Hi All

Firstly I posted a topic a few months ago looking for PA18 clone advice in South Africa and it was a huge help...so thank you. I have decided that I will be going the PA18 Clone experimental route.

My problem is I am trying to reinvent the wheel with the build (and I know it will cost more time and Money and is probably a stupid idea ,but I guess it is just what I want) . My engine choice is the Edgeperformance 917Ti and Thomas has been very helpful so far.

My two biggest perceived issues are going to be the CG and the engine mount.

1. The 917Ti is about a 195-200 Lbs engine and the Titan 340 is a 245-260 Lbs engine. I will be adding a CS propellor to the build and trying to find the heaviest governor and propellor combination and possibly adding a 10Lbs spacer to the propellor assembly. What I don't want to do is extend the engine cowling. My question is do you think with the experience on the forum that doing these things will be enough to keep the PA18 clone within CG limits when loaded with 2 x 200 Lbs people and majority of the heavy if not all the baggage in the pod rather than behind the rear passenger.
-Mounting the engine as far forward as possible in the cowling
-Adding a CS propellor system and 10Lbs pound spacer in the assembly
-Moving the battery as far forward as possible in the engine bay
-Potentially adding a second Battery

2. The engine mount will have to be made to spec and I know it will be a challenge but from what I can see not impossible.

I guess I am asking for any other ways to help and or fix (find) the problems faced in the build rather than tell me why I shouldn't be doing it. With that in mind I need to expose my ignorance, I have no build experience and PA18 experience is limited here in South Africa so hence coming to the Backcountry Forum for advice and suggestions.

It will be a standard PA18 clone Kit 4 inches wider
48 Gallon fuel tanks
A cargo Pod (cargo Only)
Acme Shocks
26 inch Wheels
Not sure if this information is relevant but just trying to give the whole picture.

Regards

You will probably get some good info on this forum. You might also want to visit SuperCub.org and ask questions there. Good luck with the build.

Do a weight and balance calculations using a stock 150 hp cub and see how much you move the CG with the plans you have. Use a Titanium single leaf tail spring, Not one of the heavy shocked units and a 3200 tailwheel. That will help. Use a standard cub cowling that way it is easy to extend if you need a longer mount to make it work. The latest and greatest usually means the least tested but if you like to tinker go for it.
DENNY

The plan to not have anything behind the passenger is great for a 2 hour flight. After that total BS!! Front of belly pod has tie down gear, axe, shovel, tool bag, stove, sleeping bag emergency gear, water. If you plan on an overnight now you need tent, chairs, bags, guns, food, clothing, booze, booze!! that is all behind the passenger so add at least 150 lbs to the W&B behind the passenger so you have a useful plane when you are done! Not the best for the plane you describe but build it for what you want. Just make sure you know what you want to do with it!
DENNY

Like Denny said, do some calculations and see where you come out. I would think about extending the engine mount forward rather than trying to add a bunch of weight. In my mind, the goal should be to retain as much of the weight savings as possible. I completely agree that you will have weight behind the passenger. There just is not enough volume to carry it all in the pod.

Joe

I'd extend the engine mount as far forward as you are "ascetically" comfortable with and since it will be a custom build fabricate it out of the heaviest wall tubing possible for added weight. You could even fill the tubes with steel shot for added weight. You might want to re-enforce the firewall as well for the additional weight of an "fortified" engine mount.