Engine Selection M14P

[James Corgan]

Good evening,

Just a simple question to anybody that might have an answer. I've been investigating options for my choice in engines. I've narrowed it down to the O-540 or possibly the M-14P. Has anybody married this engine (M-14P) to the Bearhawk? I know it is about 100lbs heavier than what is recommended, but with some of the engine configurations that I've seen, the airplane looks to be able to handle this weight. Any thoughts? keep in mind, I'm still trying to convince myself that I'd like to see the M-14P on the front of my bird when she is complete down the road (long ways down the road).

[jaredyates]

There was a fellow who was reengineering the Bearhawk to be an m-14 airplane some years ago, but I that project has stalled. I'm sure it could be done, but the result would really be a different airplane. I suspect it would effectively be a 1 or 2-seater unless you were able to engineer it for a higher gross weight also. If you are willing to sacrifice payload and seats for performance, look to a Patrol, which could be a rocket with 200hp, and much lower feeding costs.

[Dan R.]

Can it be done, Yes. Should it be done, that's up to you. But like a V-8 engine in a VW bug, you will have limitations. When you are through, it will not be a Bearhawk. It will be a completely different aircraft and are you up to designing a completely new aircraft.
A Patrol with a light 200 hp engine would be a fun aircraft.
Dan R.

[fixnflyr]

Yes it could be done but I don't think it would be as good of an airplane. If you look at what you will have to give up in order to gain in other areas it does not add up to be a good trade off. Along with more HP comes more fuel burn equals less range. Bigger tanks mean less pay load. Gross weight increase means structural improvements and maybe more tail volume for the added thrust. More gross weight means higher wing loading which equals higher stall speed. Higher stall speed means longer runway requirement or add more wing area which adds more weight. It is a bucket full of compromises.
I think one of the best ways to add performance is to take weight out or add lightness. It doesn't cost that much not to install extra stuff.
I bet a light weight Bearhawk with a 300 HP IO-540 would out perform the Radial conversion and have more payload.
Radial's do sound cool though..........
Just my $.02,
Fixnflyr

[Dan R.]

If its not there, it weights nothing, cost nothing, an its 100% reliable.

[James Corgan]

Not what I wanted to hear, but, my experience is minimal and I'm learning. I appreciate the advise. My intention is to use the airplane for myself as well as my family for 3 day weekend trips to anywhere. So I guess that puts me back in line with the O-540. Anybody have any other thoughts as to other engine options? I've read some on the Franklin 220 and like what I see, but my concerns are parts availability in the future. Franklin engines have not had the best run of luck in the last 20+ years. another thought is a Mazda 13B conversion. My concerns here are reliability with my family riding along. Again, I'm not ready to buy, just trying to narrow options down.......Unfortunately, time allows me to dream big sometimes....hence the M14P. That is a sweet sounding engine.

[nuggets]

hi james

Not sure if you have seen this ,rod smith wrote up a piece on engine choice`s here in 1999 , http://www.bearhawkin.com/FAQ-Engine...r_the_Bearhawk

scroll down the page ,Budd Davisson gives the M14 a mention , it may help you to decide

[bearhawk2015]

Do it, it'll be awsome. It will take a little extra work but you'll have something that nobody else will have. Reading http://www.bearhawkin.com/FAQ-Engine...r_the_Bearhawk it looks very doable. It's experimental so experiment.

[kestrel]

It will take off much shorter than it will land. To land shorter you need to remove weight and/or upgrade the flaps. Power won't help. ...but it sure would look and sound cool! ;-) -- Bearhawk

[jaredyates]

