Please no wife tales on this one. Why are some UK people advising exhaust valves to 0,25 mm. I do know why but need to be convinced of the benefit. I have service 1000’s of A-models and ALWAYS adjusted the exhaust valve at 0,20 mm just like Citroën recommend. Never had any problems even in extreme hot condition in the Australian out back, driving for weeks, no worries.

i set around tight 9 thou road up to 17 thou race,

I know its done to allow more heat to move away from the valves. No worries when racing but why on earth set the valves to 0.25 on standard street cars. They do not over heat if the engine is serviced correctly. If/when driving around the UK winter with this setting, the engine oil never get to correct working temp. not good for engine. Even with 0.20 mm its struggeling to warm up, hence the plastic cover in front of the fan.

Hi Viking,
too late this evening/morning to launch into heavy technical stuff, but surely it's obvious that valve clearances can have no effect on the overall temperature of an engine?

That will be determined by the condition of its cooling system, plus the throttle opening, ignition timing, fuel/air ratio and so on...

ken

It may be kindergarden stuff but worth looking at.
http://www.volksfolks.org/trainingfilms ... tments.mov

Incorrect adjusted valves do indeed effect the engine temp.

valve timing too
the ammount of overlap on the cam and any exhaust back pressure(if it exists.....but lets not go back down that one )

i had used 0.3 for a bit but now starting to look at using smaller.

my engine seems happy at 5500rpm just sits there all day below 5000 it just isnt as smooth

Sean