How much oil is NOT ENOUGH to the rockers and other pushrod Q's?


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By Whitey - 15 Years Ago
Hello All,

Still seeking knowledge being a first time y blocker.  As previously stated mine is in a classic ski boat with a 272 that I bought and have been fixing up as it was very neglected for several years.  I have been reading madly all the forums I can find re oiling and thanks heaps to all who replied to my previous entries re: engine banging etc.

Just to explain where I'm at: The old girl is running like a dream, but has dropped the no2 exhaust pushrod twice now and luckily has not bent it or the valve with the subsequent banging until she was turned off.  It was refitted the last time after a quick inspection, nipped her up (probably a bit tighter that it should be) and got back to shore with no dramas as I was about 20 min gentle drive from the boat ramp.  As previously stated the adjuster is obviously alot further wound in than the rest and I plan to do idiot checks today as the motor specs are still unknown, and it's wear and use.  The previous owner has shown he was a bit dodgy and I plan to remove the pushrods to check they are all the same size length, as well as the adjuster screw on the rockers, just to make sure he didn't add a different stray along the way of different size.  This is just trying to explain why this one is the only rocker with alot of adjustment (nearly no thread visible on top of lock nut) compared to the rest, that have about 1/4 inch. 

You all have previously ruled out a failed lifter, so I have been told by a mechanical friend she may have a worn lobe on the cam to explain the greater adjustment.  If this is so, would she run so happily (idling and under power) with a difference in the cam.  I also plan to do a compression test to check the valves are seating.  I'm not exactly sure of the type of heads as it looks like ECG-S but it's a bit corroded, but according to John Mummert's site it is in the correct place for 55 heads, so I'm assuming it is ECG-B.

Now the oiling question.  The left side is oiling like a champion, actually splashes around the place into the valley at idle, but the right is alot drier.  It does get oil to all pushrods, but the no2 exhaust (problem one) is the least and at idle after a while you can see a bead of oil build up (large drop) between rocker and pushrod, but not running down the rod like the left side.  The other rods on the right eventually do get a slight trickle, but I haven't had a look after she's been running at speed to see if this increased the flow.  Is this enough to keep them lubed, as I guess it would also splash about inside the covers at speed assisting the drier one.  Would this cause the cam lobe to wear out, hence the greater adjustment required, and if so should the cam be replaced?  Should a new set of pushrods and/or lifters be replaced at the same time.

Any help is greatly appreciated as I'm still tinkering and loving it, much to the wife's disgust!!!  I haven't cracked the motor at all and would love to do a full rebuild, but simply don't have the cash for it.  Besides I want to learn about the old girl myself!!

Cheers Geoff

By Daniel Jessup - 15 Years Ago
My two cents on checking out that valve train is to view the no2 exhaust valve as it responds to its cam lobe. Is it going down into the cylinder head as much as the other exhaust valves are? I know this is eyeballing it, but this will give you some idea of what things are like and maybe even rule out the question of a seriously worn cam lobe. Maybe you could turn the crank by hand and watch to see how deep that valve goes in comparison to the others.

As you probably surmised, checking that particular push rod with the others is another good idea. After all these years, you can never be certain on a used motor.

I would also suggest removin the rocker arm/shaft assembly that has little oiling. Sometimes only the shafts are clogged. If so, great. If not, you need to check the oil passage that delivers oil to the shaft.

Hope it goes well for you...

By Whitey - 15 Years Ago
Well I conducted some of the idiot checks.  All of the exhaust pushrods are the same size, as too are the adjusting screws.  I have to wait for another pair of hands to assist with the compression tests and also eyeballing the depth of valve movement for the cam, to either turn over by hand or hit the ignition for the starter.

Once that's done, I'll take off the rocker shaft to check for oil blockages to see if that helps.

Please keep the theories and assistance coming!

Geoff 

By Hoosier Hurricane - 15 Years Ago
Geoff:

It is quite likely your engine has what we call a cross drilled cam for rocker oiling.  Ford found that with that system one side would send more oil to the rockers than the other, and issued a service letter with their "fix".  They explained how to put a restrictor in the left rocker oil passage to increase flow to the right.  If, as you say, a pool of oil builds up on the top of the the pushrod, that is enough oil.  There is a small hole from the center of the rocker pivot hole to the underside of the adjustment screw.  When you have the rockers off, check that hole to be sure it isn't sludged closed.

Have you carefully checked for a broken valve spring on #2 exhaust?  That could cause the pushrod to jump off.