They should be noisy ... I'm not happy unless I can hear mine, and I usually set them to 0.25, mostly because the 0.15 and 0.10 feeler gauges are the only ones I can still read the numbers on after years rattling around my toolbox. I know they're wider than Haynes recommends, anyway. Don't worry about it, rattly tappets never hurt anyone.

Actually, they have

Engines in general, if the valve clearance is excessive, some of the camshaft’s usable lift is consumed just taking up the slack in the valve train to close up the excessive clearance, and won’t actually be used to lift the valve to the desired open position. This results in power loss, due to the valve not opening as far, opening later, and closing earlier, than intended by the manufacturer. It also result in excessive ticking noise when the engine is running, as the valve is not opening and closing as smoothly as it should, due to being on a steeper part of the camshaft lift profile when opening and closing. The valve-gear is also "hammered" more than with the correct setting. So there is some "hurting" going on with wrong settings.

Some people have worked on 2CV's for ages, and they have valuable knowledge. I know some will say wider is better on a 2CV, and I will not argue that. Simply because I don't have the necessary experience, just 4 years with just my own 2CV's(But all my life with other Citroen models), to say one way or another. But of the two wrongs of to small and to large setting, it's better with to large than to small. Everybody agrees to that.

But for my self, I have always set valves to manufacturers spec., 2CV or not. I simply trust the engineers who built the engine. Never had any valve-related troubles so far

Joe

if your dad did the tappets to 0.2 and now they are wider it would suggeat that the heads may need re torquing

what oil seal do you need to take the head off to do??

if you have been running loose heads and its been pinking it may be worth taking the head off anyway to check that there has been no erosion of the barrel contact part of the head. Smear of copper grease on assembly

timing.
peg the flywheel,mark the bell housing and closest tooth count round 7 mark that one with bigger mark ,32*, max etc

start engine point strobe at marks and slowly rev it to 3.5krpm at which point the big mark should be in line with the bellhousing one and the first should be under the bellhousing

tappets
a slightly wider tappet gives better power due to the cam timing, ok so it causes increased wear but so does accessing that exta power, swings and roundabouts,win some loose some , get nothing for free etc
The original setting would have been stated for both quietest possible running and maximum service interval/reliability.
wider tappets will not have caused pinking problems
too tight and then there is burnt valves and starting problems

Sean

Sorry haven't read all of it. Replace the advance weights and set the timing 8 de. before TDC static, no worries even on low octane fuel. Pinging gone.

i've never done weights viking! although its a 2cv... how hard could it be?

Eirijk,
the factor which you do not seem to have considered is that fuel containing tetraethyl lead was in use at the time the 602 engine was designed.
Even though this engine uses hardened valve seats, the rate of valve seat recession _will_ be faster when the engine is fed unleaded fuel, especially when driven hard, so either the intervals between valve clearance checking & adjustment need to be made shorter or the target setting for the exhaust valve increased _slightly_.

Using 0.2mm for the inlets is on the upper limit of Citroen's recommendation anyway, so I fail to see how anyone can quibble about that.
Increasing the exhaust valve setting to 0.25mm is such a small amount that any additional inertia loading on the valve gear is unlikely to be significant.
It certainly hasn't done my everyday engine any harm, since that has covered well over 200,000 miles, the majority of that on unleaded fuel and towing a trailer weighing around 350 kg.

Things didn't work quite so well for a customer of mine from Wales, who set off for the WM in Czech last year without adjusting the valve clearances on his Dyane.
Although it made it home again, by that stage it was running so badly that it was towed here to be 'resuscitated'.
Easy enough to fix, as in the 2,000 miles to Most and back, both exhaust valves had lost all of their clearance, but luckily the valves hadn't been burnt out...

ken.