"Well, my 145 runs on a single carb-setup. LPG here in holland is about 1/3 of the price of unleaded (40 eurocents). Usualy we pay about 900 Euro roadtax for a LPG-Car (this depends also on the weight) but because it's an oldtimer, there is not roadtax at all, so it's a bonus for the hobby. I have an underfloor arrangement with a small petroltank and a 55 ltr lpg-tank all out of sight (it's an estate) consumtion is 10 km to the litre so with the safety valve modfied a little bit, I can run about 450 km on one tank, wich is the average for me for one week."
Here are some tips from Tony on building up a LPG-specific head:
"Well, I can only tell you what I did. Unless the valveguides are worn, they don't need any special attention. The stemseals I only put on the inlet-valves (to prevent sucking oil in on deceleration). Exhaust valves are still lubricated generously without the seals with no negative results. What realy is needed are stellite (hardened) valveseats for the exhaust valves because otherwise you have to keep adjusting the tappets and the valves will end up in the head due to a lack of protection by the lead.
With adjustment every 3000 miles a standard head will last about 30,000 miles. This is always the case with cast-iron heads, alloy heads usually already have inserts. I also tried some leadsubstitude products, but not satisfactory. They don't keep what they promise, if you want performance out of you engine (wich means high revs), the inserts are the only way to go!
Also try to port the head as much as possible, so get the inside as smooth as possible and make sure that there is no step around the inserts, grind-in the valves with lapping-compount, first with course and finaly with fine until the contact faces of seat and valve are dullgrey. There is still one thing that needs special attention though, inside the head there is a copper pipe in the waterchannel that distributes the coolant directly from the pump evenly to the valveseats because they are the hottest point of the engine. These pipes tend to come loose and float in the head, thus preventing even cooling and mostly resulting in a split head or burned valves on cilinder 4 which is the farmost cylinder from the pump. Through the thermostat hole you can check the pipe for loosness, if the head is off you can also hear it rattling if you rock the head.
Most of al the things above I had to find out myself, since most people just run their cars without concerning to much, but not I! You are most welcome to put these advices on the forum if you like. For now good luck and keep these old swedes rolling and as we say 'A volvo is not just for Christmas' ".
