stunthanger.com

Engine basics => Engine set up tips => Topic started by: Glen Wearden on January 09, 2007, 01:31:18 PM

Title: Fox 35 and muffler pressure
Post by: Glen Wearden on January 09, 2007, 01:31:18 PM
I have always thought that the Fox 35 does not like muffler pressure; that they like standard vent tanks.  That idea may be changing........I had Lew Woolard fix up an old 40th Anniversary engine with his normal rework and added one of those blue heads with the offset plug.  I haven't really flown it, but I put it on a profile Smoothie, and have run it in the backyard.  I'm using a GRW 4oz. uniflow with muffler pressure.  The first run was sort of wierd because I hadn't hooked the pressure line back on the muffler, and hadn't blocked the overflow -- duh!  The second run, with the plumbing hooked up right, was great.  I set the needle for a kind of fast 4, with the engine trying to break into 2 every couple of seconds.  When the nose went up, it kicked into a nice 2, but smoothly, not harshly.  It maintained the 2 until the nose came level and then smoothly went to 4.  Seems to run the same way inverted.  I may have to readjust after flying it, when centrifugal force comes into play.  We'll see.  Anyhoo....this particular Foxy 35 seems to like pressure...........Glen
Title: Re: Fox 35 and muffler pressure
Post by: L0U CRANE on January 17, 2007, 05:34:21 PM
Glen,

Glad to hear you have a good running setup!

Part of it could also be  having a Master 'lay hands' on it. Lew does good work, even if he spells our name wrong...

Title: Re: Fox 35 and muffler pressure
Post by: Glen Wearden on January 17, 2007, 11:14:47 PM
Hi, Lou.  You're right; Lew does great work.  I also had him rework a Fox 40, the one with the square venturi housing.  It runs great on the ground.  Hope I can get both in the air when the ice storm goes away.   Glen
Title: Re: Fox 35 and muffler pressure
Post by: Glen Wearden on February 21, 2007, 02:42:39 PM
Finally got to fly the "Woolardized" Fox 35 with muffler pressure, today.  Worked great; launched at a steady 4 cycle, and it went smoothly into 2 in maneuvers; plenty of power to pull the plane over the top in wingovers; no burp on the outsides; ran the same inverted as right side up; didn't go lean until right at the end of the run.  Very nice.  Now, I need to get the plane to fly as good as the engine runs.    Glen
Title: re
Post by: HelenJames on September 25, 2010, 12:17:52 AM
Something alike was discussed on the ask.com,i can give someone a link if anybody need it
Title: Re: Fox 35 and muffler pressure
Post by: Jim Thomerson on September 27, 2010, 01:37:56 PM
Somewhere on the forum is a picture of my Fox 35 with world's smallest and least effective muffler.  I'll post andother picture when I get home.  Basically a piece of tin over part of the exhaust with a pressure tap.   Runs fine!
Title: Re: Fox 35 and muffler pressure
Post by: Kim Mortimore on September 27, 2010, 06:14:14 PM
Something alike was discussed on the ask.com,i can give someone a link if anybody need it

Hi Helen,
I would like to see the ask.com discussion.  Can you post the link here, or do you prefer email?

Thanks,