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Building Tips and technical articles. => Building techniques => Topic started by: Bill Adair on March 17, 2009, 04:20:38 PM

Title: Tank size for McCoy 35 Red Head
Post by: Bill Adair on March 17, 2009, 04:20:38 PM

Running a new McCoy 35 RH engine, on a Sig Skyray 35. The small (2 oz) clunk tank that came with it can't be plumbed for  stunt, because of the fixed vents and pickup.

The Skyray also has non-standard two wheel landing gear that intrudes into the tank space slightly, limiting the tank length to 3.5", and that would be with tubes that are located top and bottom so they do not protrude forward of the front of the tank.

Anyone know what size tank would be appropriate for this old engine?

I'm running Fox (Duke's) fuel that originally had 10 percent nitro, and 20 percent Castor oil, with added Castor to bring it up to 28 percent pure Castor. The engine has a great 4-2 break, but cuts out inverted with the current tank, as Jeff C. found out when he flew it for me.  ~^

Jeff made a great recovery, and the engine caught again as soon as it was upright!  H^^

Brodak makes "wide wedge uniflow" tanks that look like they will fit, but I don't know what capacity to order?

Any help appreciated.

Bill

Title: Re: Tank size for McCoy 35 Red Head
Post by: Bob Furr on March 18, 2009, 11:48:45 AM

Bill,
If you are wanting to fly the full pattern you will need about 4 ounces of fuel.   I like chicken hopper tanks on skyrays but the wide brodak tank will probably work fine.   Chicken hopper tanks are hard to locate and tend to be a bit expensive.
Bob Furr

Title: Re: Tank size for McCoy 35 Red Head
Post by: Bill Adair on March 18, 2009, 06:21:12 PM

Bob,

Thanks for the tank info.  H^^

I was thinking a 3 oz tank would work, but have a new 4 oz GRW tank that looks like it will fit.

Bill

Title: Re: Tank size for McCoy 35 Red Head
Post by: Scott B. Riese on March 19, 2009, 09:33:11 PM

We could make you one!  y1