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Posted: Wed Dec 12, 2007 11:23 pm
by frankrede
aaron1225 wrote:you should grind down those corners
I should not.
The flat edge holds it straight and works as a base.
Posted: Thu Dec 13, 2007 12:37 am
by TwitchTheAussie
Just to be safe I'd MIG weld everything. Just to be safe. Other than that use a remote detonator and be careful with the spark plugs.
Posted: Thu Dec 13, 2007 4:23 pm
by DYI
Did you read the entire topic Twitch?
The whole thing is MIG welded.
And what mixes do you plan on taking it to frank? It looks like it could take 20x easily.
Posted: Thu Dec 13, 2007 10:17 pm
by frankrede
Thats exactly what I have in mind.
Or atleast to the highest mix I can take it too with my air compressor
Posted: Thu Dec 13, 2007 10:46 pm
by DYI
With everything accounted for, assuming excellent fueling techniques, 20x would be about 290 psi preignition. That must be one impressive compressor. If you have a normal compressor however, you could pressurise a tank with a homemade high pressure pump for the air source. Either that, or a regged HPA tank, but I think the first option would be cheaper.
Posted: Thu Dec 13, 2007 10:52 pm
by frankrede
DYI wrote:With everything accounted for, assuming excellent fueling techniques, 20x would be about 290 psi preignition. That must be one impressive compressor. If you have a normal compressor however, you could pressurise a tank with a homemade high pressure pump for the air source. Either that, or a regged HPA tank, but I think the first option would be cheaper.
Yea. I knew it was something crazy. I would figure something out.
Posted: Sun Dec 16, 2007 1:37 am
by SpudBlaster15
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Posted: Sun Dec 16, 2007 5:19 am
by Novacastrian
DYI wrote:With everything accounted for, assuming excellent fueling techniques, 20x would be about 290 psi preignition. That must be one impressive compressor. If you have a normal compressor however, you could pressurise a tank with a homemade high pressure pump for the air source. Either that, or a regged HPA tank, but I think the first option would be cheaper.
Ok, i know that propane CAN start to turn liquid at around 90psi, having said that i have fueled my mini hybrid to 90psi with no troubles.
My question is this- at 290psi what is the chance of non-liquification?
Btw, great idea with the pre-pressurised tank DYI, i was looking for a simple way to pressurise hybrids in the field.
Posted: Sun Dec 16, 2007 8:42 am
by spanerman
would keeping the chamber warm or cold, can never remember reduce the chances of liquification?
Posted: Sun Dec 16, 2007 9:35 am
by DYI
Due to the low propane:air ratio, I'm pretty sure that partial pressure would stop the propane from liquifying at any easily achievable mix. I don't know for sure though. I do know that a 20x mix would be really impressive.
Posted: Sun Dec 16, 2007 9:41 am
by mark.f
Some say that because of partial pressures, the propane will not liquefy in a propane:air mixture past 90 PSIG. They say it will take around 2,143 PSIG to liquefy it in a 4.2% mix. Don't know that for a fact, though.
Posted: Sun Dec 16, 2007 10:08 am
by DYI
Assuming that the pressure in a propane tank is around 110 psig, the limit imposed by that is a 183x mix, which would equate to ~2790 psig.
If we also assume that the partial pressure argument is correct (which I suspect it is, due to _Fnord's 11x tests), then it seems as though about 141x is the limit. I wonder what kind of pressure a 100x mix would generate?
Posted: Sun Dec 16, 2007 10:12 am
by spanerman
more than id want to be within a mile of

Posted: Sun Dec 16, 2007 10:15 am
by DYI
I'm guessing over 10kpsi in adiabatic conditions. Dammit, now you've got me wanting to build a 20x oxy/MAPP hybrid...
Posted: Sun Dec 16, 2007 11:02 am
by spanerman
^thank god your on a different continent to me
