Mercruiser 5.7L Cranks but no signs of life

[alldodge]

loosened the nut until there was movement between rocker and rod. tightenned until no up/down rod movement and added 1/4 turn. then rotated crank 1 turn to 180deg out and set lash on other 8 valves.

Never heard of that way

 

[tpenfield]

180 degree rotation would not be correct. Should be a full 360 degree rotation to get the other 8 valves. . . not sure what you did . . "180 degrees" or "one turn" (360 degrees). Keep in mind that there are 2 full rotations (720 degrees) to a full cycle of cylinder firings on a 4-stroke engine.

Here is the valve adjustment procedure from the Mercruiser Manual (#17). . . not sure if this is the exact manual for your engine, but it should get you there.
[FONT=&quot].
1. Crank engine with starter or turn over in normal direction of rotation until timing mark on torsional damper lines up with center ?0? mark on timing tab, and engine is in No. 1 firing position (i.e TDC on compression stroke). This may be determined by placing fingers on No. 1 valve as mark on torsional damper comes near ?0? mark on timing mark. If valves move as mark comes up to timing tab, engine is in No. 6 firing position and should be turned over one more time to reach No. 1 position.
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[FONT=&quot]2. With engine in No. 1 firing position as determined above, the following valves may be adjusted.[/FONT]
[FONT=&quot]Exhaust - 1-3-4-8 Intake - 1-2-5-7 [/FONT]
.
[FONT=&quot]3. Back out adjusting nut until lash is felt at push rod, then turn in adjusting nut until all lash is removed. This can be determined by moving push rod up and down while turning adjusting nut until all play is removed [/FONT]
[FONT=&quot].
4. Hydraulic lifters now can be adjusted by tightening adjustment nut an additional one turn. (this is known as the pre-load on the lifter). No other adjustment is required. [/FONT]
[FONT=&quot].
5. Crank engine one revolution until pointer ?0? mark and torsional damper mark are again in alignment. This is No.6 firing position. With engine in this position, the following valves may be adjusted as previously outlined.[/FONT]
[FONT=&quot]Exhaust - 2-5-6-7 Intake - 3-4-6-8 [/FONT]
.
You mentioned that you were using a Clymer manual as a reference. :noidea: Those tend not to be the best thing to use for a tear-down and rebuild.

 

[Mad Props]

If you didn't follow the Mercruiser procedure above, lucky for you, i think the noise your hearing is WAAAAY to much clearance on rockers and choking the engine out... If you can't remember what the procedure was, take off your valve covers and spin the motor a full 720 degrees slowly and check the push rods at certain intervals and see if any of them are loose...

If you didn't follow the procedure right, push rods are gonna be really loose.

 

[MAW31]

I'm at boat. Now. Plugs r out. Compressions r between 160 and 195. That's a high variance for heads that were recently cleaned up and lapped imo. I had done a 1/4 turn extra after removing valve lash play.

So your saying that at no time should any valve have play observable. I'm gonna pull covers and look right now.

 

[tpenfield]

I'm at boat. Now. Plugs r out. Compressions r between 160 and 195. That's a high variance for heads that were recently cleaned up and lapped imo. I had done a 1/4 turn extra after removing valve lash play.

So your saying that at no time should any valve have play observable. I'm gonna pull covers and look right now.

195 PSi might mean liquid (oil/water) :noidea: in the cylinders. 160 seems good.

Best to follow the procedure for the valve lash setting rather than going it on your own.

Based on your descriptions so far, it is not apparent that you are:

1) setting the lash when the cam for that particular valve is at the low point of the lobe. You might be doing this, it is just not apparent from what you described and the videos sound like a mess.

2) giving enough pre-load after you tighten the rocker arm to the point where the push rod no longer can wiggle up/down. 1/4 turn is a bit light . . . The procedure calls for 1 full turn of the wrench, but I have found 3/4 of a turn is usually sufficient.

Keep in mind that once you adjust the valves, the lifters will adjust themselves accordingly as the engine is run. So when you pull the valve cover off you may find some not as tight as when you first adjusted them. There is also a procedure for adjusting the valves with the engine running . . .

There may still be other issues with the engine, as 'we' were wondering what was done to the lower end (pistons, connecting rods, crankshaft, etc). but it would be hard to evaluate that until you have the valve train all set.

 

[MAW31]

Tpenfield: on my first attempt, I followed your instructions exactly... Save for the fact that I was rotating the rods till I could not spin them and then added an additional turn. When it ran it was noisy (vid 1). Went back and added another half rotation to all rocker nuts. Motor never started. Next day I started over and this time just removed any up/down movement and added 1/4 turn, (vid 2). Now reobserving valves but if I DO observe loose valves, what is the correction process? I must be missing something fundamental here me thinks.

Port side is: 1357 IE EI IE EI
Stbd: 2468 IE EI IE EI
as crank nears tdc, no valve movement on #1 valves = power stroke
1 full crank rotation to tdc again puts me at #6 tdc

Gonna get some water and take valve covers off

 

[MAW31]

Just saw ur post the field. When I pulled plugs this morning no water and plugs looked normal as far as oil goes. I could just add a half turn to all valves since u think I was light with the 1/4 turn

 

[MAW31]

The field = tpenfield (autocorrect is my enemy)

 

[MAW31]

I have not gotten eyes on lower end. I should not have said torn down but rather pulled intake and heads.

 

[Bt Doctur]

My ,My, My so much to do adjusting by the book. Try adjusting each cylinder ,Install 2 longer bolts in the manifolds, slide manifolds away for clearance to remove the valve covers.The valves are orientated as E,I,I,E,E,I,I,E front to back. Rotate the motor untill a intake valve open s and closes ,this put that cylinder on its compression stroke ,adjust both pushrods, move to the next intake, and do the same thing and so on
Install valve covers, install manifold bolts, test and report

 

[MAW31]

Roger that bt. I'm on it.

 

[tpenfield]

Just saw ur post the field. When I pulled plugs this morning no water and plugs looked normal as far as oil goes. I could just add a half turn to all valves since u think I was light with the 1/4 turn

The thing is that it is not certain that the valves are adjusted correctly or even in the ball park. So just adding 1/2 turn may not be the solution for all valves.

Also, Bt Doctur noted a different valve pattern that what you posted . . . that may be the source of the confusion :noidea: I like his approach of adjusting the 2 valves of each cylinder when you are on the compression stroke of that cylinder . . . sure you got to rotate the engine 90 degrees 8 times, but you know that you are adjusting the correct 2 valves on each cylinder.

 

[alldodge]

When all done adjusting look real close at the rocker studs and see if anyone of them are a few threads lower then the others. Make this comment because you may have some collapsed lifters and don't know it. Once the valves close there may not be enough spring force to bring the lifter back up full

 

[MAW31]

First off, thank you everyone. Special thanks to tpenfield, AllDodge, and BT Doctor.

As you all had suspected, it was a horrible valve train job I was doing. and I am stumped as to how I could have so consistently been getting it so wrong on the valve lash settings. With so many things being changed at the same time, i could not tell what change was causing what and a frustrated mind doesn't always think so clearly.

In the end, when i pulled the covers off again, as one person wrote: valves sounded WAY too loose. and they were. godawful loose. embarrassingly so.

i followed BT's directions on observing the Intake open, then close - and adjust both intake an exhaust valve lash at that time.

Once through adjusting, I observed the rocker stud threads showing (per AllDodge) and that helped.

The motor is running! and running strong.
Here is a video of the first minute or so after the last valve train adjustment.

THANK YOU ALL.
THANK YOU EVERYONE.