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Building Tips and technical articles. => 1/2 A building. => Topic started by: Larry Renger on August 12, 2012, 08:33:39 PM

Title: It seemed a good idea at the time ...
Post by: Larry Renger on August 12, 2012, 08:33:39 PM

Here are photos of some of my diesel engines!  I also have all the PAW diesels .15 and smaller.  Plus Cox conversions and a couple of Cub .049s.

First photo is the British contingent, an AM 2.5, Frog .049 (I think the size is right), and Albon Bambi .009.

Second photo is American:  Cox Conquest .15 with Davis Conversion and my own custom venturi, Cub .074 and McCoy .049

Third photo is the teeney weeny, unavailabilium set:  Valentine .006, Cox .020 with Davis Crank and head, Arne Hende .036 Drone replica and Arne Hende .036 Dooling replica.

That Conquest is the most powerful .15 diesel I have ever run!  What a beast.    ~^

I haven't been able to get the Drone running, but will give it a shot soon with Aerodyne "small engine" fuel.  I haven't tried out the Dooling or Valentine.

I scored the Frog on Saturday for $25.  Great compression!  Should be a runner.  #^

Title: Re: It seemed a good idea at the time ...
Post by: George on August 13, 2012, 10:45:12 AM

Larry,
Did you get that Bambi .009 running? I seem to remember that you were making some alterations to improve it.

George

Title: Re: It seemed a good idea at the time ...
Post by: Larry Renger on August 13, 2012, 10:49:52 AM

Yes, it now runs just fine.  The drive washer was rubbing on the case, I turned the case down about .005, and end of problem.

Title: Re: It seemed a good idea at the time ...
Post by: Andrew Tinsley on August 19, 2012, 11:03:47 AM

Hi Larry,
 The Frog description of your little diesel is a Frog 80. A Frog 0.49 is a glow version, using the same crankcase, but different cylinder. You got a good deal at $25, hope it runs well!

Regards,

Andrew.

Title: Re: It seemed a good idea at the time ...
Post by: Larry Renger on August 19, 2012, 09:55:39 PM

I got 9000 rpm on a 7x4 prop with "iffy" fuel.  I probably will try a 6x5, with a lot less blade area next.  And good Aerodyne small engine diesel fuel.  I just wanted to see if it had any "juice" left.  It is a bit worn, but with an electric starter, will kick right off.  I do need to add a brass bushing behind the drive washer if an electric starter is going to be in its future.

I am considering putting this, the Cub .049 diesel or Cub .074 diesel on my Baby Clown.  The B Clown is currently having some finish touch-up, so an engine switch at the same time would be reasonable.

Title: Re: It seemed a good idea at the time ...
Post by: Jim Thomerson on August 20, 2012, 02:54:37 PM

I have an AM 25 flying at the moment, on a Taipan 9 x 4 prop, and am well pleased with it.  I've been using a starter and need to get a washer as you describe.  The virtue of using a starter is that it will start with some partial choking, at the running compression and needle settings.

Title: Re: It seemed a good idea at the time ...
Post by: Andrew Tinsley on August 20, 2012, 03:58:19 PM

Hello Larry,
  Just looked up some details on the Frog 80 on Ron Chernich's website. Seems there were 3 marks of the Frog 80. The Mk1 is fitted with an o ring contrapiston. The later ones are normal contrapistons. Seem that my 80 is one with the o ring and I never noticed the difference in handling. There was one word of warning. The head is held on with two bolts. The torque settings need to be maintained, as it is VERY easy to distort the cylinder. Do NOT remove the head unless it is absolutely necessary. Glad I read that, as I had no idea it was so critical on this engine.

Regards,

Andrew.

Title: Re: It seemed a good idea at the time ...
Post by: Tim Wescott on August 20, 2012, 04:10:33 PM

You need to build a plane for the Albon.  I'll post the plans if anyone's interested.