To shim or not to shim valve springs
02-14-2015, 08:51 PM
#61
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Thread Starter
Thanks folks.
I'm not even sure if it is what I thought it was but my 482 (which is really a 496 now) has closed heads with dome pistons. I thought it was figured out somewhere around 11 to 1
I'm not even sure if it is what I thought it was but my 482 (which is really a 496 now) has closed heads with dome pistons. I thought it was figured out somewhere around 11 to 1
08-01-2015, 01:44 AM
#62
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Thread Starter
Hey folks,
Here to eat a little crow.
Back to the first picture of the head that seemed to get a few of us a little upset. Well, I had to pull the motor for other reasons. Since a couple sets of head builds ago I went crazy and bought spring seat cutters, valve guide seal cutter, valve spring height micrometer and an assortment of shims so now if a head comes off a motor it get the once over. Also have learned a lot about what is available in locks and keepers of different heights. Not an expert by a long shot but besides milling or cutting new valve seats I can finally do the rest in house.
So the heads hit the work bench. Not expecting much. They were already shimmed when I took them apart the last time so I figure they were adjusted right before. Get out my stuff and start measuring. Spring height should be 2.000 but yet I found spring heights as low as 1.849 without any shims. So I first get a set of .050+ locks and try them. Measure again and was only getting .025 out of them. Hummmm…. So I get a new set of matching (to the springs) keepers. Put them in and measure it up and between the new keepers and the .050 locks I picked up another .075 and the locks fit much deeper in the new keepers like they should. Still had to cut the spring seats some but nothing like I would have had to if I used the old keepers. Best I can figure after doing some research the old keepers are meant to be shorter for some reason.
Now everything is between 1.990 and 2.000 with at least one hardened shim under each spring and everything was measured for coil bind and to see if the keepers will hit the seals.
Here to eat a little crow.
Back to the first picture of the head that seemed to get a few of us a little upset. Well, I had to pull the motor for other reasons. Since a couple sets of head builds ago I went crazy and bought spring seat cutters, valve guide seal cutter, valve spring height micrometer and an assortment of shims so now if a head comes off a motor it get the once over. Also have learned a lot about what is available in locks and keepers of different heights. Not an expert by a long shot but besides milling or cutting new valve seats I can finally do the rest in house.
So the heads hit the work bench. Not expecting much. They were already shimmed when I took them apart the last time so I figure they were adjusted right before. Get out my stuff and start measuring. Spring height should be 2.000 but yet I found spring heights as low as 1.849 without any shims. So I first get a set of .050+ locks and try them. Measure again and was only getting .025 out of them. Hummmm…. So I get a new set of matching (to the springs) keepers. Put them in and measure it up and between the new keepers and the .050 locks I picked up another .075 and the locks fit much deeper in the new keepers like they should. Still had to cut the spring seats some but nothing like I would have had to if I used the old keepers. Best I can figure after doing some research the old keepers are meant to be shorter for some reason.
Now everything is between 1.990 and 2.000 with at least one hardened shim under each spring and everything was measured for coil bind and to see if the keepers will hit the seals.
08-01-2015, 09:23 AM
#63
Registered
I would have measured the valves,they sound like they were stock lengths.should have changed valves to +.050-.100" longer.not a fan of cutting the spring pockets any deeper,can over time crack,especially w/ solids.
08-01-2015, 11:24 AM
#64
Registered
Thread Starter
I would have went that way but after measuring everything I also found spring pockets that were 2.025 in the same head. So I didn't cut them any deeper then was already done.
