Scaled Lockwood Build

[InventorZeke]

Hi all, I'm still fairly new to the forums yet a long time pulsejet enthusiast, and attempting my first build. I pretty much scaled a Lockwood Hiller Design I found online in half and made the intake 100mm longer. Does this look like it would operate as designed?

[InventorZeke]

Anyone? Any advice is greatly appreciated before I invest in having parts made.

[metiz]

As a general rule, don't scale engines, it usually doesn't work as expected. The lockwood design can probably be scaled like this and it will probably run but don't expect 50% thrust, more like 20
If you want a 25 pound engine, why not try the M20

[InventorZeke]

[metiz], Thanks for your reply and nice to make your acquaintance; I have looked through your impressive current M500 build with a fascinated regard for your work.

About the M2O, I don't have a great answer for that; I guess I've never been quite as fond of the 'focused wave style' or 'forced anti-node thermo-jets' as I believe they are classified, as the Lockwood-Hiller.

What you say about scaling makes sense to me also; decreasing all measurements by a factor of (1/2) will affect the volume function by much greater amount. That's ok though; 20lbs of thrust would be fine by me!

[InventorZeke]

Also, the 50mm primary intake diameter is of some importance to me; which is why I scaled the design I found with originally 100mm intake.

[metiz]

when I say "20" I mean percent, not pounds, so probably closer to 10 pounds. You can use Pyrojoe's recipe for beginners to design an engine to whatever thrust specifications you want; you can even design it to use your materials on hand

[RC Man]

As a Newbee here, (ME) I would say Pyros stuff is pretty accurate, I built one to specs, and it rumbled on a almost empty bottle,
Than tried it on butane, was better, rumble was louder, but to little pressure on the tank.
No start, but I was pleased with what I accomplished, For a beginner on Pulse Jets.

Ive made Harleys with 80ci. motors to 120 hp. on gas, but these PJ Motors are something else, blowback on the intake, Hmm, exh. to small, or is the CC to small?

I would go by PyroJoes specs first, till ya know what different stuff effects these motors, First, Fire one up, than think, why it ran.
These things dont have any Real CC on them like a normal motor, they kinda just use the backpressure to combust the mixture in the chamber, and they run.

Goin to get a Beer now, so Ill be back later.

Frank

PS. How many of us PJ people are in here anyway, anymore ?