Calculating top speed on ice...

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PyroJoe
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Re: Calculating top speed on ice...

Post by PyroJoe » Wed Jul 08, 2009 3:06 pm

GRIM,
Do you remember the "lazy" flame height at the tail before the air was brought on?

I remember Anne had a specific flame height at the tail, which when the air was applied she would chatter right away. May help to know that parameter. It seemed to put the engine in the correct fuel range more quickly during startup.

Joe

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Re: Calculating top speed on ice...

Post by Johansson » Wed Jul 08, 2009 3:21 pm

GRIM wrote: Hey Anders ,
Being as you are planning to only use one propane cylinder, you might try blocking one inlet , I tried this , didnt seem to be any better , subsequently lost the lollpop in the sand and never tried again
Hi Grim! I´ll keep your advice in mind so I have another thing to try if the engine proves to be a tricky bastard to get running.
GRIM wrote:For what its worth , do try to obtain another gas cylinder,and run them in paralell, I think you will struggle with only one
Will do that, hopefully one of my friends has a bottle so I won´t have to buy one. I connect them so the two bottles feeds gas into the single hose before the T, right? With a bottle hooked directly to each injector it would be difficult to balance the propane flow between the two injectors.

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Re: Calculating top speed on ice...

Post by GRIM » Wed Jul 08, 2009 3:55 pm

PyroJoe wrote:Do you remember the "lazy" flame height at the tail before the air was brought on?
Hi Joe, Good Point , but to be truthful there doesnt seem to be a magic position , (well I havent found it yet anyway) something like 2 meters , loads of gas , ha ,
PyroJoe wrote:I connect them so the two bottles feeds gas into the single hose before the T, right? With a bottle hooked directly to each injector it would be difficult to balance the propane flow between the two injectors.


Yes I think the two bottles should be connected to a tee before the existing tee, a ball valve between the tees would be prudent, for emergency stops ,

Having said that, I wouldnt mind trying one cylinder on each injector , you will finish up with both cylinders full open anyway, so balance shouldnt be a big issue ,

One of the issues , is the positon that one has to "stand" to be able to use a leaf blower, the plume of flame from the exhaust gets real hot , but you know that , :wink:,

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Re: Calculating top speed on ice...

Post by Johansson » Wed Jul 08, 2009 4:19 pm

What about running on liquid propane? No problem running on a single bottle, perhaps a copper preheat coil is needed?

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Re: Calculating top speed on ice...

Post by GRIM » Thu Jul 09, 2009 12:41 am

I cant comment much on that one , havent tried liquid propane on Thunderchine ,

I have on smaller engines , and the really alarming thing is how much fuel they seem to burn in comparison to the same engine on vapor,
I can only assume a fair percentage goes out the tailpipe unburned,

I am sure a well sized vaporizing coil and injector setup would improve things though ,

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Re: Calculating top speed on ice...

Post by Johansson » Thu Jul 09, 2009 5:05 am

Perhaps I should make a preheat coil and run with the bottle inverted after all, it´s not very hot outside at the moment so the bottle will chill down quick if I run it on vapour. A well made coil can later be used as a vapour coil for liquid fuel so I won´t waste any time or material by doing this.

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Re: Calculating top speed on ice...

Post by milisavljevic » Thu Jul 09, 2009 5:55 am

Hejsan Anders!
Johansson wrote: Perhaps I should make a preheat coil and run with the bottle inverted after all.
Sounds like a plan. The net effect is that you are injectoring vapor, so you only need to concentrate
on getting your vaporising coil designed then fabricated correctly. Many example exist on the forum.

Start with Joe's setup as a reference. I believe you recently received a "care package" with photos... :wink:
Johansson wrote: A well made coil can later be used as a vapour coil for liquid fuel so I won´t waste any time or material by doing this.
Exactamundo. You need the vaporising coil for the modulating injector design, anyway. So, why not.

Now, hop to it! :D

Cheers,
M.
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Re: Calculating top speed on ice...

Post by Johansson » Thu Jul 09, 2009 5:19 pm

When I make the vapour coil I will fit spacers between the turns to separate them a bit, my guess is that the coil will absorb more heat when the turns aren´t in contact with each other. Perhaps it won´t make any difference but I might as well give it a try.

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Re: Calculating top speed on ice...

Post by milisavljevic » Thu Jul 09, 2009 5:40 pm

Hej!

Keep in mind that in the vicinity of the combustor-transition join, the circumference is ca. 450 mm;
not so many turns are required to collect sufficient energy for vaporisation. Again, note Joe's setup.

Also note the excellent advice offered on this thread re: how, what, and where to connect to a coil.

Cheers,
M.
no safe haven for merchant scum


for ye merchants who do the prop'r t'ing only if
ye be haul'd-up on charges b'fore ye ship-mates
an' threat'nd wit' forfeiture of all ye precious loot
hear this - so-called stand-up guys YE BE NOT

avast!
Cap'n M.

