Valve adjustment
Thread Starter
Pro
Joined: Feb 2005
Posts: 627
Likes: 5
From: Frisco TX
Valve adjustment
I have the engine at tdc. What valves do I adjust? Then i assume i rotate 180 out and get the rest of them.
Also how do I know when I've got the nut tight enough? Do i tighten til there's a little tightness then turn the nut a little more. Thanks
Also how do I know when I've got the nut tight enough? Do i tighten til there's a little tightness then turn the nut a little more. Thanks
Race Director
Joined: Apr 2011
Posts: 11,183
Likes: 3,335
From: North of Toronto - Ontario
I've never done them that method (different valves at the different points)
The method I've always used (engine off) is to set the tdc for #1 making sure both valves are closed (ignition)
Loosen the nut off a little and then tighten until the pushrod just touches, (some lift, some spin, do whatever you want until you can feel it change. Then tighten another 1/2 turn
Rotate the engine 90 degrees and do both valves on #8
another 90 and do #4
another 90 and do #3
another 90 (back on the timing mark) and do #6
etc
OR
With #1 TDC
intake valves on cylinders 1, 2, 5, & 7
exhaust valves on 1, 3, 4, & 8
Rotate around 1 full turn (360)
intake valves on 3, 4, 6, & 8
exhaust valves on 2, 5, 6, & 7
Personally I use the first method and I know I got them all, and I prefer to lift the rods rather than spinning them. I find it hard to tell with then spin changes but can usually get when the light lifting stops
HIH
Mooser
The method I've always used (engine off) is to set the tdc for #1 making sure both valves are closed (ignition)
Loosen the nut off a little and then tighten until the pushrod just touches, (some lift, some spin, do whatever you want until you can feel it change. Then tighten another 1/2 turn
Rotate the engine 90 degrees and do both valves on #8
another 90 and do #4
another 90 and do #3
another 90 (back on the timing mark) and do #6
etc
OR
With #1 TDC
intake valves on cylinders 1, 2, 5, & 7
exhaust valves on 1, 3, 4, & 8
Rotate around 1 full turn (360)
intake valves on 3, 4, 6, & 8
exhaust valves on 2, 5, 6, & 7
Personally I use the first method and I know I got them all, and I prefer to lift the rods rather than spinning them. I find it hard to tell with then spin changes but can usually get when the light lifting stops
HIH
Mooser
Melting Slicks
Joined: May 2006
Posts: 3,303
Likes: 14
From: Lynn MA
What cam is in it THAT makes a big difference, if running a big solid roller the following method will not work and that is because of the ramp design of the lobe
With #1 TDC
intake valves on cylinders 1, 2, 5, & 7
exhaust valves on 1, 3, 4, & 8
Rotate around 1 full turn (360)
intake valves on 3, 4, 6, & 8
exhaust valves on 2, 5, 6, & 7
We just did my dads BBC, took awhile, but did each exhaust and intake valve cylinder by cylinder with 90 degree rotations
With #1 TDC
intake valves on cylinders 1, 2, 5, & 7
exhaust valves on 1, 3, 4, & 8
Rotate around 1 full turn (360)
intake valves on 3, 4, 6, & 8
exhaust valves on 2, 5, 6, & 7
We just did my dads BBC, took awhile, but did each exhaust and intake valve cylinder by cylinder with 90 degree rotations
Melting Slicks
Joined: May 2006
Posts: 3,303
Likes: 14
From: Lynn MA
If hydraulic you can use that method and want to adjust by zero lash, meaning that when you tighten adjust them, when on the correct cylinder as you rotate through and do each cylinder, you want to simply just be able to rotate the pushrods with your fingers....if you can't spin them they are too tight, if you are like a hot dog in a hallway they are too loose, they should spin with using your finger and thumb, with some resistance
