Hi all,

I am building my first kit (4*60) after learning to fly my Nexstar. I have the wing completed and am ready to start on the fuselage. My question is the difficulty level in modifying the airplane to have a Magnum 91rfs mounted inverted and covered with a fiberglass cowl from Fiberglass Specialties. The thrustline wont be an issue to get right, I am more concerned how difficult it will be to modify the tank floor to get the tank stopper to line up with or be 1/8th inch below the centerline of the carb (Dubro 12oz tank). Obviously I don't need to do this, but 4 stars are a dime a dozen at my field and I think this would really set mine apart. Thanks for any help.

Iwould offer this advise. Side mount the engine. Fiberglass Specialities makes a cowl that should accomidate the engine on it's side. You can the rotate the carb 180 to change the spray bar height. That is my plans for my third 4*60, the kits on the shelf, but has slipped back on my list for now.

Other bashes for it would include a built up aileron on a clipped wing. Round the belly a bit. Really bash the canopy. Iwould also add a half inch to both the rudder and elevator. I've seen them with a curved outline and they look great. You could carry that to the wing tips also. The list goes on and on.

Don't forget though that you need to re-enforce the landing gear mount as well as the fuselage sides at the former at the TE of the wing. Those are two weak areas of the design. Ialso snapped the tail off on a bad landing. I dipped a wing and when it clipped the runway, the plane started a cartwheel. The tail snapped off right at the LEof the horzontal Stap from the snapping action of the cartwheel.

The engine is a good choice for that plane also. Prop it with an APC14x4W prop and you will have all the vertical you want.

The kit builds tail heavy, so you could space the engine forward about 3/4" to 1" to eliminate needing the 8 or 9 oz of weight for balance. with the cowl, it would clean things up nicely.

Photos when you get started please.

Don

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You should drill out the firewall so the tank fits. Then use some Silicon adhesive to fill the hole. I have done it on many planes and it's not a big deal. Make it so you can get the tank out when necessary. I have a 4* 120, and made some modifications to the firewall. Put in a larger tank etc. It's supported with a Saito 150, and hauls Ass.

I agree with CampGems about side-mounting the engine. Inverted engines can be a pain and if this is only your second airplane, I would avoid any unnecessary hassles.

Ditto on the mods - if this is your first kit, keep the modifications down to a minimum. The 4* flies so well as is that you really don't NEED to do anything special.

You,ve got a good engine picked out for your 4* and you'll get a lot of satisfaction building it yourself. For your first build and low wing , IMO your could,nt done much better.
And yes 4 *'s are a dime a dozen at the feilds and rightty so. They are simple to maintain , the upright engine and open check design puts everything easy to get at. This well be your first build, low wing, and taildragger. If you nose over on an inverted engine, it's not pretty. And if your like some of us, your second plane is going to take a beating but at the same time your going tolearnalot.
I would build the 4 * stock, besides beefingupfuse right behind the wing saddle, beefing up the landing gearmounts, and adding an extra hinge to the ailerons so you can easlyremove a bay, after you get some time under your belt.Keep it simple, learning to fly the 4 * , then Mod your 3rd plane the way you want it . You'll have a build under your belt and also know what style of plane you like to fly.

Ditto on all the above-Pictures show a 4*60 with side mount and Fiberglass specialties cowl using a OS91 which will be the same as the Magnum.
Side mount really helps in consistant running of the engine, and this setup works good, cools great and don't look to bad with the size of cowl they offer, but if I was to do it again I would invert the engine-Only because I've had experience with this plane and building.

Frenchie, Isee you use my faviorite landing gear also. That is the best gear for a 40 to 120 sized plane. Lots of spring, but more important total spring back. I've found that you can use the 60 size U-Can-Do wheel pants and you trim the pad on the gear to fit the notch on the pants. Use the same axel to hold the pants on the LG. Depending on the stance of the model, you may need to cut the pad a bit on an angle for grown clearance on the end of the pants.

Dduncanjlee, When you start your build, make sure you have readthe manual first, not just scan it, but really read it. And NEVER build ahead of the step you are doing.There are a couple places that if you dogetswep up in the build and do what you think is logical, itmay bite you. The sheeting of the wingcenter isone such place. When I started the sheeting, I finished it. Then I couldn'taccess the spar to get epoxy into the slot for the dihedral brace. Do just what the step calls for and nothing more. The instructions are very well writen. Best I've see for that matter.

Don

If you need some specific pictures - just ask. I am in the process of modifying my 4Star60 to mount the engine at 90 degrees, a tank hatch and a built up cowl. I also have a SIG Smith Miniplane cowl that fits pretty nicely.

I support campgems suggestion that the 4Star60 builds tail heavy. Before this mod I had a Saito FA 91 in a standard position, original "cowl cheeks". The tank is a Dubro 12 oz. Landing gear is the Dubro composite one shown with fairly heavy tires. , A Higley Heavy hub and an additional 3 oz of lead was needed on the back side of the firewall.The battery was snugged up against the back of the FW as well.

Oops - a note about adding right "side"thrust. The plans call for 0 degrees of side thrust. My plane needed 2 - 2 1/2 degrees of right thrust make it behave on take offs. Iwas using a Zinger 13x6/10 multi-pitch prop. This particular prop really pulls hard during throttle transition from idle-plus thru mid-throttle resulting in an agressive left hand tendancy on take off. The added right thrust made long, straight take offs 2nd nature.

http://www.rcuniverse.com/forum/m_6748796/tm.htm

Above is a build thread I did a couple years ago on the 4*60-Basic stuff, easy to do and you will have a plane that will last for years. Mine has had Hundreds & hundreds of landings, takeoffs, ect.. Just a great plane to practice everything with. Me and a buddy practice how many talkoffs and landing we can make on 1 tank of glow juice. I think 40+ is the number.

Campgem-The U-can do wheel pants you say-Always wanted to put those on-thanks for the tip

Thanks for all the replies and advice.

Looks like side mounting is the way to go. That was my original plan to side mount a Tower Hobbies 75 with a pitts muffler, but it's backorder is now pushed back untill late July so I went with the Magnum.

I am keeping the rest of the build completely stock other than adding another hinge so clipping the wing will be a hassle free option down the road.

Here are some pics of the progress so far.