Valve lash setting

[Sniper]

Interesting video I watched today.  They claim cold lash settings will increase when the engine comes up to temperature, not decrease.  So you should DECREASE the cold lash setting so that they are at spec when warmed up.  They tested it too and tell you how to test your setup as well.  Anyone try this on our stuff?

 

 

[keithb7]

 I dunno but does that guy touch a 200F valve train with bare hands at the 4:30 mark?  Does a fully warmed up hot engine smoke a little when the valve covers are freshly cracked open?

[Sniper]

I've set lash on OHV engines with my bare hands before.  I don't recall it being that hot myself, but then again when I wash dishes no one else can put their hands in the water, too hot they claim.  As for the smoke, don't recall, it has been a few years.  Heck, I set the lash on my slant six with the engine running and warmed up.

[DJ194950]

With those hands  of yours I nominate you to test this valve clearances testing of our flatheads hot and cold , engine in vehicle

 

Tighter or loosened  clearances ?

 

Document and sell the info on U Tube!.  ?  Post here for free, please!

 

U Tube star in the making.. Make enough $$ to pay someone to work on your cars!

Sit back with a cold or hot beverage and document some more while taping.  More vintages cars in your expanded garage?

 

DJ

 

 

Edited February 27, 2022 by DJ194950
spelling

[Sniper]

I'd need my Trusty Assistant on hand to film things.  Not enough hands to set the lash and video it.  Maybe next weekend.  I'm going to need another set of gaskets though.

 

Holy carp, the price of that gasket has gotten up there.

[Bryan]

I would NOT use this for our engines. Different geometry.   On ours everything is in a straight line. From the cam lobe, then tappet, then valve.  Heat expands metal and it would be linear.  That V eight isn't the same..don't know whether the pivot arm for the rocker is increasing in height, arm increasing in length at an angle to the valve, etc.  Some older guys on the forum have tried setting the valves cold with larger clearance. Seen it somewhere.

Edited February 27, 2022 by Bryan

[Sniper]

I think where the heat is concentrated and where the most growth occurs is the same for both, the valves.

[nonstop]

Just checking around and found this.

 

https://www.enginebuildermag.com/2011/08/compensating-for-a-cold-engine-when-adjusting-mechanical-lifter-valve-lash/

 

It looks like the cold lash clearance may be dictated by engine material.  For cast iron it said to add, while aluminum heads/iron block and aluminum heads/aluminum block, subtract different numbers based on the combination.

[Bryan]

https://p15-d24.com/topic/53328-hot-running-l6-valve-set-tools/?do=findComment&comment=568587

 

[DJK]

This is from my 52 Cranbrook repair manual:

[lepic56]

Look like that video was made when you  rebuilt an  engine, and you only have the ''HOT"" setting supplied by the cam compagnies,,  this 'cold'' setting could be a  ballpark  setting for the first start???   but I like the last paragraph , it makes more sense,,

You can take the “hot” setting given to you in your cam manufacturer’s catalog or cam specification card and alter it by the following amount to get a “cold” lash setting:

• Iron Block Iron Heads –  Add  .002?

• Iron Block Aluminum Heads – Subtract  .006?

• Aluminum Block Aluminum 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.