Hello Everyone

I have a 68 vette with a 327 HO engine.

Noticed a ticking on #7 cylinder

Not real loud but needed to change leaky valve cover gaskets so I decided to re-adjust all valves.

I used this method:

Get #1 to Top Dead Center

Get #6 to Top Dead Center



You will only turn the engine 2 times. TDC #1 and TDC #6

I read Lars paper as well found it on this site.

I used Lars spin until pushrod tension changes and then 1/2 turn method..

Engine runs fine now however I hear a rushing sound on start up.

It wasn't there before I touched the valves.

A Buddy says I did it incorrectly as I needed to adjust them with engine running.

I am concerned about harming the engine

I look a piece of tubing and held it to each cylinder after I was finished they all sound good.

No loud clacking or any other sounds of distress.

Thanks for any advice

Mike

Any Ideas as to the noise?

better pic

 

I have 2 concerns...

You stated that you have a "327 HO" engine. Are you sure that it's a hydraulic lifter engine, and not one with "solid" lifters? Assuming that your engine is indeed a hydraulic lifter engine, IMHO, 1/4 turn of lash adjustment is not enough. Should be at least 1/2 turn, even 3/4 turn would not be too much.

Adjusting them with the engine running can be done, but it can cause the engine to run "rough" during the process. It's better to set the valves to "zero lash" (the point at which the lifters just begin to stop clattering, as you tighten the lock nuts), then shut the engine off and turn ALL the nuts down 1/2-3/4 turn.

 

To avoid a mess, I used an old valve cover with the top off.

 

Anti-splash shields are available also that clip onto the rocker arm if you don't have an old valve cover.

 

Pretty slick there Dorian. I like that. Would be extra bonus if the valvecover clears the splash-clips.

I will catch hell from some, but I don't like setting valvelash with engine off / hand crank. There will be a day when you need to remove the harmonic balancer bolt. It will be on there so tight you will cuss at who ever did that. But it was you, cranking the engine with a breaker bar. And there is always the fear, big fear, of the bolt snapping off in the crank. No thanks.

Its so much easier, and really fast setting the valves while its running. Just attach the oil spray clips, (they come in packs of eight) and start it up. No fumbling around with feeling the pushrods, turning the crank, establishing the firing order, etc.

 

I do not like to advise anyone to use the "twist" method if they are asking the question. If you need to ask, there is a chance you will miss the drag threshold and tighten them all the way past the travel limit and you will feel the bigger drag as the valve spring begins to compress - way too far. If the pushrod is moved up and down while you tighten the nut you will feel more positively when the slack is just about gone and you are at zero lash. You want to tighten the nut (some amount) past that point. You will hear everything from a quarter turn past zero up to a full turn past zero and it really does not make any difference. You just need to be between the limits of adjustment. THE EXACT NUMBER OF TURNS DOES NOT MATTER. A little bit more turn will keep the adjustment right for longer. A little bit less turn will not be able to compensate for valve train wear as much. Racers like to stay close to zero to prevent potential high RPM valve float but in reality it will make absolutely no difference for 99% of the people driving.

If you have done this a time or two, the twist method is fine because you know how light the drag can be when you do get to zero lash.

Obviously, If you have a solid lifter engine you should not be using this method. Totally different animal.

 

 

There is simply no need to adjust rockers when running. None. Why lean over a hot running engine to adjust them if the cold engine off procedure works fine? And I do not do it via the Assembly manual either.
Each cylinder has a TDC. The valves HAVE to be shut at TDC. So put it on #1 TDC and adjust the intake and exhaust. Now go to #8 TDC (Mark the balancer every 90 degrees) and do intake and exhaust on that cylinder. Now go through the rest of the firing order 4-3-6-5-7-2......done! The pushrod jiggle up and down and 1/2 turn after is the preferred method.
To be clear.....the cam just needs to be on the basecircle to adjust the valve......watch the guys in the pits at the race track. They bump the engine over until the rocker comes back up and they go just tad more and lash that valve....then bump-bump-lash, bump-bump lash..........
The beauty of doing the lash cold is you put the covers on and if you paid attention to what you are doing, you are DONE! Unless the nut backs off or a lobe wears off...you should never need to dick with it again. Ever.
I use polylocks on everything, even ball-stud rockers because you can "feel" when the lifter starts to plunge with your fingers as you tighten it.

