valve adjustment

[salmonbob]

I have replaced the head gasket on a 2000 3.0 LX 181 CID (3.0L) MERCURY
I have a manual that I have seen posted here several times. The mercury on
line kind! Anyway in the mercury manual 3A on page 3A-11 it says to install
the push rods and rocker arms in their original locations. Torque rocker arm
nuts to 20 lb. ft. No valve adjustment is required. Valve lash is automatically
set when rocker arm nuts are torqued to specification.

O.K. has anyone had success with permanent adjustment doing it this way.

I don't want to have to get at the valves when I am back in the water,
in the spring.

 

[Don S]

Re: valve adjustment

What manual number are you looking at, it should be #26? There is a valve adjustment for your engine, and on page 3A-11 of the correct manual, only shows wear on a main bearing, while on page 3A-18 explains how to ADJUST the valves.

 

[salmonbob]

Re: valve adjustment

Do I have the wrong manual?

Engine 3A 181 CID (3.0L) 4 CYLINDER GM ENGINE

Engine Specifications 3A-3
3.0l/3.0LX
Don do you have a link to the manual you are referencing

 

[Don S]

Re: valve adjustment

I don't know if you have the right manual or not, you don't say which one you have??????
Look at the cover, or look at the bottom of each page, there should be a 90-XXXXXXXX number, what is that number.

 

[JustJason]

Re: valve adjustment

i think you have the manual for the older 120/140 gm inline 4's and 6's... you need the newer one. If i remember right, its' something like "0" lash plus 1/2 to3/4 of a turn when the engine is warm. But definitely double check the manuall. Before you go any further check the compression and log it, so after you do do the valves you can re-check it and compare it to your origial ##'s to make sure you didn't go to tight.

 

[Don S]

Re: valve adjustment

You have manual 13, for 90 to 97 engines.

Turn the page and start on 3A-12 for the proper adjustments.

You really need manual 26
http://www-alt.mercurymarine.com/mnetdata/sisdata/srvcovr.pdf

 

[ron7000]

Re: valve adjustment

alternate reality check: compression check to validate rocker arm adjustment.
this place is aweeesome.

jason, you were good bashing rapido and I'll side with you on that except for the part where you took a left turn with the analogy about people dying and airplane maintenance, that got a little lame.

where did everybody learn about engines?
everything I know, or thought I know, is wrong when I read stuff here.
Is there a book at iboats.com that I could buy, on how engines work?
Oh, and it's got to be "marine" engines.

 

[salmonbob]

Re: valve adjustment

Thanx for the response's guys.
Don the manual I have is 90-816462 2-695

Engines- 3A-11
States the reference to torque rocker arm nuts to 20 lb ft. No valve adjustment is required.

I did see the valve adjustment on page 3A-12 . But didn't see any reason
to think the preceding page was for something different?

I will assume this 20 lb ft torque is not for my engine.

I will look at the manual you have posted.

Regards.

 

[salmonbob]

Re: valve adjustment

Don I have looked at the manual you posted.
looks like the right one for my model year.

Interesting note though, page 3A-25 makes the same reference to torque
the rocker arms to 20lb-ft and put the rocker arm cover on ? !

 

[Don S]

Re: valve adjustment

I have no clue why the mention the 20 lb torque. Have NEVER seen a 3.0L engine with stops on the rocker studs to torque against.
Only ones I know of are some of the Big Blocks and V6 engines.
Of course if you look at the pictures of the heads in section 3, you will find the pictures are of a V6 or V8 engine and not the 3.0L.
Also, the manuals were NOT meant for DIYers, but for Merc trained techs. but they are better than any other manuals. Even though they have some wierd things in them at times.

 

[salmonbob]

Re: valve adjustment

I have seen some very good mechanics, learn some very helpful time saving
techniques to accomplish quality OEM repairs.
I wounder if this is one of those times.
Do you think its possible the lifters may be collapsed to centre at 20 lb ft of
torque.

 

[Don S]

Re: valve adjustment

No............

 

[salmonbob]

Re: valve adjustment

I kinda thought that may be a stretch too.

Thanx for the help.

