Oil temperature issue
08-15-2015, 09:48 AM
#31
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Looking at the diagram, if you have the oil/ps combined cooler you may have an effective 12 inch cooler which is pretty small for your bumped up power.i doubt if merc put much overkill into the system , especially in warmer waters. Good luck!
08-15-2015, 10:18 AM
#33
Registered
08-15-2015, 02:14 PM
#34
Registered
I've never found any appreciable difference is oil cooler direction. There are 2 methods of thinking. One is to flow the water and oil in the same direction. In theory, this keeps the same water and the same oil in contact longer so that they can transfer heat. The other is to flow them in the opposite direction. This allows the leading edge of the oil to constantly contact cold water. Like I said, we have tried it both ways on several different apps and have yet to see any measurable difference.
Eddie
Eddie
08-15-2015, 05:13 PM
#35
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iTrader: (3)
Here is the data sheet of the oil i'm using. The flash point is 457 deg F and the fire point is 468 deg F so why would 240 be so bad..
http://www.amsoil.com/lit/databulletins/g2883.pdf
and this is interesting also
http://www.synthetic-motor-oil-chang.../#.Vc9T1JeJt80
http://www.amsoil.com/lit/databulletins/g2883.pdf
and this is interesting also
http://www.synthetic-motor-oil-chang.../#.Vc9T1JeJt80
When you have an engine running at probably 50% of its power output, and its already seeing 240* degrees of oil temperature, I would say something is wrong. Especially, if you are not running an oil thermostat, and your water temp in the block is 140 degrees.
Heat is a killer of valvesprings. According to PAC racing springs, the difference in open pressure, from a spring thats at room temperature, to a spring that is at 350 degrees, can be as much as 90 psi loss on the springs open pressure. So, lets say you are running a basic hydraulic roller cam. Say your springs are 450lbs open at room temperature. Those springs at high rpm, with 350 degree coil temps, may only be 360lbs open. Not to mention, the springs lifespan is greatly reduced from high temperature. Now, the difference between 180 deg spring, and 240 degree spring, may only be 40psi loss of open pressure, but its still something to consider. Of course there are other factors that contribute to spring temperature, but there is no getting around, they rely on oil for cooling.
Seeing 240 degrees of sump temperature, doesn't just mean that, the oil is only getting to 240 degrees. Oil at the bearings can be much higher than that, but you wont see it on the gauge.
I am certainly no oil, or engine expert. When I research things like this for my own stuff, or friends stuff, I tend to look at what the oem's do. Just about every car/truck I have tested/monitored oil temps, are normally within 10-15% of coolant temperature (180-220). Problem with boats, is our coolant temps are not 195*, and we also run under pretty hard loads. So, the fix for this, was oil thermostats, to get the oil hot, and large enough cooler, to keep it cool . Almost every brand of oil thermostat elements out there, and there are tons of aftermarket, and OEM's, range from 180-215* elements. If running 240,250, 260 was good, we would see those elements in the fixtures.
For many many years, oil temperature control, has been a valid concern. From taxi cabs, to pickup trucks, to semi trucks, police cars, or even grocery getters, manufactures combatted high oil temperatures, with external oil coolers. These OEM's have to take into consideration, these vehicles need to last hundreds of thousands of miles. And do so, with the same valvesprings, seals, bearings, and hard parts. Not some guy from the bar who has a built small block in his nova, and puts 800 miles a year on it, and will preach about how great his boutique oil is at handling heat.
There is no getting around, that as oil, any oil, gets up past its optimal operating temperature, oxidation increases. If you said, "after a long 5 mile wide open throttle run, my oil creeps to 240*", I probably wouldnt worry about the setup. But, to say that cruising at 3500RPM, your oil temp is a steady 240*, I would be concerned. It certainly isn't gonna get cooler as you push the throttles down further. Your stock 502 combo oil cooler, was properly sized by mercury marine, for a 390-415HP engine, with stock exhaust, stock everything. It works great for that. Once you start changing things, aftermarket exhaust, more horsepower, possibly leaner fuel mixtures, higher pressure valvesprings, etc etc, things change. Hence my recommendation for a larger oil cooler. I would rather run my oil at a temperature that coincides with oems guidelines, rather than deal with the issue, by running a oil that says it can withstand the extra heat. Just my thoughts on this topic.
