503 to 532

[Guest thrasher]

Hi Guys

 

When changing from a 503 to a 532 or 582 what changes do you need to do weight & balance wise....

 

Regards Steve

 

 

[Guest TOSGcentral]

Hi,

 

 

First of all what are you converting?

 

 

If it is any of the single seaters then do not bother – too much weight and too much torque. TOSG has a 582 on a Glasshouse two seater and that requires a bit of piloting skill in engine management to deal with – because the Glasshouse is so light.

 

 

Any of the 95.25 two seaters are not really a problem. They will fit straight onto the 503 engine mounts but the extra torque will require a fixed rudder trimmer unless you get of-set engine bearers.

 

 

You may well have to saw a bit off the front of the boom! Do a dead accurate weight and balance survey on the present empty aircraft to establish the C of G.

 

 

Get your new motor totally complete and assembled with radiators, starter motor etc, weigh it and note the weight. Put it on a flat table and use a piece of dowel under the motor to find the engine’s C of G.

 

 

Measure this relative to the engine mounting holes and note that.

 

 

Now the basic problem you will have is that the 503 engine mount has a transverse cross member that prevents it being slid backwards down the boom (hence some probable boom sawing as the 532/582 weighs more than the 503).

 

 

You should by now get the picture. If you know the engine’s weight and C of G, plus have the engine mount then it is a simple calculation to determine where the engine has to be and therefore where the mount has to be and therefore how much you have to cut off the boom to do this.

 

 

Sounds flippant! Taking a saw to a boom is a bit heart stopping! The only time I have done it I spent two hours redoing the calculations until I was positive. I then took a tape measure, marked the boom, told the guys to saw it of there – and went and had a stiff beer!

 

 

The aircraft turned out bang in the middle of the C of G range! The beer was not bad either!

 

 

Aye

 

 

Tony