adjusting valves

[krisnowicki]

Do you have to adjust them under load? Or can I do it blocks after breakin

 

[Fishermark]

Re: adjusting valves

Or can I do it blocks after breakin

 

[Thad]

Re: adjusting valves

Are you refering to adjusting the rocker arms?

If so, you want to wait until the break in period at least.
I think that is what you meant

I do mine every other year or so, just to make sure everything is ok.

 

[krisnowicki]

Re: adjusting valves

I meant in the boat....not under load sorry... darn iphone

 

[Thad]

Re: adjusting valves

Alrighty then,
You need water. Muffs will work.
Adjust them with the engine not running. There is a lot of feel involved.
You have to crank/turn the engine over to move the valves/rockers into postition to be able to do all of them. When you think they are done, you have to start the engine and listen to it while it is running. Then, sometomes, go back and adjust more.
Are they tapping now?

 

[rodbolt]

Re: adjusting valves

no no no
do them on the stand, seal up the rocker covers and go play.
the nice thing is all you are doing is setting lifter plunger preload.
the horse crap about doing it running is just that.
follow the correct manual and you will see.

 

[Bondo]

Re: adjusting valves

There is a lot of feel involved.

Ayuh,.... I pretty much Always agree with ya Rodbolt,... Talkin' about Motors,+ Drives anyways,...
But Thad hit on an important tidbit there,...

I do my valves on the stand,+ it's usually a disgnostic thing if done Running...
But,...
I've lost track of the threads about fella's who equate Lash as being able to spin the pushrod,+ end up tightened, Tight...

Ayuh,...
I wouldn't call it Horsecrap, but who the 'ell wants to pull manifolds to get a valvecover off anyways,..??

 

[Don S]

Re: adjusting valves

But,...
I've lost track of the threads about fella's who equate Lash as being able to spin the pushrod,+ end up tightened, Tight...

There is the big problem. IF, and that is a big IF. A person knows what they are doing and they adjust the valves when putting the engine together, and they do it right, you NEVER have to adjust them while it's running.
I never have to adjust valves on a running engine.

The biggest problem is, when a newbe goes for zero lash where the pushrod doesn't turne, he should be using 2 fingers. Not vise grips to feel when it stops. When it stops, don't even think about trying it again, and newbe's do, so the adjust and adjust till they run out of room.
Turn it down till the push rod stops, do the additional 3/4 or full turn per the manual, and you are set to go.

Oh, yeah, you need to pump up new or rebuilt lifters before you try to adjust.

 

[Bifflefan]

Re: adjusting valves

Then, sometomes, go back and adjust more.
Are they tapping now?

If you do it right the first time, there is never a need to "go back".

 

[dr_bowtie]

Re: adjusting valves

I agree do it on the stand...there are several way to adjust rocker arms...running the engine and doing it is time consuming and messy..and with enough oil pressure oil goes everywhere and can lead to a fire....

Best way is to learn to do it right...valves are a set it and forget it kind of thing..if you need to adjust them from time to time you have more issues than just loose rockers...either that or solid lifters...

as far as twisting the push rod I dont do that...I lift the pushrod up and down just like the rocker arm would and I call it zero lash when you cant lift the pushrod off the lifter OR lift the rocker off the pushrod..then lash it...

twisting isnt something for beginners as another poster said you MUST be able to tell when the pushrod touches the lifter ans start to move the plunger...

soak the lifters in motor oil prior to installing them and I also use an oil can and force oil in the side hole until it runs out the top...that way I know it is filled...

I ALWAYS adjust lifters in a new engine BEFORE I set teh intake...it is usually a step I do right after degreeing in the cam...

 

[Apollo75]

Re: adjusting valves

Well, what are we working on ? Anything with adjustable hydraulic lifters

I think these guys have been in the bilge too long inhaling those rotten old gas fumes ---> Just joking a little fellas ---> they are spot on.

