Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - Valve Lash
Thread: Valve Lash
View Single Post
  #15 (permalink)  
Old 10-05-2007, 02:20 PM
Notorious's Avatar
Notorious Notorious is offline
Hot rodder, not street rodder!
Last photo:
Join Date: Aug 2007
Location: Bakers Mountain, NC
Posts: 507
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Y'all are making this way too hard. Although many engines spec valve adjustment for all valves from two different positions in the 360* of cam rotation, which of course is at two crank positions a full turn apart, here's a fool-proof method for any engine with an even number of cylinders. All you need to know is the firing order for the engine you're working on. I'll use the SBC firing order since it's permanently ingrained in my feeble mind. 18436572 Now, split this in two like this
You can start the process from any position in the firing order by watching the rocker arms. And by understanding that any two paired cylinders will be at TDC at the same time. In this case and with this firing order, the paired cylinders are 1&6, 8&5, 4&7 and 3&2. One will be on the compression stroke and it's mate will be in the valve overlap period. That's the time at which the exhaust is almost closed and the intake is just starting to open. We'll refer to this as the point at which the valves for that cylinder are "rocking." Begin by hand turning or bumping the engine over with a momentary switch set-up hooked to the starter solenoid. Watch for an exhaust valve that is closing. Continue turning until it's accompanying intake valve just starts to open. Stop there. Now you adjust the valves in the paired cylinder to this one. This will be the one that is at TDC on it's compression stroke. This means that most assuredly that those two valves are fully closed. From this point on, you now know precisely where you are in the firing order and can proceed from there. Take note of the valves that were "rocking" and go to the next cylinder in the firing order. As you begin to turn it again, you'll see that it's exhaust valve is in the process of closing. Watch it just as before while turning the engine until it's almost closed and the intake valve for that cylinder just starts to open. Stop again and adjust the valves for the "mated" cylinder in the order.

Last edited by Notorious; 10-05-2007 at 02:56 PM.
Reply With Quote