RE: Cox "Thermal Hopper" glow heads

I bought a Spacehopper back in '61. Gave it to a friend for many years and recently got it back. Took it apart and looked at it. The piston is two piece, like many of the early 1/2A pistons and pretty loose. I replaced it with a modern Cox piston and put on a TD high compression head. Runs very well. So I think that was the original piston and cylinder on it and a modern Cox head will fit. Designman says a TD piston and cylinder will fit a Spacehopper.

Hope this helps.

>PS: although it is FF, the "Half Alpha" from MAN in '59 also
>shows the Thermal Hopper with the cage mount.

I'm thinking Ron St. Jean's Ramrod 250 may have also but it may have been tubing standoffs rather than the cage.

I got a set of Bluetail Fly plans a few years ago from John Pond. I used an Atwood (the other engine option on the plans).
The BF is from MAN 5610 and is shown on page 37 of the "Classic Era Construction Drawings" from PAMPA. The construction article is printed on the John Pond plans.
If you are serious about building one I'll try to locate my plans.

I guess I didn't write clearly enough.

I agree that increasing the compression won't make a conversion head work right; loss of performance is the result of other factors. In fact that is exactly the point I was trying to make. Thanks for clearing it up.

Jake,

Burnis Ray of Parts is Parts still has the old #302 heads for $8.00

Question: Was the Space Hopper released at the same time as the Olympic and Sportsman .15's? I seem to remember it being released later.
I was interested in .15's at the time and had the Olympic. Never had the Sportsman nor the Space Hopper.

Just remembered something.

If you are in a pinch for a Cox .15 glo-head you can use one of these:

Fox .09
Fox .10
Hustler .10
Gilbert .11

There are variations in combustion chamber shape but they do fit.