I'm considering adding a bit of right thrust to my 4*60 to counter some of the torque.

I've read the way to go is by adding washers, but how exactly is this done? I don't want to replace the mount unless I absolutely have to, but if it's best to go that route, I'll do it.

thanks,,,

Depending on your mount, you will place the washers between the mount and the firewall.

gezzzzzz, and all those college hours I have, I'm embarrassed, LOL. thanks

I was thinking on the mount/engine itself.

Cruzomatic, if you used a 5/32" bit to drill the holes in the mount, and #6 screws to mount the engine, there should be enough "slop" to cock the engine somewhat.

Tim,

I'm thinking I used 4 40 screws for the mount, but not sure. I'll have to check.

thanks,

No problem. I sometime make the problem more complicated than it needs to be!

Me? All too often!
Dennis-

In the LHS I've seen shims that can be put behind the motor mount. They're plastic wedges, a couple inches square or so, and come in varying degree amounts.

(But washers work just fine.)

regards,
flian'

Ooooooh, that was my 100th post!

golly

100th post,,,,way to go.

yeah, I guess I'll just add a washer or two in the mount. We'll see, maybe it's just me. The manual didn't mention anything about right thrust, but I'm thinking it might need a bit of it.

If you can find some steel washers and a surface grinder, you can grind them at an angle you need.

Grind 'em? I was thinking of just adding one or two to the assembly? Would that work?

No need to grind, unless you're a complete perfectionist. Just throw 'em under the mount bolts.
Dennis-

DB,,

Thats what I was talking about.

Huge storms today and my "out-laws" are headed into town. I should have plenty of time to add the washers.

A lot of kits have the right thrust built into the kit. The left fuselage is just about 1/8" longer than the right. If the plans don't call for it, then I would leave it out unless a taxi run proves that you need it. If your kit does need it I found that 3 washers works pretty well. I don't like the idea of the wedge pieces because they could come out due to vibration and then your motor mount would be loose!

This is what it's doing, maybe you guys can help decide if I need it.

My set up is a 4*60, TT91FS, 14x6 APC

I taxi on runway,,ease into rull throttle and give a bit of elevator. She begins to climb with authority and pulls left some. I give some right rudder and right aileron and climb out. I don't think it's the trim because after climb out and reducing the throttle she settles down nicely, flies level and straight. I have to add a bit of right aileron trim every now and then when I go with throttle up.

I would say that grinding is not necessary for a plane that is under 1.20ci. Once you get to that size or larger, I would make sure the mount has as much surface area as possible. Remember, when you add a washer, you reduce the surface area that the engine torque and stress is transfered.

What do you think, so I give it a go?

Cruse go ahead and try it if you like, Its not a huge deal. If you go the washer route then a much better route to go and is easy, is to make a plywood plate that is long enough to span two firewall bolts either across for adding down thrust or up and down for adding right thrust and drill the holes sloppy. You can try several of different thickness very easily. After you pick one just drip a little CA between the firewall and spacer plate.

The trouble with the washers is they will always start to dig into the firewall after a while and the bolts will always be getting loose and if you keep tightening them you gradually lose the right or down thrust. This is an old controlline trick from the days of wood engine mounts.

John

Well I did it. I added two #6 washers to the left side mount against the firewall. Looks good so far, everything tightened up nicely. My "out-laws" are in town, so I'll have to try and sneak away tomorrw to give 'er a test flight.