LLY: Valve Lash Help!

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Tobin LLY

New member
Jun 28, 2016
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I am in the process of doing a head gasket on the old LLY and got to the part where I need to adjust my valves and I not quite sure if Im on track. Here is the procedure I'm following:

First get cylinder No. 1 at TDC (no. 1 is front pass cylinder) on the compression stroke.

at this point you can adjust the following:

cylinder no. 1: intake and exhaust cylinder no. 2: exhaust cylinder no. 3: intake cylinder no. 5: intake cylinder no. 6: intake cylinder no. 7: exhaust cylinder no. 8: exhaust

rotate the the motor one revolution and then adjust the following:

cylinder no. 2: intake cylinder no. 3: exhaust cylinder no. 4: intake and exhaust cylinder no. 5: exhaust cylinder no. 6: exhaust cylinder no. 7: intake cylinder no. 8: intake[/COLOR]

Here is the rub...

How can I be sure I have the #1 piston all the way up at TDC? Short of pulling the head again...

Right now I have the fly wheel notch on top and centered on the block. Both the exhaust and intake rockers are free( make me think I'm at the top of the stroke). #1 intake is at what seems to be .012 and the exhaust is at .006 or .007. #3 intake is at .009 roughly. #5 intake is tight and I cant get a feeler gauge in there. #7 exhaust is free(I didn't gauge it). Can the lash be that far out, on all these rockers?

Can you tell me the proper method for checking the lash? Maybe I'm doing it wrong....

So I adjusted the Passenger side and the #5 intake was tight before I adjusted it and now, once I rotated the engine 1 revolution it is now at over .040. Whats the deal, where am I messing up?

Thanks for any help you can lend!
 
Chevy1925

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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i never go off the fly wheel. there is an arrow on the front cover that a line on the balance will line up with. that puts cyl 1 at TDC every time. follow that and you wont be questioning yourself
 
THEFERMANATOR

THEFERMANATOR

LEGALLY INSANE
Feb 16, 2009
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Cylinder #1 is always the one closest to the balancer. For the duramax they swapped #1 to the passenger side to make more room for the downpipe so they could run a center mounted turbo instead of a side mount like the 6.5l had. When in doubt, stand in front, and see which side is closest to the balancer.
 
T

Tobin LLY

New member
Jun 28, 2016
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Thanks fellas, I found TDC!

As it turns out there is a marker, more of a protrusion, on the front of the block at 9 O'clock, to line the notch on the balancer up with. There should be no movement of the #1 rocker arms for 90 degrees of travel before the balancer notch comes to the 9 o'clock position. That is the compression stroke for #1.

Be aware the threads on the adjustment screw seem verry soft... I stretched a few!
 
Chevy1925

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,743
5,911
113
Phoenix Az
Chevy1925 said:
i never go off the fly wheel. there is an arrow on the front cover that a line on the balance will line up with. that puts cyl 1 at TDC every time. follow that and you wont be questioning yourself
Click to expand...

Tobin LLY said:
Thanks fellas, I found TDC!

As it turns out there is a marker, more of a protrusion, on the front of the block at 9 O'clock, to line the notch on the balancer up with. There should be no movement of the #1 rocker arms for 90 degrees of travel before the balancer notch comes to the 9 o'clock position. That is the compression stroke for #1.

Be aware the threads on the adjustment screw seem verry soft... I stretched a few!
Click to expand...

yup, one of the first things posted in here ;) :D
 
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