1987ZTPI

i think i posted this in the wrong thread befor , i have an 87 305 TPI roller motor and i want to set valve lash i have been told to set it at 1/4 turn past zero lash and also 3/4 turn past zero lash not sure what 1 is rite and help wuld be nice.

Gramps

iTrader: (1)

its 1/4 turn. what size threads are your studs?

IOWZ28UK

Would there be any major problems if they were turned in 1 full turn? Think i read the book wrong, gonna redo to double check.

gapimpin

if you tighten it too much your valves will not close all the way... i spent 6wks not being able to use my car because i forgot the hydrolic lifters are a pita to set lash on... i finally just ran the engine and loosend the rockers till they ticked then tightened them down till it quit... worked great for me. oh yea forgot to mention i used a set of valve covers with a slot cut in them that i could get to the rocker nuts... if you run the engine with the valve covers off be prepaired to get oil all over you.

1987ZTPI

so i should adjust it until they stop ticking then a 1/4 turn after that . do u have to adjust them with the engine running or can u do it with it turned off.

sofakingdom

iTrader: (1)

With the engine running (pretty hard to get them to tick otherwise), back each off one at a time until they start to tick, then tighten it back until it just quits ticking. After doing all 16 like that, turn the motor off, and tighten every one an additional ½ turn. You could go as little as ¼ turn which is good for a high-RPM motor, or as much as one full turn which is what the factory recommends for a new motor that wants to remain untouched for the next 200,000 miles or more; anything in that range is fine; but ½ turn is what I prefer for a street motor.

Camaro355Z28

when I set mine (with motor not running, I chose to keep my fingers) I set the #1 cylinder at TDC and set all of them in a certain order. I have a sheet the right order to do them, when you finsh half of them you have to turn the motor over a full 360* so #1 cylinder is at BDC, then do the other half. You know they are set when you cant spin the pushrods with your fingertips anymore, then 1/2 turn to preload them. There may be other ways of doing it but this is the way I was told. If you want the order I did it in I can post it, just let me know...

GuitarJunki17

iTrader: (1)

This is how it is outlined in the Haynes manual, and is the method that I have used.

Rotate to #1TDC on the combustion stroke.

Tighten Intake valves 1,2,5,7 and exhaust valves 1,3,4,8

Turn engine 360 Degrees

Tighten Intake vales 3,4,6,8 and exhaust valves 2,5,6,7


Do the 1/4" overturn method. I've tried doing this with the engine running, but you get oil everywhere, and also may set a few towels on fire in the process if you arent careful, lol.

HINT: take out all the spark plugs to make it easier to turn the motor over by hand. Not only will this save you physical exertion and a few busted knuckles, it can also save your crank bolt from breaking off in the snout...that is not a fun one to get out. Oh and if you are using the position of the rocker arms to determine what stroke you are on, dont be an idiot like me and mix up the intake and exhaust valves...that took some sleuthing to get right.

digitmachine

I haven't gotten around to adjusting mine yet, but while searching for info I came across this article. http://www.chevyhiperformance.com/te...nfo/index.html

Sonix

iTrader: (1)

Unless you have oil deflectors on hand, don't even bother trying to do it with the engine running. You'll be a standing version of the aftermath of the exxon valdez, and your oil pan will be dry in a matter of 10 seconds or so.

Vizard recommends tightening the lash until it just barely holds the valve off the seat, then going back .010". Apparently makes it act more like a solid, kills the valve float concept. Up to 30HP on the top end. I think it would be a bit bad for valve train geometry, but hey, I haven't tried it yet...