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Which engine is best?

Abbygirl1

Well Known Member
OK guys....I need some help. I am in the market for a -6A. I see a lot of them that are using the IO360, 200hp. As I read it, Van's does NOT recommend this much hp on that airframe. Help!!!!!
 
Good question. I do not have the answer but I would check the weight and balance, especially with a constant speed prop. It "may" have forward CG issues.
 
Here's an option. Just the other day one of the guys at Central Cylinder (an all inclusive overhaul shop here in Omaha) was talking about an O-360 he put together for himself, but is now thinking of selling. It has moderately high-compression pistons, typical magnetos, with some nicely chromed pieces. Doesn't sound like much until he tells you how he perfecdtly machined everything perfect, all components balanced to a half a gram and then meticulously put together. Not sure about price, but would probably be in the same ball-park as any of the others. Maybe not the answer you're looking for, but the best engine IMHO is one that is dependable. Best, -Jim
 
an I or O-360-A1A is know to be one of the best lycoming engines made. read it some where. vans recommendation too. :)
 
RV-6's have anywhere from 150 HP to 300, like Bob Mills in his -6 that races at Reno.

You can't go wrong with a 180 horse engine and a friend of mine has a 225 horse engine with a CS prop on his -6A...rocketship.

We had a 180 horse -6A and loved it..fast and economical.

Best,
 
As usual, you guys never let me down.........thanks for all the replies. Being a Van's "newbie", I will be calling on the esteemed expertise of you during this process. I also am lucky to have a 2 time RV builder in the hanger next door. My thanks in advance to all of you and to my hanger neighbor, Ed, for all your advice and experience.
 
200hp 6A

There is 200hp 6A here in NC in our group of RVs at 8A7....it goes like stink and perhaps the owner may chime in.
 
OK guys....I need some help. I am in the market for a -6A. I see a lot of them that are using the IO360, 200hp. As I read it, Van's does NOT recommend this much hp on that airframe. Help!!!!!
Ok you?re in the market for a used/flying RV, the best airplane and engine you can get is one that has seen regular service from the time of first flight or last overhaul to date, 50 hours a year minimum, 100 a year would be better, not only will the engine be in good condition but the rest of the airplane/systems will have been maintained throughout. You buy an airplane that?s a sitter and you won?t know what?s wrong tell you fly it about 100 hours and everything starts going south due to prior neglect.

I have the 200HP IO-360-A1A on an RV-4, the power is not an issue, check the W&B of each airplane but the CG does not have to be a problem if equipment/batteries are arraigned accordingly.
 
Just bought my 6a. Looked at 180 hp first. The cg was forward of the forward limit. Big deal ? I don't know. I got a really light 6a 160hp cs. I am very happy with it. As others have said get something that's been treated well. Mine was fwf brand new practically. I've been told its quiet and smooth. If you don't fly in the mountains much I can't imagine needing 180 hp but then again i wouldn't mind 180 :)
 
I've got a -6 with carbureted 160hp O-320, wood prop... and on hot summer days with two aboard, I've certainly wished for an extra 20hp a time or two :eek:

Also with all my camping gear loaded in the back for Oshkosh, having a little more weight on the nose would've helped make it less pitch-sensitive.

But despite that, it's still quite fast and fun... I've seen 195-200 mph TAS at altitude running at "full rental power" burning 8.9 gph, and when I'm solo and just putt-putting around for fun, I can throttle back to 2100 RPM and still go 145 mph on a tad over 5 gph :D
 
We've owned 3 RV6's as follows: #1 was a TG with 0320/150HP, #2 was and0320 with 160HP and our present baby is an 0360 with 180HP. The first two were changed from wooden props to Catto fibreglas props. Big difference in performance. Our present jewel has a Sensinich metal prop. All were FP props. With that info here is our (my) opinion. All three planes are great performers. We've never had a problem getting airborne or with CG's. All that being said , we have to say that the 180 HP is the best all around engine we've used. Since we are both "full figured" people, we are able to carry a little extra load in the utility catagory (1800LBS) with no problems. We are able to cruise at 155 knots at 2500 RPM burning around 9 gph. If we back down to 2350 rpm, we see fuel burn around 7.8 gph. Hope this helps. I personally feel that 200hp is overkill in an RV6 or 7 unless you are going to race.
 
When I first saw "200 HP" my thought was angle valve engine which one past post stated can be about 30 pounds heavier than a parallel valve O-360 variant.

As others are eating popcorn, this may not be all factual info and I will be corrected.

As far as helping you to look into CG data, if you wish I can send you my empty CG data for a carbureted O-360 and Catto prop. I can also send one of the programs that allow you to quickly see how weight additions (people/cargo/fuel) impact CG.
 
Ron Lee, if you could send me that info I would appreciate it. This search is going to get interesting, I can already tell. Thanks in advance. Just private message it to me.
 
Now I have numbers. My parallel valve O-360 with Catto prop has the following W&B info:

Weight: 1038 pounds
Arm: 68.15 inches
Moment: 70739.7

With this I have to have a 100 pound pilot and no baggage to get close to the forward CG limit of 68.7 inches and in this configuration I am still 1.1 inches aft of the forward CG limit. So all is good.

Magically convert my plane to an angle valve engine and Hartzell prop and I add 39 pounds on the engine and prop governor at 35 inches arm. This is an increased moment of 39 x 35 = 1365.

The prop adds 35 pounds at a 10 inch arm for an increased moment of 10 x 35 = 350. The 35 pounds number could be off by five pounds or so but is close enough for this initial assessment.

Assuming that my assumptions on weight and arm are adequately close, that changes the W&B data as follows:

Weight: 1112 pounds (1038 + 39 + 35)
Arm: 65.16 inches (72454.7 / 1112)
Moment: 72454.7 (70739.7 + 1365 + 350)

The empty CG is moved three (3) inches forward. Put that same 100 pound pilot in and the CG is 67.06 inches or about 1.6 inches FORWARD of the forward CG limit.

Do verify my process and math. This did not consider CG changes like moving the battery aft. Add 25 pounds to the baggage area and with a minimum of a 150 pound pilot you are just aft of the forward limit.

Another point to consider is the reduction in useful load.
 
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Since it sounds like you are a newbie, may I make a suggestion?. Build a 7 or 9 with a O-230 Lycoming so you can use auto fuel. Or build a RV12 and enjoy the ride. Even a 12 is faster than a Cessna 172. Its my belief that the 7 & 9 came about because of 6 owners saying can you do this or that. Thats my two cents. I have a RV9A with a IO 320, Who knows what fuel will be for us in Two years.
 
Since it sounds like you are a newbie, may I make a suggestion?. Build a 7 or 9 with a O-230 Lycoming so you can use auto fuel. Or build a RV12 and enjoy the ride. Even a 12 is faster than a Cessna 172. Its my belief that the 7 & 9 came about because of 6 owners saying can you do this or that. Thats my two cents. I have a RV9A with a IO 320, Who knows what fuel will be for us in Two years.
I think he is looking to purchase a flying airplane.
 
I skimmed through Barnstormers and did not notice any 200 HP RV-6A aircraft. Plenty of 160 HP which I would not buy on account of my biased opinionated opinion on engine size.
 
I agree that the O360 is my preference, simply because it has enough HP and can use , cautiously, auto fuel. At least that's what I'm hoping. And, yes, I'm looking for an already built -6.
 
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