Can't adjust all valves within spec

[Murph]

I'm in the middle of adjusting my valves at the moment. I'm doing them cold as this is the first time for me. So far I've found that all the exhaust valves have had a much larger clearance than .25mm and all the inlet valves have been very tight. Now I've just come to the inlet valve on number 3 and I simply can't get it with in spec. The largest I can get the gap before the stud doesn't screw down anymore is less than 0.05mm when it should be 0.20mm. There is a gap there now at least.

So any ideas why all the exhaust valves are loose and the inlet tight. Also, is it a big concern that I can't get inlet no. 3 in spec? If all goes to plan I'll only be running this motor for another few months at most.....so I'm not too worried if it's perfect or not.

[Ed]

Sounds like your head may have had some work on it. Or is really worn. What type of head is it and is there a chance that it has a different cam?

On your #3 inlet a few things come to mind:

1. Since your valves were out of adjustment the valve has worn into the seat.

2. Someone replaced the valves for some that are a little longer. Different heads use different length valves.

How many miles does the engine have?

Maybe do a compression test to see what condition your engine is in?

Getting your valves running properly is very important. The last thing you want is to break a valve.

[Murph]

The head is an E88 with a lot of km's on it.....not exactly sure but were talking ~500000km. From another forum we pretty much worked out the tight clearance on the inlet valves was due to valve recession into the soft bronze seats, whereas the exahust vavle seats are steel, so don't suffer the recession problem. The large clearances on the exahust valves were just due to general valve train wear.

As is that valve I can't get within spec has a clearance of between 0.1mm and 0.15mm. I'll only be running this motor for another few months and it isn't causing any problems, so I figure I'll leave it well alone.

Compression test before doing the vavles came up with 150 130 110 135 120 120. I'd say it's no coincidence that no.3 inlet vavle clearance (or lack of) was the tightest, and no.3 has the least compression. I'm planning on doing another compression test some time soon.....should be interesting to see how it changes.