Skip Wolfe

I am getting ready to assemble the head I got from Ski and have a question on the spring spacers. I have 10 spacers of 3 different thicknesses. I am assuming these spacers go under the spring seats against the head and are used to make up for variations in the head castings so that all of the springs are compressed the same amount – is this a correct assumption?

If so, I was planning on measuring the distance from the spring seat to the end of the valve and then use the various spacers to make this distance equal for all the valves – correct?

As usual, I am up against the clock and need to get the head together and on the car tomorrow if possible.

Thanks,

hosrom_951

One thing to consider, when you measure the valve spring height, you measure the spring height when installed.

The shims come in two sizes, 1.0mm and 0.5mm, i don't know how you got a third thickness. The manual states two, and when i measured what i got there was only two as well

Exhaust valve spring height should be set at 40.0mm +0.5mm
Intake valve spring height should be set at 41.0mm +0.5mm

Never have the valve spring height (for either exhaust or intake) installed below or above those values, and you are right, the shims are the first things to be installed, then the lower retainer, spring, upper retainer and locks.

This is what i saved a few months back from google, on how to check the installed height:

Skip Wolfe

Thanks Hosrom. Two of the three different thickness are very close to one another so it must just be small variations of the same spacer. The come out to match the 1 and .5 mm - I need to get me a digital caliper that measures in metric.

Is that height measuring tool something that is readily available?

hosrom_951

You can get valve spring micrometers, which i never used and have no idea if they even fit in these cylinder heads. I know some rennlisters use the end of a dial/digital caliper (the end that sticks out), i used a telescoping gage (like the picture above) and a micrometer.

May i ask, did you replace the valve guides, have the valve seats cut? has the cylinder head gone though any work? (just making sure you are not missing anything that needs checking).

RKD in OKC

The tool shown is called a Hole Gauge and is a standard measurement tool. Hole Gauges require dial calipers or O.D. micrometers to get a number.

Skip Wolfe

Thanks again. One more question - are the 40.0mm +0.5mm and 41.0mm +0.5mm specs to be measured as shown in the pic - from bottom retainer to lower edge of upper retainer?

The guides are new, and the valves and seats are in good shape.

hosrom_951

Skip: Yes, just like the picture

Since you have new guides, was a valve job (valve seat cutting) done? it is really a must when you replace the guides to have teh valve seats cut, unless the valves are brand new.

m42racer

Quote
"I am getting ready to assemble the head I got from Ski and have a question on the spring spacers. I have 10 spacers of 3 different thicknesses. I am assuming these spacers go under the spring seats against the head and are used to make up for variations in the head castings so that all of the springs are compressed the same amount – is this a correct assumption?"

Thats not really the case. What you are trying to do is to have the same installed pressure or seat pressure and hopefully the same open pressures, along with some acceptable coil bind distance. Shimming give you the chance to change the installed heights in the effort to give equal or as near as possible equal seat pressures. The problem is that not all springs are made the same and old used springs change alot, or sag.

The factory specs (for new springs) give and installed height(closed). This should on new seats and be at pressures acceptable. If the seats have been cut, the Valves cut, you may need to add more shims to get to the correct height, but if the springs are used, then pressures may still be off. Care must be taken to ensure that adding more shims you do not increase the wire stress too high and increase the chance of spring failure. Adding more Cam lift adds another dimension here.

You are checking the distance between the Top Retainer and the Spring Base where the outer spring seats. Another way is to use your Dial indicator if you have one. Make a 1" round spacer that you can put in place of the spring. Then use the indicator to measure the difference, add the 1" and this is your retainer height. Do the math and add the shims to obtain the closest installed height. This will only give you what the installed height should be. It will not tell you the pressures or the Coil bind distance. The pressures are what is required, but without a spring tester, all you can do is the distance checks.
If you want to know the pressures and do it correctly, then you will need to go to a builder who can set up the pressures and shimming for you.

eospeed

You have to check coil bind.If If you dont have enough you will break a spring/lifter /wipe the cam