Valve lash

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Bigdummy

Bigdummy

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Trick flow heads . 016 intake and .018 exhaust sout I go up .002 I forgot it's been a while to adjust them?
 
I think with aluminum heads, go down .002, as the aluminum will expand more than the steel. Or adjust hot and running.
 
EOIC

When the the EXHAUST starts to OPEN, adjust that intake
When the INTAKE has opened and nearly CLOSED, adjust that exhaust
 
I got a few cold like 27 on the exhaust and 23 intake so I'll tighten them up
 
Nothing like busted knuckles!I dont have a 5/8 valve lash tool just 9/16.....

20220419_125941.jpg
 
Bigdummy said:
Trick flow heads . 016 intake and .018 exhaust sout I go up .002 I forgot it's been a while to adjust them?
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If those lash adjustments are recommended @ .016/.018 hot........then with aluminum heads and an iron block I would set the lash cold at .010" intake and .012" exhaust.
 
IQ52 said:
If those lash adjustments are recommended @ .016/.018 hot........then with aluminum heads and an iron block I would set the lash cold at .010" intake and .012" exhaust.
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Excellent info from a great source! Does the same hold true with Eddy heads? I have a Comp street solid roller in my 470" It wants .016 and .018 hot. I hate checking them hot so can I also do .010 and .012 cold. I know every engine is different but.....??
 
Dcuda69 said:
Excellent info from a great source! Does the same hold true with Eddy heads? I have a Comp street solid roller in my 470" It wants .016 and .018 hot. I hate checking them hot so can I also do .010 and .012 cold. I know every engine is different but.....??
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In my experience yes. Aluminum Edlebrock, Indy, Trick Flow, 440 Source, Speed Master. 10-12 years ago (maybe more) I found out about it reading a Chevy engine build article using Edelbrock Aluminum heads. Then the Edelbrock Tech Line told me their heads wouldn't do that when I was purposely testing and measuring the valve lash on a set of Edelbrock 440 RPM heads. From cold to hot I was seeing a +.005"-.006" change in lash. Never consulted Edelbrock's Tech Line after that.

And by-the-by, with aluminum block and aluminum heads I tighten the cold lash .010"-.012" from the hot lash setting. Gets a little dicey with a very tight lash cam.
 
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To me, 0.006" is a lot to take out of the lash for alum heads. My experience has been about 0.003".

However, this is so easy to check, it beats me why more people do not do this simple test that will give an accurate number for their combo.

Have your tools ready. Get the engine to operating temp & then switch off. Quickly remove a valve cover & find a loose rocker. Measure the lash & record it. Come back in the morning when the engine is cold & re-measure. You now have your hot-cold difference.
 
Bewy said:
Have your tools ready. Get the engine to operating temp & then switch off. Quickly remove a valve cover & find a loose rocker. Measure the lash & record it. Come back in the morning when the engine is cold & re-measure. You now have your hot-cold difference.
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Yep, that's the way you do it.
 
I left and will get it done when I get home. Thanks to IQ52 and everyone in gonna set them cold and warm it up and check em again hot. I had forgot and am always foggy brained.Thats why I got a slow car. Im lucky to be still working my hands have Neuropathy in them and breaking them loose is hard.My machinist talked me into these rocker arms and I wanted Harland Sharp.Im going to grind down a wrench to fit better so it don't slip off easy.Im camped out for the night outside Knoxville TN on my way to BWI. I had to drive instead of flying.
 
IQ52 said:
In my experience yes. Aluminum Edlebrock, Indy, Trick Flow, 440 Source, Speed Master. 10-12 years ago (maybe more) I found out about it reading a Chevy engine build article using Edelbrock Aluminum heads. Then the Edelbrock Tech Line told me their heads wouldn't do that when I was purposely testing and measuring the valve lash on a set of Edelbrock 440 RPM heads. From cold to hot I was seeing a +.005"-.006" change in lash. Never consulted Edelbrock's Tech Line after that.

And by-the-by, with aluminum block and aluminum heads I tighten the cold lash .010"-.012" from the hot lash setting. Gets a little dicey with a very tight lash cam.
Click to expand...

Bewy said:
To me, 0.006" is a lot to take out of the lash for alum heads. My experience has been about 0.003".

However, this is so easy to check, it beats me why more people do not do this simple test that will give an accurate number for their combo.

Have your tools ready. Get the engine to operating temp & then switch off. Quickly remove a valve cover & find a loose rocker. Measure the lash & record it. Come back in the morning when the engine is cold & re-measure. You now have your hot-cold difference.
Click to expand...

Thanks to both of you guys! Much appreciate the info. I'll check them hot(haven't touched them in a couple years) Then adjust to .016/.018 then let it cool. I'll report back my findings for the rest of the group. I always enjoy both of your input on the engine threads as I know you guys know your stuff! Didn't mean to hijack the op's thread....sorry! Stay tuned!
 
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