Oil Pressure drop
- Thread starter bigboostedmk3
- Start date
A good rule of thumb is 10 psi per 1000 RPM's. The stock oiling system will start bypassing oil back into the oil pan at 40 psi though. If you get or have a fulle oil cooler/filter relocation kit, the oil pressures will be even higher, better flowing, and the capacity for oil with be roughly 1 quart more if you run large lines and an oversized filter. Another good practice is to use a good group 3 or a group 4/5 oil, Change the oil filter (I prefer wix) every 4000 miles, and the oil at 8000, with 1 quart extra on top of the full mark.
thanks again i new about the 1 qt over full and i am running an aftermarket oil cooler but not a relocation kit, thats next on the list, and i tend to change my oil and flter every 3000 km.
Changing that soon is a waste of money and oil, you are lining the big oil companies pockets with more money by going that route.
When you get rid of the stock oil filter mounting block, that's when you'll see the big increase in oil pressure and flow. Use a good oil thermostat, a mocal 180* will be fine.
When you get rid of the stock oil filter mounting block, that's when you'll see the big increase in oil pressure and flow. Use a good oil thermostat, a mocal 180* will be fine.
You can be in neutral and in the driveway...bigboostedmk3 said:
I've said more then apparently is going to sink in. Good luck, hope you don't meet your demise with double the power.
starscream5000 said:
damn man you seem to be pretty sure of yourself
Warmer operating temps will reduce viscosity and lower pressure because there is less resistance to flow. Hot+humid = more heat than just hot. Thats why the owners manual says to put in thicker oil during the summer and thinner in the winter.
I think you guys misread what he said at the beginning. He didnt say that it was at 5psi at all RPMs, he said that it dropped 5psi ACROSS THE BOARD and that it was 5psi at IDLE.
He never said that it dropped 35psi
He never said that it dropped 35psi
I've already pointed this out. ::dead horse::p5150 said:
You said (when quoting SS5k's misunderstanding post) that weather could possibly lower oil pressure to 5 psi at any RPM; which is absolutely incorrect.
He also said he had 12-15 psi at idle.
I think you need to read a little more thoroughly, or maybe you just can't comprehend it?
Yes, I did misread it and I already acknowledged that in a previous post .
Ian, I seen your ninja edit.
.Ian, I seen your ninja edit
.
mkIIIman089 said:
Oh I comprehend it just fine - Why is it so hard to believe that hotter weather would lower his idle oil pressure?
LOL first one wouldn't hot linkstarscream5000 said:Yes, I did misread it and I already acknowledged that in a previous post
Ian, I seen your ninja edit
It's not hard to comprehend, but not down to 5 psi all across the board like I had misread and was thinking he was talking about. Again, things weren't cleared up until after I made the post you pointed out. Comprehend? .
.
p5150 said:
unless you know of somewhere in this planet that the ambient temp will get above 212 degree farenheight, not happening
or in other words.
if It is not above 212 degree farenheight ambient. The oil viscosity will not get any thinner except at start up and that is it.
SAE Technical Paper 2001-01-1073. Note the * for the side-bar at the end. Fwiw...
Many times the heat transferred to the lubrication system from combustion, and the kinetic components of an engine, are overlooked until a problem arises during dynamometer or track testing.
A study was undertaken to develop a heat flow and heat transfer model of an engine's lubrication system to predict primarily sump oil temperatures, and secondarily, coolant temperatures. The temperature relationships between the oil and coolant were found to be most interesting. This technical brief is a summary of the referenced paper.
The model was developed to account for numerous items in the engine /lubrication system:
1, Engine Speed and Load,
2. Head and Block Geometry
3. Bearing clearances
4. piston design
5. coolant and ambient temperatures
6. material properties.
If the engine had an oil squirter system, this was included as well.
