Valve Adjustment.

[rcb280z]

Can someone explain to me why a hot valve lash adjustment is more desirable over a cold one? I have always done a cold one only. Maybe I'm missing something by not doing a hot one. It seem to me like you wouldn't get a good one "hot" anyway. It takes time and I think by the time you get to the last cylinder the engine has cooled enough to not be right. (?) 

Edited March 9, 2015 by rcb280z

[Zed Head]

I've pondered and commented on this before.  I had the same thoughts.  My guess is that Nissan went to recommending hot because most engines are hot when mechanics work on them.  It's actually riskier hot, because the lash gets tighter when the engine cools.  So if you're too tight hot, but still have some lash, you could burn a valve when starting cold.

 

In theory, all of the metal of the individual valves expands at the same rate. so proper cold lash will equal proper hot lash.  Cold should be the best way to do it.  But hot seems to be a rite-of-passage, like changing a spindle pin.

[240260280z]

No cool valves & No hot hands way:

1. You can quickly measure when hot then note the ones out-of-spec and by how much.

2. When the engine cools, re-measure just the ones out of spec and adjust by the out-of-spec amount.

If you can't measure quickly and worry about cooling valves, just do the intakes in one hot/cold session then the exhaust in another.

[rcb280z]

So I guess if you do it cold and don't hear any crazy valve train noise then just go with it. I have been doing it cold for almost 30 years with no issue. Must be more a preference. But I may try what Blue suggests just to see if I get any difference. Usually when I do an adjustment I always go one size above and below the actual measurement. If its 0.008 I found that if I check with a 0.007 (its loose) and 0.009 (usually can't get it in) Im guaranteed a good measurement. Maybe that's why I have no issues.

[rossiz]

my understanding is that when the engine is up to temp, its within a predictable range, because the cooling system is designed to keep it there. when it's cold, it can be 70 degrees out or 0 degrees out - both are considered "cold" but potentially big swings as well. doing the valves hot has never been a problem for me - just have the few tools necessary all at the ready, car in neutral, pull the plugs, pop the valve cover and check/adjust as you go. i turn the cam with a big crescent wrench at the bosses to get lobes up. i start at #1 and things are still too hot to handle when i get to #6.

 

interestingly, i've always found a few tight, a few loose when i do a hot adjust after a cold one, but when i've done a hot adjust and check later on (after running a few days) it's always been spot on.

 

i adjust to snug fit, where the next size feeler gauge won't go in.

[Travel'n Man]

I do mine cold as well. No issues at all I use the "fit - do not fit" method as well

Edited March 10, 2015 by Travel'n Man

[siteunseen]

Cold for me too, then another quick "fits or doesn't fit" when hot.  But I don't remember readjusting a single valve when hot.

 

Is there some other way to find "Kammy's World Famous Valve Adjustment"?  I tried linking it for someone on here awhile back and it was gone.

Edited March 10, 2015 by siteunseen

[240260280z]

KAMMY's GREAT TUTORIAL SAVED:

https://web.archive.org/web/20080720024048/http://www.picturetrail.com/gallery/view?p=12&uid=786489&gid=1803105

[SteveJ]

I have relied 

 

KAMMY's GREAT TUTORIAL SAVED:

https://web.archive.org/web/20080720024048/http://www.picturetrail.com/gallery/view?p=12&uid=786489&gid=1803105

I have relied upon the Internet Wayback Machine for years. 

[rcb280z]

Yeah Cliff, Iv'e never done a hot one either. But I have never pulled the valve cover after a warm up to recheck either. Might try that just to know.