If the lifters are new / good used ---> place in a container so the lifter is covered in oil and use a push-rod to pump the lifter up ----> when it don't pump any more it is done.

I will skip the cold test stand procedure as they have covered it.

Hot adjustment ---> engine and oil must be at normal operating temperature so all the parts are hot and expanded / stretched fully. If one of the rockers have been clacking when warn then it should be clacking by now.

Remove valve cover and install rocker clips to keep the oil from squirting out the top of the rocker arm all over the engine ---> do one side at a time unless you are quick ---> loosen all the rockers arms one at a time while the engine is running until you hear a clacking then down to no noise ---> if they were out of adjustment the engine should be running much smoother now ---> one at a time adjust the rockers down to engine specifications a quarter turn at a time ----> this may cause engine to run rough until the lifter bleeds down.

When finished check gaskets and install rocker / valve covers.

If something is still clacking on and off ---> you need to replace or clean lifter / lifters are cheap and not worth the time and effort disassembling and cleaning.

I remove the rocker arms and remove the push-rod to check for wear on the push rod ends and for bent push rods --- if unsure about a bent push rod roll them across a flat surface ---> the ends will wear and you can tell by the pitting and a larger opening than the ones with less wear or a new push rod ---> I use chrome molly push rods and they last a long time.

This should be a breeze as the engine is only running at 140-degrees and the exhaust is cool to the touch if the cooling system is working right

Happy boating

OFM

___________________________________
"If the boat is not sinking or on fire ---- Relax."

 

[Silvertip]

Re: adjusting valves

The very messy process of adjusting lifters on a running engine can be accomplished with a lot less mess by cutting a slot in an old set of valve covers along a line directly above the adjustment nuts. You can get real hi-tech by simply drilling holes in a cover over each nut, just large enough to get a socket through. You now have much less oil flying around. I would also recommend that you not loosen ALL rockers. Loosen and adjust one at a time so you can actually hear the one you are working on and not all of them at once. But then this is all moot if you do it right with the engine on a stand.

 

[littlebookworm]

Re: adjusting valves

You guys discussing adjusting valves with the engine running are all right, and probably all wrong. In cars, adjusting a GM small block with the engine warmed up and running is messy, at best, but accurate. Using the clips or trimmed back valve covers takes care of some of the mess. I did it that way for years when I worked on cars. But, a Mercruiser is different in that you usually can't remove or install the valve covers unless you remove the exhaust manifolds. That's setting yourself up for extra work with no real reward. Just follow the service manual directions and adjust them with the engine off and you'll be fine. If they go out of adjustment, then you've got bad lifters or a loose rocker mounting stud. Hy

 

[Apollo75]

Re: adjusting valves

I think his engine is still in the boat ---> what would be the difference if it is ?
He still has to remove the rocker / valve covers for a cold or hot adjustment.

At least the people that read the threads know a little more about adjusting valves. I think that is what these posts are for.

Now they know they need to remove the exhaust manifolds to get the valve covers off in some applications.

OFM

___________________________________
"If the boat is not sinking or on fire ---- Relax."

 

[tfret]

Re: adjusting valves

I am a "newbie" with a 1984 Mercruiser 260, 5.7L with almost 900 hours on it that I've owned for 3 seasons. As far as I know the valves have never been adjusted. I was planning to do it this fall before I winterize the boat. I plan to do it in the boat with the engine off, using the manual, which calls for the "spin until it stops" method. I understand the comments about this being one of those things a person must develope "a feel" for. Are there any suggestions for a newbie tackling this task for the first time?

 

[Apollo75]

Re: adjusting valves

That 350 has a lot of adjustment on the lifter pre-load ---- like 1/4 to 1 full turn will be fine. You can adjust them if you like --- I would just forget it if the engine is running good and not making lifter clacking noise.

You jumped on someone else's post --- that is why you were not answered.

Just start your own post if you have questions.


Good Luck

OFM

___________________________________
"If the boat is not sinking or on fire ---- Relax."