Bare Bones head rebuild

Invectivus":25yftj5x said:

"To do a basic rebuild of a head (at a machine shop), would that be a hot tank, maybe replace guides, install hardened seats if needed, probably mill head to increase CR?

My responsibility would be check valve guide play and CC chambers to determine what/how much is needed."

1. That's pretty much it in a nut shell.

"is there a good way to check the springs to verify they're in spec? all I can think of short of a special tool is to get 2 weights matching their open and closed seat pressure, and measure the spring height under each load. seems hokey to me, but it doesn't seem right to give a mess of springs to someone to test for me. at least, not cost effective. I've just got a mess of springs and I've forgotten where any in particular came from."

2. You cannot check closed or open spring pressure accurately without using a valve spring compressor, But you can do a lot putting some of your time to pick out a good set of valve spring for a stock or mild performance rebuild. Start by examining the all the valve springs you have to pick out the ones that all match by the springs wire Dia., color of paint stripe (if there still is one), tallest in height, coils look to have same spacing, etc. Next you can set the springs on a flat surface and use a square (framing or machinist type if you have one) to see if the springs all stand up nice and straight. Check that they also stand up the same height or very close. if you came up with a full set that are matched then the chances are very good that you will now have a useable set that can be shimmed to correct spring height. If you are using exhaust rotators the exhaust springs will be shorter then the intakes set them both with their retainer on top of the springs to check heights are close to each other. One other thing you can do If you have a good vise you is use it to check and measure the height at spring bind if you are using an other then stock cam. IE lots of lift. If you do that though be real carful as springs can get away from you and go flying.

"I figure if the valves/springs are ok, do a gentle hand lap, disassemble/clean the valve rocker assembly, measure for new pushrods to match the shave, and replace the thermostat."

Am I missing anything? trying to go basic.

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