zc valves
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zc valves
ok my zc will arive at my door in like 3 days. When i get it i will check the valves and the pistons. I want to know what to look for, to tell if the valves are good or bad? I don't know very much about valves and how to tell what condition they are in. The pistins and cylinders i know what to look for. Valves i don't.
Thanks
Thanks
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From: Kills.
Re: zc valves (cr-x si)
Just do a leakdown test. No need to take the head apart.
To answer your question about what to look for with a valve, the stem shouldn't have any vertical scratches on it. If it does, it and the guide may need to be replaced.
Lay the valve on it's side and roll it slowly and carefully watch for any out of roundness. If you see ANYTHING, replace the valve.
Look at the valve face where it seals against the valve seat. It should be shiney all the way around. If not, it's not sealing properly and will leak compression. It could be bent (see previous test), or the valve spring coule be weak.*
If you see alot of carbony/ oily **** on the tulip of the intake valve, that's oil being sucked in through the valve seal, and that should be replaced, as well as the valve cleaned.
Check stem height with a straight edge or something. Refer to your shop manual (you do have one, right?) for the specs.
*Valve springs get weak over time. I doubt any ZC will have weak springs, but for the sake of knowledge, I'll explain what to do to check spring condition...
Free height can be checked with a combination square or with a set of calipers. If it's too long or too short, just replace.
Spring tension is measured on a spring tester. Compress the spring to the spec or installed height and read the scale. If the tension isn't within specs, the spring has weakened and must be replaced or shimmed. My personal opinion is that shimming is good for mom's minivan, but is a band aid patch for a serious problem that will bite you later on down the road.
Spring squareness can be checked with a combination square. Put the spring on a flat surface and rotate it while checking for a gap between the side of the spring and the square. If it's not square, replace.
There's ALOT more to check and know about valves, but I'll leave it at that for now...
To answer your question about what to look for with a valve, the stem shouldn't have any vertical scratches on it. If it does, it and the guide may need to be replaced.
Lay the valve on it's side and roll it slowly and carefully watch for any out of roundness. If you see ANYTHING, replace the valve.
Look at the valve face where it seals against the valve seat. It should be shiney all the way around. If not, it's not sealing properly and will leak compression. It could be bent (see previous test), or the valve spring coule be weak.*
If you see alot of carbony/ oily **** on the tulip of the intake valve, that's oil being sucked in through the valve seal, and that should be replaced, as well as the valve cleaned.
Check stem height with a straight edge or something. Refer to your shop manual (you do have one, right?) for the specs.
*Valve springs get weak over time. I doubt any ZC will have weak springs, but for the sake of knowledge, I'll explain what to do to check spring condition...
Free height can be checked with a combination square or with a set of calipers. If it's too long or too short, just replace.
Spring tension is measured on a spring tester. Compress the spring to the spec or installed height and read the scale. If the tension isn't within specs, the spring has weakened and must be replaced or shimmed. My personal opinion is that shimming is good for mom's minivan, but is a band aid patch for a serious problem that will bite you later on down the road.
Spring squareness can be checked with a combination square. Put the spring on a flat surface and rotate it while checking for a gap between the side of the spring and the square. If it's not square, replace.
There's ALOT more to check and know about valves, but I'll leave it at that for now...
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DJ_SaNdOz
Honda CRX / EF Civic (1988 - 1991)
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May 31, 2003 08:50 AM
