Hello In light of the previous discussion on NVA height in the venturi and my own curiosity is there an advantage side-mounting my engine in my P39 Airacobra build . My model is a slightly scaled up P39 by R Woodhead (Aeromodeller design from the 1970's 60" with OS 50) The original was upright engine which ruins the slim front profile and
side-mounting would help here, without to much reworking as the design is bearers in bulkheads and planking.
 I have not started the fuselage yet just the wing and control surfaces. I want something I can enter it in scale to replace my profile scale P39 (35 size) but still fly it in Stunt and appreciate I am not going to win/do well in either class but just want to compete as usual.  Thanks Gerald

Hello Randy

Now is the embarrassing part as I am a committed Fox engine enthusiast 
I originally intended to use one of my Fox Hawks in it as I have run a number of them on my profile P51 (yes side mount proved good) but admit they are far from ideal as they get hot with their metal fins and paper gaskets .Also I found if you use a restrictive muffler or 13x6 prop they are not happy which limits things to a stock muffler and 12x6 or equivalent. Timing is a little radical too and suction not the best with the standard venturi . Was tossing up a Fox Eagle 74 but admit it is flawed too and may overheat with a large load . The model is big at 920sq and will be heavy as I am building it.
Whats the point you are probably be thinking but I have to live up to my reputation as a non standard person who loves American cars and Fox engines here in New Zealand , I was a Fox agent a long time back but no one wanted their engines!   
Sorry for being difficult but I do not want to disappoint my critics and like scale multipurpose stunters 

Hello Randy

Now is the embarrassing part as I am a committed Fox engine enthusiast 
I originally intended to use one of my Fox Hawks in it as I have run a number of them on my profile P51 (yes side mount proved good) but admit they are far from ideal as they get hot with their metal fins and paper gaskets .Also I found if you use a restrictive muffler or 13x6 prop they are not happy which limits things to a stock muffler and 12x6 or equivalent. Timing is a little radical too and suction not the best with the standard venturi . Was tossing up a Fox Eagle 74 but admit it is flawed too and may overheat with a large load . The model is big at 920sq and will be heavy as I am building it.
Whats the point you are probably be thinking but I have to live up to my reputation as a non standard person who loves American cars and Fox engines here in New Zealand , I was a Fox agent a long time back but no one wanted their engines!   
Sorry for being difficult but I do not want to disappoint my critics and like scale multipurpose stunters 

Hi Gerald

I would at least use  the 74, you can mount it  either way you want, maybe just inverted, I don't see you having much of a  heat problem with, just make sure the carb is  working and adjusted properly
Send us a picture of your build, be  nice to see  what you come up with

Randy

Gerald, I have both the Eagle 4 .74 as well as the .78. They both make about the same max power but the .78 seems happier with the larger props and is overall much easier handling than the .74. Plus you can hit the .78 with loads of nitro and not degrade the handling. The same can not be said of the .74.
Phil

HI Gerald, The usable power of the .78 I far more effective and easier handling than the .74. As for comparing the .78 to the OS .80, there is no comparison. I had a Telemaster that I was flying with a Fox RC .59 that was pretty well worn out. I went and bought a new OS .80 and installed it in the Telemaster, After the first flight, I was sick. The performance was about the same as with the worn out Fox .59.
Phil