Scrapheap teaser

Bruce · Post by **Bruce** » Fri Nov 14, 2003 7:49 am

For those who haven't or can't see the Scrapheap Challenge Jet-cars episode, I've put a *very* short clip on the web at:

http://www.interestingprojects.com/shcbits01.mpg (18 seconds/1.5MB)

See what happens when you expose otherwise composed TV presenters to the noise of a pulsejet :-)

Post by **Mike Everman** » Fri Nov 14, 2003 3:26 pm

Very cool, Bruce! What led you to doing that show?

Bruce · Post by **Bruce** » Fri Nov 14, 2003 10:47 pm

A group of us had been lobbying the show's producers to do a jet-engine challenge for quite some time and eventually they caved in to the pressure ;-)

They tried the jet-racer concept out on Junkyard Wars first where a turbo-charger turbine was pitted against a thermojet. Details fo the prototype thermojet design used can be found here:

http://www.gas-turbines.com/thermojet/thermojet.htm

The thermojet won -- but mainly because it had a *huge* V8 engine driving the fan, not because the injected fuel contributed to the thrust -- but it looked good they tell me ;-)

Apparently that episode was very popular and well-received so they decided to do a Scrapheap version.

Given the historical connections between pulsejets and Britain, they finally accepted that a pulsejet-powered vehicle would be risky but worthwhile.

They contacted me (mainly because of my web presence I guess) and asked if I'd be prepared to help. After a bout a microsecond of considered thought I said "ummm, oh, well, I guess, if I have to" :-)

The rest is history as they say.

Graham C. Williams · Post by **Graham C. Williams** » Sun Nov 16, 2003 11:46 pm

Dear Bruce.
What was all that flame doing coming out if the exhaust? Bit of excess fuel?
I can only guess it's something the producer insisted on to make the run a bit more dramatic.
Graham.

Stephen H · Post by **Stephen H** » Mon Nov 17, 2003 2:22 am

thats one cool facial expression :-0.. haha... that kart seemed to go reasonibly good speed, do you know how fast?

Stephen

Bruce · Post by **Bruce** » Mon Nov 17, 2003 4:06 am

[quote="Graham C. Williams"]Dear Bruce.
What was all that flame doing coming out if the exhaust? Bit of excess fuel?
I can only guess it's something the producer insisted on to make the run a bit more dramatic.
Graham.[/quote]

I just did a bit of a Hollywood for the cameras (it was a TV program after all ;-).

As I crossed the finish line I shut down the engine then opened up the fuel valve again to produce the big "tail of fire" -- I knew they'd love that bit :-)

Bruce · Post by **Bruce** » Mon Nov 17, 2003 4:09 am

[quote="Stephen H"]thats one cool facial expression :-0.. haha... that kart seemed to go reasonibly good speed, do you know how fast?

Stephen[/quote]

We were doing about 45mph according to the guy driving the camera-car in the next lane. That's not bad considering the engine was built in just 10 hours and, although it looked light, the frame was from thick-wall stainless steel RHS.

The other thing that was working against us (and even more against the other team) was that the drag strip was incredibly "sticky". It was actually about 32 degrees that day and all the tar was melting. That had a real adverse effect on how easily the vehicles rolled along.

You've got to be careful of those "dangerous pulsejet engines" though eh? :-)

Post by **Mike Everman** » Thu Nov 20, 2003 5:45 pm

Bruce, there's a "Junkyard Wars" this coming wed. in the States on Jet Cars; is this the same show with a different name?

Bruce · Post by **Bruce** » Thu Nov 20, 2003 10:37 pm

Yeah, it's rebranded for the US market.

I think it screens on Wednesday and Sunday of next week (from memory).