Does LPG run hotter?

**Cannon** · 5th July 2011, 05:37 PM

Hi all,

I've had my system in for a few weeks & I'm loving it

However I've noticed the coolant temp is about 2-3 degrees hotter than usual.

Is this normal?

If the mixture is too lean does it run hotter?

It used to hover around 92 but 93-95 is the norm on LPG now.

2003 V8 4.0 Thor

Thanks for reading

**rovercare** · 5th July 2011, 06:59 PM

Originally Posted by Cannon

Hi all,

I've had my system in for a few weeks & I'm loving it

However I've noticed the coolant temp is about 2-3 degrees hotter than usual.

Is this normal?

If the mixture is too lean does it run hotter?

It used to hover around 92 but 93-95 is the norm on LPG now.

2003 V8 4.0 Thor

Thanks for reading

Alters the cooling path ever so slightly as its warms the gas through the convertor, using the heater circuit

**bee utey** · 5th July 2011, 09:24 PM

LPG burns more slowly so tends to create extra waste heat if the engine isn't specifically built for gas, so yes, the effect is real although slight as you found out.

pottsey · 16th August 2011, 01:24 PM

I am noticing the same with my 97' on LPG but the temp is roughly 10 degrees higher at anytime...
Any suggestions at all on how to add extra cooling or lower the temp any? Will be a real test if we get a decent summer this year towing the boat!

**Cannon** · 16th August 2011, 02:00 PM

My temperatures tended to increase more & more over the passed couple of weeks.

Turns out my Viscous fan was on the way out & totally died last week.

I'm picking up the car today so I'll see what the temps are with a working fan.

**bee utey** · 16th August 2011, 03:11 PM

Originally Posted by pottsey

I am noticing the same with my 97' on LPG but the temp is roughly 10 degrees higher at anytime...
Any suggestions at all on how to add extra cooling or lower the temp any? Will be a real test if we get a decent summer this year towing the boat!

First question is: what ignition advance setting are you running? It should be around 10 degrees BTDC at idle.

Second question is: how long since your radiator was rodded? Thermostat and fan clutch need to be in good nick too. A 3.9 should run fine on LPG in all but 40C+ weather.

**djam1** · 16th August 2011, 07:30 PM

I run a 3.5 on gas in over 50 degree temps without issue

**bee utey** · 16th August 2011, 07:41 PM

Originally Posted by djam1

I run a 3.5 on gas in over 50 degree temps without issue

Yep and the 3.5 is the best RV8 for reliability as the coolant jackets aren't compromised by bigger bores.

**Cannon** · 7th September 2011, 09:07 AM

Originally Posted by bee utey

First question is: what ignition advance setting are you running? It should be around 10 degrees BTDC at idle.

Second question is: how long since your radiator was rodded? Thermostat and fan clutch need to be in good nick too. A 3.9 should run fine on LPG in all but 40C+ weather.

Firstly it's a 4.0 Thor motor in a 2003 Disco

Secondly my thermostat was stuffed & my radiator was 40% blocked

Running like a dream at normal 90-92 degrees

**SlowRide** · 19th November 2011, 12:12 AM

I run straight LPG and have done for a few years now - but on a Suzuki Sierra, not a LR - either way the theory is still the same.

LPG will run hotter on a dual fuel installation as standard petrol timing isn't quite right to make the most of the higher octane content in gas. It's not enough to make it ping or detonate, but it's not quite optimum.

To get the best out of LPG, you really need to recurve the distributor to 14º initial timing, and 28º all out (among a few other tweaks)... but, vice versa, change the dizzy to chase maximum LPG power, it will have an adverse impact on how your engine runs on petrol. Either way it's a balanced compromise when you run two fuels with different combustion characteristics.

Best tune to suit petrol than LPG, as LPG is more forgiving.

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