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Discussion Starter · #1 ·
hey guys... going to fire this friday.
One thing Ive been thinking about is my lash.... on my cam card, it has a hot lash of.012 which is a pretty tight lash.
Should I have it a little looser to break-in? I emailed Comp and they say just use the .012 but the guy I talked to didnt exacty install confidence in me.
Thanks!
 

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Setting cold lash depends on whether you've got aluminum or iron heads. I believe with aluminum heads, you want to set your lash tighter (as much as .004 I think?), as the heads grow more than the pushrod, and so your lash loosens up as the engine warms. With iron heads, I think you want cold lash a little on the looser side, and as the engine warms the lash will tighten up.

With a recommended lash as tight as .012, and iron heads like your 'my cars' indicates (Windsor Jrs), I would fudge a little on the loose side, maybe set it to around .015? My camshaft has a recommended lash of .022, and I think most solid lifter cams are in that range except the newer ones designed for tight lash, so I think you should be plenty safe with anything less than .020 lash.
 

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Use the hot setting while the engine is cold for breakin. That way you'll be sure that the lifters will rattle a little and be more likely to spin during breakin.

I have done it that way many times with no trouble at all.

Good luck,

Greg
 

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Discussion Starter · #4 ·
Funny thing is my comp card does not specifiy hot or cold... just say lash @ .012... but on thier website they say any specified lash is hot.
Can I assume they mean hot?
 

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ALL factory lash specs are while HOT!
 

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Pretty sure your lash should be adjusted when the engine is hot--not entirely sure about it though since you have a different cam.

Here is what I used when I installed my Comp Cam solid during pre-startup --barely had to adjust it later (from Crane-- http://www.cranecams.com/?show=techarticle&id=2 ):

"Compensating for a Cold Engine when Adjusting Valve Lash

When installing a new cam, the engine will be cold but the lash specifications are for a hot engine. What are you to do? There is a correction factor that can be used to get close. We mentioned that the alloy of the engine parts can be affected by thermal expansion in different ways, therefore the amount of correction factor to the lash setting depends on whether the cylinder heads and block are made out of cast iron or aluminum.

You can take the "hot" setting given to you in the catalog or cam specification card and alter it by the following amount to get a "cold" lash setting.

With iron block and iron heads, add .002"
With iron block and aluminum heads, subtract .006".
With both aluminum block and heads, subtract .012".

Remember this correction adjustment is approximate and is only meant to get you close for the initial start up of the engine. After the engine is warmed up to its proper operating temperature range, you must go back and reset all the valves to the proper "hot" valve lash settings. "

_________________
Dennis

65' Stang

393W Stroker, Wide Toploader 4 Spd, 9" 3:70 Posi

Victor Jr. Heads, Vic Jr. Intake, 750dp, 236/561 Solid Cam, 9.6CR, 1 3/4" Headers, Lakewood, Subframes, Caltracs



<font size=-1>[ This Message was edited by: dennis111 on 7/20/06 7:34am ]</font>
 

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good luck with the fire-up/break-in TK... hate to see you have to watch us from the stands this year!
 
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