ZL1 Cam Cold Lash

[bbbentley]

From what I could find, the 9181 ZL1 has a hot lash of I=.024, E=.026 ? Anyone care to give a cold lash setting? I’m guessing subtract .002 off the above specs? Any help appreciated. Thanks sYc.

[L_e_e]

From what I could find, the 9181 ZL1 has a hot lash of I=.024, E=.026 ? Anyone care to give a cold lash setting? I’m guessing subtract .002 off the above specs? Any help appreciated. Thanks sYc.

With iron heads you want to ADD 0.002"

[jerry455]

What if engine has factory aluminum heads? Still add .002?

[lbnaz]

I set mine as per specs w/alum heads and had no issue. Larry

[RobR]

From what I could find, the 9181 ZL1 has a hot lash of I=.024, E=.026 ? Anyone care to give a cold lash setting? I’m guessing subtract .002 off the above specs? Any help appreciated. Thanks sYc.

Head material?

Block material?

[bbbentley]

Head material?

Block material?

Iron&iron. Basic L72 w zl1cam

[rszmjt]

Iron heads & block add .002. With aluminum heads set cold lash tighter about .005-.006 on a rat motor. If it’s aluminum block & heads about .010 tighter cold. The thermal expansion of aluminum causes the lash to increase hot.

[RobR]

Like you said, I would go .002” LESS than the hot lash spec. ‪for break-in.‬ Then
‪with the engine at running temp, shut it off, and set the valves on one cylinder to the Hot lash on the cam card.‬
‪Let the engine fully cool down. ‬
‪Measure the lash on that cylinder that you set hot.‬
‪That will be the cold lash setting to use on all the cylinders.‬

[KenMaisano]

If it is a aluminum block and heads set .012 tighter when cold. .012 .014 You will be very close to your .024 .026 when hot.

[bbbentley]

Like you said, I would go .002” LESS than the hot lash spec. ‪for break-in.‬ Then
‪with the engine at running temp, shut it off, and set the valves on one cylinder to the Hot lash on the cam card.‬
‪Let the engine fully cool down. ‬
‪Measure the lash on that cylinder that you set hot.‬
‪That will be the cold lash setting to use on all the cylinders.‬

Trusting my own experience, and your reassurance, I set them .002 tighter or I.022-E.024. Great idea on the reverse calculating lash method.

[napa68]

While this document revolves around small blocks, the principles apply. These suggestions are with iron block and heads. This procedure works VERY well IMO

http://www.metroli.org/pdf/WHITE%20PAPER_Solid%20Lifter%20Cam%20Valve%20Adjus tment.pdf

[1971ls6]

Mine grows.013 with the beer can motor