Re: straight 8 head resurface

Posted by HH56 On 2023/7/3 12:32:45

I'd think very hard about that much coming off particularly if you cannot be sure the head was never machined before.

If you do decide to try it by all means do not bolt the head down before testing. Use something like a layer of thin modeling clay on the head above the valves. Lay the head back on the block without any nuts or the gasket and turn the engine thru a complete valve cycle looking for any evidence the head is raising. If you don't see anything then pull the head off and check the clay for signs any of the valves raised high enough to leave an impression. Go from there if there are impressions to decide whether it is minimal and a slight clearance grind of the combustion chamber above the imprint is enough of if the head will need to be scrapped.

If you are lucky that much off will be tolerable but also keep in mind that if the car has hydraulic lifters, those were probably low so in use could raise the valves slightly higher.