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Old September 9th 2008, 00:34
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Humble Humble is offline
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Join Date: Jan 2003
Location: Boulder Creek, CA
Posts: 758
I can't believe I forgot to update this.... Well the motor is built and in the car but here's the rest of how it got there.

How to setup proper rocker geometry. Now I know for the most part you can just bolt on rockers, cut your push rods (or find used ones) and go, but it's not the best thing for your motor. Good rocker geometry will prevent excess wear on the valves, guides, lash caps, rockers and push rods. Ideally you want to have a 90* angle between your rocker arm and push rod at half of your total lift. This prevents extreme angles between the rocker, push rod, and lash cap that could wear down your adjusters, push rod tips, rocker tips, and lash caps. This also keeps side-loading the valve step to a minimum which prevents ovalled out valve stem guides.

So here i'm using a dial indicator to figure out total lift at the valve which is .471".


Now if I setup my rockers with no spacers this is what the angle looks like, very bad. The rocker is resting on the back of the lash cap, there's a really bad angle on the push rod to the adjuster cup, and the push rod would probably rub on the push rod tube.






Now using the total lift number I got before I half it to get .2355". At .2355" I need to get the angle between the push rod and the rocker as close to 90* as possible. With .195" worth of rocker block shims, it was as close as I could get and still have enough threads on the rocker studs to bolt it all down.


relaxed


and full lift


Much better with the spacers in. While I'm on the subject of rockers, when you setup your geometry make sure you check how the foot on the rocker meets the lash cap. You want it as close to the middle as possible but slightly offset. The idea behind this is that the action of the rocker sweeping across the lash cap will rotate the valve so that everything wears evenly and prevents the valve from developing hot spots.

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