looking at '75 fox combat spec. w/ smooth head. who knows about this year /model

[paulwells66]

I"m eyeballing a '75 fox combat spec. w/ smooth head. who knows about this year /model.
This one has a square (not coffin) backplate. Thinking of using it with restrictor and vented tank in a super combat streak.
Was going to use a mccoy in this plane but I don't trust that engine

thanks

[john e. holliday]

I am flying a Combat Streak with McCoy 35 Redhead.  Not as fast as with a Combat Special.  But still a lot of fun.  Use a uni-flo tank for good results.

[paulwells66]

That's just the problem...I already buried a vented tank in the fuselage so uniflow is not an option. I worry about the McCoy cutting out with the vented tank. What do you think?

[frank mccune]

     I have a CS with a McCoy .35 RH and it is a great combination!

     Frank

[Richard Imhoff]

Good motor on low nitro and 9" props but in the day on high nitro and 8" props they all broke the crankshafts.
 Good motor plenty of power on 10% just stay away from high nitro and high RPM's and the crank will stay in one chunk.

[paulwells66]

thanks!

[Lyle Spiegel]

I have one of those. It was known as a "baldie". At this point, I will be glad if I could handle a combat streak with 9 inch prop on 10%. I have a Ringmaster running a OS 35S and it is a good workout. Hoping to build a Voodoo with my JCS as a challenge.

[Peter in Fairfax, VA]

They all broke cranks.  Chucking up the crank in a lathe and cutting the bore smoother was thought to possibly help.  Maybe. 

They ran great until the crank broke.  That was my experience.  Yes, 40% nitro was typical.

Peter

[Howard Rush]

The Black shafts were the worst. 

The case would crack at the bottom of the front bearing, too.

[paulwells66]

Yikes!  the seller would not be happy to hear all this lol. Maybe I"ll ask for a discount