When you change stuff like camshafts, lifters, rocker arms, valves, PUSH
RODS, etc. Then all bets are off. Oldsmobiles did NOT COME FROM THE FACTORY
WITH ADJUSTABLE VALVE TRAINS. So, everything from valve lift, how far the
valve stems extend into the heads after a machine shop finishes grinding
the seats, valve faces, and stems, push rod length, lifter plunger travel
range, thread pitch on the valve adjusters, ALL CAN, AND DO INDEED, affect
preload. What a can of worms you have created for yourself.
Jim Hupy
Salem, Oregon
> > I talked to Dick Patterson, he said 1/2 turn.
> > But the real question is how far off is too far and holds the valve open?
> > Not enough and it ticks, but too far??
>
> Kieth,
>
> One of the reasons for hydraulic lash adjusters is that they have a huge
> sense of humor..... When they are working right.
>
> If you are doing the set even warm, the exhaust stems are so hot that
> there is not much thermal expansion left for them. And, don't even worry
> about
> the intakes, they don't change enough to be an issue at all.
>
> The thing that is important if you are doing a cold set is that you are
> setting the at TDC for that cylinder. Some one is bound to tell you that
> you
> only need to set the crank in two positions... Set #1 TDC and then you
> can set #5I #7E #4I #9M (just seeing if you were paying attention....)
>
> Really - That is a recipe for a mistake. The nolo contendre for best way
> to set or inspect lash is this...
> Write the firing order in two rows
> 1 8 4 3
> 6 5 7 2 For a 455
> Now roll the crank until #1 is in cross-over (Exhaust is closing and
> Intake is opening). Now you know the #6 should be on the dwell of the cam
> and
> you can set both those valves. This is the way we always did it in the
> contract labs that I ran. Why this way? Because it is absolutely certain
> that the valves you are working on are the right two. Unless you only
> work on one specific engine family, it is confusing and this is a sure way
> though that confusion.
>
> Side Joke: I did once own a Honda 350-4 (loved that bike). In the
> manual, under adjusting the valve lash it said,"Position the crankshaft so
> all the
> valves are closed." My guess is that someone copied this from the 2
> cylinder manual.
>
> Matt
> --
> Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL,
> GMCES
> Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum
> Brakes with Applied Control Arms
> SE Michigan - Near DTW - Twixt A2 and Detroit
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