stunthanger.com
Building Tips and technical articles. => 1/2 A building. => Topic started by: Mark Mc on March 11, 2023, 06:06:51 PM
-
I found this while doing more unpacking and sorting. I think I got this in the same box that my Testors P-39 and Cox .15 Comanche were in, but I can’t say for sure. What I can say for sure is that this is a crime. Apparently, back in the days of the Space Bug (’52-’58), people who didn’t want to buy a Thermal Hopper would butcher their Space Bug to use an external tank.
(https://i.postimg.cc/sgV8qgg2/20230311-183156.jpg) (https://postimg.cc/nCP0QZ78)
Hopefully, the norm was to do a better job than this. I guess I’ll have to do some work with some jeweler’s files to see if I can correct this hack job and make it presentable.
Mark
-
I've never taken a close look at one of these engines....but I have seen the "necked down" cylinder somewhere before..maybe as a carry over to the next generation...?
Did the Space Bug / Thermal Hopper perform as well as the Baby Bee or Black Widow...?
I'm guilty of drilling into the side of a few Baby Bee tanks to run a line back to a 2 oz tank...... H^^
-
Chuck,
From what I've read in old articles, the Spacebug has a little more performance than a Black Widow. There was a racing carb and head that you could buy that would add about a 5-10% speed increase, depending on prop used. I assume the head was just a high compression head like you would use on a later TeeDee. Not sure how a different carb would work, other than just screwing a larger inlet to the venturi tube.
These stepped cylinders are the early style. I'm not sure exactly when Cox went away from them, but I like them. Interestingly, since this is an early engine, the glow head of the later engines will not work on a Spacebug. The bottom of the glow head is narrower than the later glow plugs. Hopefully this glow head is good, as I only have one spare head with the narrower bottom.
This is an abomination in my mind. Drilling holes in a Babe Bee tank is alright. It only takes a couple of minutes to replace the drilled out tank with a new/used one, and old Babe Bee tanks are everywhere since people often swapped them out for the 8cc tanks.
Mark
-
Chuck,
From what I've read in old articles, the Spacebug has a little more performance than a Black Widow. There was a racing carb and head that you could buy that would add about a 5-10% speed increase, depending on prop used. I assume the head was just a high compression head like you would use on a later TeeDee. Not sure how a different carb would work, other than just screwing a larger inlet to the venturi tube.
These stepped cylinders are the early style. I'm not sure exactly when Cox went away from them, but I like them. Interestingly, since this is an early engine, the glow head of the later engines will not work on a Spacebug. The bottom of the glow head is narrower than the later glow plugs. Hopefully this glow head is good, as I only have one spare head with the narrower bottom.
This is an abomination in my mind. Drilling holes in a Babe Bee tank is alright. It only takes a couple of minutes to replace the drilled out tank with a new/used one, and old Babe Bee tanks are everywhere since people often swapped them out for the 8cc tanks.
Mark
Mark..there's one guy I know of who used to take a burned out Cox head and do the mods for a Nelson plug. IIRC the threads are 11/32..but the sketchy part of his work... is that he used the point of a phillips screwdriver to mill the tapered seat. To complicate matters..he is a New Zealander who was living in Japan..so who knows where his screwdriver "milling bit" came from with the perfectly matched seat angle.
He was a regular at the RCU 1/2A forum who went by JAPANMAN..a very talented and resourceful machinist who always seemed to prove that IF THERE IS A WILL...THERE IS A WAY.
At any rate the Nelson plugs were the best value when I bought them from Larry Driskill at his "KITTING IT TOGETHER" web site and every bit as power as original Cox...but it's been many years since I priced Nelson plugs.