Dummy Loads

[junction]

Hello, Jan I've been working on a Dummy load project, and I'm not sure on its total power handling.

What I used to make The Dummy Load:
 
 1x Paint Tin with lid ( New )
 1x So239 ( Attached to lid )
66x 3.3K ohm resistors ( 2Watt ) Carbon not wire wound!!
 1x 10w60 Oil ( Synthese )
 1x Copper clad ground plane ( Round to match paint tin ) 
 1x Copper rod ( Centre + Pin )

I used this formula for the resistors   Example 3.3k = 3300 ohm . So 3300 divided by 66 = 50 ohm . This should give me 66x 2watt = 132 Watt of continuous power handling easily as the resistors are sitting in the oil to keep them cool.

So with this information, How much Power and for how long can I push my dummy load. it only gets warmish after 3mins at 130watts. But I want it to handle at least 160 Watts for at least 10-15 mins while I tune this up.

Please Help Me