Outer Limits 4x4 Board

Why is it all the LPG cars I've driven let you drive for another 10km on half throttle but LPG forklifts give no warning and stop dead, on the opposite corner of the factory from the bottle storage
Bottle mounting height perhaps?

Figuring that it is a bit easier to carry a bottle to the forklift than need the extra distance cost vs benefit.

Imagine pushing the car that 100kms.

Mainly probably to piss you off though

The pickup tube in a car system is about 25mm from the floor of the tank while in a forklift bottle it sits about 5mm from the floor.

So when the car tank is "empty" ....... there is still 20 mm of LPG in the tank while in a forklift theres zip !

Put a car LPG tank on a forklift and you'll get that extra few K's.....
Put a forklift tank on a car and you'll stop as soon as its empty.

Just the way they make em

Kingy

V8Patrol wrote:The pickup tube in a car system is about 25mm from the floor of the tank while in a forklift bottle it sits about 5mm from the floor.

So when the car tank is "empty" ....... there is still 20 mm of LPG in the tank while in a forklift theres zip !

Put a car LPG tank on a forklift and you'll get that extra few K's.....
Put a forklift tank on a car and you'll stop as soon as its empty.

Just the way they make em

Kingy

I could believe that except that forklift bottles are lying on their side, so I'd think the pickup if it was seriously offset that much the bottle would run out differently depending on which side it was turned to.

i would think its to do with the size of the gas feed line.
proportionaly the forks feed is much larger than a cars. ie it will allow enough vapour flow to allow full power from a forks small motor. wether the motor is drawing liquid gas or vapor its still enough fuel for running, where in a car, vapor is only enough for limited guts.
when the vapor is gone - you got nothing.

popeye wrote:i would think its to do with the size of the gas feed line.
proportionaly the forks feed is much larger than a cars. ie it will allow enough vapour flow to allow full power from a forks small motor. wether the motor is drawing liquid gas or vapor its still enough fuel for running, where in a car, vapor is only enough for limited guts.
when the vapor is gone - you got nothing.

Possible, hoses for fork lifts are pretty serious size, but tthat would also be for maechanical strength, temperature of bottles perhaps, forklift bottles are often in the sun during the day, cars are in shade underneath.

do the experiment - adjust the shutoff valve by turning it towards the off position until you loose some power at full throttle, them open it up a bit like a 1/4 turn. run the tank till empty. if you get some warning of the gas running out - it's the line size. if not, then you probably touched the wrong valve. Imeadiatly swap forks with the new bloke who can't speak english too goodly

Rainbow Warrior wrote:I could believe that except that forklift bottles are lying on their side, so I'd think the pickup if it was seriously offset that much the bottle would run out differently depending on which side it was turned to.

Car bottles are also on their "side"..... its the relevant distance from the pickup tube inside the tanks to the "floor" ( or as you called it 'side' ) of the tank

Feed lines "can" have an effect but it is only a limited effect....even feed lines similar to a car size will see the forklift stop rather than simply loose power as in a car situation.

Small tanks also have some effect in the equasion but again its a limited effect..... cars fitted with small tanks still run on for some distance ( although reduced ) but the forklift stops !

The reason forklift bottles have the pickup tube so close to the floor is that they are a removable item and often the operator doesnt put the full tank in absolutely perfect in relation to the internal pickup feed tubes location. As a result the manafactures allow for this "error" of fitting by simply placing the feed line close to the floor of the tank....

Kingy

V8Patrol wrote: Car bottles are also on their "side"..... its the relevant distance from the pickup tube inside the tanks to the "floor" ( or as you called it 'side' ) of the tank

Feed lines "can" have an effect but it is only a limited effect....even feed lines similar to a car size will see the forklift stop rather than simply loose power as in a car situation.

Small tanks also have some effect in the equasion but again its a limited effect..... cars fitted with small tanks still run on for some distance ( although reduced ) but the forklift stops !

The reason forklift bottles have the pickup tube so close to the floor is that they are a removable item and often the operator doesnt put the full tank in absolutely perfect in relation to the internal pickup feed tubes location. As a result the manafactures allow for this "error" of fitting by simply placing the feed line close to the floor of the tank....

Kingy

Yeah, but does that mean if the bottle isn't rotated the same way every time it will run out when it's not actually empty. I've always tried to level the guage, but sometimes the hose connection position prevents this.

i think youll find that cars run gas computers which allow changes in the mixtures so they can run leanmer or richer depending on the amount of gas being drawn in on the intake stroke

chevJ40 wrote:cars run gas computers

Never seen a " gas computers " on a car yet !!!!...... that is unless you mean the puter which controls the ignition in fuel injected motors ?

There are two main types of LPG "feed" systems.....
& before we go any further......
there are 2 main things under the bonnet which deliver and control the gas, they are ...
A/
The MIXER..... its sole purpose is to mix the gas with air as it enters the intake manifold
B/
The CONVERTER ..... is converts the LIQUID LPG into a vapour using heat from the engine ( usually through the engines cooling system IE: hot water )

There are obviously other bits under the hood too ... a safety switch which stops the flow of LPG when the engine is killed and also a LPG lockout valve.... it too stops the gas when the engine is killed.
But thats about it !


Back to the 2 types of systems.....

1/
COMPLEX.
The complex system uses a complex converter which does ALL the metering of LPG into the engine via a "Simplex" mixer. The simplex mixer usually is a ring setup that sits between the carby and air cleaner.

2/
SIMPLEX.
The simplex system uses a simplex converter, its only job is to convert the liquid LPG to a vapour. Its the complex mixer that meters the flow of vapour LPG to the engine, this complex mixer usually sits ON TOP of the carby and uses a replacement airfilter system

Rules....
You cant run a complex converter with a complex mixer ..... not compatible
You cant run a simplex converter with a simplex mixer .... not compatible

Generally.....
COMPLEX systems are used on small engines.... IE: 4 & 6 cylinder motors
SIMPLEX systems are used on larger engines ... IE: V8's and some of the larger capacity sixes.


As for a puter .............
Not unless your talking about LPG injection and even then its a replacement puter for the engine management system not soley for controling the LPG.


Kingy