when 10 to 1 pistons were fitted you could get 100 octane leaded petrol now with unleaded you lose the lubricating quality of the lead so when using LPG you need some flash lube or something similar to prevent valve recession if you have not got stellite valve seats .
Vehicles made for unleaded fuel have already got seat that will prevent this .I dont know if the RR you have has got them but I would use the Lower comp pistons and then you can run on unleaded fuel with out preignition which can kill an engine.
 
ukadamwest said:
It's only going to be a couple of degrees difference surely. . ?
Click to expand...

The spark is advanced from the static setting dynamically by the distributor at higher RPMs. The distributor fitted to the LC engine may not give enough advance for the HC engine, you will have to look at the parts list and see if a different distributor was fitted to HC engines. It's not quite as simple as just fitting higher compression pistons.
 
Thanks Wammers..

Indeed it seems you are correct, the Parts Cat shows a different dizzy for the 9.35 and the 8.13/8.25 CR engines and a different vacuum module also.

The PC shows an electronic ignition dizzy for the CR differences
 
ukadamwest said:
Thanks Wammers..

Indeed it seems you are correct, the Parts Cat shows a different dizzy for the 9.35 and the 8.13/8.25 CR engines and a different vacuum module also.

The PC shows an electronic ignition dizzy for the CR differences
Click to expand...

There you go. ;);) I did a bit of useful trolling. :D:D:D
 
Who's the Glow worm Tony??

Hope it is not a reference to either Adam or myself !!
 
Grand....

Tomorrow evening is to strip the other head and see whats what with the valves.....but the other head is the one with the valves stuck open and the valves don't look good!!

f250.JPG
 
Ant.. I won those overhauled heads we looked at..

no *need* to strip the other head down, can do it at leisure for S**ts and Giggles
 
After Ant's efforts to recover the pistons.. I thought I would have a go... 30 minutes later with some elbow grease here's the first...
20151030_113446_zpsvkklmfkm.jpg


Only joking.. New pistons and gudgeon pins arrived
 
Hummm shiney, keep up the good work shame Ant couldnt save the pistons, but loveing every new thrilling installment:)
 
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