How to measure valve spring height?

[Dave Kost]

I am re assembling my heads on a 2.7 engine and I want to measure the valve spring heights. The spring sits inside the valve spring platform and under the retainer.

Can some post a picture showing how this is accurately measured?

Thanks.

[cgarr]

Dave, I use a light spring to hold things in place then measure my gauge after taking the measurement.

[safe]

I just measured from the top of the base to the top of the retainer and then added/subtacted the known thickness of the retainer and depth of the base.
Accurate enough? Probably, since the thinnest shim is 0.25 mm.

[Dave Kost]

Thanks.

It worked perfectly!

[boyt911sc]

Originally Posted by safe

I just measured from the top of the base to the top of the retainer and then added/subtacted the known thickness of the retainer and depth of the base.
Accurate enough? Probably, since the thinnest shim is 0.25 mm.

Magnus,

So the compressed height/length of the valve springs is referred as the spring height (installed)? So adding/removing shim alters the compression value for the springs accordingly? At what point (test) you could say that the springs are old and tired. And needed replacements(?). This is my predicament about valve springs' evaluation. Please share your thought about the subject. Thanks.

Tony

[cgarr]

Here are my thoughts for whats its worth after checking 100's of springs over the years: There is no better spring out there for a stock engine up to 7k Porsche really got it right with these springs and why they have used the same setup for decades. I rarely find a bad spring, seat pressures are consistent at the same installed height, but remember your height change will change the pressure and some over shim the spring to get more pressure but then you can run into spring bind with higher lift cams. If your not building an all out race engine don't waste your money on performance springs, it just robs HP, crates more heat and ware on the rockers and cams.

[safe]

Craig has tons of more experience than me, but I share the opinion that they last "forever".
We recently checked a friends 993 that has 15000 race only miles, we thought it could have bad springs, but all springs were OK.