Oversize valves in B36 head? - The Unofficial BMW M5 Messageboard (m5board.com)

cspargo · 11th February 2009, 18:59

So I'm having my cylinder head rebuild, replacing guides, a few exhaust valve seats, etc. Got me thinking about the relative value of replacing the stock valves with oversize.

Any input one way or the other?

Any cautions on replacing the guides? Don't know if they're machined out or pressed... ( Good thing I'm not doing the work.....

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corneredge · 12th February 2009, 05:08

I don't see a reason why you couldn't upgrade to the S38B38 valves, just be sure to check valve springs and other variables as well.

roortube · 14th February 2009, 00:02

you should call the guys at VAC motor sports...they're in the USA and have consderable experience w/ S38 performance up grades. They'll be able to walk you through the pro's and con's of cylinder head modification as it relates to this specific engine.

WillM5 · 15th February 2009, 10:11

Korman Motorsports uses bigger valves in their setups as well. Metric Mechanic knows a great deal about the S38 Valve train as well. I have delt with them personally and the owner Jim Rowe has a vast knowledge of the motor. I almost went with the upgraded valves on my engine but didnt as i was on a budget. I did use there valve guides thou, and they are by far the best i have come by. 1-573-765-1269 and ask for Jim, great guy and will tell you anything you want to know about your valvetrain. Tell him Will sent you.