Does the whole top of the cylinder head fill completely with oil?
General ?: How does oil work in cylinder head?
- Thread starter cutchemist42
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Only if something is wrong.
I had a Monte Carlo that was sludged and would fill up when you were climbing a hill and had to run higher revs.
At idle there is a trickle of oil to the cylinder head, at high RPM's it's more like a shower, but it should never be a bath.
I had a Monte Carlo that was sludged and would fill up when you were climbing a hill and had to run higher revs.
At idle there is a trickle of oil to the cylinder head, at high RPM's it's more like a shower, but it should never be a bath.
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Aren`t there oil squirters that sit below the pistons that lubricate the cylinder walls?
So then are the camshafts and lobes exposed to oil?
Originally Posted By: cutchemist42
So then are the camshafts and lobes exposed to oil?
Oh, yes. Copiously.
While the engine is running, great volumes of oil are pumped and sprayed and squirted all over the inside of the valve cover, and all over everything inside the valve cover. Then it's whipped around by the cam lobes and the valves popping up and down.
There's so much oil and oil-mist being pumped and slung around that automakers install baffles in the underside of the valve cover to keep that oil from being pushed into the crankcase breather pipe.
While all this pumping and whipping is happening, the oil that's already been slung around drains back into the oil pan, to make room for fresh oil being pumped up and slung around: it's a constant cycle.
Go start your own engine. While it's running, remove the oil filler cap, peek inside and take a look at what's happening. Some engines will throw so much oil that you may make a mess of the valve cover and possibly your clothes.
So then are the camshafts and lobes exposed to oil?
Oh, yes. Copiously.
While the engine is running, great volumes of oil are pumped and sprayed and squirted all over the inside of the valve cover, and all over everything inside the valve cover. Then it's whipped around by the cam lobes and the valves popping up and down.
There's so much oil and oil-mist being pumped and slung around that automakers install baffles in the underside of the valve cover to keep that oil from being pushed into the crankcase breather pipe.
While all this pumping and whipping is happening, the oil that's already been slung around drains back into the oil pan, to make room for fresh oil being pumped up and slung around: it's a constant cycle.
Go start your own engine. While it's running, remove the oil filler cap, peek inside and take a look at what's happening. Some engines will throw so much oil that you may make a mess of the valve cover and possibly your clothes.
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Does the whole top of the cylinder head fill completely with oil?
No, except maybe for the "hot soak" when the car is turned off and the oil has to drain from the head back down to the block. Then it pools in the block and oil pan. "Hot soak" is when the engine is hottest, as the fluids are not circulating and they get to bake for a little while. The underhood acts as an oven so when you come back to your car 10-20 minutes, the engine is hottest when you turn the key then is supposed to cool back down somewhat quickly to normal as coolant and oil is circulated, to transfer heat. Its never "hot" or "cold" just "within spec" and for some cars that can be hotter.. it all depends. Blocked passages can cause more heat but even then, circulating oil can handle it. It is akin to a runner after he or she stops running.
In the BLOCK, the oil forms a literal layer that the moving bearings "ride" on and that avoids metal-to-metal contact and engine seizing. It is why so many mechanics believe - commonly - that thicker is better. (If only that were the whole story however.) For "other moving parts too." It also drains down into the cylinder wall, and the bottom of the piston flicks the oil back up in to the head as well.
In the head, i can see why you would think oil "pools" you have obviously seen a car with its head off with a head gaskeet repair and cylinders filled with coolant as if they are pools. That is abnormal. The collant got in due to a mechanical failure. The oil is only on the cylinder WALLS, which gets very very hot by the way.
Generally, the area in and above the head has oil flying around and lubricating not much except to drain back down to the cylinder, and also going on/around the rotating camshaft.
Thinner oil moves, and lubes, better, and can most liley handle the heat. Hot oil moves the best. Its the bottom of the engine with your "rotational mass" that tests it. If it can pass that it is good to go.
