Well my MCS started misfiring last week on #1 which led down a long path of determining the problem. After checking/replacing all of the obvious ignition/fuel items the problem still persisted. The engine was firing on all cylinders as proved by removing a plug wire and having the idle worsen, but something still wasn't right. This led to a compression test and finally a leak-down test. With #1 @ TDC air was leaking past the exhaust valves. The head is currently off and disassembled, and the problem seems to be pitted exhaust valves that were holding carbon deposits preventing the valves from completely closing. I'm currently in the process of lapping the valves, but I don't know if they are too far gone to save.

That brings me to a request from NAM members. Could someone give me the valve specs from the Bentley manual? A picture or a scan would be great. I need to get this head back together ASAP, and I don't have time/money to wait for the Bentley manual to ship. If anyone could help I would be most appreciative.

Thanks,
Josh

 

What specs do you need? Seat angles?
Since everything is apart, you'd be best off just replacing the valves and lapping the seats.
See attached file for seat specs.

 

MrBean, thanks for the info. I managed to find those specs on the Bentley website, but that's all they provided. I wanted to know the installed valve height (from he tip of the valve stem to the a location on the head). As I grind the valves the stems move upward and I want to make sure that they are still within spec. As it stands my valve seats are getting close to the maximum and I can't really grind much.

This is what I'm looking for:
http://www.kmotion.biz/images/Installed.jpg

Thanks again for the help,
Josh

 

Sorry, my manual doesn't have that info.

 

These are the most detailed specs I have found. The Bentley includes very little on engine internals.

http://www.bmw-planet.com/lib/mini/ENGINE%20TECH.pdf

 

Thanks MrBean and David.R53 for the info.

 

Did you ever figure out what the stock distance of the exhaust valve should be? From the tip of the valve to the spring perch area or top of the stock valve guide? I'm also installing new valves. I can see the new ones are a wee tad shorter than the original pitted valves. Which makes sense if the old original valve moved "up" over time as the base wore out...

 

.oops double post