convert cng bus to propane

Natural Gas, CNG, LNG, NGV, CH4
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shunit
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convert cng bus to propane

Post by shunit » Mon Jul 18, 2011 11:16 am

anyone know if I can convert my E-450 shuttle bus from cng to propane? Thanks!


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Steptoe
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Re: convert cng bus to propane

Post by Steptoe » Mon Jul 18, 2011 4:46 pm

What systenm does it have?
tank, lines, converter , mixer?
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shunit
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Re: convert cng bus to propane

Post by shunit » Mon Jul 18, 2011 8:07 pm

Hi,

It is factory CNG and it has tanks. That's all I know :(

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Steptoe
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Re: convert cng bus to propane

Post by Steptoe » Tue Jul 19, 2011 12:28 am

Well when I converted by camaro from CNG to LPG 20 odd yrs ago...Impco system.
Swapped the tank.....not sure if the CNG and LpG tanks are interchangeable, but do kinow the cng tank has a far higher pressure rating...
Changed the steel cng lines to flexable LPG line....well sort of, the cng line is still in the car....but not used.
Changed the electic shut off solenoid to the IMPCO vff vaccuum shut off.
Converter, L mosel, Changed the front cover (and diapham I think from memoery) and spring to orange.
The mixer (duel fuel) I changed to a 425 mixer as went dedicated....BUT Im sure ?I was duel fuel on the LPG for a short while??? and didnt have to do anything to the mixer???


E-450 shuttle bus..we dont have them in NZ so as to being injection/ carbed petrol/deseil, I have no idea...
The other guys on the site will be of far more help will
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Frank
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Re: convert cng bus to propane

Post by Frank » Tue Jul 19, 2011 11:15 am

Hi Shunit and welcome to the forum.

Very little is interchangeable between LPG and CNG and the Compuvalve in the GFI system that is likely on your van is problematic. The CNG cylinders are designed to hold 3000 or 3600 psi natural gas while LPG tanks are designed to hold much lower pressure (up to 312 psi) liquid fuel. The CNG Compuvalve is different from the LPG Compuvalve because it has a different number of high pressure injectors. Pretty much the only thing that can be reused are the fuel rails and injector sleeves.

Are you interested in changing to LPG because CNG is unavailable or because the CNG system needs repair?

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Steptoe
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Re: convert cng bus to propane

Post by Steptoe » Fri Sep 16, 2011 7:36 pm

CNG is high pressure the stuff that is suppied under ground for home heating...not thestuff in suppied tanks which is LPG low press petroleum gas , a propane/butane blend
CNG is methane. compressed natural gas
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