help us please

[noneya55]

well i am in an engineering class right now and my instructor picked me and another student to build a pulse jet engine to put on a go kart and it our first one we will ever build can i have some help on what plans i should use and i have access to alot of tools so that is not a problem
thanks

[metiz]

There are about 3 options: 1 the Thunderchine, 2 a lockwood (U-bend) and 3 the M40.

Option 1 is not realy an option. the first revision is incredibly unstable and has VERY tight build tollerences. A lockwood will give you the most thrust (~55lbs) but they're mighty inefficient. The M40 has about 42 pounds of thrust and is a lot more fuel economic, the build is a bit more challenging though.

For a lockwood (U-bend) engine, use these plans: Lockwood

The M40 can be found here

There are more plans out there for U-bend engines but they're not as good as this one. Resist the urge to go for an easy, low cone build

[noneya55]

thanks

[noneya55]

on the lockwood plan what are the tolerances and where do you recommend i put the spark plug and fuel injector?

[metiz]

Asume +2/-1mm for length (per cone/ pipe) and +1-1 for diameters. These engines can take a lot more but try to keep the build within tollerances for best results

[noneya55]

thanks a lot but what about the fuel injector and the spark plug

[metiz]

Put the sparkplug on any part of the cc, not super critical. Often, a fuel rail is used, a simple injector through the intake will also work, but fueling big U-bends is not my cup of tea. Anyone want to join in?

[keith mcconnell]

I've got drawings of the way I did mine. I don't know how to post the link but if you search big lockwood pulse jet or my name I think you can find it. Also I've got some videos on youtube. One of them is a walk around showing how I did everything. If go on youtube search my user name geardaddyart and I think you will find them. If you can't find them let me know and I'll see if I can figure out how to post the link.

Keith

[noneya55]

my instructor wants to know how thick the stainless steel needs to be?

[metiz]

1mm is a good thickness. anything less than that though and you might need to reinforce the cc and tailcone to prevent buckling, especially with normal steel. Are you going to use normal or stainless steel?

[remcolent]

On this plan all dimentions are internal.
for the bend this is 76 mm is it ok to use 80 mm tube thick 2 mm for this and build the rest from 1 mm stainles??

Thanks
REmco

[metiz]

Sure, as long as the internal diameters stay as specified