[Zoomie5.0]

Here's the vital stats:
Full roller rockers 1.7 ratio on an e-cam, gt40 heads, summit roller lifters, stock style pushrods (don't recall exact length, but they are "welded ball" style). All items are brand-new with about 250 miles on the rebuild. Oil pressure gauge reads "normal"

Here are the symptoms:
-Loud pencil tapping sound on exhaust valve for cylinder #5. Sound was isolated to that valve/cylinder by unplugging #5 injector and #5 spark plug and running engine.
-With valve cover removed, an excessive amount of oil is seen to come from cylinder #5's exhaust rocker. Compared to the rest of the valvetrain it appears to be 3-5x the flow of oil coming up through the pushrod.
-Oil flows immediately from the #5 exhaust on startup, wheras the other rockers take a couple seconds to get to their typical trickle
-Rocker arms have 90* restrictors so that the oil coming up through the pushrod comes straight out onto the rocker bearing, unlike the stock ones that simply spray oil up onto the valve cover
-Suspected lifter does not "feel squishy" when compared to other lifters by applying direct manual pressure with a pushrod

Suspected problems:
-Oil restrictor in rocker is way out of spec
-Collapsed lifter (due to faulty check valve)

The odd thing about it is that in all of the searches done about collapsed lifters, the excessive oil flow is never mentioned. Obviously the lifter in question is getting oil, but assumedly is not pressurizing or "pumping up" (resulting in the noise) and simply
allowing the full force of the oil in that galley to pass through the pushrod.

Tomorrow I will try switching around rocker arms and pushrods in a vain attempt to confirm the theory that it is a lifter, but I would appreciate the opinions or affirmations that others may offer.

[EagleAutosports]

Collapsed lifters don't cause excessive oil flow, if anything they usually cause less flow because the plunger has collapsed and not siphoning the oil upwards. It may not be necessarily collapsed but it still could be a lifter problem, try the idea of switching the rockers and see what happens.

[Foxx88]

Ya, switch to a 1.6 rocker as Eagle already suggested. The noise problem should go away. Good luck!

[Zoomie5.0]

Originally Posted by EagleAutosports

Collapsed lifters don't cause excessive oil flow, if anything they usually cause less flow because the plunger has collapsed and not siphoning the oil upwards. It may not be necessarily collapsed but it still could be a lifter problem, try the idea of switching the rockers and see what happens.

I tried switching rocker arms and pushrods around Sunday. No luck, there is a still a deluge of oil pouring out and the noise is still present. It is probably the lifter, but the oil pouring out is a condundrum. I tried applying manual pressure to the pushrods also when they were on the cam base circle and the questionable lifter did not have a different 'feel' from it's healthy neighbor.

Off with the intake so I can have a look then! Why couldn't the GT40 heads have been like cleveland heads, with big openings so you can get to the lifters with the engine completely intact...


Eagle (or any mod) can you bump this thread over to 5.0 Tech... I coulda swore thats were I put it initially!

Originally Posted by Foxx88

Ya, switch to a 1.6 rocker as Eagle already suggested. The noise problem should go away. Good luck!

Eagle didn't say anything about 1.6 rockers... and it's not a simple noise problem. The oil gushing from that pushrod indicates otherwise. I have plenty of valve to piston clearance with the 1.7s and see no valid reason to change to a 1.6 ratio rocker when I have a full set of aluminum double roller 1.7s

[Zoomie5.0]

AAR:

Pulled the lifter and took it apart. It ate a bunch of sludge and metal frag that was probably hanging around in the oil galley (since it is the first one in line from the oil pump)

All the gunk kept it from properly pressurizing or "pumping up"

/thread