Other Speed Record Breakers Are Available!

User avatar
Renegadenemo
Posts: 4712
Joined: Mon Dec 01, 2008 12:29 pm
Location: N E England
Contact:

Re: Other Speed Record Breakers Are Available!

Post by Renegadenemo » Sat Sep 29, 2018 6:17 pm

At the very least I'd want two gas generators with a single jetpipe. Imagine the asymmetric thrust if one went out. It would be a better job with a single Viper and a reheat, I reckon. The one we tweaked for the jet car delivered a phenomenal amount of power for its size. Horrid, screechy little engines they are too. Had to learn the fuel system to get the car to deliver its full potential but it didn't half go!
I'm only a plumber from Cannock...

"As to reward, my profession is its own reward;" Sherlock Holmes.

I have wrought my simple plan
If I give one hour of joy
To the boy who’s half a man,
Or the man who’s half a boy.

Sir Arthur Conan Doyle.

User avatar
mtskull
Posts: 623
Joined: Thu Jan 21, 2010 10:32 pm
Location: West Yorkshire

Re: Other Speed Record Breakers Are Available!

Post by mtskull » Sun Sep 30, 2018 9:00 am

Having read a little more of the Longbow back story, it would appear that a large part of the rationale behind the twin Viper setup is that Vipers were available and they couldn't find a suitable Orpheus. Lots of RB 199's currently for sale though; oodles of thrust and still 300kg lighter than two Vipers. Mind you, that's easy for me to say, as I'm not the one footing the bill....
Obstacles are those frightful things you see when you take your eyes off your goals.

User avatar
Mike Bull
Posts: 4620
Joined: Mon Dec 01, 2008 1:57 pm

Re: Other Speed Record Breakers Are Available!

Post by Mike Bull » Sun Sep 30, 2018 10:04 am

Renegadenemo wrote:
Sat Sep 29, 2018 6:17 pm
Had to learn the fuel system to get the car to deliver its full potential but it didn't half go!
What Bill means is, he rocked up having never seen a Viper before and had it running that same afternoon, when they'd not got it lit in 3 years of trying! :lol:

User avatar
Renegadenemo
Posts: 4712
Joined: Mon Dec 01, 2008 12:29 pm
Location: N E England
Contact:

Re: Other Speed Record Breakers Are Available!

Post by Renegadenemo » Sun Sep 30, 2018 4:59 pm

Lots of RB 199's currently for sale though; oodles of thrust and still 300kg lighter than two Vipers.
I think getting hold of MOST of a RB199 would be easy enough but I think it would be real challenge to actually get a tune out of it. I know nothing about it but I'd wager it has lots of offboard systems and ancillaries that you'd have a hell of a job getting hold of or tricking the engine into thinking it had one. Where's Stuart for a more knowledgeable opinion?

I doubt very much whether there'd be much technical info available either seeing as it's still very much a supported engine. Even the Viper still has bits and bobs of support for aircraft forces around the world so getting to the bottom of how the BFCU works (barometric fuel control unit) was a task in itself and it's a thing you can hold in your hand that was designed for a drone engine. But it happens to be a R-R part amongst a nest of familiar Lucas gubbins so try finding out about it!

I still think that for value for money, power and weight an afterburning Viper would be the best option. The setup on the car is crude but effective with little, if any, weight penalty. Bit of a downside to the Viper is it has a lot of mag/thorium in it so it needs treating with respect if there's any corrosion product about.
I'm only a plumber from Cannock...

"As to reward, my profession is its own reward;" Sherlock Holmes.

I have wrought my simple plan
If I give one hour of joy
To the boy who’s half a man,
Or the man who’s half a boy.

Sir Arthur Conan Doyle.

User avatar
Richie
Posts: 1195
Joined: Mon Mar 07, 2011 3:12 pm

Re: Other Speed Record Breakers Are Available!

Post by Richie » Sun Sep 30, 2018 7:12 pm

Ah Thorium, that stuff that Bill truly fears above all else !
Clarence come out ov zat tank at vonz !

Malcolm Ops
Posts: 112
Joined: Mon Jul 10, 2017 4:09 pm

Re: Other Speed Record Breakers Are Available!