Oil oils used to thin out and thick oil was used to combat that. (Would be thick enough even when hot and thin, with inferior oil.) Nowadays.. thick oil isnt required nearly as much as it was. Though every engine is particular and some like it thick.
Does the whole top of the cylinder head fill completely with oil?
No, except maybe for the "hot soak" when the car is turned off and the oil has to drain from the head back down to the block. Then it pools in the block and oil pan. "Hot soak" is when the engine is hottest, as the fluids are not circulating and they get to bake for a little while. The underhood acts as an oven so when you come back to your car 10-20 minutes, the engine is hottest when you turn the key then is supposed to cool back down somewhat quickly to normal as coolant and oil is circulated, to transfer heat. Its never "hot" or "cold" just "within spec" and for some cars that can be hotter.. it all depends. Blocked passages can cause more heat but even then, circulating oil can handle it. It is akin to a runner after he or she stops running.
In the BLOCK, the oil forms a literal layer that the moving bearings "ride" on and that avoids metal-to-metal contact and engine seizing. It is why so many mechanics believe - commonly - that thicker is better. (If only that were the whole story however.) For "other moving parts too." It also drains down into the cylinder wall, and the bottom of the piston flicks the oil back up in to the head as well.
In the head, i can see why you would think oil "pools" you have obviously seen a car with its head off with a head gaskeet repair and cylinders filled with coolant as if they are pools. That is abnormal. The collant got in due to a mechanical failure. The oil is only on the cylinder WALLS, which gets very very hot by the way.
Generally, the area in and above the head has oil flying around and lubricating not much except to drain back down to the cylinder, and also going on/around the rotating camshaft.
Thinner oil moves, and lubes, better, and can most liley handle the heat. Hot oil moves the best. Its the bottom of the engine with your "rotational mass" that tests it. If it can pass that it is good to go.
Oil oils used to thin out and thick oil was used to combat that. (Would be thick enough even when hot and thin, with inferior oil.) Nowadays.. thick oil isnt required nearly as much as it was. Though every engine is particular and some like it thick.
Originally Posted By: cutchemist42
Does the whole top of the cylinder head fill completely with oil?
Sometimes.
Does the whole top of the cylinder head fill completely with oil?
Sometimes.
Originally Posted By: garlicbreadman
http://www.youtube.com/watch?v=nsa6kq-qqIE&feature=player_embedded
Look at all that oil mist! That's what the valve-cover baffles are there for.
And check out how the valve springs rotate. I didn't know they did that. Thanks for the link.
http://www.youtube.com/watch?v=nsa6kq-qqIE&feature=player_embedded
Look at all that oil mist! That's what the valve-cover baffles are there for.
And check out how the valve springs rotate. I didn't know they did that. Thanks for the link.
Oil squirters are rare. Actually used to cool the pistons in turbos, not so much for lubing.
Pistons and rings are normally splash lubricated.
OHC engines have pressurized bearings for the cam, and the excess leakage and splash lubricates the lobes.
Pushrod engines have oil in pushrods that leak at the end and lube the rockers and valves.
Ensuring good drainback from the head is a builder's concern.
Past stock limits, built engines sometimes have problems.
Pistons and rings are normally splash lubricated.
OHC engines have pressurized bearings for the cam, and the excess leakage and splash lubricates the lobes.
Pushrod engines have oil in pushrods that leak at the end and lube the rockers and valves.
Ensuring good drainback from the head is a builder's concern.
Past stock limits, built engines sometimes have problems.
Pull the valve cover and start the engine. You'll see how the cylinder head gets lubricated.
^Funniest and worst advice I've heard on here in a while, all in one.
Originally Posted By: garlicbreadman
http://www.youtube.com/watch?v=nsa6kq-qqIE&feature=player_embedded
OMG!
http://www.youtube.com/watch?v=nsa6kq-qqIE&feature=player_embedded
OMG!
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