3,0L cylinderhead

[affa]

Hi
I am adjusting the valves on my 3,0L mercruiser 2002 mod, and was wondering if it`s the intake or the exhaust valves that is on each end of the cylinderheads?
Regards
Affa

 

[Bt Doctur]

E,I,I,E,E,I,I,E

 

[affa]

Ok, ty

 

[affa]

When I adjust the valves, and turn 3/4 after zero lash, there is no compression, am I doing it wrong?
I am sure I started with the number 1 to fire on the distributor, and adjusted the others when it`s firing at number 4 (TDC I supose)
Regards
Affa

 

[Bondo]

When I adjust the valves, and turn 3/4 after zero lash, there is no compression, am I doing it wrong?
I am sure I started with the number 1 to fire on the distributor, and adjusted the others when it`s firing at number 4 (TDC I supose)
Regards
Affa

Ayuh,.... My guess is yer well past zero lash when ya think you've gotten to 0 lash,...

 

[Bt Doctur]

I don't know where you got that information to adjust the valves, they are adjusted with the motor running , loosen until they clack, tighten until no more clack, slowly go 3/4 turn more
To adjust them staticly without the motor running:
locate intake valve, rotate motor until intake valve opens and then closes, this is the compression stroke for that cylinder. loosen rocker nut until there is free play in the push rod. Tighten nut until you can no longer SPIN the rod with your fingers, then go 3/4 more

 

[MikDee]

I don't know where you got that information to adjust the valves, they are adjusted with the motor running , loosen until they clack, tighten until no more clack, slowly go 3/4 turn more
To adjust them staticly without the motor running:
locate intake valve, rotate motor until intake valve opens and then closes, this is the compression stroke for that cylinder. loosen rocker nut until there is free play in the push rod. Tighten nut until you can no longer SPIN the rod with your fingers, then go 3/4 more

Exactly, but I only go down 1/2 a turn, it seems the engine runs more lively that way.

 

[Howard Sterndrive]

I always set the valves with a compression gauge. Sounds like you have one right there already. I use a remote start switch and a comp gauge.
Loosen the nut till the rocker rattles, then tighten it until compression drops off. Split the difference and voila - perfect adjustment.

 

[affa]

Ok thanks, this is what I did:
"Tighten nut until you can no longer SPIN the rod with your fingers, then go 3/4 more"
Now I tried starting when I couldn`t spin the rod, without more turns, and it started fine, strange..
Regards
Affa

 

[fishrdan]

"Tighten nut until you can no longer SPIN the rod with your fingers

That could mean different things, to different people....

Are you tightening the rocker nut down until you can no longer physically spin the push rod with all your might? If so, that's wrong.

You should spin the push rod while lightly holding it between 2 fingers, then slooooowly tighten the rocker nut until you feel the push rod drag or slip between your fingers. You're going to be spinning the push rod back-forth with no resistance, then all of a sudden, it won't spin freely anymore,,,, because there is no longer any clearance between the rocker, push rod and lifter. You're trying to get to "zero-lash" with no clearance between the rocker, push rod and lifter,,, while not compressing the spring(s) inside the lifter. Compressing the springs in the lifter is is what you're doing with the additional 3/4 turn, setting lifter pre-load.

OR, you can do as Bt Doctor suggested and set the lifters with the engine running. I've done it both ways, both ways work, with the engine running is easier (but messier).

 

[aerobat]

When I adjust the valves, and turn 3/4 after zero lash, there is no compression, am I doing it wrong?

you did something significantly wrong, sure. make sure to cránk or start the engine for a moment before adjusting so the hydraulic lifters are filled with oil. and do not mess up compression TDC with exhaust TDC on the first cylinder when starting the work.

 

[affa]

OK, thanks it`s running fine now
Regards
Affa

 

[MikDee]

OK, thanks it`s running fine now
Regards
Affa

I hope you did the preload on the lifters, because if you didn't, somewhere in the near future, you will start to hear tapping (a lifter went loose), then you'll hafta take the valve cover off, and adjust them all over again!

I'm old school, and learned to do this with the engine running on small block chevy's before any other method, I could do it in my sleep! I know it's messy, but a sure fire way of getting them right!
Now, if you want to use this method, loosen up all the rockers till you have a bit of play in them, start your engine, and let it warm up (valve cover on) no damage if they're a bit loose, but you don't want them tight! once warmed, take off the valve cover, and listen,,, then begin turning each rocker nut down slowly just a little at a time, till the noise stops,,, give it a few seconds to adjust, then turn it down slowly another 1/2 a turn, and you're done,,, Then move on to the rest of the rockers, and do the same thing. You will easily be able to do this, and set all your valves just by stopping the clacking noise. Any questions?