Valve lash question

sox · 03-22-2022, 01:04 PM

I read an article on Thermal expansion pertaining to valve lash on mechanical cams. I hate doing valves on a hot engine. Crane cams has a guide that states on a iron block and aluminum heads subtract 0.006 on your hot lash if you want to do them cold. Does anyone go by this.

ss chief · 03-22-2022, 01:25 PM

There can be variations between engines and a combination of blocks and heads.
This is what I have done in the past.
Warm up the engine to 150-160, set your hot lash number on one cylinder. Let it sit until it is dead cold. Check the lash and you have determined your cold numbers.

sox · 03-22-2022, 01:33 PM

That’s a great idea. I will try that.

garyc · 03-22-2022, 02:48 PM

most cold lash settings from cam company's are for getting close for starting, they all recommend setting hot for final. that's a good idea for setting hot then check cold

silversedan · 03-22-2022, 09:55 PM

I've used the -.006 rule on my hemi and a wedge and rechecked hot and the results were the same. it's a good rule of thumb after you decide what your valve lash needs to be.

03-22-2022, 01:04 PM	#1
sox Junior Member Join Date: May 2008 Posts: 96 Likes: 9 Liked 13 Times in 8 Posts	Valve lash question I read an article on Thermal expansion pertaining to valve lash on mechanical cams. I hate doing valves on a hot engine. Crane cams has a guide that states on a iron block and aluminum heads subtract 0.006 on your hot lash if you want to do them cold. Does anyone go by this.

03-22-2022, 01:25 PM	#2
ss chief Junior Member Join Date: Aug 2007 Posts: 85 Likes: 0 Liked 46 Times in 12 Posts	Re: Valve lash question There can be variations between engines and a combination of blocks and heads. This is what I have done in the past. Warm up the engine to 150-160, set your hot lash number on one cylinder. Let it sit until it is dead cold. Check the lash and you have determined your cold numbers.

03-22-2022, 01:33 PM	#3
sox Junior Member Join Date: May 2008 Posts: 96 Likes: 9 Liked 13 Times in 8 Posts	Re: Valve lash question That’s a great idea. I will try that.

03-22-2022, 02:48 PM	#4
garyc Member Join Date: Mar 2021 Posts: 124 Likes: 0 Liked 51 Times in 30 Posts	Re: Valve lash question most cold lash settings from cam company's are for getting close for starting, they all recommend setting hot for final. that's a good idea for setting hot then check cold Last edited by garyc; 03-22-2022 at 02:50 PM.

03-22-2022, 09:55 PM	#5
silversedan Junior Member Join Date: Dec 2019 Posts: 11 Likes: 21 Liked 15 Times in 6 Posts	Re: Valve lash question I've used the -.006 rule on my hemi and a wedge and rechecked hot and the results were the same. it's a good rule of thumb after you decide what your valve lash needs to be.