Author Topic: TCS Valve Clearance Question: .009 to .011 for exhaust valves only, right?  (Read 288 times)

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Offline thehackmechanic

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TCS Valve Clearance Question: .009 to .011 for exhaust valves only, right?
« on: Wednesday,March 04, 2020, 06:08:23 AM »
Forgive me for beating the dead horse, but I'm a noob who wants to be really sure he's not screwing this up.

I see that, in the manual, it lists the valve clearance spec as 0.005 to 0.007 for the intake valves, and for exhaust the clearance is 0.006 to 0.008 up to engine number 9951, and 0.009 to 0.011 for later engines. I see that there is a recommendation that 0.009 to 0.011 be used for all engines. I just want to be certain: That .009 to .011 is still for the exhaust valve clearance only, right? The recommended intake clearance spec is still 0.005 to 0.007, correct?

Thanks.

--Rob Siegel
'74 TCS, 24k miles, up and running after 40 years
'72 BMW 2002tii
'72 BMW Bavaria
'73 BMW 3.0CSi
'79 BMW Euro 635CSi
'99 BMW Z3M Coupe
'99 BMW Z3
'96 Winnebago Rialta

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Offline EuropaTC

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Re: TCS Valve Clearance Question: .009 to .011 for exhaust valves only, right?
« Reply #1 on: Wednesday,March 04, 2020, 08:35:43 AM »
The inlet is 5 to 7 thou', the exhaust 9 to 11 thou.

The reason there were 2 settings for the exhaust (6-8, 9-11) was apparently because a different material was used for the exhaust valves originally and it was down to thermal expansion.  Because it's expected that the very early valves are no longer around, there's a recommendation to use the 9-11 settings. 

If you're working on the TC engine then Miles Wilkins book is definitely worth having. He goes into a lot of details, even quoting the valve materials used.

Brian

Offline Roger

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Re: TCS Valve Clearance Question: .009 to .011 for exhaust valves only, right?
« Reply #2 on: Wednesday,March 04, 2020, 09:32:21 AM »
And, funnily enough, it's the same answer on this forum as on the Elan forum!