Apparently though, what you are saying, debunks the myths here on oso, that "slowing down flow", will actually cool the engine/oil better, than it "flowing too fast".
08-15-2015, 08:15 PM
#36
VIP Member
VIP MemberThread Starter
Sometimes, its not just about what the oil can handle. Oil has two jobs. Lubricating parts, and COOLING parts.
When you have an engine running at probably 50% of its power output, and its already seeing 240* degrees of oil temperature, I would say something is wrong. Especially, if you are not running an oil thermostat, and your water temp in the block is 140 degrees.
Heat is a killer of valvesprings. According to PAC racing springs, the difference in open pressure, from a spring thats at room temperature, to a spring that is at 350 degrees, can be as much as 90 psi loss on the springs open pressure. So, lets say you are running a basic hydraulic roller cam. Say your springs are 450lbs open at room temperature. Those springs at high rpm, with 350 degree coil temps, may only be 360lbs open. Not to mention, the springs lifespan is greatly reduced from high temperature. Now, the difference between 180 deg spring, and 240 degree spring, may only be 40psi loss of open pressure, but its still something to consider. Of course there are other factors that contribute to spring temperature, but there is no getting around, they rely on oil for cooling.
Seeing 240 degrees of sump temperature, doesn't just mean that, the oil is only getting to 240 degrees. Oil at the bearings can be much higher than that, but you wont see it on the gauge.
I am certainly no oil, or engine expert. When I research things like this for my own stuff, or friends stuff, I tend to look at what the oem's do. Just about every car/truck I have tested/monitored oil temps, are normally within 10-15% of coolant temperature (180-220). Problem with boats, is our coolant temps are not 195*, and we also run under pretty hard loads. So, the fix for this, was oil thermostats, to get the oil hot, and large enough cooler, to keep it cool . Almost every brand of oil thermostat elements out there, and there are tons of aftermarket, and OEM's, range from 180-215* elements. If running 240,250, 260 was good, we would see those elements in the fixtures.
For many many years, oil temperature control, has been a valid concern. From taxi cabs, to pickup trucks, to semi trucks, police cars, or even grocery getters, manufactures combatted high oil temperatures, with external oil coolers. These OEM's have to take into consideration, these vehicles need to last hundreds of thousands of miles. And do so, with the same valvesprings, seals, bearings, and hard parts. Not some guy from the bar who has a built small block in his nova, and puts 800 miles a year on it, and will preach about how great his boutique oil is at handling heat.
There is no getting around, that as oil, any oil, gets up past its optimal operating temperature, oxidation increases. If you said, "after a long 5 mile wide open throttle run, my oil creeps to 240*", I probably wouldnt worry about the setup. But, to say that cruising at 3500RPM, your oil temp is a steady 240*, I would be concerned. It certainly isn't gonna get cooler as you push the throttles down further. Your stock 502 combo oil cooler, was properly sized by mercury marine, for a 390-415HP engine, with stock exhaust, stock everything. It works great for that. Once you start changing things, aftermarket exhaust, more horsepower, possibly leaner fuel mixtures, higher pressure valvesprings, etc etc, things change. Hence my recommendation for a larger oil cooler. I would rather run my oil at a temperature that coincides with oems guidelines, rather than deal with the issue, by running a oil that says it can withstand the extra heat. Just my thoughts on this topic.
Apparently though, what you are saying, debunks the myths here on oso, that "slowing down flow", will actually cool the engine/oil better, than it "flowing too fast".
When you have an engine running at probably 50% of its power output, and its already seeing 240* degrees of oil temperature, I would say something is wrong. Especially, if you are not running an oil thermostat, and your water temp in the block is 140 degrees.
Heat is a killer of valvesprings. According to PAC racing springs, the difference in open pressure, from a spring thats at room temperature, to a spring that is at 350 degrees, can be as much as 90 psi loss on the springs open pressure. So, lets say you are running a basic hydraulic roller cam. Say your springs are 450lbs open at room temperature. Those springs at high rpm, with 350 degree coil temps, may only be 360lbs open. Not to mention, the springs lifespan is greatly reduced from high temperature. Now, the difference between 180 deg spring, and 240 degree spring, may only be 40psi loss of open pressure, but its still something to consider. Of course there are other factors that contribute to spring temperature, but there is no getting around, they rely on oil for cooling.
