[Imhoff43]

This may get quite long but I hope it will spawn some good discussion for all. I have a Fox Eagle 60 loop scavenged engine. This engine has a very high compression and was designed to fun on 5% nitro with 29% castor oil? I believe it was also designed to run without a muffler? I know that low nitro will retard the igniton point. I also believe the high oil content will retard the timing as well. Now lets move to the year 2004.

Assuming that everything is constant including the glow plug (Fox Idle Bar) the following is the sitiutation.

The fuel available at most LHS is 10% nitro and 18% oil. If the above is accurarate then this engine will have an extrimly advance ignition point.

How do I go about fixing this? The following are some of my thoughts.

1. Jack the head up with an additional shim.
2. Go to a colder glow plug (I am not sure of the heat range of the Fox Idle Bar plug? Any suggestions for a plug)
3. Add addtional oil to the fuel.
4. Add a modern muffler (What will a modern muffler do to this engine?)

I ask these questions because this engine runs very hot and quits even at a very rich needle setting.

[AJCoholic]

Check out this site

http://www.flitelinesolutions.com/


It caters to the Fox engines, in particular what is required to fix the situation. It stems from the fact that when these engines were being made, Duke Fox was trying to make use of FAI (no nitro) fuel and thus the high compressions.

The 60's are fixed either by remachining the head or the head button (depending upon what model).

I am actually the guy they (the fellows that run the site) recommend for machining, but it is pretty straight forward and if you have access to a lathe you can perform the mods yourself.