Outer Limits 4x4 Board

Hi guys,
I am relatively new to this LPG caper and am still trying to get my head around it so please bare with me.

I’ve a 2a with a 302 Cleveland which is set up for dual fuel. The car has been running pretty hot even on long runs, god help what it would be like in low range in the mountains. I have just moved to Brissy from Melb and the poor girl doesn’t like the heat.

I have just had the radiator (Ford GT, rather large) overhauled which didn’t make any difference. I backed the timing back from around 12-13 BTDC to around 9-10 BTDC thinking that it might run a bit cooler. The girl starts well, and runs well, however, when I pull up at the lights (sometimes) she will not take off when I put my foot down. Sort of splutters and has to be nursed back to health for a few seconds or so. This has only occured since I backed off the timing.

It is running a Aussie B2 gas converter into a 650 Holly, I understand that you should tune for one or the other in my case gas (fuel is ok on the highway in the city I just pull out the choke a fraction to keep up the revs) the RPMs are around 500. Does the gas air mixture influence the running temp? It may sound funny but I'm running out of ideas. The only screw into the converter that I can see is an allen key.

Thanks in advance Tim.

i'm not rite into gas but i got a f truck that runs on . when it was getting tuned the dude said if it runs a bit hot to richin it up a little . u mite have to find some one that dose gas tuning and get the heads up .

Retarding the timing will make it run hotter, the combustion takes place later and more heat passes into the cooant jacket via the exhaust port and cylinder head. The timing requiement can be worked out correctly on a chassis dyno and honestly a recurve of the distributor is most likely required for optimal performance.
The splutter is most likely a lean miss, and /or high resistance in a secondary ignition component; ie, plug, lead, cap ,rotor, coil. More timing will help cover the problem but is not the solution. I have seen incorrect coil voltages on engine conversions, due to the use of electronic ignition with ballast resistors and other such issue.
The mixture should also be set on the dyno as it is the only practical way to load the vehicle in the areas that the problems are occuring to check mixture and ignition patterns.

If it overheats when idling you should be looking at air flow, clutch fans, shrouds etc.
Yes the mixture can effect the running temperature, lean mixtures burn hot and that heat is transfered to the cooling system.


Joel

Thanks very much for taking the time to reply. Much appreciated.

Tim