Mercury 312

C

cavecreekjake

Member
Don’t have access to the car right now…so, question - is there a valley cover beneath the intake ? Or do I just need intake gaskets when removing the intake to access the valve train…?
Thanks
 
Last edited:
cavecreekjake said:
Don’t have access to the car right now…so, question - is there a valley cover beneath the intake ? Or do I just need intake gaskets when removing the intake to access the valve train…?
Thanks
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There is no need to remove either the intake nor the valley cover. The rocker arms and pushrods are all accessible by just removing the valve covers.
If for some reason you need to remove a lifter, you will need to remove the camshaft and pull the oil pan. This is because the lifters come out the bottom only. They are called mushroom lifters because the base is much larger diameter than the body. They are solid (mechanical), by the way.
 
1 ticking lifter on a y block ,it is probably out of adjustment. set the valve lash. ck a service manual for spec. Y blocks do not have hyd. lifters, they are solid lifters only. remove the valve covers and adjust the valves , it may save you a lot of work for nothing
 
Stock spec for rocker arm gap,is .019. See if you can locate the noisy rocker and make sure the push rod goes up and down
 
If you can't get rid of noisy valve train, remove rocker arm assy and check for excessive wear in rockers or the shafts. I tore into my 292 this winter and found 3 bad rockers and badly wore rocker shaft. replaced the shafts and 3 rockers and sounds great now. shafts and rocker arms are available on line. If you remove the rocker assy, the push rods may stick to the rockers or drop down past the lifters. . not to worry. a magnet will remove them. the push rods can only go down inside a couple inches. also replace all push rods into original positions.
 
While you're in there you might check the loose / noisy one for a bent pushrod.
They can bend if a valve is sticking.
 
.019 is hot lash. However, Tim McMaster (y-blockguy.com) likes to tighten lash to .015 "to quiet things down) on Y-blocks with stock cams. Cold lash should be .001-.002 more than hot lash; however, there is very little expansion on engines with both cast iron block and heads.
 
I watched the y-blockguy video and he set his lash at .019 I think. the truck sounded like hell. isn't .015 a tad tight?
 
Tighter than what's specified in Ford manuals, but surely Tim knows what he's doing. He also said that he uses .020 lash for one of the aftermarket cams he uses, but he didn't say which.
 
55blacktie said:
.019 is hot lash. However, Tim McMaster (y-blockguy.com) likes to tighten lash to .015 "to quiet things down) on Y-blocks with stock cams. Cold lash should be .001-.002 more than hot lash; however, there is very little expansion on engines with both cast iron block and heads.
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I set my '55 272 at .015" lash cold. Sounds a lot quieter and runs just fine.

Sal
 
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