SPACE BUG Jr. (gosh) TEST RUN

Jason_WI wrote:I think that's a Spacebug Jr.

it is a space bug jr and i think you have a rare on with the white tank assembly ps the yellow ones are the most common .dose it have a pre 55 head on it ? or is it a later nomal style thred

thanks
Greg

cox24711 wrote:

Jason_WI wrote:I think that's a Spacebug Jr.

it is a space bug jr and i think you have a rare on with the white tank assembly  ps the yellow ones are the most common .dose it have a pre 55 head on it ? or is it a later nomal style thred

thanks
Greg

Please tell me about both heads on these things????? Pics perhaps?????

How do you tell in pics just what it what? I've been keen to buy one for years as I have plenty of .049 reed heads and .049/.051 Tee Dee heads, and I would hate to purchase an early one with a blown head or blow the head myself using it.

#302 Pre 1955 Standard Head - Hemispherical shape - Low Compression - Smaller dia. threads - used on Space Bug, Thermal Hopper, Space Bug Jnr and Strato Bug Only.[24]

#302-1 Post 1955 Standard Head - Hemispherical shape - Low Compression - Larger dia. threads - used on all engines produced post 1955 until the #325 head was produced in 1979.[25]

#325 Standard Head - Hemispherical shape - Low Compression - Larger dia. threads - used on all post 1956 engines except Tee Dees, QZ, Killer Bees, Venom and Texaco. Replaced 302-1 head in 1979.
there are several different exterior appearances to standard glow heads, all noting a slightly different internal shape, compression and glow coil heat. [26]

#1702 Hi Compression Head - Trumpet shaped - High Compression - knurled top - 4 fins on early, 3 fins on later (fastest), 2 fins on most recent - used on Tee Dees, Killer Bees, QZ and Venom. differences range from 4 fin heads being high compression dome shaped to high compression trumpet shaped. [27]

#315 Texaco Head - Hemispherical shape - Low Compression - 5 fins - used on Texaco Engine only. Supposedly allows greater cooling for engine when swinging larger propellers.[28]

gossie wrote:

cox24711 wrote:

Jason_WI wrote:I think that's a Spacebug Jr.

it is a space bug jr and i think you have a rare on with the white tank assembly  ps the yellow ones are the most common .dose it have a pre 55 head on it ? or is it a later nomal style thred

thanks
Greg

Please tell me about both heads on these things?????   Pics perhaps?????

How do you tell in pics just what it what?   I've been keen to buy one for years as I have plenty of .049 reed heads and .049/.051 Tee Dee heads, and I would hate to purchase an early one with a blown head or blow the head myself using it.

if i blew one i would drill 5 mm hole then tap it with the same thread as a glow plug and then done!
just like bernie's but with a pre 55' head

Okay thanks. But let's face it, the old and new heads look the same from the outside as such.

I doubt I would know what head it had if I bought an early engine until I pulled the head to see if a modern type plug would screw into it or not.

gossie wrote:Okay thanks.   But let's face it, the old and new heads look the same from the outside as such.

I doubt I would know what head it had if I bought an early engine until I pulled the head to see if a modern type plug would screw into it or not.

the threads are different so they are not in ter change able the pre 55 on is not in production and are very rare to buy replace ments because the last time they were made was i believe was 67

cox24711 wrote:

gossie wrote:Okay thanks.   But let's face it, the old and new heads look the same from the outside as such.

I doubt I would know what head it had if I bought an early engine until I pulled the head to see if a modern type plug would screw into it or not.

the threads are different so  they are not in ter change able the pre 55 on is not in production and are very rare to buy replace ments because the last time they were made was i believe was 67

And that's exactly why I'm dubious about purchasing one in case it has the impossible to get head in it.

if i blew one i would drill 5 mm hole then tap it with the same thread as a glow plug and then done!
just like bernie's glo head adapter but with a pre 55' head

Are the cylinders interchangeable between Space Bug jr. and the later ones?

That was good info and a reminder about the heads. I'll have to go through my stuff and pick out the good looking 302-1's to mount on my "collectible" engines to keep them looking original.

If you just want a functional head rather than an "authentic" head on an early Cox engine, the OK Cub heads which use a standard plug will fit the pre '55 Cox cylinders. It's sort of like an early Cox head adaptor, only by accident. I can't vouch for how they run, but the thread dimensions are apparently the same and I think we established over on 049 Collectors group that the they will physically fit. So if you want to run one of these engines for interest's sake but don't want to risk you original working head, Cub heads are easy to come by.

Rod.

Good info Greg you have done your home work ,, I don't know if that one is the smaller thread or not , I couldn't get it off when cleaning up the cyl. came off and that was good enough as to not muff it up ! cleaned this engine in denatured alcohol for about a month then tooth brushed and Q tips work well,, the reed removal is a little tricky and have to bee carful with the retainer,  I have some extras and keep the amps down to not worry about the running , Greg I think the BLUE one is the more rare one it sure cost more there was a collector I beat out for it for a big penny    I want to run one of my Space Bus next soon as I get the stand set up . Eric

You can tell the old cyl. (and head) from the newer by looking at the profile. Also the old head seals (gasket) at the top of the cyl. and the newer at the bottom of the head.
Photos from .049 Collectors Group
older



newer

The first Space Bug Jr. was the white nylon plastic version, quickly followed by yellow, red and blue, i don't think any one is more rare than another. The white version came with a prop nut and later the tapered acorn style prop nut, supposedly designed to used your fingers to stop reverse runs. The neat thing about the SBJ is the smaller thin exhaust ports, designed for easy starts, they had the ability to swing a very large prop, one magazine back in the day had RPM results (unusable, but cool) with a 10x6", i alway thought it would be cool to video a SBJ swinging a 11x3 prop!

Thanks Crank , I new there was a way to tell but had forgotten Mark that would be cool to see for sure and it is very easy to start , I like that since my time and patience's is slim now a day . I have seen these on prop rods was that original ? Eric

yep, that's where the blue tank version was mostly used for.

crankbndr wrote:You can tell the old cyl. (and head) from the newer by looking at the profile. Also the old head seals (gasket) at the top of the cyl. and the newer at the bottom of the head.
Photos from .049 Collectors Group
older



newer

My SB jr (White Tank) has a strange head, It's the newer large diameter 302-1 but still has the little fin on top at the electrode apparently it's pretty rare. Here's a pic. (Bandit)

I ran one a year or two ago on a 10x6. The video is sideways, but you get the idea.

www.coxengineforum.com/t4227-space-bug-jr-10x6?highlight=space+bug+jr+10%C3%976

Ron

Ron did you have that flash light on so your tach would read under florescent lighting ? Cool run yea not good for the ball socket You cant tighten up

getback wrote: ... Cool run yea not good for the ball socket You cant tighten up  

Yup! Some don't reset so well.

George

Nice one George!

Yeah, I pulled out the 3 piece piston in favor of a newer one for this experiment.

Eric, my shop has flourescent lighting so yes, that's why I was using a flashlight.

cox24711 wrote:if i blew one i would drill 5 mm hole then tap it with the same thread as a glow plug and then done!
just like bernie's glo head adapter but with a pre 55' head

Is there an original thread to this, if not how does this work on a modern head?

What do you consider modern if you mean standard yes with the right cly./pis. to fit , in 1955 they changed over to the standard size threads , this was my thread just talking about how much I enjoyed running one of space bug jr. for the first time Eric

i've all ways wanted one of those pre babe bee 049 engines they are so beautiful and elegant i've:cox engine: always wanted a space bug they are soo cool