In the process of finishing most of a quick-build kit with a Lycoming engine, I've realized that there is significant opportunity cost to building an airplane, even if one uses a quick-build kit and the engine that the airplane was designed for. Spending 1700 hours on building means not spending 1700 hours doing any number of other things. Spending 3500 hours, well, that's a lot of hiking/camping/gardening/learning/etc. I think of this in the context of having a young family myself. If you were to complete a Bearhawk-inspired radial airplane, it would be quite a feat and no doubt a recreational and educational experience. But if your goal is to have quality experiences with your family, odds are that you will have failed at that goal. If you are able to get the family involved enough in the construction, and teach them the math and science so that they could do the engineering, then maybe this will not be the case- but I think a truly honest assessment will lead to the conclusion that the path to building a "plain old Lycoming" Bearhawk is still a very long path. Keep in mind that the Bearhawk has very good performance, even with the 360 that it was designed around. The 540 is a real hot-rod option that usually comes with a price premium on the order of $10k initially, and and empty weight penalty of around 100 pounds. Then there is the ongoing cost of fuel consumption- even if you throttle it way back for cruise to get the burn of a 360, you'll still have the high fuel flow at takeoff power. Lots of folks have gone with the 540, but don't let that lead you to believe that the bottom of your engine choice spectrum should be the 540. I think it's less of a starting point, and more of an ending point. If the sound of the engine is enough to make you want to go through all of that expense and hassle, you could save time and money by a factor of 10 or more, and just make up a speaker system that plays radial engine sound and even machine guns. On the topic of other engines, my unscientific count shows more Bearhawks that have been converted from other engines to Lycomings than Bearhawks that are happily flying with non-Lycoming/Continental engines. I don't want to come across as being poopy-pants about innovation and dreams. Rather, just to point out that building has a high cost, that can be made much higher by choosing an engine that nobody else will have. Add in that you'll have an airplane that is likely to be operationally inferior to the one that would have been easier and cheaper to build, with exceptions that I can count on half of one hand.

[X'N]

Got to say this looks awesome!

[kestrel]

I was fortunate to find someone selling a complete flying Bearhawk, as my goal was to take a growing family flying with me. ...a family that no longer fits in an RV-4. -- Bearhawk

[Battson]

Got to say this looks awesome!

The empty weight on that drawing has to be a pipe-dream. I think that must have been done in the earlier days.

[Glenn Patterson]

Personally if you wish to get your project done it is faster to go with a Lycoming engine for assembly purposes. Exhaust, electronic ignitions, spinners, props etc are readily available. There is not a lot of time lost engineering and modifying everything to work with a unique engine. There are lots of sources for parts and aftermarket parts. We are installing a Continental 210 hp IO-360 and that is far enough off the path for me with the unique fuel system, building the exhaust, and reshaping the typical nose bowl to accommodate the engine. There is a lot of time consumed in building an airplane & I think the shorter the build time the greater the possibility of actually completing it before burn out or losing interest.

The Continental IO-360 was attractive as it was dyno'd at rebuild to be 210 hp, the prop turned out to be reasonable, & with the custom tuned exhaust and electronic ignition it should be at 225hp. That is almost the same hp as a 540 on mogas and with about a 100 lb.s lighter. Anyways recommendation is to go with a Lycoming or Continental as there is lots available, plenty of experience in the group and enough anecdotal information to veryify that the Bearhawk behaves decent with these engines. Continental 470's are a solid engine choice as well if one is after bigger horsepower. No matter if it is Lycoming or Continental do a little research on each version to see which are the best. Sourcing custom parts or parts with limited sources will get expensive and offset any bargain with an alternative engine. I guess one thing too is that we will give honest opinion based on our BH experiences to help one avoid falling in a hole.

We have a friend with auto engine in his Murphy Rebel and he has it apart a lot seeking some solution to issues that just keep bouncing out of the bushes. He is in a deeper moneywise than if he had just bought the Lycoming 320 and it is too expensive to bounce the engine but a Lycoming would have put him in the air & kepy him flying.

I too hate the ancient flying engines and their crude technologies but have resigned myself that it is a better place to be. Honda flew a liquid cooled 225 hp light weight engine into Oshkosh about 9 years ago, Honda touted its performance & showed the engine off at Oshkosh, It looked like finally light aircraft engines were going to make a leap in the new millenium but Honda has not been heard since. It was a bad tease.

http://www.aero-news.net/index.cfm?do=main.textpost&id=974d3daf-9c77-492e-a35e-52ae8e21502a

We are 9 years into this project & the end is in sight. We thought the airplane would have been flying already & expect it to be this summer. Jared makes a good point on hours and costs. If one believe that building an airplane from scratch will be economical then that is a mistake.

all the best
Glenn

[Julian]

Stick to the 540 it is an aircraft engine and you want have to mod the airframe to use it. My 540 powered Bearhawk will carry 4 men full main gas and still have room for bags,and will take off I less distance than you can land it. N868JD