The Stovebolt Site Forums The Shop Area Engine Shop The Gunson Colortune plug...

I'm curious...has anyone here bought one of these recently and tried it? I mean the ones being sold today...not the ones from the 50s, 60s, 70s. Reactions? Thoughts? Anything? If so, can you tell me if the box showed where it was made? The country, I mean. Not the location of the distributor.

If you find this plug interesting, you might also want to read about what this guy did. Pretty clever and it cost him a lot less:

https://www.theflyingbanana.com/tfbtechtips.htm

Jon,

Thank you for sharing this with us. I have seen these plugs used on a couple of car restoration shows. I thought they looked interesting. I wonder if any of the guys in this site have had any experience with them? Would be curious to hear what they have to say about them. The whole link that you attached to your post has some good information. The alternative material "Tygon" used instead of rubber fuel lines, for modern fuel with ethanol in it. That is a good tip. We just have ethanol free gas available to us, here in Arizona. Well, unless you want to drive a 150 miles to a very rural area, that happens to carry it.

By the way, the very first one that I looked at on ebay, says it is manufactured in " The United Kingdom" ships from the USA. So it probably leaks oil. That's why the English don't make computers. Because they haven't been able to figure out a way to make them leak oil. Just sayin.

Thanks again,
Rugo

Those things are interesting gimmicks- - - - - -I'm sure P.T. Barnum would have been selling them a century ago if he had the chance. The problem is that interpreting combustion flame front color is a very subjective thing at best, and there are far too many variables involved to make such things a reliable way of evaluating fuel mixtures. I had a single cylinder "glass engine" in my classroom for several years. The cylinder was made of tempered glass and the piston rings were made of leather to prevent scratching the glass. A plastic shield surrounded the cylinder, and compressed air was blown into the shield to cool the cylinder. With a delay-flash timing light, I could "freeze" the piston at whatever height in the cylinder I wanted and we could watch the color of the flame front as the fuel burned. A very rich mixture had a yellow color, and as the mixture was leaned out the color went from yellow to orange, to light blue, to a deep "Prussian Blue" just before the mixture got too lean to burn. It was an interesting way to teach air/fuel mixtures, but totally impractical as a way to actually tune an engine. We ran that thing on all sorts of fuel- - - -gasoline, alcohol, Propane, lighter fluid, Mineral Spirits, Lacquer thinner, even a mix of gasoline and Diesel. It didn't have enough compression to run on straight Diesel, even with a spark plug trying to light it. I usually ran it on alcohol or Propane- - - - other fuels had a tendency to soot up the cylinder and it was a pan in the posteriori to disassemble it and clean the glass.

Just my opinion- - - - -based on close to 30 years' time using that engine as a teaching aid! Now, pretty soon somebody who's the president of his own fan club will come along and assure everybody I'm spreading a load of fertilizer!
Jerry

Jerry,

I was hoping you would weigh with your experience and knowledge. I wondered how you could accurately interpret the colors of the flame accurately. Certainly glad that we have guys that have the practical experience, that are willing to share that experience with us. Saves a lot of us a lot of time, effort and money.

Thanks,
Rugo

I remember the same or similar glass cylinder engine in shop class in high school, it was fun.
Wonder if a clear spark plug only shows you a little bit of one color, not necessarily the color of everything going on in the cylinder?

Here's a you tube video of one in operation:



Jerry

That is a really good video, showing exactly what is going on.

Rugo

Back in the 1950's Perfect circle piston ring company had a stovebolt six in their training facility with a quartz insert in a cylinder. It was possible to watch that one on a dyno when under load. With a timing light pointed at the window, it was possible to see the piston rings slowly rotate around the piston. So much for the idea that ring gaps MUST be spaced out at specific intervals when an engine is assembled! The gaps might line up occasionally, but not long enough to make any difference in the real world!
Jerry

Jerry,

"With a timing light pointed at the window, it was possible to see the piston rings slowly rotate around the piston. "

If you can set that up demonstration at a Stovebolt reunion/gathering, I will make an effort to attend.

Thanks,

Tim, the Homecoming is worthy of your attendance even without a novelty engine display.

That would take a lot more technical ability than I can manage- - - - -Just doing the machine work to put that window into a cylinder takes some very sophisticated machining, and clear quartz doesn't exactly grow on trees! The MD-1 star tracker navigation system we used on B-52's had a polished quartz dome about 4 inches in diameter that was mounted at the top of the wing root, and that one piece of electronic gear in the system cost a bit over $10,000.00.

I am hoping to have a trailer-mounted run stand complete with a bellhousing dyno up and running sometime soon. That probably won't happen this year, however- - - -too many other pots on the stovetop already!
Jerry