 

[Buttanic]

Re: valve adjustment

alternate reality check: compression check to validate rocker arm adjustment.
this place is aweeesome.

jason, you were good bashing rapido and I'll side with you on that except for the part where you took a left turn with the analogy about people dying and airplane maintenance, that got a little lame.

where did everybody learn about engines?
everything I know, or thought I know, is wrong when I read stuff here.
Is there a book at iboats.com that I could buy, on how engines work?
Oh, and it's got to be "marine" engines.

Marine engines work just like any other engine. Only the equipment on the outside of the engine is marine, such as exhaust manifolds, starters, alternators, carburators, etc. and all of those pieces work just like the auto pieces as for as operation of the engine goes.

 

[JustJason]

Re: valve adjustment

alternate reality check: compression check to validate rocker arm adjustment.
this place is aweeesome.

absolutely!!!! what don't you agree with??? i don't do it.. i don't need to i'm not a n00b. However if i had an engine with low compression that would be the first place i go.

I'll side with you on that except for the part where you took a left turn with the analogy about people dying and airplane maintenance, that got a little lame.

Say what you want. When I lived in florida, on the news, there were always reports of people dying, sinking boats, fires etc. EVERY DAY!!! boat fires don't start themselves.
On a side note, and a hair off topic. But i was flying from orlando to boston a few years ago on an MD80. While we where still climbing towards cruising altitude, 1 of the engines lost a cowling. The engine immediately went into limited power mode and the plane started to loose altitude. The pilot then realized that the engine that went also had the compressor on it to maintain cabin pressure. He came on the com saying he was going to decend quickly and if the pressure got to low in the cabin the emergency masks would deploy.
How the h#ll does a cowling fall off?????????????????????

 

[JustJason]

Re: valve adjustment

oh and during the "rapid decent" it was soooo hard that everything that wasn't buckled down was up in the air.... luggage, bags, laptops, and even my beer that i ended up wearing by the end of the flight.

 

[180shabah]

Re: valve adjustment

oh and during the "rapid decent" it was soooo hard that everything that wasn't buckled down was up in the air.... luggage, bags, laptops, and even my beer that i ended up wearing by the end of the flight.

How did that $8 airline beer get loose from your hand?????

 

[JustJason]

Re: valve adjustment

nahhhh... only 1rst class for me... so it's free I actually let it go so i could pull on my buckle strap for dear life.

 

[ron7000]

Re: valve adjustment

absolutely!!!!
How the h#ll does a cowling fall off?????????????????????

People die all the time, just like that. Why, you could wake up dead tomorrow!

maybe raul put a cowling from a different plane onto the MD80?
or the mechanic gets all his information from iplanes.com

if you don't do a compression test to verify rocker arm adjustment, then why would you recommend it?

If you get correct compression numbers then does that mean the rockers are adjusted properly and the lifters have the correct preload? I was hoping to understand how you apply a cylinder compression test in this manner to determine correct lifter/rocker arm adjustment.

Before blindly following some bull**** on paper I think salmonbob needs to first figure out the difference between valvetrains with pedestal mount non-adjustable rocker arms versus adjustable rocker arms. Then he will know what he's doing before he ****s up his motor and has something in common with freebee.

 

[JustJason]

Re: valve adjustment

Why, you could wake up dead tomorrow!

nahhh... not likely... i'm not a tubby... and like a cat, i seem to have 9 lives.

maybe raul put a cowling from a different plane onto the MD80?
or the mechanic gets all his information from iplanes.com

you know... i never thought of that... i should check on it though...

If you get correct compression numbers then does that mean the rockers are adjusted properly and the lifters have the correct preload?

of course not... it certainly won't tell you if a valve is to loose. (unless a stem pulled and a rocker is bouncing all over the place... seen that happen plenty of times too)

I was hoping to understand how you apply a cylinder compression test in this manner to determine correct lifter/rocker arm adjustment.

well... if you check the compression. do your adjustment.. recheck the comp and if all the numbers go down... your to tight.

Before blindly following some bull**** on paper I think salmonbob needs to first figure out the difference between valvetrains with pedestal mount non-adjustable rocker arms versus adjustable rocker arms.

he has a 3.0 dude... the procedure for this motor (and also the 2.5L) hasn't changed since the 2.5L came out in 1963/64ish.

There's not much to it really.