Last valve adjustment

[SHickey]

Hello,

In the search for eliminating a tick in my motor, it was suggested to remove the hydraulic lifters, clean and reinstall them. I did that and my motor (1976 MC 165 with a MC-1 OD) is running smoother than ever.

Before I bolt down the valve cover I would like to do one more valve adjustment if that makes sense. Right now the I have all the valve stem bolts snugged down 1/4 turn tight it eliminate each valve from ticking. Oil is pumping (some squirting) through the pushrods and they are all spinning and the motor is running smooth and responsive.

My question is whether or not 1/4 turn tight is reasonable for all of the valve stem bolts or is any more tightening necessary for these reliable straight six motors?? I use the socket handle to measure the amount of tightness on each bolt and basically set each bolt 1/4 tighter to eliminate the tapping sound if that makes sense.

It is too cold to take the boats out today unless you fish. The NYS Barge Canal is filled up for another boating season.

Thanks in advance for any suggestions.

 

[Bondo]

Ayuh,.... Standard lash adjustment on a Chevy motor with hyd. lifters is 3/4 turn past zero lash,....

That puts the plunger 'bout midway it's potential travel,...

 

[SHickey]

Awesome!!

Thanks for the response and it will be no problem setting the valve stem bolts 3/4 tight instead of 1/4 tight.

I will do the final adjustment tonight or tomorrow and put that tick away for good!!

Thanks again for the response!!

 

[alldodge]

Awesome!!

Thanks for the response and it will be no problem setting the valve stem bolts 3/4 tight instead of 1/4 tight.

I will do the final adjustment tonight or tomorrow and put that tick away for good!!

Thanks again for the response!!

NO this is not what Bondo said

And just incase I'm over reacting, do you know how to get to zero lash?

 

[SHickey]

I do not know how to get to zero lash. After I freed up the lifters and adjusted each stem nut to the point of light tapping, I tightened each one until the tap was completely gone and then 1/4 turn more. Now every valve is quiet and the motor is running very smooth.

Would I be hurting anything if I added 1/2 more turn to the 1/4 turn I already have? My technical motor knowledge is pretty limited so I am only going by feel and sound so far. Is it OK to adjust the valves while the motor is running @ 600 - 700 RPM?

Thanks again for the responses!!

 

[alldodge]

Would I be hurting anything if I added 1/2 more turn to the 1/4 turn I already have

Yes your going to damage something, you have hydraulic lifters and your adjusting them similar to solid ones, one difference is solid lifers use a feeler gauge for clearance. There is a possibility your lifters are shot because of previous post indicating your hearing tapping/clicking. Leaving them like your doing it will cause the valves to stay open as the heat of the motor increases (heat expands)

To get zero lash, the rocker stud is loosened until there is slop on the push rod. The valve is closed, with your fingers your can rotate the push rod in you fingers and can also raise and lower it between the rocker arm and the lifter. Start tightening the rocker stud a bit at a time until the up and down movement stops. Once it stops this is zero lash. You then tighten the nut 3/4 turn more.

You should always be able to rotate the push rod some, but the up/down movement is the key your feeling for

 

[SHickey]

Thank you for your response.

I can do exactly what you said to find zero lash and then tighten 3/4 turn. Is it necessary to rotate the motor during the process due to the cam moving some of the lifters up ans down or can this be done once and then it's done for good??

Again thanks for the response and thanks for saving my .... ( I was ready to button her up but I just needed to check with the experts because I had some doubt over my valve adjustment procedures)

 

[alldodge]

You have to rotate the motor over until the valve your working on is closed. It will take more rotations but for simplicity. Have one valve being opened by the cam, then adjust the one which is not moving and is closed. Use something like a grease pencil to mark the ones you adjusted. Rotate a bit more and repeat until all are done