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50 LX Merc Valve timming

S

Steve Royle

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"I have a 5.0lx Merc V8 , GMC

"I have a 5.0lx Merc V8 , GMC block, 1991, I have just replaced the H/gaskets after one of the banks blew. I have been told that the valve timming in relation to the Hydro lifters is difficult. Can anybody give any advice on this matter. I did not remove the lifters from the block and kept all the push rods in order. thank you for any assistance."
 
"Piece of cake if you do one c

"Piece of cake if you do one cylinder at a time.

First, remove spark plugs (to make it easier to turn the motor over.) Using a socket wrench, rotate crank, via the damper pulley bolt, until the exhaust valve of the first cylinder (front or back)is open wide. Adjust the intake on that cylinder (by spinning the push rod between two fingers. When you feel a load on it, turn it down one full turn.) Next, rotate the motor until the intake you just adjusted is wide open, then adjust the exhaust valve. Then go to the next cylinder and repeat.

Piece of cake!

Jeff"
 
consult a manual if you haven&

consult a manual if you haven't already. That link is right on time. SlowJeff describes the "engine off" hydraulic lifter method. The only way I've adjusted hydraulic tapet valves is the messy way with the engine running. [see link]. some people use a set of valve covers with the top cut out to eliminate the mess of oil while adjusting with the engine running.
 
"Thanks for your help I will g

"Thanks for your help I will give it a go this week-end. Does it matter if the oil has run out of the lifters, as it will have by now, if I still set them as discribed above ?"
 
"Steve

Jeffs way is the cle


"Steve

Jeffs way is the cleanest way to do your valve adjustment but unless you have done them before I would only pull them down 3/4 of a turn once you felt the pushrod starting to load.

I am a fan of the hot run adjusting method as David descrides, when I assemble an engine I normaly set the valves clearences approximatly, cold, then start the engine up and warm it up then final adjust them with the engine warm and running.

I just find, particularly if there is a bit of wear in a camshaft, you get better results setting the valves with the engine running even though you may make a bit of a mess.

Cheers
Peter C"
 
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