Venturi on the O.S. 105 necessary?

[troasb]

Hi

So far I have been running my N7 with my O.S. 105 HZ-R without the huge venturi O.S. have included with this engine. If I am going to use the venturi, I'll have to cut out quite a lot in the fan housing. I have not wanted to do this so far as it obviously will reduce the cooling power of the fan, and also as I am not a 3D smack pilot I thought that the possible extra power from the venturi is not needed. And so far, I have all the power I can use. Do you think I should use the venturi or not?

Best regards
Trond
Norway

[Chris Sexton]

I have done it either way. Currently my n7 doesn't have it installed


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[troasb]

I have done it either way. Currently my n7 doesn't have it installed


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Hi Chris

Thank you for your answer, but the most interessting thing when you have tried boths, is if you can
fell any differences in power and heat build up?

Best regards
Trond
Norway

[Kevin Feil]

Trond,

 If you are mindful and neat and take your time trimming the Fan Shroud, I can assure you , you Will Not have any issues regarding excessive heat build up. This isn't a factor with running this power plant, as far as the Velocity Stack consider it as a little mini super charger ( Increases Velocity of the incoming air while decreasing the pressure ) basically optimizes performance, will it run without it, of course ! Will it hurt the engine if you don't run it? Of Course Not. But if you are in fact a 3D smack kinda guy, then you definitely want it installed. Based on your flying style, you aren't missing anything not having it installed.

Lastly , something that I have always kept in mind when trying to decide what equipment I should run to include what powerplant to choose. ( The motor of choice for the N7 is the OS 105, Matt runs it with the Velocity stack installed and flies his machine without a single issue, I can assure you if there were ever a doubt regarding lack of cooling due to modifying the fan shroud, he would have designed it differently. )
Hope this helps as well. You have a nice machine, and it will serve you well.

Best Regards,

Kevin

[troasb]

Trond,

 If you are mindful and neat and take your time trimming the Fan Shroud, I can assure you , you Will Not have any issues regarding excessive heat build up. This isn't a factor with running this power plant, as far as the Velocity Stack consider it as a little mini super charger ( Increases Velocity of the incoming air while decreasing the pressure ) basically optimizes performance, will it run without it, of course ! Will it hurt the engine if you don't run it? Of Course Not. But if you are in fact a 3D smack kinda guy, then you definitely want it installed. Based on your flying style, you aren't missing anything not having it installed.

Lastly , something that I have always kept in mind when trying to decide what equipment I should run to include what powerplant to choose. ( The motor of choice for the N7 is the OS 105, Matt runs it with the Velocity stack installed and flies his machine without a single issue, I can assure you if there were ever a doubt regarding lack of cooling due to modifying the fan shroud, he would have designed it differently. )
Hope this helps as well. You have a nice machine, and it will serve you well.

Best Regards,

Kevin

Hi Kevin

Thank you very much for your useful reply, it answered all my questions and wonderings about this matter. As I am far from a smack 3D pilot, just trying to learn a little 3D and otherwise flying mostly sport, I don't need the extra little power from the venturi. I have more power than I can use as it is. And I think there are a couple of advantages of not using the venturi and that is that the cooling is better and the engine may use a little less fuel adding to the flight time.

Best regards
Trond
Norway

[Drew Robinson]

I have used the Venturi since day one on my twin n7s. I have gotten accustomed to just slight trim of the fan shroud to make it fit. If your not looking for as much power as possible I'd agree you could go either way!