engine thoughts/questions

[fairchild1934]

Thinking about possible engines for the 4 place.
There is an angle valve IO-360 at 200 hp---
the expensive 540 at about 230+ or -
the continental 360 at about ( i think) 200 HP
and the continental 470 at 220 (?)

Both the conte's are way cheaper than the Lycomings......

Looks like the conts win for $$ per HP........
what would be the downsides of them (besides the "different" engine mount geometry---- in terms of performance ........

The 540 are so high now I cant believe. a prop strike one with 2000+ hours they want 15K+$ for---- a core-----are they just scalping now ?????

I have a possibly good 0-320 150 hp----- so I am considering switching gear to a 2 seater-- which would me more appropriate for 150 hp ..........

T

[rodsmith]

You are right on Lycoming engine prices. Still I think you can find a better deal on a 540 than the one you mention. Forum members have completed planes with both the 360 and 470 Continentals, hopefully they can give you some advice.

[Nev]

A very interesting discussion. One thing to consider is how the engine weight will affect CG, and your typical loaded operating weight, as engine weight and subsequent CG position can have quite an influence on handling, and airframe loading.

I wrote an article about some of my experiences and thoughts regarding this HERE on bearhawkblog.com.

[fairchild1934]

thank you NEV--- I will read that in detail.
I think Whee went through this conundrum some time ago but I cant remember what he finally selected. My 0-320 didnt cost much--- and its at least had a top overhaul--- I see possibly new cylinders and definately new pistons. have not looked inside yet.....

[fairchild1934]

So why---- wouldnt we just adjust the length of our motor mounts----- shorter for 540 and an inch or two longer for a 360 and preserve the balance of the elevators ? i seen to remember some one doing that somewhere ?

also I have noticed that o-470 are more common than the io-360 ..... is the cont 360 an oK engine too ? or maybe just used in smaller numbers by
piper and cessna ? (so there are not as many cores out there)

[Ray Strickland]

I put an angle valve Lyc IO-360 on my 4-place and really do wish I had made the mount at least 1, probably 2 inches longer.

[TimTall]

I built my A model with an IO-470 conti. 260hp stock but it’s pushing more than that with a few upgrades. It’s a bit more complicated for a few reasons than a lycoming but nothing too serious for a first time builder like myself.

The fuel injection pushes the engine forward a few inches so there’s some cowling issues to deal with and the CofG moves forward a little.

There’s advantages too. The air intake is inside the cowl
so there’s no annoying air box to deal with on the bottom of the cowl. The mags are on the front of the accessory case so they’re super easy to access. I can remove and replace the starter and the alternator with the cowling on because they are at the rear of the engine. And more.

And they’re cheaper and more plentiful.

Message me if you want more info.

[svyolo]

There are a LOT more used CS props for sale for Conti's as well. Most Cessna 180 series used Conti's and lots of them have engine/prop upgrades. If I had it to do all over, I might have given more consideration to a 0-470.

[Bissetg]

My experience with the Lyc IO360 with eignition and tickled cylinders is that swinging a Trailblazer it produces more Static Thrust than a Maule M5 235.

Power to weight is important so are $$$.

my opinion is the lighter the plane the better and nicer it handles.

if I was starting again my choices would be

Lycoming or Lycon IO360/390/ or stroke 375.

Personally I’m not a fan of the 540 but I would be if I wanted to climb quicker, or go faster.

The other thing I like in a land of escalating Avgas prices is the fuel burn.

Not sure what DA you operate at but a turbocharged Lyc 360 could be an option?

[fairchild1934]

Im not really high here--- about 1800---- but there are mountins to the west a bit higher-- maybe another 1500 on top of that. So maybe 5 or 6000 if
you wanted to overfly them. They are not so much mountains as a plateau. The actual mountains are to the southeast and north. (im near Kingsport)

when I look at o-470 vs cont 360---- it looks like the 360 is 210 hp vs about 230-250 for the 470--- and 100 lbs difference in weight.
so it looks like ethe cont. 360 could be more hp/pound. looks fairly much in the same range as the Lycoming io-360 - roughly---- except for price......

i think I remember reading that bob recommended that much over 400 lbs was too heavy. but the 360's are most of 100 lbs lighter than that.
and I DO like the smoothness of the cont. engines I have ridden behind. and Ilike the can being lower down. maybe less corrosion and more oil flow (?)