Post by Malcolm Ops » Sun Sep 30, 2018 9:51 pm

Renegadenemo wrote:
Sun Sep 30, 2018 4:59 pm
I still think that for value for money, power and weight an afterburning Viper would be the best option. The setup on the car is crude but effective with little, if any, weight penalty.
Although Craig Arfons spoke of adding an afterburner to his J85 powered jet hydroplane, this form of power enhancement has not been used on water, I have heard comments that the sudden application of power could destabilise a craft. [The 'idea' of two viper jets mounted on a boat has been the outright WSR craft design route of Alan Sabberton from Norfolk since his project started].
Malcolm Ops

Derby, England

User avatar
Mike Bull
Posts: 4620
Joined: Mon Dec 01, 2008 1:57 pm

Re: Other Speed Record Breakers Are Available!

Post by Mike Bull » Mon Oct 01, 2018 11:05 am

Malcolm Ops wrote:
Sun Sep 30, 2018 9:51 pm
[The 'idea' of two viper jets mounted on a boat has been the outright WSR craft design route of Alan Sabberton from Norfolk since his project started].
I thought, 'who?' but then realised, I'd seen this before-

http://www.edp24.co.uk/news/hoveton-man ... -1-4418313

User avatar
mtskull
Posts: 623
Joined: Thu Jan 21, 2010 10:32 pm
Location: West Yorkshire

Re: Other Speed Record Breakers Are Available!

Post by mtskull » Mon Oct 01, 2018 9:56 pm

Mike Bull wrote:
Mon Oct 01, 2018 11:05 am
Malcolm Ops wrote:
Sun Sep 30, 2018 9:51 pm
[The 'idea' of two viper jets mounted on a boat has been the outright WSR craft design route of Alan Sabberton from Norfolk since his project started].
I thought, 'who?' but then realised, I'd seen this before-

http://www.edp24.co.uk/news/hoveton-man ... -1-4418313
That's a pretty model but, blimey, I hate to contemplate the effects of a loss of thrust on one engine when they are set so far from the centreline.....

I know that local newspapers aren't especially noted for accurate reporting but how on earth did they work out that 4000lbs of thrust equates to 16000 horsepower? The boat would have to achieve 1500mph for that to be true! Maybe they looked up some reference material for Concorde....
Obstacles are those frightful things you see when you take your eyes off your goals.

User avatar
mtskull
Posts: 623
Joined: Thu Jan 21, 2010 10:32 pm
Location: West Yorkshire

Re: Other Speed Record Breakers Are Available!

Post by mtskull » Mon Oct 01, 2018 10:01 pm

Whoops, pressed "reply with quote" instead of "edit".
Last edited by mtskull on Wed Oct 03, 2018 7:31 am, edited 1 time in total.
Obstacles are those frightful things you see when you take your eyes off your goals.

User avatar
Renegadenemo
Posts: 4712
Joined: Mon Dec 01, 2008 12:29 pm
Location: N E England
Contact:

Re: Other Speed Record Breakers Are Available!

Post by Renegadenemo » Wed Oct 03, 2018 12:14 am

Although Craig Arfons spoke of adding an afterburner to his J85 powered jet hydroplane, this form of power enhancement has not been used on water, I have heard comments that the sudden application of power could destabilise a craft.
I've heard this many times too and having felt the reheat explode in my face and thump my chest as the car launched I can only imagine the havoc it might cause a boat accelerating and trying to maintain equilibrium at the interface between two fluids. Then I think, so where is everyone's imagination? Unless my thinking is fatally flawed (and it wouldn't be the first time by any stretch) surely it's possible to light the reheat softly and throttle it up?
Just because there's no application for a soft-starting, throttleable reheat doesn't mean it's a big deal to engineer one. Stick a throttle valve in the line, crack it to idle - wherever you want that to be - and let the afterburner light then open the valve progressively.
I'm only a plumber from Cannock...

"As to reward, my profession is its own reward;" Sherlock Holmes.

I have wrought my simple plan
If I give one hour of joy
To the boy who’s half a man,
Or the man who’s half a boy.

Sir Arthur Conan Doyle.

Post Reply