Sig's website and on the outside of the box says this is a .65 to .90 size 4 stroke engine aircraft. But as soon as you read thru the directions it says to use a .65 to .80 4 stroke followed by engines larger then those listed are not recommended. I have however read a post here about the hog-bipe with a .91 fourstroke and it balanced perfectly. So before I spend the money or do something unsafe, I would just like to hear from my peers it's a good thing to use a .91 OS in this plane. Now I just hope this is the right topic for this. Should I have gone to the engines fourm?

First, I've never owned or flown a Sig Hog Bipe. So consider my advice with that in mind.

I doubt that there would be a serious problem with using an OS 91 4 stroke. I would suggest, that to be safe, you add some reinforcement to the firewall.

I would imagine that the 91 would give you excellent vertical! You might want to back off on the throttle when pulling out of loops or dives though. No sense ripping the wings off.
Dennis-

My friend and I have these Hog Bipes with OS .70 4 strokes in them and they fly just perfect.

Go for the .91. One fellow in our club has one with a Saito .91 in it, and it is the perfect match. I may buy this kit just for a .91 I have on the shelf after watching his fly. I would want to find a fiberglass cowl to replace the cheek pieces, though.

Pilgrim

My Hog Bipe flies beautifully with a TT .91 four stroke on it. I wouldn't want any other engine. A friend also flies his Hog Bipe with a Saito .91.

For more info on what engines people are using and lots of pictures of Hog Bipes go to www.fubarhill.com/ and check out those planes.

I personally think anything less than a .91 four stroke would be a waste on this fine flying airplane.

Enjoy.

Jim

Flew my Hog Bipe with a YS91, Great combo.

My Hog Bipe has a Saito .91. Takes off at about 5/8 throttle. There's enough in there to pull you out of trouble too.

Great engine/plane combo and I concur in your checking out Fubar Hill.

Bob

I have built and flown a couple of these great bipes. Both have had a .61 Magnum 2 cycle and fly great. I have seen many with .92 4 cycles on them and even one with a 1.20!

Here is my latest one, round cowl, re-shaped tail feathers, and a rounded fuse.

You only have too much engine when the landing gear is too short to let the prop clear the ground! :stupid:

I believe that Stan's Fibreglass has a cowl for the Hog Bipe.

I had a magnum 80 fs, and mine was a bit underpowered. A .91 would seem perfect

The instructions must be out of date. I'll be sure to post a pic when I'm done. Thanks to all.

My Hog Bipe flies very well with a Saito 80. Plenty of power and it balanced perfectly.

I started building my Hog Bipe in November and finished on Memorial day. Took my time.
I read quite a bit here on rc universe about the subject before I began building and gave consideration to the powerplant and landing gear plate.
I opted for a .91 magnum four stroke cause I couldn't pass up the deal I got and as far as the landing gear plate I cut a piece of scrap ply and glued it perpendicular to the leading edge of the plate so both front and rear edges of the plate are supported and structurally sound. It worked perfect. The rest is pure Hog Bipe.
As far as the .91 goes I am glad I didn't go any smaller.
My plane is covered in 21st century fabric and CG'd without adding any weight anywhere.
I also opted for the dual servo setup for the aelerons and am glad I did.
I read a lot of complaints of the plane having a tendancy to nose over on landing and mine did the first landing as it came to a stop. I simply added a little more elevator movement at the control horn and solved the problem. As I roll to a stop I am at full up elevator and the tail wheel stays on the ground.
Back to the engine. The .91 will get the plane off the ground nice and gently at less than half throttle at a gentle climb rate. And will pull the plane vertical maybe 200 feet before it stalls and hangs there. It's also got enough snort to pull you out of a not-so-good situation i.e. getting away from trees and such as you are learning how slow your hog will fly and still handle well.
All the recommended throw rates seemed good to me except the additional elevator throw I gave it to prevent nose-overs.
I have really enjoyed learning to fly this plane this week. I put a gallon of fuel through it already.
I will post pictures of my plane when my wife gets the prints back.

Otis J

Flew mine with a YS 91, terrific combination.