Fox .40 BB Rat Race

[Dan McEntee]

   Hello Again Group!
     Again, I'm just posting this in the main forum for general information and to learn the history of the engine.
 
    Along with the Elfin, I was given a new Fox .40 BB Rat Race engine that still has the sticker on the side of the main case. It is set up with what I think I recognize as Bill Johnson modifications for throttle for carrier use. The exhaust is cut and slide blade installed, and flapper on the intake with accompanying linkage to a home made pivot for the throttle push rod to attach to. The pivot is made from tubing and has a TEE at one end that looks like fuel line is supposed to attach to it. I got to meet and talk to Bill Johnson on a few occasions when he came into Mark Twain Hobby where I have worked part time for the last 35 years or so and he showed me several examples of his work. I found out that in the sixties, he used to live quite near the house I grew up in! Well within walking distance for me. If O had known that at the time, I may have become more of a carrier flier as time went by!

    Again, not looking for set ups or anything, just genral information on what I have here. I have several plans and kits for vintage carrier models, and can picture this engine in a profile model or even full fuse model. What class would the .40  fall under, clas 1 or class 2?

  Thanks again and HAPPY THANKSGIVING!
    Dan McEntee

[john e. holliday]

Don't know for sure, but he should still be alive and in the St Louis area.  I have two McCoy Redhead .60's he set up for carrier class II.  One quite a few local contest with them.

[Dave_Trible]

.40s for class I ,  .60s for class II,  profile I believe is limited to .36.  I think you could fly the .40 in class II but it wouldn't be competitive with the .60s for top end.

Dave

[Mike Anderson]

My guess is that this is set up to run crankcase pressure - the pivoting arm with the fuel inlet is most likely a fuel meter to keep from flooding out at low throttle when using a pressurized tank.  It would be legal for Class 1 only, if less than .4029 cu. in.  It would be legal for Class 2 only, if .4029 or greater.  Profiles are limited to .3661 or less and no crankcase pressure.  You could put it on a Profile plane, but could only fly Class 1, and would get no scale points.  It could also be entered in Nostalgia Class 1.

[Bob Heywood]

This engine with the Bill Johnson set-up is ideal for Class I Nostalgia. Not so much for modern Class I.

The attached documents are Bill's write-ups for the theory and set-up of his system.

[Randy Cuberly]

.40s for class I ,  .60s for class II,  profile I believe is limited to .36.  I think you could fly the .40 in class II but it wouldn't be competitive with the .60s for top end.

Dave

The current class II record is held by Burt Brokaw with a Nelson 45.  It's true that you can use up to a 65 in class II but the top guys seem to use Nelson 45's with the tuned muffler. They are awesome!  Class I is pretty much dominated by Nelson 40's with the tuned muffler.  The Profile record is also held by Burt Brokaw with a large case Nelson .36 with tuned muffler.

Randy Cuberly