Technical Valve spring micrometer...who makes a good one?

Doing the SBC heads on my son's '60 chevy pickup and trying to measure the valve spring height. The valve spring micrometer from Proform tools feels and looks like a quality piece but it doesn't measure accurately. The markings on the side correspond to the overall height of the tool, not from retainer's bottom to the bottom of the tool. I have found that I can measure with it but then subtract .014 to get the correct measurement. This isn't bad but kind of a pain in the ass. Who makes a good tool that reads correctly? A quick search looks like Summit, Jegs, etc. all sell the same one that Proform sells??
Thanks-

 

In addition, the aftermarket retainers we are using don't fit inside the top of the tool. Stock ones do...

 

In post 2 you answered your own question from post 1 the retainers you have are designed in a way that they don't fit the tool right. I'd imagine that "doesn't fit is your .014 difference.
Old school wrenches used a snap gauge and caliper or micrometer before the spring micrometer came into use.

 

Since shims only come in .015, ,030, and ,060, just how close do you need to be. Try measuring your tools hight with a dial caliper, then sand it down to the correct hight, no need to keep subtracting when sand paper would it once.

 

^^^^^ Each spring should be measured first and noted for it's given pressure and height them matched to valve that fits measurement best.

 

The trick way is measure all of the valves and find the shortest height. Then shim the rest of them to this figure as close as possible +/- .020"

 

Thanks for the insight - the .014 difference exists when using a stock retainer that does fit the tool, maybe I can try and take a few pics to explain my self clearer.

 

these particular heads I can't fit a snap gauge in squarely...

 

So (if the pictures are clear) you can see the mic. is set so that it reads 1.80, yet when it is checked with caliper it is actually 1.66

 

The OP's .014 is actually .140...I have in the past machined a valve spring mic to correct the reading to the retainers/spring seat I was using..40 years ago so don't remember details but some lathe work should get him where he needs to be..

 

Another technique is to simply cut up a couple few pieces of heavy wire or rod, coat hanger etc, in different lengths measured with your calipers, and round the ends. Use them as a kind of go/no go gauge when you check each assembly stack up minus the spring and add a shim or two as required. The main thing is to get the installed height of each spring within spec, it will run noticeably better. Weak/worn out valve springs are commonly overlooked.

 

oops, you are correct, .140 rather than .014
thanks for catching that

 

Everone that has posted here is missing an important measurement...DID YOU MEASURE HOW DEEP YOU GROUND THE SEATS IN YOR HEADS??? didn't think so.....

 

Cheap checker. Stock of lets say 1/8" x 1/8" x 1.700. Now weld a handle off the middle of it so it ends up looking like a T. Think of it as a "go no go" gauge. It will go for sure, now throw in a feeler gauge under the retainer and over the t gauge and add things up.

 

The "go-no go" idea is intriguing, been thinking of doing something similar to use when measuring the springs pressure in the vise.
Not being argumentative, but won't measuring the height of the springs essentially tell me how deep the seats are, as in needing to shim to get back to the correct height??
Thanks-

 

What's measured on the heads is the distance between the machined pad the spring rides on and the underside of the valve retainer. What you end up doing is installing a shim or two to kind of pre-compress the spring whether it's .020" or .030" say, this increases the spring pressure on the valve to spec. The shim itself isn't counted when measuring spring height. Measure all 16 and find the shortest height. Then shim the rest as close as you can to that one. This makes every spring more consistent with each other.

I replaced all 16 with heads installed and managed not to lose any of the 32 valve keepers down inside the engine, or across the garage. PITA. Was pretty proud of myself. It's tougher to setup without a valve micrometer, they don't make one that fits on Y block heads. So I eyeballed each with a machinist rule. Close enough for my purposes and it runs noticeably smoother.

Weak valve springs will cause the valve to bounce on the seat several times before closing robbing power and will float at high RPM. Any engine will basically only rev as high as the weakest spring.

 

I hesitate to say this but has your caliper been calibrated?

 

Using a caliper measure the distance between the retainer bottom and the spring seat for each valve (it should be the same for all if you cut the seats correctly). On a spring tester measure each spring height at the seat pressure you want to use. Then fill in the difference with the closest shim you can get. If you are not sure the seats are equal you can still juggle the shim height for each valve.

Phil

 

Is it really necessary to try to measure the valve spring height in your son's '60 SBC chevy pickup? Enlighten me. Jack E/NJ

 

Sorry, I guess my work on race engines didn't take into account it was s street engine....Phil

 

Heck no, it's not necessary, though neither is owning a '60 chevy pickup for that matter. It will run better though with fresh valve springs.