lpg feed pipe size on 500 bhp engine.

[LPGC]

When ahem I mean if (of course) I do this mod I'd test it allowed filling using either compressed air or perhaps preferably a liquid gas supply before fitting the modded valve onto the tank.
But what size tap did you put in the pinhole - widening the pinhole can mean the pin skews and gets stuck instead of sliding out of the hole, result is that the valve is broke because unless the pin comes out to just the right extent the fill valve won't allow any gas into the tank. I haven't disassembled the fill shut off valve but obviously there will be other ways of disabling the fill shut off valve so if you did mess the pin hole up the valve won't be completely broken, I'm sure you'll be able to disassemble it and disable the fill shut off valve another way.

[Brian_H]

Taken from his post further up

NOW , as my valve is described as for 240 to 250 mm high tank , i can assume that in a 250mm tank i wont get my full 80 % but if i had a 240 mm tank i would , so my float is maybe teschnically 10mm too low at cut off point ?

[robertXX]

Yes 250 mm tank height. And the valve is for 240 to 250. Re pin hole. I used a tiny 3 mm tap I think it was. Easy sliding fit no pushing needed.

[LPGC]

Taken from his post further up

NOW , as my valve is described as for 240 to 250 mm high tank , i can assume that in a 250mm tank i wont get my full 80 % but if i had a 240 mm tank i would , so my float is maybe teschnically 10mm too low at cut off point ?

Or 8mm if we were going to be fussy lol (80% of the extra 10mm height). 10mm Taller tank but imagine if the tank was 50mm taller so 290mm and we fitted the same 240 valve but bent the float up 50mm, it would then fill to the same headroom as a 240mm tank (48mm for 80% in 240mm tank) but 48mm headroom in a 290height tank would it was filling to 83.5%. Not that it would make any sense to fit the 240 valve in a 290 tank, with the float bent up 50mm the range of travel wouldn't allow the float to get near the bottom of the tank so the gauge wouldn't work properly. Haven't put much thought into this but valve designers might also expect the valve on various height tanks to be mounted (valve boss height) at various heights above tank bottom.

Yes 250 mm tank height. And the valve is for 240 to 250. Re pin hole. I used a tiny 3 mm tap I think it was. Easy sliding fit no pushing needed.

Should be OK then.

[LPGC]

I suppose to get rid of air in a tank we could put a litre or so of gas in the tank before installation, turn the tank upside down so the pickup pipe is at the top and let some gas and air out of it by removing the solenoid post or by energising the solenoid. Air should come out with the gas and since a litre of liquid gas turns into many litres of gas vapour it should flush a lot of air out of the tank.. So even if pump pressure is low there'll be hardly any air left in the tank to pressurise above the rising liquid gas level as you fill the tank (which again seems to be a problem for filling tanks to even 80% these days in cold weather when some pumps pressure are low, particularly on new installs when air has not yet been forced toward the reducer because the tank hasn't been run to empty enough times).

[robertXX]

ok dokey i went for 20mm float adjustment ,went to stn , and wopped in 21 litres ,then removed the old tank ,and slotted in the new one ,which was pretty blimmen heavy !

hopefully the cut off will still work....

[robertXX]

Simon, why would you block the float action ? and what happens when it get to be totally full ...does the pump just grind to a halt ? oh and what happens if the tank gets hot !

[LPGC]

You'd block it if you wanted the tank to fill to 100%.. When it gets totally full the pump stops, they don't pump at a high enough pressure to open the over pressure release valve.
If you fill to 100% and the tank heats up then of course with no more space for expansion the pressure goes up tremendously and the over pressure relief valve would open. But if you fill to 100%, pay for the fuel and start driving straight away the tank is very soon not 100% full anymore. You wouldn't want to fill to 100% in winter, drive just a couple of miles home and leave the car parked in a heated garage lol.

[robertXX]

At Bicester in the hanger.

[LPGC]

So you wouldn't want to fill a tank to 100% full at the hanger (if you have filling capabilities there) and leave the car in the hanger with a 100% full tank. But depending on tank capacity and mpg you might be OK filling to 100% 10 miles away then parking up in the hanger.

[robertXX]

ah no simon that was a messsage for gilbert at bicester scramble car meet .

is a sign its not shutting off automatically ,that it does not seem to stop flow cleanly but keep creeping ? or is that just a new tank full of air syndrome .

i got 21l in it ,PUT TANK IN CAR ,, drove to stn 6 miles away ,got 30 litres in and it was just creeping in bit by bit , in fact , for a 60litre tank , that must mean is shutting off ?

[Brian_H]

Most multivalves I've had do exactly that, will keep filling very slowly once the shutoff has operated (like you can watch .01 of a litre going in every 3-4 seconds).

The 4 hole tank I had didn't, that would shut off and that was it.

[robertXX]

thanks brian , it was doing .very approx...0.1 litre every second ,then would stop then another burst .and occilating like that .

[Brian_H]

Sounds about right - wouldn't worry about that as don't think you can do anything about it.

[Gilbertd]

At Bicester in the hanger.

Bugger! Never having been there before I found it was far bigger than I expected. We walked around for a good 2 hours looking at anything and everything (never seen so much exotica in one place at one time, and wouldn't have expected it at this time of year either). Just didn't go into the hangar, there was so much else to see parked up all over the place. I'm sure there were other bits we missed and I never did find the two other guys that suggested I went and meet up with them either. We'll definitely go next time they do another though.

[Brian_H]

ah no simon that was a messsage for gilbert at bicester scramble car meet .

is a sign its not shutting off automatically ,that it does not seem to stop flow cleanly but keep creeping ? or is that just a new tank full of air syndrome .

i got 21l in it ,PUT TANK IN CAR ,, drove to stn 6 miles away ,got 30 litres in and it was just creeping in bit by bit , in fact , for a 60litre tank , that must mean is shutting off ?

Does sound about right to me, You may find it fills a bit more when its warmer weather anyway, I usually notice a bit of difference then.

May also depend where your filling it as some places just seem to cut off earlier, particularly if the ground isn't level that your parked on.

[robertXX]

From what Simon was saying above. Is it true to say that with a totally empty tank filled up , and then I used up about half the gas and filled again , that it would take more gas to fill the second time ?

I am trying to work out my mpg. So i filled it up
This morning. On top of the 20 l I put in the tank before fitting to the car I got in another 31 l. Then drove to Bicester and back 50 miles and then got in 28 litres. So 8.02 mpg. But if the second fill gets more in then that confuses my calcs. If you see what i mean ?

[Brian_H]

When I've had the tank totally empty, I usually couple the hose up and let it stop making noise before trying to fill. Partly because when i tried without waiting it tended to upset the pump. I think Dai said typically you'd get a couple of litres of gas from the pressure in the hose equalising like that before you hold the button.

Your best bet is to fill, do your journey and then fill again at the same pump, take what your second fill says against the distance to calculate. (the fill after the journey)

[robertXX]

indeed Brian , this was only trying to cater for the effects of a very first time fill being maybe possibly a slightly smaller amount than the next fill due to the air in the tank thingy simon was commenting on , i did not really understand it fully. but i thought perhaps the 2nd fill would be getting more in the tank than the first .(that way i can fool myself its doing better mpg than my calcs )

[robertXX]

oh here's another thought , i wonder if fitting a thermostat or two to the cooling system would have a dramatic effect on economy ?