Fox 15 1975+

George I never got into the tach thing until a few years back and since then I haven't run this engine. I just currently finished some foamies to fly a bunch of this stuff. I have enough cases and parts to complete several of these .15's. Props used for these were 7x4 Rev Ups. Making RPM claims on these are pretty much obsolete when you compare the current Russian F2D stuff. It blows these out of the water. If I was to use a prop I would certainly choose a old Taipan 7x4 or a woodie but I'm curious to see if the F2D glass props would work. I'm venturing to say that this particular engine will tach on the ground at 22-24k with the Nelson head button. My bench tests a few weeks ago were using 10% nitro and 22% oil. For the 3 engines I ran all set up for suction, they ran at 20K swinging a 7x4. My club uses a lot of FP .15's for combat. When we hit 20K on the FP .15 it had it's venturi removed and was running on 35% nitro. All in all I think these Fox's are certainly overlooked. These engines don't need to be overloaded with the syrup of 25% oil content. 20% oil content is fine on these engines. High nitro isn't out of the question here. I use a lot of high nitro fuel . Ken