on takeoff, and it's hard on the crank at high pitch or yaw rates.

Downsides? Rear seat and baggage capability is reduced. An RV-8 loaded to the rear limit has very little pitch stability when slowed, and little stick force gradient with G increase. It's not difficult to fly, or unsafe for the aware, but it isn't pleasant.

Power: Angle valve 360's, 390's, and 400's with a constant speed pull like draft horses. Do a formation takeoff behind a parallel valve 360 fixed pitch, and you find yourself at partial throttle, wondering what is wrong with that guy's airplane. Build tip; an angle valve motor just barely fits in the standard RV-8 cowl.

Ahh, so pick a hot-rodded lightweight engine? Let's get real. It's not hard to get more power out of a Lycoming, but nobody installs upgraded parts. In addition, a pumped up parallel valve can be a challenge to cool; limited fin area, and you can't use the power if CHT is too high. I usually suggest against mods strictly for increased HP, and besides, most of the HP claims heard on the FBO porch are BS anyway. I'm not sayin' mods are bad. Things like porting for flow balance and electronic ignition make the engine a pleasure to use; any little power boost is gravy.

So, back to mission. If the airplane is going to spend most of it hours solo, mixing it up with the other local lunatics, giving rides with zero baggage, etc, I'd look at a composite constant speed and a parallel IO-360-M1B. Build it light, and you're talking Big Fun.

If the mission focus is cross country with wife and baggage, an angle valve with a metal Hartzell is the better hauler. In a pinch, either choice can do either mission.

My own is a 390 with a metal Hartzell. The mission was hauling Ms. Patti, complete with, ahhh, stuff, or a buddy and an heap of camping gear, or a few cases of Spotted Cow. The fastback increases rear baggage volume. I don't fly aggressive acro, and rarely G past 3, so the required stick force for pitch isn't a big deal. It can be hot where I live; the 390/CS combination bullets up to altitude quickly, at gross. Light, solo, cold air? No such thing as too much power, here made with displacement, not high cylinder pressure.

It fits my mission. Think about yours.


Excellent post, enjoyed that & learned even more. As we all know anything to do with aviation is a trade off, just how uch you are willing to trade is personal choice:) Thanks for posting that very good read:):)
 
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Yeah, I think so...

Just curious - do you have times where you feel like that missing 20-30 hp would make a big difference?

There are lots of variables, but I believe that all things equal, lighter and more HP is desirable. I've only flown in half a dozen RV-8's. One of them was light AND had an AV 200hp IO-360. It performed really well. The others were all 180hp 360's with either CS or FP props. I have a 180hp with a FP prop that is pretty light (1012 EW), and I'd say that what I have is in the middle of the pack.

Dan's write up is excellent - and considering the mission no doubt important. I almost always have my bride in the back. Performance is fine - but if I could add a 20 more HP with/out a weight penalty, and then add a CS Carbon Fiber Prop on the front, I think that would be ideal. I could actually use a little more weight up front, and that would probably put my CG right where I want it.
 
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Thanks to all of you for taking the time to weigh in. It's a steep learning curve and I've learned a lot already. At present, I'm soliciting bids for a IO375 with vertical induction and emags. Constant speed prop, with a Whirlwind. Don't know yet about pistons/cylinders; still reading. Did a quick once-through Dan H's engine survey in Kitplanes during work today; will re-read more slowly tonight over a beer. And I really appreciate Dan's thoughts regarding weight/balance and flying characteristics which, frankly, weren't even on my radar screen but should have been. My intention is to spend my retirement flying around the country with my bags/camping gear in the back; not doing hammerheads and inverted flight behind the Barrett-tuned 360 I had in my Pitts years ago. Learning formation flying sounds like a lot of fun. I'd like to learn more by being involved in building the engine: Superior still has that option (for $1000 extra), Titan no longer has that option (but kudos to J.B. at Continental for being helpful and upfront about it), and Aerosport has engine school for $500 with, it seems, supplies from both Titan and Superior (again, still learning on this). Overthinking all this is probably, on balance, more useful than underthinking it, so the research continues. Please feel free to keep the comments coming and thanks again.
 
My real reason

I didn't want the scoop on the bottom of the cowl...I think it looks better without...drove me the M1B...
 
I didn't want the scoop on the bottom of the cowl...I think it looks better without...drove me the M1B...

+1. First RV-8A was a vertical AFP injection system as Van?s only sold the O-360-A1A (with carb) at the time. I sold the carb without ever taking it out of the box.

The new project has the M1B engine. A vertical intake engine works, but (in my opinion) distracts from the graceful RV-8 lines.

Carl
 
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