LPG freezing probs

[Fly100]

Guys

I could use a little help with my LPG system.

The problem I have is it keeps freezing up.Now at the bottom of the part that freezes there is a water jacket that takes hot water from the top of the motor (Its T'ed into the existing system) runs it round the vaporiser and then returns it back into the motor to be added to the rest of the water and ejected all as per normal.

Right for some time it seems to be air locking thus allowing now water to run through sad LPG parts and therefore they freeze up. Boat stops….much swearing fix boat and we are all good for the rest of the day.Any ideas how I can stop the air lock or add some sort of auto bleed to it.
It’s a PCM 351 Ford motor with a professional install of the LPG kit.

Cheers

FLY

[herd2243]

My first LPG boat, did the same thing but only at the start of the season, what I used to do is, before I started the boat I would disconnect the hose going into the chamber, start the boat (keeping it at 2000 rpm), wait until the water comes out the hose at high pressure, then push the hose back on, tighten up the hose clip, waiting for the water to come out at high presure should get rid of the air gaps in the system. (you may have to do this to the other hose as well) However the champer can still freeze up if the boat is left at idle speed for sometime, or lots of starting and stopping, then running at really slow speeds. Hope this helps...

[Fly100]

Right, an error on my part here.The pipe that feeds the vapouriser comes out of the manfold.It looks like an adapter is fitted where the temp gauge takes it reading from.Water then travels though the LPG kit and returns back into the system down near the raw water pump area at the front of the motor.Im guessing the water is pulled through rather than pumped ?

FLY

[whataboat]

sounds like the flow is restricted probably by silt and rust

[jos]

First water should be taken where presure is high, thats on the watercirculation pump.

First season you first flush the engine at home with the garden hose.
At idle it takes to long to fill the engine when epmty, sitting in the lake..
On revs it freezes quick, lack of water.

Second, mine was 3 years old, the used all brass fitting for the plumbing. Ecxept for one fitting, a steel one.

So the engine started fine, ran for a few minutes, and then the power lost.

The steel fitting rusted over winter, was 3/4 and now rusted clogged it to 1/16. Only my hose gave a light freeze not the regulator, was hard to diagnose.

Air lock should never be a problem if the is circulation.
There should be a presuure difference at all time, so its very important where you tap the water.

[NigelC]

The connection on the inlet manifold sounds OK. I am not sure about the other connection. On mine, the 'other connection' is where the block drain off point is on the rear port side of the engine, below the exhaust manifold. Most Ford conversions I have seen are plumbed this way.
Not saying yours is wrong, just that I haven't seen that before.
The other issue you may have is that the vaporiser may need servicing. The water compartment can get gummed up and stop water flow. Overhaul kits should be readily available assuming you have the Impco system.