[targa911man]

Wil Ferch had an interesting post here:

http://forums.pelicanparts.com/showt...197#post927197

He suggests that with the valve screw having a 1mm pitch, if you screw it down and back out 1/8 turn you should have a .125 mm gap. This is .025 outside perfect spec but within tolerance, I think. (You're probably lucky to get it within .025 with a feeler.) The math is irrefutable, so what are we missing? Having just redone the 4-5-6 gaps (luckily intake only) after doing the full adjust over the weekend, I wish I knew then what I know now. Is the valve adjusting feeler tool lobby so powerful that they have suppressed this knowledge from the public? How far will they go? Is Wil's life (holy cow! and now mine!) in danger?

[rickc]

That seems logical, but probably doesn't eliminate the need for the feeler gauge to make sure that the gap did not move after the nut was tightened.
It is similar to tightening the setscrew down on the feeler gauge. Might be worth trying both ways to see the degree of accuracy vs error.
Rick
'78 930

[Jim Richards]

I'm not sure how accurate this will be. Guestimating 1/8th of a turn. I'm sure I can do it to +/- 1/16th of a turn, maybe better if I'm really, really careful. So, that means my adjustments would be between 0.0025" - 0.0074". I think I'd do a better job with the feeler gauge.

[targa911man]

I agree you'd need to check it with a feeler, but how about this: take a short straight edge and line it up with the slot in the screw when it's tight, then back off til the slot's at a 45 deg. angle to the straight edge. For that matter you could easily use a small protractor to eliminate the guesswork on the angle. I just did my valves so I won't be doing them again for a while. Who wants to be the guinea pig?

[William Miller]

Good timing for me. I'm rebuilding my engine and just installed most of my rockers yesterday.
I actually did it this way on a temporary basis while I installed the rockers on the right side. I wanted to get a little play so as I turned the crank to index for the next cylinder I could check to see which were loose and tight.

I wasn't careful but it worked for my needs. I plan to adjust them all at one time once all the rockers are in.

With the engine out it's real easy.
I'll try it on a couple and let you know what I find out.
I'm sure it would be much harder with the engine in the car because I doubt you can get a sight line that is exactly over the head of the screw.
Mirror's might work.

Doing it with the feeler gauge is really not that hard. I'll pass on a tip someone told me. "Before inserting the feeler gauge, back the adjusting screw out a lot at least 3-4 turns. This gives a lot of room to get the feeler gauge in the right spot. Then tighten the allen screw back in to make the final adjustment."

Before I knew this I was only backing the screw out a little bit and trying to slip the blade of the feeler into the razor thin slot.

[targa911man]

Originally Posted by William Miller

Doing it with the feeler gauge is really not that hard. I'll pass on a tip someone told me. "Before inserting the feeler gauge, back the adjusting screw out a lot at least 3-4 turns. This gives a lot of room to get the feeler gauge in the right spot. Then tighten the allen screw back in to make the final adjustment."

That's the way I do it, except I've found about 2 turns is usually sufficient. Good that you posted it.

[William Miller]

I never actually counted how many turns, I'm sure 2 is probably plenty!

[William Miller]

I adjusted the valves. I tried the visual method. I didn't like it. It's too easy using the feeler gauge method. I couldn't help but check it with the feeler gauge anyway. I also think it will be easier with the engine in the car because in many cases you can't get a direct line of sight over the head of the adjustment screw.

[RoninLB]

turning the screw a fixed amount is a good refrence.. that and a feel for the rocker float could bail you out one day.. and if you turn a wrench 40hrs a week it may be "good enough"

some guys will argue for a dial indicator.. I guess the hard cam timming info is their reference.. IMO the variation of the rocker train gives a false sense of victory. so, IMO, do what works for you.. get a feel for the rockers and listen all the time to the rockers dancing.........Ron

[William Miller]

I pulled my rebuilt engine out because of a leaky rear main seal.
When looking for the leak I herd at least one rocker that sounded very noisy. I started w #1 and found it to be loose both the intake and exhaust valve. I readjusted and checked the valve timing with the dial indicator. With the newly adjusted #1 intake valve the valve timing advanced timing advanced a little less than 0.1mm. This, I'm sure is the initial wear or breakin of the new rocker shafts to the old camshaft.
I also did not remove the timing chain covers and tension the chain so that may have caused some of the varience.

I will replace the seal and adjust the rest over the next few days. My guess is that I will find a few more loose and one or two (the noisy ones really loose.)

This adjustment is really premature because the engine only has about 60-70 miles on it. But I might as well do it cause it so easy when it's out of the car.

Hopefully the new seal will resolve the oil leak issue and I can drive it for a while and get the rest of the break in done.