Brumby LPG conversion

smiles · Post by **smiles** » Tue Mar 09, 2010 1:23 am

Mate! You are such a help - thanks! I'll knock up a tank cover this weekend. The car is running pretty well. Got about 390km so far out of the 75 litre tank which is almost empty. I'm looking forward to seeing some possible improvement after the distributor mechanical advance mod and some more tuning of the gas mixture settings. There were two problems with the system when I picked up the car. It would back fire in the exhaust a lot when gearing down, and when the engine was under load- when going up hills, there would be a bang from under the bonnet and momentary loss of power, so I assume the gas in the manifold was lighting up due to an over rich mixture, etc. Leaned it out by screwing the knob in the hose to the mixer in a few turns and both problems are solved. I hope I am approaching this in the right way..

steptoe · Post by **steptoe** » Tue Mar 09, 2010 8:43 am

The tune should not be up to you to get right first time though. With LPG it is best to get it right. Too rich burns hotter like Diesel, too rich in petrol runs cooler to an extent. Too rich in LPG and Diesel gets too hot for a lot of things.

I use NGK plugs BP7ES - a colder heat range plug and reduce gap by 0.2mm from specs as per NGK technical recommendations. Don't be tight on ignition components, they need to be in better condition as the spark works a bit harder to fire - making life hard for the coil. So, I use the plugs above, renew dizzy cap and rotor more often and good leads - Eagle Performance (web site and in the 02 47 region of syd nsw region) black leads with gold print LPG spec leads.

With tank cover access is required in emergency for taps. Send me a PM with email and I'll send you a few pics of mine to give you starters

steptoe · Post by **steptoe** » Tue Mar 09, 2010 8:45 am

Is that 75 litre useable or water capacity? Useable is 80% +/- 2% of WC

smiles · Post by **smiles** » Tue Mar 09, 2010 7:23 pm

That's 75 L water capacity. Does that sound about right? (400km for 60L) I sent a PM.

steptoe · Post by **steptoe** » Wed Mar 10, 2010 2:54 am

SENT me a PM? Not got it yet! I'll send you 1. That is 60 litres of LPG +/- 2% . If you have petrol as well that makes it easy to check capacity. Hard for my dedicated system to rely on exactness or I'm pushing !!

11.5 to 12.5 litres LPG to 100km or 540km is my fill by distance has been 64 to 72 litres depending on slope of servo floor and fuel slurp rate.

smiles · Post by **smiles** » Wed Mar 10, 2010 7:10 pm

"Too rich burns hotter like Diesel, too rich in petrol runs cooler to an extent. Too rich in LPG and Diesel gets too hot for a lot of things."

Does it burn too hot if LPG is too lean as well, or am I safe to lean it right out until it loses power?

steptoe · Post by **steptoe** » Wed Mar 10, 2010 10:16 pm

cannot say if too lean too hot - I can say too lean, too much load on ignition, too much engine load and you get a backfire