That there be my post in another thread.Originally Posted by Ldub
I can't find it now, but wasn't there a reference to LPG conversion having a tendancy of burning exhaust valves?....
http://vehicross.info/forums/showpos...93&postcount=7
When LPG conversions first came out, they recommended that you changed the exhaust valves to those that had been made of?? or treated with?? Stellite.
IIRC it is a change in materials that makes the valve harder and allows it to withstand hotter temps.
But gee - that memory is about 20 years old - might have all changed since then.
Might also only work down under where the exhaust gasses fall out of the cylinders.
You guys up on top have to push the gas out.
Although, looks appropriate in this instance.
It would be nice to measure the adjustment of a few valves before dismantling, and then dismantle to check condition. If condition worsens with valves out of adjustment, that would just about pin it down.
While I am on my soap box - I agree with Scott - replace the head bolts if you can get them.
Cylinder head gasket crush is one of the hardest things to get right when assembling an engine, and new bolts just add that little bit of extra insurance.
I have done it with old bolts, but only on older cars (pre 1980) when the torque values are lower, and the cylinder pressures less.
On those engines, I had to re-torque the head after about 1000 miles.
Some of these newer engines even have a "waisted" neck on the bolt (reduced diameter) to control the plastic deformation.
That type of bolt cannot hold the same tension when used again.
PK
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