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RV-6, 7, 8 (A) engine size

Engine size selection

  • Initially O-320 or smaller

    Votes: 34 22.2%

  • Later increased power/installed larger engine

    Votes: 6 3.9%

  • Later decreased power/installed smaller engine

    Votes: 0 0.0%

  • Initially O-360 or larger

    Votes: 117 76.5%

  • Later increased power/installed larger engine

    Votes: 3 2.0%

  • Later decreased power/installed smaller engine

    Votes: 1 0.7%
  • Total voters
    153
Ron Lee

Ron Lee

Well Known Member
I am curious about the engine selection that people make and if they ever change. Please indicate your initial engine selection then if you ever changed it to get more or less horsepower.

Increasing power may be as simple as putting in higher compression pistons or more extensive as a new engine with more horsepower.
 
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Still changing

I still haven't bought an engine, but here's the progress. I am not posting any WHY's on here, as it could easily get out of hand.

13B Mazda Rotary a la PowerSport Aviation
Renesis Mazda Rotary (This was a VERY short-lived idea)
13B Mazda Rotary a la Tracy
200HP IO-360 from Someone, several excellent choices
210HP IO-390 from Barrett (Current top choice)

I also investigated Deltahawk, Mistral, and Innodyn, but I never considered them viable for my purposes.

I may change my mind again, who knows. I do know that I will be ordering an engine in less than a year, and after that....no more changes.

I encourage all builders to not completely discard ANY engine options. Establish the mission of your aircraft and write it down. Then research all the engine options, standard and alternative. Write down the pros and cons and rank them. Keep doing research and as you learn more, the rankings change, as do you desires.
 
Lyc.....

Hi Ron,
The 0-360 Lyc is by far THE engine of choice for the majority of current RV'ers but the 0-320's aren't slouches either. Our mission was/is to go places fast and do some aerobatics/flight instruction. You can equal 0-320 fuel consumption at their speeds as well. Our hot Georgia summers with high density altitudes proved last weekend what a great choice the 180 Lyc was with two big guys and full tanks aboard for transition training. As far as resale is concerned, it seems that the auto engine guys are taking a big hit to sell those airplanes as well.

My .02,
Pierre
 
Good points Pierre

Density altitude here in Colorado reaches 10,000' (yes ten thousand) this time of year. Then consider going over the mountains or to Leadville where DA can be >12,000' on the ground.

I purposely only considered Lycoming type engines and am mainly trying to get anecdotal data about my view of engine size selection (not mentioned here so as to not bias results).

Plus there is a guy in here now who is pondering this very decision and this may help him and many others.

Resale is one consideration.

I considered including a CS vs fixed pitch option but decided that would make it too busy.
 
Bigger

Ron,
I overlooked the fact that you're in Colorado. By all means consider even an IO-390 and CS prop for 12,000' Da's.

Pierre
 
The price difference between an O-320 and an O-360 is less than $1,500. At resale the O-360 equipped RV's will usually bring $10,000 more. Fuel burn is the same at the same speed. Weight differencxe is 8 to 10 lbs.

Martin Sutter
building and flying RV's since 1988
 
I really like the performance and simplicity my Lycoming 0-360 A1A and Hartzell BA prop give my 7A. Leadville is a piece of cake even at gross. We had fun last May out in CO. Maybe we'll get to meet next year.

Roberta
 
Great Thread, RV-8 Engines

Thanks for a very useful thread Ron.

I'm obsessed with studying engines and props for my -8. I just about to complete the wings, about to write the fuselage check and will stick to my original plan of simple and light.

Lyclone 360, I like the idea of fuel injection, but it's hard to argue with carb simple. Probably at least one non-mag ignition and a FP prop.
 
O-360

Hi All,

The PLAN is to KISS... O-360 w/FP. Power, simplicity, weight, less $$ for the prop, better resale than an O-320. Then again, that part of the garage is still empty.... if an O-320 appeard on my doorstep, I'd be hard pressed to send it on it's way :)

Jeff
 
I have flown my -6 out of Leadville, over the mountains to Longmont with a tired (2500 hr) O-320-E3D (~150 hp) and
sensenich wood prop and had no problem. Density altitude was over 13,000'. Bigger engines are nice to have. Just pointing out that they are NOT necessary.
 
The engine for my 8A is an ECI kit with cold air induction,LASAR,high compression pistons and Vetterman tuned exhaust (not available from Vans).It should put out about the same HP as the IO-390 for $18000 less cost.Plan first flight next month.
 
My initial thoughts on engine size

I assumed that the O-360 or larger would be the majority choice and it was.

I did not expect anyone with a larger engine to change to one of less horsepower.

I expected more O-320s to later change to more power than O-360. Percentage wise that happened even with this small sample size.

I am one of the O-360 that is changing to higher horsepower. Since I was forced to overhaul the engine (in progress) I decided to go to 9.2:1 pistons. After mucho research on up to 10:1 pistons I was going to use 9.5:1 but could not find affordable ones. Some cautioned against higher than 8.5 pistons (can't use auto fuel and lowered TBO). I have no desire to use auto fuel and at the altitudes I fly at the engine rarely even sees 75% power.

Then I bought a high performance camshaft from Sky King that may provide more torque.

Finally I had the new cylinders ported and flow matched by Lycon. Some articles suggest 4 HP or more improvement from this process. Even if that is not accurate, the process should even the combustion process and help make a smoother running engine.

What all this means in actual performance is to be seen.
 
250 hrs now on the O-320 in the 7A, put a many O-360's in the prop wash. :D
With fuel prices soaring up up up... I'm liking the 320 more & more each and everyday. :)
 
The best advice I got when I was considering the purchase of a used RV6 was "Get the big engine" The only minus is the initial purchase price and I think someone said that is only about $1500. If you want the lower fuel burn and power of the O320 just limit how far you push the throttle in.
http://en.wikipedia.org/wiki/Flat_rated
 
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Danger Will Robinson said:
The best advice I got when I was considering the purchase of a used RV6 was "Get the big engine" The only minus is the initial purchase price and I think someone said that is only about $1500. If you want the lower fuel burn and power of the O320 just limit how far you push the throttle in.
http://en.wikipedia.org/wiki/Flat_rated
Click to expand...

And pulling the throttle out...........works. My 0360 RV6A could get right down to the lower fuel consumption, that a 9A uses with it's 0320. On the other hand, I can climb faster, and ultimately cruise faster, when desired.

L.Adamson
 
Heck... you should have went with the Big Engine... IO390 or IO540 in your RV and then add a designated fuel credit card you can just leave in the plane. :D
 
LifeofReiley said:
Heck... you should have went with the Big Engine... IO390 or IO540 in your RV and then add a designated fuel credit card you can just leave in the plane. :D
Click to expand...

Bigger engines can help you escape density altitude problems. Although, the plan is to avoid them in the first place, it seems that a lot of pilots still get caught with the problem. The ability to quickly climb, has much to do with horsepower.....:D As I live in mountain country, the extra horses are worth it.

L.Adamson
 
Started many moons ago with an E-Subie 2.5L allegedly 165 HP. Luckily saw the light before I made a big mistake, and went with an IO-360, one of my better decisions
 
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