# Converting a petrol generator to LPG (dual fuel)



## fairytooth (Apr 5, 2012)

There are a few companies that can supply ready converted generators OR just the kits to convert your own generator.

Does anyone have any experience of these?


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## Teutone (Apr 5, 2012)

I am looking at this as well and would ask before a purchase if you can start the gennie on LPG.


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## fairytooth (Apr 5, 2012)

Yes, you can.  You must use one fuel or the other, not together.  If LPG, petrol must be turned off and carb drained first.  But it can run direct from bbq point if you have one.


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## oldish hippy (Apr 5, 2012)

ask viktor he around uk somewhere


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## Viktor (Apr 5, 2012)

Fairytooth....give Edge Technology a ring...they are the main UK dealers for Honda and are experts at gas conversion.

Honda generators at Edge Technology: + pramac,sdmo,stephill 

If you are too far from them, I'm sure they could suggest a converter they work with....best to get them to do it so nothing goes wrong at a later time.

This is the link to the Gas kit page:  http://www.edgetechnology.co.uk/lpgas/lpg_con_kits.htm


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## ellisboy (Apr 5, 2012)

Thanks Victor! Very interesting link :cheers:


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## fairytooth (Apr 6, 2012)

Thanks for the info Viktor.  I have already been in contact with Edge who say they no longer supply kits for diy assembly.

I presume they have experienced problems.  That's what prompted my original post.

I think I'll just stick with petrol until someone else comes up with a good Garrett carb adaptor for retro fitting with LPG.


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## Viktor (Apr 6, 2012)

Thanks for the update.  Best let them (or other authorised installer), do the conversion for you then....seems perhaps the kit customers aren't managing the installation themselves properly right enough.


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## fifthwheel (Apr 7, 2012)

fairytooth said:


> There are a few companies that can supply ready converted generators OR just the kits to convert your own generator.
> 
> Does anyone have any experience of these?



Hope the link works Tinley Tech Limited Autogas conversion equipment     john.


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## jarvo8 (Nov 6, 2012)

fifthwheel said:


> Hope the link works Tinley Tech Limited Autogas conversion equipment     john.



HI

Not a sales pitch but we sell what we believe is the cheapest NEW Generator LPG conversion kit for propane/butane gas bottle
This kit will convert your generator to run on a propane/butane cylinder bottles. Our kits will fit 99% of generators. 

Our kits are also designed as Tri fuel kits. They fit onto petrol engines and allow you to run the generator on LPG, NG, while still enabling you to switch back to petrol if you wish. 

(You just have to make sure that no petrol is in the generator when using Gas). 

Conversions of small petrol engine appliances and equipment to LPG is becoming increasingly popular not least because of the cost savings - today's technology makes conversion relatively simple and provides many benefits. 

Some benefits of LPG/NG: 

• Lower running costs - LPG/NG gas is about 50% cheaper than petrol. 

• Cleaner emissions allow use in public areas. 

• Lower maintenance costs with extended life for spark plugs and engine oil. 

• No storage problems compared with petrol. 

• No reduction in performance - power outputs do not change. 

You will require suitable gas regulator to match the bottled gas you are using. 

We are the cheapest anywhere only £120


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## fifthwheel (Nov 6, 2012)

Is this a reply from Tinley Tech?


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## keenman (Jan 31, 2013)

I'm finding it hard to locate a company  that would convert my 7KV petrol generator to LPG.

Does anyone of a local company in Scotland please?

Thanks guys..


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## Viktor (Feb 1, 2013)

Just a quick point.  Most kits have a straight out gas pipe connection (as in the photo below) from the regulator which fits onto the side of the generator.  I found when I got mine which was second hand that the pipe was kinked at this point through flexing when being stored (as the pipe is moved to the side), so I had Edge Tec replaced this with a right angle connector and new pipe.


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## fairytooth (Mar 15, 2013)

I got cold feet in the end with mine.  I like the idea of being able to convert back again but will stay with petrol.  Ironically, it's when the LPG starts running low the gennie comes out anyway so running it on LPG would defeat the object a bit for me.

Having wilded across France a few times with it now I will leave it as it is.  Still interested in hearing others experiences  of course...