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Re: Calculating top speed on ice...

Post by Johansson » Fri Jul 10, 2009 7:19 pm

No spacers were needed for the vapour coil after all, it has a tight fit to the CC and should be able to produce plenty of steam. Once I switch from propane to liquid fuel I will have to make a better connection between the coil and the injectors, I don´t think that the propane hoses will survive the heat for any longer periods.
Sparken 069.jpg
Sparken 071.jpg
I removed the ejectors for this test, until we have tuned the injectors they will only be in the way.
Sparken 073.jpg
Sparken 074.jpg
A lead weight was made to keep the tail from jumping around if it wants to lift from the rear mount cradle.
Sparken 075.jpg
We made an important discovery tonight, Erik and I. We found out that lead weighs exactly 14 times more than beer! :shock:
Sparken 080.jpg
Sparken 083.jpg
Sparken 084.jpg

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Re: Lighter than lead

Post by milisavljevic » Sat Jul 11, 2009 3:07 am

Hejsan Anders and Erik!
Johansson wrote: We made an important discovery tonight, Erik and I.
We found out that lead weighs exactly 14 times more than beer!
That was one reason I switched from drinking lead to ale.
Another was the sickness (shakes and tremors) the lead lagers caused me.
The disappointing head (no head at all...) you get when you a pour pint of your favourite lead.

But the real reason (the last straw, as it were) I stopped drinking lead: I got tired of burning my tongue! :evil:

Cheers,
M.

PS: !!! GOOD LUCK WITH YOUR ENGINE TESTING ON THE WEEKEND !!! :P
no safe haven for merchant scum


for ye merchants who do the prop'r t'ing only if
ye be haul'd-up on charges b'fore ye ship-mates
an' threat'nd wit' forfeiture of all ye precious loot
hear this - so-called stand-up guys YE BE NOT

avast!
Cap'n M.

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Re: Calculating top speed on ice...

Post by Johansson » Sat Jul 11, 2009 10:49 pm

Succe.JPG
(more info, pics and video tomorrow, must sleep now...)

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Congratulations!

Post by milisavljevic » Sun Jul 12, 2009 12:08 am

Hejsan Anders!

!!! Woot !!!

Looking forward to your next, (hopefully) information rich, posting! :D

Cheers,
M.
no safe haven for merchant scum


for ye merchants who do the prop'r t'ing only if
ye be haul'd-up on charges b'fore ye ship-mates
an' threat'nd wit' forfeiture of all ye precious loot
hear this - so-called stand-up guys YE BE NOT

avast!
Cap'n M.

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Re: Calculating top speed on ice...

Post by Mike Everman » Sun Jul 12, 2009 5:44 am

Cool, love the thumbs ups!
Mike
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Re: Calculating top speed on ice...

Post by Johansson » Sun Jul 12, 2009 9:20 am

Good morning everybody.
Sparken 085.jpg
resized_DSC03235.jpg
http://www.youtube.com/watch?v=fL6NtpeB0iA

As you can see we had a very successful first test, we wasted much propane on starting attempts since I had to adjust the "throttle" on the bottle valve while Låmbas ran the leaf blower and the sync between us was not always the best since talking to each other was rather difficult... :mrgreen:
resized_DSC03240.jpg
I have a few more clips of the running engine so I will put together a second video and upload it later today.

After a couple of attempts I crimped the injectors down to a 1x7mm slot and it started much easier after that, we ran out of propane before I could tune the injector placement any further but it is not really needed since I now will start rebuilding the kick for liquid fueling.

My guess is that the engine was hard to start because of the liquid propane, before the CC was cherry red the injectors were frozen all the way down the intakes. That might also have caused the "late" combustion zone in the transition cone/tail coupler rather than in the CC, they were glowing hard and flaked all over after ~8 seconds of running but then when the CC heated up the frost on the coil melted and the combustion zone seemed to move further up towards the CC.
Sparken 087.jpg
Sparken 088.jpg
Sparken 089.jpg
As you can see on the last pic above the coil bent the front coil mount a bit when it got chilled from the propane, not enough for it to matter but anyway. I consider this engine a test engine and will most likely build a stainless one once this one runs as it should.

I didn´t take any thrust readings this time, no need to do that before I have it running properly on liquid fuel. Standing beside the engine it feels like it gives the cart a pretty good push, my gocart pulls 20kg with afterburner and my guess is that the kick pulled a bit more. 8)
resized_DSC03254.jpg
resized_DSC03253.jpg
Another good thing is that the tail won´t lift from the rear cradle mount, I had the lead weight there just in case but it didn´t look like it was needed.
resized_DSC03256.jpg
Any jet engineer should have coffee and cookies nearby in case of emergency. :mrgreen:

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