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Adjust valves...while running or crank by hand?
https://www.slantsix.org/forum/viewtopic.php?t=5407
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Author:  tallinboy [ Sun May 04, 2003 7:10 am ]
Post subject: 

If I could remember correctly from back in science, I beleive that when metals heat up they actually shrink, so if you were to adjust them cold you would actually want to adjust them tighter than spec. So when the motor does heat up they would loosen up right?

Author:  Patrick Devlin [ Sun May 04, 2003 11:03 am ]
Post subject: 

Nope, metal expands when it heats up. Most other substances expand when heated, too...except for water, which occupies more volume when solid than when liquid.

Author:  zorg [ Sun May 04, 2003 3:55 pm ]
Post subject:  don't worry

For anyone who is concerned about adjusting the valves while the engine is running, it's not hard. I was more than a little concerned, being new to working on my engine, but it was a piece of cake. Now I'm addicted... :D Keep the idle way down and it's quite easy.

Author:  tallinboy [ Mon May 05, 2003 5:25 am ]
Post subject: 

Thanks Patrick! I must have been sleeping during most of Science. That just changes everything. See I Had a crack in my exhaust mani, and I figured while I had everything apart, might as well check out the head and valve conditions figuring that I know there has been 100,000 since last rebuild. Come to find out there was a heaping crack right down the center of the head gasket. No wonder it's been runnin hot this whole time! good thing I got bored right? By the way the specs say to torque the head to 70 ft/lbs hot, what would I set them at cold to start?

Author:  Dart270 [ Mon May 05, 2003 7:09 am ]
Post subject: 

Just to follow up on the science thing - the reason the valve clearances get looser (and bolts get unstuck when you heat them), is that if everything (for ex, all steel/iron parts) expands at the same rate, the gaps also expand proportionally.

Lou

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