I will be putting one of these engines in an aeroworks 31% 540T, which also happens to be my first large scale plane. Since I'm new to gassers, will I notice a difference between these? Is the QS worth the extra $$$? Will the QS even fit in the Edge? Or should I just stick with the normal 3w75ius?

Thanks

I have the 75ius on that plane, and it is an amazing setup!
just to make sure I got the right engine model - I'm talking about the rear intake type.

I fits into the cowl when installed inverted, when the cylinder head and plug cap sticks out (picture enclosed).
I did have a bit of a froblem to fit the mountinf plate onto the firewall, if you don't intend to use it it's fine.
FYI, I didn't use standoffs because of the CG, meaning I had to open a pretty big hole in the firewall for the carb,
plus, i hade to sand one engine box corner to fit the pitts muffler (pictures inclosed).

for simlysity - go with the US, the side mounted carb will make it easier on you to install, but keep in mind thaat the IUS/QS are more accurate and smoot, as most rear intake are.
as much as power in concerned - the 6.5hp US will take this plane easily to 3D,
but THE IS NOT SUCH THING AS OVERPOEWR!!! if you wand to take her all the way - go for the IUS/QS.

This was my first big one too. no doubt - the best choise!!!

what is your system setup?

GOOD LUCK!!!

Hey Weatherman, just buy the 3w-75us from from Aircraft-international. I think they are about $550 and it will have more than enough power for your application. the setup is easier because you dont have to have the carberator in the motor box. That can get sloppy and hard to get at to tune.

My 3w-75us is on my Carden 30% cap. weight 20lbs. More than enough power. Pulls a Mezjlik 26-10 at 6100.

Thanks for the feedback! Nice pictures from both of you.

JRozman, what kind of wood and standoff's did you use on your 3w? The engine box looks very nice and well built. Is it varnished?

I have the 75IUS on my 31% Edge! Great combo. No need for the QS unless you want pretty!!!! I used wood dowels for my standoffs(about 1/2") and everything is working fine. You will have to cut a small hole for the cark adjust screws to stick out and might think about using a pitts muffler. You'll have to butcher the right side for the standard muffler.

Weatherman, motorbox is standard build per plans on this kit. the standoffs I got from aerografix. Aluminum. I stood the motor off enough so the pitts muffler would clear the firewall.

I used a mix of 30 min epoxy thinned with denatured alcohol to gas proof the motor box.

I had a machine shop cut my needles shorter so they would not stick out of the cowl.

What does the piece of Tygon almost touching the muffler do?

(Saw a friend's 33% deadstick when similarly routed Tygon melted through.)

Scott, the pic makes it look close, but there is about 3 inches seperation. The muffler stacks angle back. The tube is flush under the motor box. Scroll up to the first pic without the cowl and you will see what I mean.

That tube is the carb snorkel anyway. It runs into the fuse to regulate the air on the air side of the carb. There would be no consequence if it burned through.

Jess