homemade jet bathtub that was powered by a BBQ propane tank

[55dcyinely]

Second Generation, Master Blaster 2. The second annual Ely Nevada Cave Lake Bathtub Race on Saturday June 25th 2011. Only 84 days left.
This is a preview of my entry for this year’s race. A twin Lockwood pulse jet engine. The prototype worked so I built the full scale
Lockwood pulse jet, two 4" intake and two 5-1/2" exhaust ports. Haven't tested it. But it should be loud enough. The propane tanks on last year’s model scared the
local Sheriff’s department and the fish and game officers to death! The Capitan of the Sheriff's department was quoted as saying "it is an accident waiting to happen there are going to engine parts spread over the entire lake!" So I'm running high octane gasoline. Which means extra weight of a battery and a fuel pump.
I hope to have some competition this year!

Mike, have you started on that PUTT-PUTT?
Viv, Jutte, what's your entries going to be?
See ya'll there.
Oh and Metiz, is this one big enough?

[Viv]

Hi Doug

That's a monster your building there what did the prototype run like? any pics, are your clamps holding the exhaust pipes able to slide due to heat expansion?

Oh and ordinary pump gas will be fine no need or high octane any thing on a pulse jet

Viv

[55dcyinely]

Hi Viv,
I didn't take any pitchers of the prototype. It ran good but when I gave it full throttle it acted like a flooded auto engine. The fellow that helped build the prototype bought it from me.
And even used it to thaw out one of the Copper minings earth movers this last winter. He said it used about 14 gallons of propane.
Yes, the engine mounts will allow for movement. I really don't expect it to move any faster than last years model.

Basically pulsejets are not much good with displacement hulls but if you could get a decent hull up on the plane they'd be great. by Bruce Simpson

And I think I'll hand out free hearing protection too.

[Jutte]

Whoa ...yeah...they'll be hard out trying to find all those
engine parts from a valveless engine....

[55dcyinely]

Hey Jutte,
I tried to explain what a Pulse Jet Engine is. But, the Sheriff is the LAW and if he says it dangerous! well thats the end of discussion.
Most of the people really thought it was cool. Even if it only went 4 knots an hour. After all that the event planning committee
invited me back this year. Should be some real fun, Bathtubs and Beer! Of course the Fish and Game won't let anyone participate
if you've been drinking before the race.

[55dcyinely]

Viv,
I was really just pulling your leg when I said:

even used it to thaw out one of the Copper minings earth movers this last winter. He said it used about 14 gallons of propane

We were talking about your YouTube video (PHS burner fitted with acoustic decoupler) but never pursued that avenue.
Thanks again

[55dcyinely]

Hi Doug

That's a monster your building there what did the prototype run like? any pics, are your clamps holding the exhaust pipes able to slide due to heat expansion?

Oh and ordinary pump gas will be fine no need or high octane any thing on a pulse jet

Viv

I read somewhere high octane gasoline made a real difference.
I forgot to mention where my inspiration for this project came from.

file_61_2849.jpg (20.75 KiB) Viewed 798 times

Mike Build Log
http://www.pulse-jets.com/phpbb3/viewtopic.php?f=3&t=4595&st=0&sk=t&sd=a&start=195
As the project gets closer to completion I'll post more up dates. Maybe.

[Mike Everman]

Wow, Doug, that's an amazing piece of work!
I'd love to build up the putt-putt-for-my-butt, but life is a bit hectic. I'm seriously considering coming out for that in any case. I've got it on the calendar, and another time a month before to say "it's in a month, dummy, shit or get off the pot!"

[Viv]

Hi Doug

I think I would still go with plain old pump gas if I could, do you recall were you came across the high octane making a difference and the circumstances it was run under? we do know that ethanol mix's tend to mess with pump seals and probably alters the performance, downwards or upwards? no idea

Viv

[55dcyinely]

Hi Doug

I think I would still go with plain old pump gas if I could, do you recall were you came across the high octane making a difference and the circumstances it was run under? we do know that ethanol mix's tend to mess with pump seals and probably alters the performance, downwards or upwards? no idea

Viv

Viv,
I've looked for the article saying high octane gasoline was better. Maybe better for a (pulse detonation engines) RE: VS talks about high octane fuel. Comment: by PyroJoe
And now that I look back even the beck tech said methanol is a better fuel than gasoline. I have a bunch of methanol 97% would that be better?
Maybe that is why the prototype acted like it was flooding out? I've always used propane, but the State of Nevada, Fish and Game want emergence cut off switches
on all motorized boats this year. I did buy a MSD electrical fuel pump, seemed to work fine.

[Viv]

Hi Doug

I have played with the other fuels but its another story I wont share here for obvious reasons I am surprised in way they want liquid fuels for safety reasons as at least gas wont form an oil slick oh well... just make sure all the lines are good and tight and cant spring a leak under pressure, that would not be fun with you in the tub with it, I assume you will have a fire extinguisher on the boat with you?

Just for clarity did the prototype flood on propane or petrol?

Viv

[55dcyinely]

Hello Mike,
I was talking to an Ed Dempsey, out in your neck of the woods. I needed some help on an old military 3 phase 4 wire 400 HZ aircraft motor.
At first I had no idea who he was, and later embarrassed. He holds the worlds fastest electric car record. At the Bonneville salt flats! 110 miles
from my home. Here's one of his web sites; http://www.dwra.net/founder.htm
Seems he knows of work. He's really smart and all round nice guy.

Viv,
It was gasoline, that seemed to make act like weird.

Thanks Fellows

[tufty]

Given that you'll be running on water, it seems to me that water injection might well give you a handy boost.

[55dcyinely]

Given that you'll be running on water, it seems to me that water injection might well give you a handy boost.

Hi tufty,
Funny you mention that but I’ve already set up another pump from a RV camper specifically for pumping water.
Personally, I don’t see any advantage in trying to run on water. But you, mentioning water injection most defiantly over the plastic fiber pontoons will keep them from melting.

[tufty]

Put succinctly, water injection = extra massflow = extra thrust.

Eric Beck is the man for chapter and verse on it. Here's some good stuff Mark found - viewtopic.php?f=2&t=4628&st=0&sk=t&sd=a&hilit=water+injection#p54152

Oh, and augmentors.