Valves, 0.1mm, turn, Whaat? 0.2!!

[Zendalar]

Ok, could somebody tell me what I am doing wrong. I am adjusting the valves in the same order as my cars (911T) ignition. Last night I adjusted valves couple times and everytime I adjusted one intake valve to 0.1mm and went on with the others, and went to check them again, the valves were 0.2mm. Not all, but some. I cranked some more and then the gap was "randomly" on others.

I have adjusted valves before (not on Porsche though), and the valves do sound just normal...Why was the gap 0.2 then?

//Zen



[This message has been edited by Zendalar (edited 06-11-2001).]

[Jdub]

I don't get this one: the only time I have had random results was in a BMW R75/5 that used brass bushes betwixt the rocker and the shaft: worn elliptically, the bush would cause a different measurement for every rotation (ever hear a 2-opposed BMW motorcycle that has cyclic clicking from the 'heads when idleing?).

In all events, you have a result you didn't expect. I think Warren or JohnW can help here, but I would venture to say that when you cinched the locknut down, you somehow moved the threaded post. Or, you didn't check your measurement after cinching? Beyond this, if you KNOW your measure pre- and post-cinching was identical, then something is worn and, during engine rotation, this wear is causing differing results.

I would be VERY interested in anyone else's opionion on this one. I hadn't thought that the Pcar could be inconsistent in this manner.

Jw

[john walker's workshop]

i would think that you haven't quite gotten the feel for the 911 adjustment yet. you must use the proper gauge holder to even get close. then the adjustment is correct just at the point where the gauge will just pass under the swivel foot with two or three twisting motions. if it slips in or out easily, it's too loose. too tight and the gauge will get bent up. it takes practice to just take up a tiny bit of clearance to fine tune your adjustment to perfection.

[This message has been edited by john walker's workshop (edited 06-12-2001).]

[Zendalar]

Yes, I have this modified normal feeling gauge its a L shaped. The way I measured it was that I adjusted the feel and tightened it up. After tightening I tested the gap again and if it were not correct, I readjusted it. So I did the tightening all right. Maybe there are some worn parts that cause this, after all, the valve head has this brass cylindrical thing right above. So maybe there was oil inside it.

//Zen