Energy balance equations and heat input sources were incorporated into the Model, with heat sources and heat sinks within the engine accounted for. To verify the model, the model was plotted against full-up V8 engine data from a dynamometer. The model correlated quite well with the dynamometer data, with a slight under-estimation of oil sump temperature at high rpm. It was found that the piston undercrown contributed about 70 to 80% of the heat into the oil with bearings contributing 10 to 20% of the heat energy to the oil.
Here is a breakdown of heat sources for 2,000 RPM to WOT:
Energy to Oil from Piston Undercrown - 76%
Main and Big End Bearings - 13%
Camshaft Bearings - 1%
Energy to oil from Cylinder Wall - 0%
Oil Deck in Head - 2%
Oil Pump Energy - 8%
At 4,000 RPM WOT, the only increase in heat energy came from the Main and Big End bearings at 19%, a 6% increase from 2,000 RPM WOT. The Piston Undercrown's energy contribution to oil temp was 4% less at 72% for the 4,000 RPM to WOT case.
The predicted sump (bulk) oil temperature versus the coolant temperature was shown to be about 18 to 20 degrees C higher for the oil than for the coolant at 2,000 RPM to WOT. At 4,000 RPM to WOT the oil sump temperature was about 50 degrees C higher than the coolant temperature. The slope for both RPM ranges was about 0.7 C/C, which means that on the average, the Oil Sump temperature is always 1.2 to 1.43 times higher than the coolant temp.
*An interesting side-bar of this study was that the sump (bulk) oil temperature increased only 0.3 C for every 1.0 C increase in ambient (outside) temperatures.
·Zoz, Steve, Engine Lubrication Model for Sump Oil Temperature Prediction
SAE Paper 2001-01-1073.
Many times the heat transferred to the lubrication system from combustion, and the kinetic components of an engine, are overlooked until a problem arises during dynamometer or track testing.
A study was undertaken to develop a heat flow and heat transfer model of an engine's lubrication system to predict primarily sump oil temperatures, and secondarily, coolant temperatures. The temperature relationships between the oil and coolant were found to be most interesting. This technical brief is a summary of the referenced paper.
The model was developed to account for numerous items in the engine /lubrication system:
1, Engine Speed and Load,
2. Head and Block Geometry
3. Bearing clearances
4. piston design
5. coolant and ambient temperatures
6. material properties.
If the engine had an oil squirter system, this was included as well.
Energy balance equations and heat input sources were incorporated into the Model, with heat sources and heat sinks within the engine accounted for. To verify the model, the model was plotted against full-up V8 engine data from a dynamometer. The model correlated quite well with the dynamometer data, with a slight under-estimation of oil sump temperature at high rpm. It was found that the piston undercrown contributed about 70 to 80% of the heat into the oil with bearings contributing 10 to 20% of the heat energy to the oil.
Here is a breakdown of heat sources for 2,000 RPM to WOT:
Energy to Oil from Piston Undercrown - 76%
Main and Big End Bearings - 13%
Camshaft Bearings - 1%
Energy to oil from Cylinder Wall - 0%
Oil Deck in Head - 2%
Oil Pump Energy - 8%
At 4,000 RPM WOT, the only increase in heat energy came from the Main and Big End bearings at 19%, a 6% increase from 2,000 RPM WOT. The Piston Undercrown's energy contribution to oil temp was 4% less at 72% for the 4,000 RPM to WOT case.
The predicted sump (bulk) oil temperature versus the coolant temperature was shown to be about 18 to 20 degrees C higher for the oil than for the coolant at 2,000 RPM to WOT. At 4,000 RPM to WOT the oil sump temperature was about 50 degrees C higher than the coolant temperature. The slope for both RPM ranges was about 0.7 C/C, which means that on the average, the Oil Sump temperature is always 1.2 to 1.43 times higher than the coolant temp.
*An interesting side-bar of this study was that the sump (bulk) oil temperature increased only 0.3 C for every 1.0 C increase in ambient (outside) temperatures.
·Zoz, Steve, Engine Lubrication Model for Sump Oil Temperature Prediction
SAE Paper 2001-01-1073.