I need help with my OS GT 33 installing it into 27% EDGE 540
 

<span style="background-color: rgba(255, 255, 255, 0);">I am trying to install a GT 33 gas engine inside my Great Planes edge 540 and the cowling isn't letting the engine fit to well. It appears to look like I must cut out a hole in the bottom of the cowing with a Dremel tool but I am not sure if there's a way to install this engine without cutting any holes. I know the hole may be a small one on the underside of the engine, but to me it looks a lot cleaner and nicer if the Cowling is all one piece with nothing exposed except the propeller and the spinner.

I am also having a question regarding the drilling template on the OS 33. I was told there is no template and you have to make one yourself from the measurements that one sees on the schematic inside the instruction manual. I believe the dimensions they give you is wrong because it says hole to hole is 70 mm wide by 54 mm high. From my measurements the width of the center point of the holes is 73 mm across and the high is 52 mm which is a big difference when mounting a powerful engine with a torque index!

I have already drilled two sets of holes and I still can't get this correct. Are there any helpful tips anybody out there can give me? And if so please send them my way I will greatly appreciate any help I can get. I am trying to get the cowling on the plane with the GT33 mounted upside down and DO NOT want to have any holes cut anywhere in the bottom of the cowling. Is that doable or not.

My name is John and I can be reached at 973-229-5252. Give me a call me or text me if that is faster for you.</span>

RE: I need help with my OS GT 33 installing it into 27% EDGE 540
 

Have you considred mounting the engine with the cylinder parallel to the ground? Would that help? As for a drilling template, why make one of plywood to get the hole spacing correct and then using that to locate the holes in the firewill? It looks like you would have to remove the carb tempoarily, but it might be worthwhile.

RE: I need help with my OS GT 33 installing it into 27% EDGE 540
 

It's normal to have to cut a model airplane's cowling to accommodate the engine. No way to get around it. You just try to minimize the damage. Also, please realize that you may have to cut the cowl quite a bit to allow for proper cooling, depending upon the engine's actual performance once you start flying it.

We'll check what OS printed in their manual, and let them know of any discrepancies. Many engines don't come with a template at all...or even a chart with measurements. You have to measure the engine and go from there. Every installation is a custom job, so you wind up doing a lot of measuring, anyway.

RE: I need help with my OS GT 33 installing it into 27% EDGE 540
 

The measurements in the manual are spot on, i'm not sure how he got it wrong. I used a piece of card to make a template