www.pulse-jets.com

I am attaching some pictures of the Straight Pipe engine.
It is my best running unit and most powerful for its diameter.
Also super super loud ! Got to have ear plugs and aviation head set,
it is unbearable.

Second set is of Larry's Lady Ann.
It gave me lot of trouble to set it right. It is very touchy on the fuel
line position. Had to deviate quite a bit from Larry's proposed depth
inside the intake. Finaly I ended up only 12 mm in.
Now it runs like a champ. You can see, it gets very, very hot almost
along the entire length.

That's my story for now !

Ed

I do like the straight pipe, makes things a lot easier and there is a beautiful simplicity about it. If there were someone making a pulsejet calendar, I would want this one included.
Mark

A wrong picture sent.
Here is the latest Straight II.
It runs, but not full power, I have to tweak the intake.

Hi Ed! Been busy, that's great. So, what's inside that straight pipe?

Mike Everman wrote:Hi Ed! Been busy, that's great. So, what's inside that straight pipe?

Hi, Mike ! Good to hear from you !
Trere are some buffles inside that pipe - we all know that something must be there.
It makes the engine lot more rigid and there is very limited heat distortion. Since it is incredibly loud, it is pure fun to play with it.
It looks very promissing.
If you want more info, feel free to ask.

Are you still considering a run to northern Arizona ? We can make lot of noice together.

ed knesl wrote:Second set is of Larry's Lady Ann.
It gave me lot of trouble to set it right. It is very touchy on the fuel
line position. Had to deviate quite a bit from Larry's proposed depth
inside the intake. Finaly I ended up only 12 mm in.
Now it runs like a champ. You can see, it gets very, very hot almost
along the entire length.

Ed -

Nice runs - beautiful shots of her running out, too!

Strange stuff about the fuel spout. Are you using just a straight cut-off end, or something fancier? I had a lot of trouble getting mine going at first - but I was restricting the fuel flow too much (in my case, by running the regulator pressure too low). Once that was fixed, she was running nicely with the spout halfway down the pipe.

I have now also tried my (somewhat defective) .012 inch gap Zilla-Jector, which projects the fuel outward more than downstream. Can't get her to sustain! However, I didn't try any shallow positions, just 50 percent in or more - to no avail. Now that I've heard your experience, I may try that again with it just forward of the intake flare. However, if that works, there SHOULD be a corresponding deep position that's good, too - and less wasteful, of course. I think the success I had with the farther-in positions was probably due to higher downstream velocity. That was with a pretty tight lemniscate end (only 3/16-inch brake line) and I have now opened that up a lot by cutting the two sides back at a more rakish angle, but haven't had a chance to try it out yet. The outlet area is much improved, though - probably twice what I had in the earlier successful runs.

Great stuff, Ed! I think the straight one is really nice. I have always liked that intake style (somewhat akin to my Fo Mi Chin II, Smooth Lady and Sveldt Lady engines). My only "negative" comment would be that the intake seems pretty tight for an engine with such a large main pipe volume. But hey - it runs! Really nice work, sir.

Keep playing with your Lady Anne when you have time. There really should be a fuel position just ahead of the halfway point of the straight intake section that should work.

L Cottrill

Hi, Larry !

I used 3/16" copper tubing with the square cut off, leaving the round
opening. Propane was controled by the tank valve only.
I started about mid way in, than moved depper. It was always cuting
off when air removed. Later I moved the opposite direction and finaly
at 12 mm from the flair it run flawlessly. At this position a got instant
start, also easy throttle back and forth.
I thing there are no two engines totally alike due to fabricating tolerances,
intake flare, e.t.c.. Also I believe that material used makes differencies due to its own heat conductivity based on thickness and type of alloy.
That must affect the air flow thru the engine.
It definitely developed full power, since I went all way to flame out and
it was thundering.

The straight pipe engine has internal buffles, so its volume is not as large as it appears to be. Intake size is based on these baffles restriction areas.
This one is fabulously balanced. It is also very tolerant to the fuel line
position.
Starting procedure is : Open air from 12 V inflator and subsequently
open fuel valve. In the very moment she comes to life and the air gets
disconnected. Adjust the throttle. Any time I tried, always the same.

Again, this is the fine art of tunning all the components and I believe
that it must be done in any of current and future engines

It would be great if we can eventually test our Ladies together and
be able to pinpoint differencies. Next meet would be good.
We have to talk to Mike.

Does your engine also get red hot almost on its entire length ?

Thanks, Ed