Seeing 240 degrees of sump temperature, doesn't just mean that, the oil is only getting to 240 degrees. Oil at the bearings can be much higher than that, but you wont see it on the gauge.
I am certainly no oil, or engine expert. When I research things like this for my own stuff, or friends stuff, I tend to look at what the oem's do. Just about every car/truck I have tested/monitored oil temps, are normally within 10-15% of coolant temperature (180-220). Problem with boats, is our coolant temps are not 195*, and we also run under pretty hard loads. So, the fix for this, was oil thermostats, to get the oil hot, and large enough cooler, to keep it cool . Almost every brand of oil thermostat elements out there, and there are tons of aftermarket, and OEM's, range from 180-215* elements. If running 240,250, 260 was good, we would see those elements in the fixtures.
For many many years, oil temperature control, has been a valid concern. From taxi cabs, to pickup trucks, to semi trucks, police cars, or even grocery getters, manufactures combatted high oil temperatures, with external oil coolers. These OEM's have to take into consideration, these vehicles need to last hundreds of thousands of miles. And do so, with the same valvesprings, seals, bearings, and hard parts. Not some guy from the bar who has a built small block in his nova, and puts 800 miles a year on it, and will preach about how great his boutique oil is at handling heat.
There is no getting around, that as oil, any oil, gets up past its optimal operating temperature, oxidation increases. If you said, "after a long 5 mile wide open throttle run, my oil creeps to 240*", I probably wouldnt worry about the setup. But, to say that cruising at 3500RPM, your oil temp is a steady 240*, I would be concerned. It certainly isn't gonna get cooler as you push the throttles down further. Your stock 502 combo oil cooler, was properly sized by mercury marine, for a 390-415HP engine, with stock exhaust, stock everything. It works great for that. Once you start changing things, aftermarket exhaust, more horsepower, possibly leaner fuel mixtures, higher pressure valvesprings, etc etc, things change. Hence my recommendation for a larger oil cooler. I would rather run my oil at a temperature that coincides with oems guidelines, rather than deal with the issue, by running a oil that says it can withstand the extra heat. Just my thoughts on this topic.
Apparently though, what you are saying, debunks the myths here on oso, that "slowing down flow", will actually cool the engine/oil better, than it "flowing too fast".
Last edited by 35fountain; 08-15-2015 at 08:29 PM.
08-16-2015, 06:12 AM
#37
VIP Member
VIP MemberThread Starter
I am in the commercial refrigeration business by trade and i deal with a lot of water cooled condensers no different than an oil cooler. Instead of removing heat from engine oil it is removing the heat from refrigerant.It is the same concept. Water in at one side and refrigerant out of that side, water out of the other side and refrigerant in on that side. Opposite direction to remove heat efficiently. The Mercruiser diagram previously posted agrees with me except my boat is going in the same direction which is wrong and will be changed. It has to make a difference, that's the way heat exchangers work. Yesterday I was at 3200 rpms@225 degrees and WOT for 30 secs and it went up to 245 . Short blast, boat full of people who don't like to go too fast lol. I have never seen my oil temps above 250-260 even after a hard WOT run. I am going to put my water dumps back in to relieve some pressure and lower the oil temp. I will post the difference with the dumps
https://www.youtube.com/watch?v=_az6A4TKAiE
https://www.youtube.com/watch?v=_az6A4TKAiE
Last edited by 35fountain; 08-16-2015 at 06:29 AM.
08-16-2015, 06:42 AM
#38
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250-260 on the cold side after cooler is way too much... Get a bigger cooler...
I agree with flowing opposite directions water and oil, on the same hand I agree with Eddie looking at it this way, I cool with 70 degree water flowing through nonstop.... It's gonna cool good no matter what direction it flows...
Cruising temps for me are 170 ish yesterday at 4200 no oil or water stats
I agree with flowing opposite directions water and oil, on the same hand I agree with Eddie looking at it this way, I cool with 70 degree water flowing through nonstop.... It's gonna cool good no matter what direction it flows...
Cruising temps for me are 170 ish yesterday at 4200 no oil or water stats
