Foolproof V6 Valve Lash Adjustment Procedure (Page 1/1) reinhart JUL 11, 02:03 AM Some of you may remember I had a thread several months back where my 88 GT toasted one bank of its valve lifters. If you read that thread you know I was able to get the car put back together. It's been running great now and I even saw a 15% improvement in gas mileage since I redid the valve lifters. https://www.fiero.nl/forum/Forum2/HTML/145858.html At the time, I had spent a ton of time pouring through a bunch of threads on correct valve adjustments, ruined cams, noisy valves etc from not getting the valve lash set correctly. There are many theories floating around about 1/2 turn after drag or 2-1/2 turn or anything in between. The problem is and the reason this is so difficult for people to get correctly is it's far too subjective a measurement (drag) or (resistance). Or there might be a lifter that isn't releasing fully and when tightening what actually would be the correct value is bottoming out which is where the cam get trashed. One guy might have things dry or oiled or there's a piece of dust in there or the stars are aligned differently. The chances of getting all 12 right using the resistance method are not good. If you want the valve lash adjusted perfectly, there is one foolproof way to do it. When doing valves, most people remove the upper and middle plenums to get the valve covers off (although there are a few reports that Houdini and a few others was able to get the valve covers off with the entire intake still there). If you've gotten the upper and middle intakes out, just remove the lower intake. Once the lowers are out, you can see the valve lifters and their travel. Now measure the travel of your lifters from top to bottom using a caliper with a depth gauge, and divide by 2. That will get you the midpoint of the lifter travel and that's where you'll want to tighten the valves to. I believe going off memory the total travel was 8 mm and I set tightened my valves to the midpoint of the travel which is 4mm. You need to remember to adjust the lifters when they are not on the cam lobes to do this correctly. That's it. Yes it is an extra hour of work but well worth it in my mind even if you have no other reason to remove the lower intake. olejoedad JUL 11, 08:34 AM Using resistance to determine zero lash is not correct. Zero lash is when the pushrod will not move up and down between the rocker and the lifter. Rather than rotating the pushrod, the pushrod should be moved up and down. When it can't be moved up and down, you have zero lash. It is really very easy to do. Raydar JUL 13, 09:51 AM quote Originally posted by olejoedad: Using resistance to determine zero lash is not correct. Zero lash is when the pushrod will not move up and down between the rocker and the lifter. Rather than rotating the pushrod, the pushrod should be moved up and down. When it can't be moved up and down, you have zero lash. It is really very easy to do. Second this. I wiggle the pushrod. When it stops moving, you're at zero lash. As slick as most of the assembly lubes are, and as smooth as the pushrod tips (and matching "cups") are, it's very easy to crank down past zero lash and not even realize it. Fortunately, I figured this out before I broke anything. Patrick JUL 13, 03:54 PM quote Originally posted by olejoedad: Rather than rotating the pushrod, the pushrod should be moved up and down. When it can't be moved up and down, you have zero lash. quote Originally posted by Raydar: Second this. I wiggle the pushrod. When it stops moving, you're at zero lash. Third this. Slight variation (but same result), I rock the rocker. reinhart JUL 16, 07:46 AM Not sure the terminology. Point is how to adjust valves in a foolproof manner without being too loose and having your lifters top out and come apart or too tight and wiping out your cam.