First light problems

[CH007]

First of all hello to everyone. I have looked at building a pulse jet for many years but never got round to it. I have finally welded one up. I work in the food industry so all the pipe and fitting are 316 stainless steel dairy fittings and tube.

I fired it up for first time today and it ran but only with airline forcing air through intake and wouldnt self sustain without it. It does keep running without sparkplug but not without forced air.

The combustion chamber is 3" diameter and 6" long with a 3" - 1.5" conical reducer then leading to 1.5" tailpipe. The intake is 1" diameter (third of cc which seems to work well for others) The intake protudes at 45 degrees into combustion chamber about halfway. I also have a 45 degree mitre cut on tube to reduce blast running back up intake.

I think one problem was the tiy fuel line into intake. it's 5mm brake tube so about 2mm inside diameter and I have a feeling this was problem. It only popped and banged on low fuel setting then when i opened vlave it sounded better but still wouldnt run without forced air.

Please see pics and a vid link below for some detail

http://www.youtube.com/watch?v=hQotw-ZYGMw

[Mark]

I like that 316 pipe, the pieces are kind of like Tinkertoys that you can join together. I can tell the testing isn't going to go over well in your neighborhood though. Oh!

[metiz]

Ok couple of things. do not let your intake portrude into the cc, Doesn't work for most engines and is not necessary.
Do not let your intake go into a cone. Just make it a straight pipe with a flare on the end
increase your tailpipe length by about 25/30%
Decrease the length of your cc to about 4.3"
Let your injector float in the centre of the intake so the jet of fuel flows straight back. Don't fix the injector like that, you'll likely need to tweak the distance and if you've got it welded to the intake you're stuffed.

[CH007]

thanks for the replies people

The neighbours are a good bunch and more fascinated by my hobbies than annoyed.

If the engine runs at what sounds like a fairly decent frequency then sure;y it should run with that size cc with the mods to intake you suggest? I will take off cone and just flare end although I will try bigger fuel line before anything.

Cheers

Colin