PAC 1518 Springs - which locks/retainers
09-07-2011, 09:56 PM
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PAC 1518 Springs - which locks/retainers I bought a set of PAC 1518 valve springs to replace my old Combination motorsports 612 springs.
I need to buy the retainers/locks before I can do the install, which ones should I buy? I was thinking Comp?
The heads are LE1s, so they have the stock valve and seat I believe.
I need to buy the retainers/locks before I can do the install, which ones should I buy? I was thinking Comp?
The heads are LE1s, so they have the stock valve and seat I believe.
10-06-2011, 09:14 PM
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So I did some more research and found a thread saying that 10* hardware was better than 7*.
Would these parts work for me?
795-16 steel retainers
611-16 locks
4705-16 spring seats
There is also a set of locks that is +.050 for 1.75" installed height. How do I know what my installed height should be?
Would these parts work for me?
795-16 steel retainers
611-16 locks
4705-16 spring seats
There is also a set of locks that is +.050 for 1.75" installed height. How do I know what my installed height should be?
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10-07-2011, 12:15 AM
#9
Your spring height should be about 1.75.
At 1.80 install height seat pressure is 130 and open pressure at 1.20 is 318. (They list the same specs for the 1218 and 1518 which I wouldn't see why they would be the same, maybe it's a misprint) However.
To get the pressure that you need you will have to use a .030 and a .015 shim. I know that will be 1.755 but that will be close enough.
If that cam does have .550 lift it will only get you to a 1.25 compressed spring height and if it does only have 318 at open you definitely need to be at 1.20.
Leaving it at 1.80 will result in not enough spring pressure which can cause valve float and some other problems.
If you are doing it yourself you will get a height mic gauge, some shims and a few tools. 4753 is the shim kit number.
If you are taking it to a machine shop make sure you sit down with them and ask them specific questions. Tell them what springs you have and the lift on your cam. Then ask them what they would set the install height at. If they say 1.80 go somewhere else. For some reason, setting up a cylinder head correctly is like some black voodoo art or something. My local machine shop set my heads up wrong; wrong spring height, was 1.81 should be 1.72, didn't catch that I was sent the wrong retainers/seat locators and several other things. I have since, from help of a very good sponsor, understand and know how to setup a cylinder head now. Some shops just slap the springs on and go.
As far as the hardware goes I would probably call PAC or get a hold of one of the sponsors on here and ask them what to use. There are too many different retainers/locks out there to just guess.
IMO it's always best to call a manufacturer or sponsor to double check. Lloyd will get you lined out. A friend of mine used Lloyds heads and cam on his 95 Z and Lloyd was great to deal with.
If you set your heads up there are many different things that need to be checked. Just trying to point you in the right direction and save you some of the **** I have went through.
At 1.80 install height seat pressure is 130 and open pressure at 1.20 is 318. (They list the same specs for the 1218 and 1518 which I wouldn't see why they would be the same, maybe it's a misprint) However.
To get the pressure that you need you will have to use a .030 and a .015 shim. I know that will be 1.755 but that will be close enough.
If that cam does have .550 lift it will only get you to a 1.25 compressed spring height and if it does only have 318 at open you definitely need to be at 1.20.
Leaving it at 1.80 will result in not enough spring pressure which can cause valve float and some other problems.
If you are doing it yourself you will get a height mic gauge, some shims and a few tools. 4753 is the shim kit number.
If you are taking it to a machine shop make sure you sit down with them and ask them specific questions. Tell them what springs you have and the lift on your cam. Then ask them what they would set the install height at. If they say 1.80 go somewhere else. For some reason, setting up a cylinder head correctly is like some black voodoo art or something. My local machine shop set my heads up wrong; wrong spring height, was 1.81 should be 1.72, didn't catch that I was sent the wrong retainers/seat locators and several other things. I have since, from help of a very good sponsor, understand and know how to setup a cylinder head now. Some shops just slap the springs on and go.
As far as the hardware goes I would probably call PAC or get a hold of one of the sponsors on here and ask them what to use. There are too many different retainers/locks out there to just guess.
IMO it's always best to call a manufacturer or sponsor to double check. Lloyd will get you lined out. A friend of mine used Lloyds heads and cam on his 95 Z and Lloyd was great to deal with.
If you set your heads up there are many different things that need to be checked. Just trying to point you in the right direction and save you some of the **** I have went through.
Last edited by LilJayV10; 10-07-2011 at 12:41 AM.
10-07-2011, 12:33 AM
#10
OK it just occurred to me while brushing my teeth. I was thinking of the +.050 locks as reducing your install height. They don't. I remembered what the problem was when I used them before.
One you will be adding .050 to your spring height. So if you start out at 1.8 it will be 1.85 with the locks because it's raising the retainer up away from the spring pocket. Kinda counter productive when it needs to be 1.75
The other issue is since the retainer is further up it can hit the inside of the rocker arm.
One you will be adding .050 to your spring height. So if you start out at 1.8 it will be 1.85 with the locks because it's raising the retainer up away from the spring pocket. Kinda counter productive when it needs to be 1.75
The other issue is since the retainer is further up it can hit the inside of the rocker arm.
Last edited by LilJayV10; 10-07-2011 at 12:43 AM.
10-07-2011, 09:37 AM
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Just talked to Lloyd on the phone, he said the CC 4705-16 seats, CC 795-16 10* retainers, and 614-16 10* +0.050 locks should be good setup to a 1.78" install height with a min of 140-145lbs seat pressure.
The 4705 seats are thick, so the 614 +0.050 locks keep the installed height from being too short.
I'm going to get the shim pack and a spring height mic to make sure.
The 4705 seats are thick, so the 614 +0.050 locks keep the installed height from being too short.
I'm going to get the shim pack and a spring height mic to make sure.
