The standard deck height on a #010 block is 9.025. I had mine decked to 9.010 or .015 less.

I've got Comp Cams 4130 standard length pushrods. Should I be concerned with rocker roller contact with the valve tip?

The engine is done but still on the stand with valve covers on. This is just one of those things in back of my mind that's bugging me.

This was not a total after thought as I did roughly eyeball it after setting the lifters but I did not Blue the tips.

Thanks in advance. I like to sleep nights.



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Engine: SBC 4-bolt #010, Balanced 383 Eagle crank assembly, 4340 crank and 4340 H-Bean 6.0 rods with SRP flat tops.
DART IE 200/72cc heads (10.1:1 C/R) with Harland Sharp 1.5 full rockers and Comp Cams XE274H (230/236 .487/.490 110LSA 1,800-6,000 RPM).
Edelbrock RPM manifold with 750 (VAC/Electric) Holley.
MSD Pro-Billet (Vac) with 6AL box.
My best guess (Dyno 2000) is about 400HP and 430TQ??

 

i sure don't know everything about it but the rule i use is to increase push rod length buy .100 for .150 more in lift ,deck or head milling or a combination of all. then you get into the gray areas like .075 more. if i get up around .500 lift i go to longer push rods. look in a comp or lunati catalog they both have great tech section to better understand all that's involved with cams and the valve train.

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ICON Motorsports

1st & 3rd
MM Black Diamond 538 F&AM

 

Changa,

Ed is on the right track, but there are some bits of information missing. What is the base circle of the cam? Your lowered deck would indicate the need for shorter pushrods, but a performance cam grinde generally has a smaller base circle, so the differences would tend to negate each other. The question is how much base circle reduction is there, and what other changes were made. If you've installed guide plates and altered the rocker stud positions, you have to consider those changes as well..

AS a general rule of thumb, the rocker arm should be perpendicular to the stud at 1/3 of the lift of the lobe. This is generally sufficient to provide adequate clearance at the retainers at both ends of the valve travel, and prevent excessive lateral forces on either the valve or push rod.



The addition of guide plates, length of push rods, length of valve stems, installed height of valves, milling of the heads and/or deck, rocker ratio, and lash position will affect the position of the rocker. It's good that you are checking now, while the engine is still in the stand.

BTW - You are obviously concerned or you wouldn't be hacking at the keyboard at 3:30 AM...

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Later,
Vader
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"Let the bodies hit the floor!"
Adobe Acrobat Reader

[This message has been edited by Vader (edited May 28, 2001).]

 

Just what I was looking for (both of you) -- Thanks!

Not to take away from the Bravo above, (this reminds me of detective Columbo from a few years back), 'I have one more question' -- If I Dykem Blued the tips of the Valve Stem, reset the rocker and turned the crank several times through the valve lift cycle and found the wear pattern to be centered on the Tip would'nt that say OK?

and if not centered, change the pushrod length until it was centered?

You guys got me thinking again, dammit, but that's just why I got into my first build.

 

Jegs, maybe Summit to, have adjustable pushrod length checkers. This may help in determining the correct length. They are about $25. Plus they got a plastic "rocker arm" to help determine the length needed. They're like $12 I think. Just an FYI.