ROCNDAV

iTrader: (100)

I read that my valve springs should be checked every 20K miles. I have them off of my heads right now, and I would like to get a base measurement so I have something to compare them to in 20,000 miles.

I have a valve spring pressure tool that I can mount in a vice or arbor.

So my questions are:

1. Do I measure at installed height and also at coil bind?

2. Do I measure the inner and out springs seperately or together as an assembly (I'd think seperate is that way, but just want to make sure).

NHRAFORMULA00

iTrader: (2)

You measure with the springs together,measure at installed height= seat pressure, then measure at the height they are rated for max lift for open pressure.seat pressure is more important than open,so if they are not close to what they are rated at,like 10-15 lbs seat pres ,replace them!

Yeahdoug

For an accurate measurement you need shim up the inner to account of the retainer step.

Old SStroker

Picky, picky picky.

What if the locator also has a step?

ROCNDAV

iTrader: (100)

Thanks guys.

Yeahdoug

Of course I"m picky

Steps on the locators? Those are not very common. I've haven't seen anyone recently from street, prostock, to nascar that runs a step on the locator.

Its a 5 pound difference on the Patriots... It makes a bigger difference on our higher rate springs.

Old SStroker

I haven't either. I was just picking your brain. The step in the special retainer was adequate and still kept the retainer mass low. It was for some of your not too common springs.

If you needed a large (.200?) difference in installed height between the inner and out (for some reason), I suppose a stepped locator could help reduce the mass of the retainer, especially if it was a "heavy" steel one.