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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: 79scott on August 17, 2015, 07:47:07 pm

Title: Setting valve lash on a 250ci integral head L6
Post by: 79scott on August 17, 2015, 07:47:07 pm

Hey guys,
I just reinstalled the cylinder head on my 250ci integrated head and need to set the valve lash. Reading through my Haynes manual it says tighten 3/4 turn past the point that you cannot spin the pushrod........is that right?

Title: Re: Setting valve lash on a 250ci integral head L6
Post by: CDog86 on August 17, 2015, 08:12:41 pm

I'm sure someone who knows for sure will chime in but I have always heard that thy should be able to spin so oil can cover the entirety of the rod as evenly as possible. But not loose enough to have a lot of play up and down

Title: Re: Setting valve lash on a 250ci integral head L6
Post by: Captkaos on August 17, 2015, 08:36:28 pm

http://www.73-87chevytrucks.com/techinfo/7387CKMans//Service/ST_330_79_1979_Chevrolet_Light_Truck_Service_Manual.pdf#page=473

Title: Re: Setting valve lash on a 250ci integral head L6
Post by: 79scott on August 20, 2015, 06:59:07 pm

Quote from: Captkaos on August 17, 2015, 08:36:28 pm

http://www.73-87chevytrucks.com/techinfo/7387CKMans//Service/ST_330_79_1979_Chevrolet_Light_Truck_Service_Manual.pdf#page=473

Is there a way to turn the engine over by hand? I don't feel a bolt head on the end of the crank shaft pulley.

Thanks

Title: Re: Setting valve lash on a 250ci integral head L6
Post by: 79scott on September 22, 2015, 06:41:27 pm

Hey Guys,
 I am following the service manual on how to set the valve lash on my L6 and I have followed it by setting the distributor to the number one cylinder adjusting the proper valves (3/4 turn past the friction point) turned the engine over to get the distributor to the number 6 position and adjusted the proper valves.
 The issue I have is after I have followed the above procedure and turned the engine over to get the distributor back to the number one cylinder the valves and pushrods are still somewhat loose.
 Do I just adjust the valves once by this method or do I go back and forth setting the distributor to cylinder one and six until all of the play is gone?
 Also should the pushrods still spin once I am done with the adjustment?

 Hope this makes sense, Thanks

Title: Re: Setting valve lash on a 250ci integral head L6
Post by: bd on September 22, 2015, 08:12:11 pm

Loose - as in vertical play (lash) between the ends of the pushrods and the rocker arms?  Or, loose - as in the pushrods just spin easily?

Title: Re: Setting valve lash on a 250ci integral head L6
Post by: 79scott on September 23, 2015, 08:30:32 am

Not so much vertical play as being able to spin the push rod without any resistance.

Title: Re: Setting valve lash on a 250ci integral head L6
Post by: bd on September 23, 2015, 08:46:03 am

That's normal, because the hydraulic lifters have not yet filled with oil.  If a pushrod didn't spin (with zero end-to-end lash) while its lifter was on the heel of the cam lobe, I would be concerned.  As long as you followed the adjustment procedure precisely, one time through for all valves, and the valve train was adequately lubricated during assembly, you should be in good shape.

Title: Re: Setting valve lash on a 250ci integral head L6
Post by: 79scott on September 23, 2015, 09:52:50 am

great thanks