Adding valve spring spacers

[Brotok]

I am re-assembling the heads of my SC after doing a valve job and am curious if it is customary to put additional spacers under the valve springs after grinding valves and seats, especially when some of the seats/valves required a lot of grinding due to pitting. The car had 300k miles on it and I decided to reuse the springs. Might it be wise to add spacers to compress the springs so as to stiffen them to compromise for aging/improve performance?

Than you.

[cgarr]

Use how many shims it takes to set the correct installed height. There is a spec to follow for this, Intake and Exhaust 34.5 - 0.3mm shoot for the lower tolerance.

[john walker's workshop]

6 shims seem to be the usual amount after a valve grind, but yours may differ after checking recommended installed height. put in 5 or 6 shims put the spring seat in and put the retainer and keepers on the valve and pull it tight. then use a small 6" metal ruler to see what you have. preferably with a metric scale. baum tools sells a height gauge but you don't really need it. new springs are a good idea, because they get tired and they're also famous for breaking, on SCs more than other engines, for some reason.

[911pcars]

John,
What is the thickness of a spring seat washer? Just one size?

Thanks,
Sherwood

[BK911]

So what determines the spring height? I don't have my spec book handy, but I seem to remember the T, E and S all use the same valves and springs, but all had different spring height specs and red lines. Does the cam set the spring height? And the spring height sets the red line? Can you adjust the T spring height to get an S red line?

[john walker's workshop]

the shims are 0.50 mm.

[911pcars]

Originally Posted by john walker's workshop

the shims are 0.50 mm.

Thank you sir.

Sherwood