Jebby

 

Thanks Jebby

So the method I used of finding TDC on #1 then adjusing


Was incorrect?

I moved the pushrod up and down till there was no more play
Then I stared to twist the pushrod unitl it began to catch

1/4 after that.

Any idea of the sound its making?

Thanks

 

I have a bump starter

Are you saying I find TDC on #1 when both rockers are up?

Set lash

Then bump to #8 TDC both rockers up set lash and so on?

 

No, that is correct.......the bump starter description is more for racers at the track.......mark the balancer every 90 degrees and that is the next cylinder......I just do it with a long breaker bar and socket on the crank bolt. I urge you to do the 1/2 turn as 1/4 can be noisy......I do 1/4 turn on offshore boats but not cars.

Jebby

 

Yes...but do it with a breaker bar......it is easy, slow, and you can watch the rockers and marks you just put on the balancer.......
I have no idea what your noise is........would have to hear it but even that may not work because my hearing sucks from too many Slayer concerts...and dyno room tuning.

Jebby

 

There is simply no reason to adjust valves when the engine is off. None. Your not right and neither am I. Or, we're both right. Both methods are acceptable.

So why not lean over a hot, running engine? Do you adjust your carb with the engine off? Do you time the engine when its off? There are times when leaning over a hot, running engine is necessary and it can be done quite safely. Adjusting valves when engine running is just plain easier and gives a better result because the valve train is at running temperature. Of course, there are idiots who pay no heed to safety and therefor more prone to injury or death. But valve adjustment can be done with engine off or running. Either way will achieve the desired result.

 

One thing to add on the breaker bar method...removing the sparkplugs makes the engine easier to turn. The engine compartment in my 69 is tight, making it tough to get the proper angle and engagement while fighting the fan and everything else. Pulling the plugs is an extra step but makes the engine easier to spin by hand and is worth the effort for me. Aligned with Jebby on the 1/2 turn preload.

Good luck - Don

 

I agree, way too easy to get it wrong. The variation in rotating force can be way less than you'd expect it to be and very hard to detect.

I suggest putting your thumb under the valve end of the rocker and lifting up on it. Then, with your first finger tap on the top of the rocker. It will click against the valve when there is any amount of lash/clearance.

Adjusting while running also works well. You can get it correct fairly easy just by the change in sound.

I also agree that hydraulic lifters should need very few adjustments during their lifetime.

 

Hydraulic lifters....on my cars, I set them the way the OP did it. But I first remove the lifters, take them apart and clean them, install them with a little bit of oil on all surfaces. That way they are unloaded, and I can SEE the travel limits. Normally, a 1/2 turn past zero lash (I use the up/down method) sets them at a little less than the halfway point, which is where I like them to be.

 

Hello and thanks for the replies

But I am more confused

I followed the method I mentioned above


The car seems to run smoothly without clacking

I still hear a whine once when starting cold

Are the valves too tight?

I am open to buying the oil deflectors and loosening one at a time if this is a better method.

 

It would have no way to cause a whine. The method you performed is fine.

Jebby

 

When removing the valve covers, did you have to loosen/move any belt driven items (alternator, AC compressor, etc)? If so, something could be slightly rubbing there when cold?

 

This is foolproof!!!

The old 0 lash for hyd cams is dumb advice someone came up with somewhere in the 70s it doesnt work like that but can bust your retaining clip. 1/2 turn is pretty safe. If one wants a solid lifter cam then put one in.