Rocker Adjustment Cold

[67 gt]

Hi all just chasing some info as I'm doing some top end work and I will be backing off all rockers, adjustment is 0.16 intake 0.18 Exhaust hot. What would be cold lash adjustment.
318, solid 268 flat tappet EQ mag heads, Crane 1.6 Gold rollers. Thank you

 

[JBurch]

Before you back the adjusters off, take a measurement, write it down, problem solved.

 

[67 gt]

Thanks... Why didn't I think if that ???????

 

[famous bob]

Thanks... Why didn't I think if that ???????

I adjust the rockers on my alum. heads .006-.007 tighter, and call it good, don`t even bother w/ hot adjustment. On iron heads I`ve heard .004 ??????????

 

[69_340_GTS]

I adjust the rockers on my alum. heads .006-.007 tighter, and call it good, don`t even bother w/ hot adjustment. On iron heads I`ve heard .004 ??????????

With the aluminum heads, did you actually check to see what the "hot" lash is? Or are you just guessing? Be good info if it's verified.

 

[roccodart440]

I've always done my valve adjustments cold and that's what the cam manufacturers speced. Your lash seems tight to me, especially if that's hot.

 

[famous bob]

With the aluminum heads, did you actually check to see what the "hot" lash is? Or are you just guessing? Be good info if it's verified.

did when I first put it together, haven`t bothered since. I have plenty of cam, not worried about loosing a couple thou lift, as long as it doesn`t rattle or tighten up.

 

[roccodart440]

The idea of knowing hot lash, IMO is so you can work on it hot if need be.

Set the lash cold, warm it up fully and check the hot lash and record it. IF you ever have to work on the VT while the engine is hot you know what to do.

My engine builder write the cold and hot lash specs under each valve cover. For reference mine calls for 28/32 cold and I run 24/28 cold.

 

[70aarcuda]

http://www.cranecams.com/pdf-tech-tips/mech-lift.pdf

 

[toolmanmike]

http://www.cranecams.com/pdf-tech-tips/mech-lift.pdf

Yep. I add .002 to my 273 specs for cold adjustment. The lash will tighten up when the engine and valve train gets to temp. That reminds me, I need to reset the lash next spring. I haven't done it for a couple years.

 

[justinp61]

On my 434 with Indy heads there is .004" difference between hot and cold.

 

[famous bob]

http://www.cranecams.com/pdf-tech-tips/mech-lift.pdf

----------------------------------------here it is !