Rocker to spring clearance

Old 11-07-2013, 04:07 AM
  #1  
ssym
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Default Rocker to spring clearance

Building a SBC. Isky EZ roll solid lifters, Comp Gold 1.6 rockers and 1.550 springs.

7.950 pushrods give good geometry, but I end up with only .025 clearance between the retainer and the rocker arm.

Is this enough or do I need to look at lash caps or other solution for more clearance?

Steve
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Old 11-07-2013, 05:17 AM
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wmeabates
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Steve, If You have .050 or more of shims under the springs You can get .050 less height locks to lower the retainer and readj.the spring. Bill.
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Old 11-07-2013, 08:31 AM
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curtisreed
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I prefer to see .060" minimum.
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Old 11-08-2013, 07:34 AM
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ssym
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Thanks guys. I'm in a quandary. Probably going to look at other rocker arms. I have .045 locators with a 1.900 install height. I hate to trash these rockers or put floating aluminum in the pan.

Steve
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Old 11-08-2013, 12:09 PM
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curtisreed
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Have you considered cutting the rockers for clearance?
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Old 11-09-2013, 05:31 AM
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ssym
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I'm getting a lot of input on this. Most recommend a minimum of .040 to .050 clearance between the rocker and the retainer/spring.

I'm curious as to what happens with less? Am I sure to make contact with the rocker with only .025? It is a blower motor and won't see more than 7000 RPM.

Steve
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Old 11-09-2013, 05:51 AM
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markdunlap
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Default Rocker

Better not take the chance. Heat expansion can change clearances.

There is nothing wrong with adding clearance by carefully removing material from the rocker arm. Just don't let any particles get into the trunnion or roller tip area. Tape them off if you have to. Rinse them afterward and soak them in oil to pre lube them.

You should be able to do a full set in less than an hour.
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Old 11-09-2013, 07:49 AM
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hammertime
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Originally Posted by curtisreed
Have you considered cutting the rockers for clearance?
x2
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Old 11-09-2013, 08:34 PM
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curtisreed
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Originally Posted by ssym
I'm getting a lot of input on this. Most recommend a minimum of .040 to .050 clearance between the rocker and the retainer/spring.

I'm curious as to what happens with less? Am I sure to make contact with the rocker with only .025? It is a blower motor and won't see more than 7000 RPM.

Steve
You have to think about spring surge and rock. Do some research on YouTube for spintron videos. If you see how much springs move around you would be amazed.

Curtis
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Old 11-10-2013, 03:08 PM
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TheYellaBrick
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WOW ! :shock: :shock: :shock: :shock: :shock: :shock: :shock:

http://www.youtube.com/watch?v=a-fs8CFnZ_g

WHAT action makes the valve spring rotate like this ?!!!

http://www.youtube.com/watch?v=6Vz4mjPKXJ0
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