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## Deleted member 207 (Mar 18, 2013)

I made my own adaptor to fit a Honda lookalike that ran a 12V 55A alternator. Making the adaptor was not that hard as I have a lathe/mill, I bought a demand regulator from the US which allowed the engine to run at an appropriate speed according to the load being put on it by the alternator. I only needed 12V as I had a 2500W inverter connected to the leisure batteries with a feed to an AC unit or to the van's 240V system. The engine ran a lot quieter than on petrol. I took off all the unused bits - petrol tank, carb, etc. installed an oil/foam air filter. I would have said that using a kit would have be a doddle - I had to do a fair bit of mucking about getting a few really small holes drilled in the adaptor.

The bloody thing got stolen whilst I was in hospital for a month or so having a stem cell transplant - I have my suspicions - it was bolted onto the rear rack and connected to the LPG tank with a flexi hose.


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## GRWXJR (Mar 18, 2013)

*Work out your LPG running costs v petrol*

I supplied a few sets in the past with Edge Technology kits on - the catering guys like the fact that you don't have to handle fuel, plus you've got more storage and a lower unit cost running LPG.

The Honda GW engines we used to have them on are unchanged apart from the addition of the gas inlet and the Garritson Valve for safety purposes.  The Garritson Valve is basically a vacuum-operated membrane-valve that (like the old Constant-Velocity carburettors) only opens when there is induction pressure (e.g. the motor is running), so if the engine shuts down for any reason, the Garritson Valve shuts the gas flow off.  Some systems where there is remote starting will also employ a solenoid valve as well.

If manual (pull-start) units, then initial start-up can be more of a chore on Gas than on petrol (and you have to prime the gas system by pressing the priming button on the Garritson valve before attempting to start, so there is a charge of gas available for the engine to use to get going).  Electric start motors spin over faster and start much better on LPG we found, as the starter motor spins the engine fast enough to create some induction vacuum pressure and draws in more gas). 

As others have said, you can run petrol or LPG on the same machine, but have to run the carb dry or drain it fully before you can switch to gas.

It used to be though that you needed to run a smaller plug gap, as this acted as a very simple way to mimic retarding the ignition to help with running on Gas.

The big problem is though, that often people running Catering and RV generators have them well enclosed where they run hotter than they ought to in certain (or even all) circumstances.  If an engine running on petrol runs a bit too hot then chances are you'll get away with it.  Do the same on gas and the higher combustion chamber temps will see you burn out the exhaust valve and seat in short order.

Basically, to justify the cost of the conversion over a standard Petrol Genny then you need to run quite a lot of hours to recoup the initial investment.  If you want to work out what the cost differential is, then (as long as you have petrol consumption data from the mfr to compare with) you can do some estimates using the following......

CONSUMPTION OF GAS CALCULATIONS:

EITHER:

HALF-POUND OF GAS PER ENGINE HORSEPOWER PER HOUR @ 100% LOAD

OR

QUARTER-KILOGRAM OF GAS PER ENGINE KILOWATT PER HOUR @ 100% LOAD


Example:

Honda 2.7kVA / 2.2kW Generator powered by GX160 5.5Hp engine:

= 5.5 multiplied by 0.5 = 2.75 lb of LPG per hour at 100% Load.

OR

= 5.5 multiplied by 0.746 (1Hp is equal to 746 Watts) = 4.10 kilowatts

= 4.10 multiplied by 0.25 = 1.026 kilograms of LPG per hour at 100% Load.


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## fairytooth (Mar 18, 2013)

That is a very informative thread, thank you very much :wave:


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## Teutone (Mar 18, 2013)

for me it wouldn't be so much the cost of LPG versus Petrol but more the smell!!
As soon you need to store the genny anywhere inside the motorhome you will smell the petrol. The fuel Tank needs to be vented for the genny to work and every drop spilled
when filling it up will smell. Running it on LPG will produce less smelly emmissions and you won't have a 5 liter jerry can to carry around (again, inside the MH).

Luckily for me it turns out we don't need a genny. Have converted all lights to LED and fitted a solar panel. Don't have a TV or anything else. so 12V is only required for lights and the hot air heating.


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## Hobgoblin (Mar 18, 2013)

Garritson valve workings here
Regulator Garretson KN Beam Impco how valve works for Propane or Natural gas generator - YouTube


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## jogguk (Mar 18, 2013)

Flip Flap said:


> Never had a problem with this genny smelling, the vent on the cap can be shut and I run it dry most times I use it. The 5 ltr can I keep in one of those vacuum bags more usually used for storing sheets etc. Handy things those for the van.



Now there's an idea! Can you get those vacuum bags big enough to get the whole genny in? 

John


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