Warthog Posted March 25, 2008 Share Posted March 25, 2008 Can you run LPG on a truck thats going to be more than likely be swimming at points in its off-road life? At the moment i have RRC with a 4.2 efi running on LPG, but have plans to run it off-road. Yeah i know the V8's give up when around water. But it would seem many forum members are addressing that problem, with success. Cheers Mark Quote Link to comment Share on other sites More sharing options...
Orange Posted March 25, 2008 Share Posted March 25, 2008 Being that LPG relies on electrics to keep it running, you'll end up with the same problem as a petrol fuelled engine........unless you megasquirt it. This system does away with the distributor which seems to cause most of the problems. If you mean the risk of the system getting filled with water.......it'll only get in if the gas can get out. If it's getting out you'd know about it wouldn't be going anywhere!! I never had any problems with my petrol V8 running in and around water, but I never really threw it at very deep stuff. My current avatar shows the deepest it went (bottom of headlights) and it drove out without a hitch. As long as you are sensible and know the limits of the vehicle, you won't have issues. Don't expect to be dumping it in a lake and driving it out, though!! Quote Link to comment Share on other sites More sharing options...
ThreeSheds Posted March 25, 2008 Share Posted March 25, 2008 I think that there is a small breather on the vapouriser (so that it knows what the ambient air pressure is), and of course the filler orifice... Both of those would need protection. Apart from that I can see no problems beyond what is normal for spark ignition engines... Quote Link to comment Share on other sites More sharing options...
sotal Posted March 25, 2008 Share Posted March 25, 2008 Someone was complaining that underslung LPG tanks don't like the sudden drop in temperature when you submerge them in freezing cold water, but I can't remember the problem it caused - might be something to look up though Quote Link to comment Share on other sites More sharing options...
Warthog Posted March 25, 2008 Author Share Posted March 25, 2008 Could there be any issue with the Vapouriser being submerged for long periods? For example, the nose of the truck is dumped in a hole with water up over the bonnet, while your winching through it? Cheers Quote Link to comment Share on other sites More sharing options...
Diff Posted March 25, 2008 Share Posted March 25, 2008 Could there be any issue with the Vapouriser being submerged for long periods? For example, the nose of the truck is dumped in a hole with water up over the bonnet, while your winching through it?Cheers If you submerge a standard vaporiser, the engine will cut out, regardless of how waterproof the engine electrics are. This is because the vaporiser has an atmospheric vent. The large diaphragm in the vaporiser is 'sucked' by the vacuum signal it receives from the mixer in the air intake, the movement of the diaphragm opens and closes the main gas jet to change the amount of gas according to demand. The other side of the diaphragm is vented to atmosphere, or it wouldn't work. You have two choices, either fit a 'snorkel' to the atmospheric vent and take the end somewhere high but still atmospheric, or you fit a 'balanced' type vapouriser which is effectively the same thing but the vent is piped into the intake air hose/snorkel. My 2.5 4 cylinder runs LPG and has a standard vaporiser fitted quite high in the engine bay. I sometimes have had water halfway up the doors but it never misses a beat. The vaporiser doesn't go under water. Hope this helps, Regards, Diff Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 25, 2008 Share Posted March 25, 2008 Yeah i know the V8's give up when around water. - get a decent ignition setup on there and it'll run submerged. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted March 25, 2008 Share Posted March 25, 2008 Depending on the model, you wouldn't want water pouring into the back of the diaphragm -would mess it up really badly, and no way really for the water to get out either.... you'd probably be best fitting a hose to it and taking it up to the snorkel along with everything else. Quote Link to comment Share on other sites More sharing options...
nas90 Posted March 25, 2008 Share Posted March 25, 2008 Been running the nas on LPG for 6 years, mud water, tarmac, no problems, engine bay coated in mud and still the vapouriser works and it is positioned at exhaust header height 85 litre tank sits on RHS wheel box inside tub, usuful capacity 66 litres (80% of 85 litres) Quote Link to comment Share on other sites More sharing options...
Warthog Posted March 25, 2008 Author Share Posted March 25, 2008 - get a decent ignition setup on there and it'll run submerged. The way of the squirt has removed the hidden demons of the V8. Only then can one enter the water without consequence But its the added input of LPG im concerned with? Of Topic: Why are the Jeep 4.0ltr 6 Cylinder engines more reliable in the swimming contests? I see XJ's and TJ's playing happily now and then? They run distributors? Quote Link to comment Share on other sites More sharing options...
Scotian Posted March 26, 2008 Share Posted March 26, 2008 Already been covered but when I used LPG I found that as soon as the evaporator got submerged in water it cut out. then it took about 5 minutes before it would start again. not sure exactly why but I'm guessing the sudden cold of the water was enough for the gas in the evaporator to freez then a thaw took a few mins. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 26, 2008 Share Posted March 26, 2008 The way of the squirt has removed the hidden demons of the V8. Only then can one enter the water without consequence But its the added input of LPG im concerned with? MS can cope with LPG, you have the bonus of switchable ignition maps for petrol/LPG, then your only concern is the vaporizer. Of Topic:Why are the Jeep 4.0ltr 6 Cylinder engines more reliable in the swimming contests? I see XJ's and TJ's playing happily now and then? They run distributors? Because it's not made by Lucas Quote Link to comment Share on other sites More sharing options...
firemannotsam Posted March 26, 2008 Share Posted March 26, 2008 Hi my Disco has been under a reasonable amount of water and the LPG or any of the other electrics did not miss a beat. good leads and sensible driving through the water so as not to get too deep or splash water to far up the engine bay will do for most normal off roading. firemannotsam Quote Link to comment Share on other sites More sharing options...
Highway_Star Posted March 26, 2008 Share Posted March 26, 2008 One problem I had early on with my LPG system and wading; it's a OMVL Millenium/AEB Leonardo closed loop system, which needs a lambda probe. As my RRC didn't come with such modern gadgets, I fitted one, at the Y joint in the exhaust. It quickly became apparent that the £25 universal Lambda probes do not like to get dunked in cold water, the thermal shock cracks the ceramic body of the probe, and it gives a constant 0.5v signal, the LPG system still ran, but very poorly, MPG was terrible. I went through 2 or three probes before I hit on the brand 'Fuelparts', which I am assured is a relative of the Prince of Darkness no less! IIRC the Fuelparts probes are slightly more costly, £30. Problem solved. Other than that I sealed up the LPG ECU by bagging it with some silica gel inside for good measure, and make sure all connectors are soldered and heat shrinked. Quote Link to comment Share on other sites More sharing options...
mickeyw Posted March 26, 2008 Share Posted March 26, 2008 I seem to recall CP Components do a 'wading kit' for the OMVL vapourisers they sell. I would think this can only be a means of extending the diagphragm air vent to somewhere dry, I simply fitted a tin shield next to the air vent to ward off any splashes. As for the other electric bits n bobs, just mount them in as high and dry a position as possible. In my own experience I have had bow waves wash over the bonnet briefly without any coughing V8 noises. Interesting to read about the lambda probes not liking a dunking, mine is a universal type made by Intermotor, it seems to still work OK but I have never had good economy from the system to start with. I believe this is more to do with a V8 sized boots. Cheers Michael Quote Link to comment Share on other sites More sharing options...
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