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-   -   Rocker to spring clearance (https://www.racingjunk.com/forums/showthread.php?t=33967)

ssym 11-07-2013 03:07 AM

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

wmeabates 11-07-2013 04:17 AM

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.

curtisreed 11-07-2013 07:31 AM

I prefer to see .060" minimum.

ssym 11-08-2013 06:34 AM

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

curtisreed 11-08-2013 11:09 AM

Have you considered cutting the rockers for clearance?

ssym 11-09-2013 04:31 AM

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

markdunlap 11-09-2013 04:51 AM

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.

hammertime 11-09-2013 06:49 AM


Originally Posted by curtisreed
Have you considered cutting the rockers for clearance?

x2

curtisreed 11-09-2013 07:34 PM


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

TheYellaBrick 11-10-2013 02:08 PM

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

zipper06 11-10-2013 06:23 PM

If you have accesss to a bridgeport mill take a 15/8" endmill and cut a radious in the rockers you'll be plenty safe that way, it can be done with a die grinder but it's alot sloppier, i've do it many time when using big blk. springs on a sm/blk head.

JMO

Zip.

curtisreed 11-11-2013 03:09 AM

Watch how much this one moves around.

https://www.youtube.com/watch?v=WtqDHJDN79w


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