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+--- Thread: Low oil pressure after shim (/showthread.php?tid=3105)
RE: Low oil pressure after shim - Unilevers - 05-22-2018
im going to bet a spun cam bearing. those buggers are hard to find sometimes without looking really close and you may not notice it.
Uni
RE: Low oil pressure after shim - pearce trucking - 05-22-2018
Hi Unilevers.
I'm still a little fuzzy on oil pressure I guess. Could you explain what happens to oil when the cam bearing spins? I know the wear rate is greatly accelerated, and as such, the oil passage to that bearing becomes enlarged. How does this significantly reduce oil pressure? I'm asking because I don't know, not because I'm disagreeing.
Thanks.
RE: Low oil pressure after shim - Waterloo - 05-22-2018
The oil passage essentially shuts down to that cylinder/piston rod, pressure drops. The bearing rotates on the crankshaft, closing off the oil passage. Messy job, but with the right tools a doable PIA job to fix in your driveway. Replace them all, if that is the issue. Use plenty of Permatex Ultra Slick and be sure the clutches go in correctly. ;-)
RE: Low oil pressure after shim - Hammerhead - 05-22-2018
(05-22-2018 )Waterloo Wrote: The oil passage essentially shuts down to that cylinder/piston rod, pressure drops. The bearing rotates on the crankshaft, closing off the oil passage. Messy job, but with the right tools a doable PIA job to fix in your driveway. Replace them all, if that is the issue. Use plenty of Permatex Ultra Slick and be sure the clutches go in correctly. ;-)
...but that's rods n mains, he was asking about cam bearings...
Same idea, just further up the line of the oil path, but not quite as easy to change in your driveway...
look at Waterloo becomin a wrench n all...next thing ya know, he's gonna have his own YouTube channel talking crap 'bout all them sissy a$$3d Owner/Ops who won't even tackle summin as simple as a head swap! Lmao!!!
RE: Low oil pressure after shim - Waterloo - 05-22-2018
Long day Hammer... I totally missed that. Baking in the sun and drenched in the sudden downpours... Relaxing then with a few beers under the canopy watching the rain, and trying to stay dry. Pooped.
Oh, damn straight on that head swap, piece of cake. ;-)
RE: Low oil pressure after shim - snailexpress - 05-23-2018
(05-22-2018 )pearce trucking Wrote: Hi Unilevers.Initially bearing will turns little bit and close oil passage completely. Now it dry and will got hot up to welding bearing to the cam. Cam is much stronger then bearing materisl and bearing starts spinning in the head. Oil passage in this bearing now is open and has no restriction to the oil flow.
I'm still a little fuzzy on oil pressure I guess. Could you explain what happens to oil when the cam bearing spins? I know the wear rate is greatly accelerated, and as such, the oil passage to that bearing becomes enlarged. How does this significantly reduce oil pressure? I'm asking because I don't know, not because I'm disagreeing.
Thanks.
All undamaged bearings ( cam and crank) now starving on oil because fluids go the way with less restriction. Next bearing is ready to go kaput. Mostly it's cam bearing because it's on the end of oil pressure system. Some pics to understand it better.
[attachment=3942][attachment=3943][attachment=3942][attachment=3944]
RE: Low oil pressure after shim - snailexpress - 05-23-2018
This is what happen if cam bearing span. Check bearings what on both ends of camshafts. If it spun camshaft is damaged too.[attachment=3945]
RE: Low oil pressure after shim - Hammerhead - 05-23-2018
^^^What snailexpress said^^^
RE: Low oil pressure after shim - Signature620 - 05-23-2018
The pressurised oil is supposed to travel to the head from the block, then to the cams, then to the rockers. So when a cam bearing spins it will increase it's diameter and/or shift forwards or backwards. This allows oil that would normally be under pressure between the cam and rockers to be released into the overhead, so much that the oil pump can't keep up, lowering the general oil pressure.