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Engine basics => Engine set up tips => Topic started by: Tim Wescott on September 08, 2016, 07:55:41 PM

Title: OS 10FP venturi and prop
Post by: Tim Wescott on September 08, 2016, 07:55:41 PM
An OS 10FP has come into my possession.  It has a custom -- and seemingly severely undersized -- venturi, and at 8-4, a severely oversized prop.  The thing doesn't want to stay running; before I do anything else I want to get it set up correctly and see what it'll do.

What's the right size for the venturi on the 10FP?
Title: Re: OS 10FP venturi and prop
Post by: Motorman on September 08, 2016, 09:00:19 PM
I had a stock Cox .049 venturi (.118") on an LA 10 with 7-3 prop. If you have an OS spray bar across the hole the right size (5/32"?) would look tiny. 

MM
Title: Re: OS 10FP venturi and prop
Post by: Akihiro Danjo on September 09, 2016, 01:45:57 AM
Quote from: Tim Wescott on September 08, 2016, 07:55:41 PM
What's the right size for the venturi on the 10FP?

Hi Tim san,
Please read this thread.
Stock venturi is 6.0mm and the stock NVA is (4.0mm stepped down) 3.5mm.
Aki

http://stunthanger.com/smf/open-forum/os-la10-useful-or-not/
Title: Re: OS 10FP venturi and prop
Post by: Tim Wescott on September 09, 2016, 10:03:58 AM
Quote from: Akihiro Danjo on September 09, 2016, 01:45:57 AM
Hi Tim san,
Please read this thread.
Stock venturi is 6.0mm and the stock NVA is (4.0mm stepped down) 3.5mm.
Aki

http://stunthanger.com/smf/open-forum/os-la10-useful-or-not/

Thank you Aki san.  That is exactly what I needed -- I have metal and plastic, I have a lathe, I have enough skill to make a venturi.  I just didn't have a clue of what sized hole I needed to make!!

This should get me on the road.
Title: Re: OS 10FP venturi and prop
Post by: Mark Scarborough on September 09, 2016, 10:48:59 AM
Quote from: Tim Wescott on September 09, 2016, 10:03:58 AM
Thank you Aki san.  That is exactly what I needed -- I have metal and plastic, I have a lathe, I have enough skill to make a venturi.  I just didn't have a clue of what sized hole I needed to make!!

This should get me on the road.
sheesh Tim, its easy, make it the proper size,, the size that promotes proper suction, proper mixture, and atomizes the fuel properly,, how hard is that, LOL D>K H^^
Title: Re: OS 10FP venturi and prop
Post by: Tim Wescott on September 09, 2016, 01:46:06 PM
Quote from: Mark Scarborough on September 09, 2016, 10:48:59 AM
sheesh Tim, its easy, make it the proper size,, the size that promotes proper suction, proper mixture, and atomizes the fuel properly,, how hard is that, LOL D>K H^^

Oh thank you Mark.  I'll just look in my drill index for one marked "the right size" and use that.  Why didn't that occur to me before?

(http://vignette1.wikia.nocookie.net/disney/images/5/5a/Who-framed-roger-rabbit-disneyscreencaps.com-7023.jpg/revision/latest/scale-to-width-down/640?cb=20150502032813)
Title: Re: OS 10FP venturi and prop
Post by: Geoff Goodworth on September 09, 2016, 10:53:30 PM
Aki's comments are correct re the spraybar. However, I've run mine using an APC 8 x 4 and it seems like a powerhouse.