valve adjustment ????

[koos]

Hey chaps, is there any sequence to adjusting the valves on an M20, everything I see just says turn the lobe up? Any help would be great. Is the gap 0.25mm?
Thanks, Mitch

[GDBN]

Hi .... 22mm socket on the crankshaft by the vibration damper .. turn clockwise until cylinder 1 (closest to the radiator) camshaft lobe is pointing down ... adjust valves ...then it will take a 1/3 turn (120 degrees) to the next one and the cylinders are adjusted in the following order 1-5-3-6-2-4.
Don't forget to remove the spark plugs or it will be harder to turn the engine
Hope this helps ....

G

[chu346]

:yeahthat:

[E30Adam]

There's a guide on this site that explains how to do it.

Have a look in the tech articles section.

There's no set order to adjusting the valves. I find it best to work from left to right or vice versa. You'll have to turn the engine over more than the way GDBN states but at least you won't forget which ones you've adjusted.

The gap is indeed 0.25mm when the engine is stone cold.

[Brianmoooore]

Hi .... 22mm socket on the crankshaft by the vibration damper .. turn clockwise

AND DON'T FORGET TO REMOVE IT WHEN YOU'VE FINISHED.
This post is based on personal experience.

[GDBN]

I don't really want to think about what the outcome was after that !!!!!

[Brianmoooore]

Surprisingly little actually, but I wouldn't have wanted to have been in the way of the flying spanner.

[Martinaston]

This is an age old debate, but what is the best way hot or cold ?

[tourer-dan]

I've only ever done them cold as the temperature will stay constant for the whole job.

[orkboss]

And you dont scold yourself on hot manifolds

[E30Adam]

And you dont scold yourself on hot manifolds

You'd be doing the job when stone cold, anyone adjusting the valve clearances with hot engine components would need their heads tested.

[GDBN]

Would the wrong valve clearance have a big effect on the idle ? Just that the idle is still not right having changed the head and I am trying to remember if the guy who built the head set the clearance at 0.2 or 0.25. I am going to check soon but would love to know if this would affect the idle.

[Martinaston]

This is the one job i absolutely despise doing on the car, you can never get them all to match exactly due to the silly little cam on the end of the rocker. You get one done ok then the next one you crush the guage so the third one the guage won't slide smoothly because it's deformed the fourth one the eccentric moves as you tighten the nut...........

The last time i set mine i did them hot and it did make a difference, if your quick you can do them in about ten minuets. The temperature doesn't drop much seeing as it takes about six hours for an engine to go cold.

If you do it this way and you get burnt then i suggest you remove your skin from the hot metal. That normally helps

GDBN
Some one on another thread mentioned that the clearences need resetting if they were done before the head was bolted to the block due to it deforming.

The correct setting is 2.5 to allow for the valve stems to expand because they will reach working temperature before the rest of the head, and if too tight will cause the cam to wear while the engine is warming up.

[GDBN]

Finished adjusting the valve clearances .... and PURRS like a kitten again. Maybe premature as I haven't been out for a spin yet but WOW what a difference ... amazing what a difference 0.05 mm makes !!
Looking forward to a quick trip to the shops later !!