cam change = spring question
cam change = spring question stil working on building the motor for my 95 Z28. I had the heads cleaned up with a valve job at the machine shop, they put on springs and set them up for the cam I was planning on using, a CC503 (224 int./230 exh. 0.503/0.510 lift 112LSA). I've decided to go with a LE 218/224 .544/.544 111 LSA. Now i don't know what type of spring is on the head and I figure I need to change them to work with the new cam. Does anyone recognise this spring?
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The machine shop reciept says ZZ-4 spring and retainer, put it doesn't look like pictures I've found. I found info on K-motion green stripes but couldn't find a picture of their green ones, but their pink stripes are a different stripe. Does anyone know?
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[/IMG]The machine shop reciept says ZZ-4 spring and retainer, put it doesn't look like pictures I've found. I found info on K-motion green stripes but couldn't find a picture of their green ones, but their pink stripes are a different stripe. Does anyone know?
they could be some cheep $16 to 40 "Z28 springs" that alot of machine shops use on hyd flat tappet stuff or even MILD (stock like) hyd rtoller cams.
The material that the spring is made of might not be able to handle a semi aggressive lobe that opens/closes the valves faster than the above mentioned cams.
You want to make sure that the springs have AT LEAST 130 lbs on the seat and 320 lbs open pressure to work with those lobes. Make sure they have a set up ht that doesn't coil bind until AT LEAST .580 lift (giving you .036 clearance from the .544 lift of that cam).
Ask them for seat pressure, open pressure and coil bind at that installed ht. Do not tell them what you need until AFTER they tell you what the springs have or amazingly these springs will have what you need, lol.
If they can not answer you of if the #'s do not dit what I have suggested, swap springs with a better set.
Lloyd
The material that the spring is made of might not be able to handle a semi aggressive lobe that opens/closes the valves faster than the above mentioned cams.
You want to make sure that the springs have AT LEAST 130 lbs on the seat and 320 lbs open pressure to work with those lobes. Make sure they have a set up ht that doesn't coil bind until AT LEAST .580 lift (giving you .036 clearance from the .544 lift of that cam).
Ask them for seat pressure, open pressure and coil bind at that installed ht. Do not tell them what you need until AFTER they tell you what the springs have or amazingly these springs will have what you need, lol.
If they can not answer you of if the #'s do not dit what I have suggested, swap springs with a better set.
Lloyd
