Re: Valve marks on head

Posted by Owen_Dyneto On 2017/6/7 14:24:01

You could first set the valve clearances to spec and then do the rather standard test, described here many times in the past. Put some modeling clay or putty on the heads of the valves, put the head on with the used gasket but DO NOT bolt the head down. Rotate the engine through several cycles; if the head rocks up and down you will want to hold it down with hand pressure, then remove the head and inspect the thickness of the clay remaining on the top of the valves. Any valves which are actually touching the head will be clearly apparent.

Alternatively but not quite so definitive would be to just lay the head in place with a used gasket and watch for any movement of the head while you slowly rotate the engine.

If you are out of clearance because the head was milled excessively, you probably won't be successful in finding a thicker-than-stock head gasket - so time to check out your spare head. Many folks over the years have tried doubling up on head gaskets but this is never successful for more than a very short time, it at all. Others have had extra thick gaskets made from solid copper sheet, quite expensive to have made and I've never seen it succeed either.