Visible Combustion Inside a Running Engine in Super Slow Motion

Ever wish you could see inside a real, running engine and witness the magic of internal combustion with your own eyes? Thanks to the wizards at Warped Perception, here’s our opportunity. Watch this. 



As we never get tired of saying here at Mac’s Motor City Garage, we love good, no-nonsense technical material, and we share it whenever we can. Courtesy of the clever people at Warped Perception, here’s a look inside a four-stoke engine while it’s in operation—and it’s a rare and revealing glimpse indeed. The video was captured at the ultra-high speed of 4,000 frames per second (for super-slow motion) and in extremely high 4K image resolution. The view doesn’t get any better than this.

Visible combustion isn’t at all new to engine research, but usually it requires a bazillion-dollar budget and a lab full of high-tech equipment. Here, they got the job done with a very basic Briggs & Stratton L-head industrial engine with a specially fabricated transparent cylinder head. The camera gear is fairly advanced, though. The entire four-stroke operating cycle—intake, compression, power, exhaust—is visible with crystal clarity, and the combustion event as well, from the start of the flame front to the finish. Just for fun, several different fuels were tried, including gasoline, isopropyl alcohol, and an alcohol-acetylene blend. Watch this and see if your view of the four-stroke combustion process doesn’t become a lot more clear in your mind. Video below.


5 thoughts on “Visible Combustion Inside a Running Engine in Super Slow Motion

  1. Very good video! I had one I used to play for my students when I taught course in diesel upgrading at the local college. It showed the injection nozzle tip from the piston. You could see the spray begin, then combustion. It was fascinating. I also recall a film put on by Shell. It took a small four cylinder motor and they had cameras placed throughout, showing the crankshaft, con-rods, timing gears and valve train in motion while it was in normal use. I’ve tried to find that film on YouTube but I’m either looking in the wrong place or it has been discarded. Thanks for posting this….

  2. Love the visualization. Quick question from an engine noob: I see the plug sparking on the in-between stroke – do they usually do this? Maybe in an attempt to clean up any unburnt fuel?

  3. It’s called waste-spark ignition. Simply allows more simple construction of the ignition system as timing need not distinguish between compression and exhaust strokes. Also, magneto (if equipped) can then be driven off crank instead of cam, more robust construction.

  4. Neat! The alcohol washed everything clean, probably even the oil from the cylinder walls. I guess that’s one reason we’re stuck with it in our gas now, it keeps the carbon from clogging the cylinder, at the cost of the increased water it brings in and corrosion it causes.
    I noticed the cracks starting to form over the intake valve, I was expecting the head to blow apart before it was over.

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