[whee]

I think everyone knows I'm somewhat of a Continental guy. Really all the brands are good but IMO O470s are the Chevy 350 of aircraft engines; they are pretty cheap, available everywhere and have tons of accessory options. That's the engine I wish I had put on my plane. I do like my Continental IO360 but I wish I had a few more ponies and a bit further forward CG. But, when my kids are gone and I'm not hauling them and their luggage around my current setup will be great. It's fast, powerful and easy on fuel.

There was a time when there were two different length engine mounts available; shorter for the 540 and longer for the 360. But builders kept installing heavy interiors so Bob went back to the standard longer engine mount. I don't think it would be a good idea to extend the 360 mount even further as that would make for a really long nose and would reduce yaw stability.

I chose the Conti IO360 for a few reasons. Among them was that they put out good power (rated 210hp) and they are essentially right in between the 540 and the Lyc 360 weight-wise. The IO470 (260hp) would have been a great option but I thought I wanted a lighter nose with a more balanced CG. That thinking doesn't work for my current mission of being a family truckster.

[Battson]

Well it all depends on your mission, as always. Hard to answer these ones without having that 'mission' discussion first.

Failing that, I can really only give you my take on how the 4-place meets my mission.

I have always said the CG is thing which limits pilots' utility in their Bearhawk 4-place. Engine and prop choices are the main factors here. This is for those looking for maximum utility, obviously. Not all pilots are going to want maximum utility.

The further forward you can station your empty CG, the more useful the aircraft as a 4-seater with full fuel and gear. I still run into this issue, event after all these years - it is a recurring problem when taking 4 people and gear "full to the roof". Ultimately it's about how much gear you can carry. If the CG is at the aft limit, the aircraft becomes unstable in pitch, it is unpleasant to fly (at best). Of course there's a forward CG limit too, but at least the aircraft is stable (if nose heavy) and can be flown with ballast or 'added power' to manage a forward CG. There's nothing you can to to manage an aft limit, except putting the baggage on the passengers lap!

But that said, I wouldn't be adding a heavier engine or prop just for weight's sake - better to balance the minimum necessary weight correctly. Choices like battery location can make some difference.

Overall, the most exhilarating (and possibly safest?) aircraft is produced with the lightest possible plane with maximum excess horsepower, allowing for maximum performance. If simply you want to get off the ground quickly with weight aboard, or outclimb terrain with ease, then it's hard to beat the -540 for pure power to weight (within the Bearhawk's airframe limits). For those who mainly plan to operate at lighter weights (solo or 1 passenger, limited gear) then a 200hp+ 360 would be a good choice. I would not recommend it for those wanting to fly high and hot often, or those looking to carry lots of weight out of backcountry settings. So it is all about your mission profile.

[AKKen07]

For anyone who is likely to load the airplane to the limits often I sure love the performance and CG of my 540 powered B model. The weight limit and CG seem to meet at the right point so that my load capacity pretty well matches the potential of the airframe. The pitch stability gets pretty low at that point but it is manageable. The proof for me was in bringing a moose home (over the clouds and Alaska Range) with me at 10,500’ with a good amount of fuel and my chunky survival bag. Less performance would likely have been a hindrance at a few points. I paid for as much as $11/gal for 100LL out there so I felt the pinch but I think it’s worth it if you want to do that sort of thing. Other folks do it with lower performing planes but it is often outside design and legal weight limits.

If you choose a lighter and lower hp engine it does give a higher weight range but CG and power may be things you’re more concerned about if you are flying outside of Kansas fully loaded.

(plus I get all kinds of attention when I blast off light it is FUN!)