motor oils prefered on performance boats
10-30-2014 | 06:26 AM
#182
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From: Merritt Is. Fl. USA
Straight from the factory mercruiser high performance / Merc Racing training classes. Also there is a Service Bulletin on this as well 95-3 to all dealers plus other related info running to low internal oil temps. Anyways here is the info taught in class years ago..
Oil thermostat and the filter adaptor. In the housing is an oil by pass valve if the oil filter should become plugged to bypass. The most important to the design is to control oil temperature in which improves engine lubrication and greatly reduces moisture in the engine.
The oil t -stat closed, the oil from the engine flows directly to the oil filter and then back to the engine, when the oil t-stat opens ie: when the oil t-stat is fully open, oil is directed first to the cooler, then back thru the oil filter and then returned to the engine. The oil t-stat starts to open at 194 degrees and is fully open at 284 degrees.
Internally a stock Mercury racing engine the oil reaches 194 degrees min at all times regardless unless a problem ie: cooling problem or a oil cooling problem of sort like for example, improper oil t-stat not working correctly or bypass problem of some sort..
My point Mercruiser does not want oil temps too low. Also they go into this great lengths in their dealer support literature about this for big blocks. This info and the Service Bulletin also includes the Bulldog engines and the 525SC, 600 SC and the 800 SC among others.
Oil thermostat and the filter adaptor. In the housing is an oil by pass valve if the oil filter should become plugged to bypass. The most important to the design is to control oil temperature in which improves engine lubrication and greatly reduces moisture in the engine.
The oil t -stat closed, the oil from the engine flows directly to the oil filter and then back to the engine, when the oil t-stat opens ie: when the oil t-stat is fully open, oil is directed first to the cooler, then back thru the oil filter and then returned to the engine. The oil t-stat starts to open at 194 degrees and is fully open at 284 degrees.
Internally a stock Mercury racing engine the oil reaches 194 degrees min at all times regardless unless a problem ie: cooling problem or a oil cooling problem of sort like for example, improper oil t-stat not working correctly or bypass problem of some sort..
My point Mercruiser does not want oil temps too low. Also they go into this great lengths in their dealer support literature about this for big blocks. This info and the Service Bulletin also includes the Bulldog engines and the 525SC, 600 SC and the 800 SC among others.
Thanks for the great info., as I'm getting ready to change my bulldog 572 Oil thermostat this weekend.
Dean
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10-30-2014 | 05:02 PM
#184
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From: On A Dirt Floor
BUP, obviously oil thermostats are beneficial to an engines health to cold is no good as is too hot. My question is how beneficial would it be to pre-heat the oil before start up? I have a ginormous aluminum pan and really wouldn't be difficult to install a heater. Just have to make sure it's properly secured. Don't want anything floating around in the oil pan. Also, I bet it would be easy to rig up a circulating system to run warm oil through out b4 start up. But, how beneficial would it be? Lets say $500 in parts and some labor. Would it be worth it?
Under say 50 with thick oil - sure. Obviously when colder, even more so.
This is assuming you are not out on a warm/hot day with 35-55F water. This is really where factory type (ie: no crossover) cooling (engine water) systems work/help.
Trying to get oil up to 180F + when in very cold water is freakin tough with a crossover cooling system.
Remember, your block and cooling system is a very large and important oil cooler / heater also.
10-30-2014 | 05:20 PM
#185
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From: AZ
For those interested, here is a chart showing energy expended with different winter rating oil viscosities along with cold pumping max energy. Even in a environment where you have for example 60 degree days, it would only benefit to run the lighter (W) winter number ie 0w vs10w,15w, 20w etc to reduce start up wear, along with warm up wear. A side benefit is greater starter life. The 100 degree celcius viscosity is unaffected. Just be sure to pick an oil without VII, and there is zero penalty to be paid.
Last edited by Borgie; 10-30-2014 at 05:22 PM.
10-30-2014 | 07:09 PM
#186
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From: On A Dirt Floor
Your typical 65-70F+ day ? I don't see much benefit.
Under say 50 with thick oil - sure. Obviously when colder, even more so.
This is assuming you are not out on a warm/hot day with 35-55F water. This is really where factory type (ie: no crossover) cooling (engine water) systems work/help.
Trying to get oil up to 180F + when in very cold water is freakin tough with a crossover cooling system.
Remember, your block and cooling system is a very large and important oil cooler / heater also.
Under say 50 with thick oil - sure. Obviously when colder, even more so.
This is assuming you are not out on a warm/hot day with 35-55F water. This is really where factory type (ie: no crossover) cooling (engine water) systems work/help.
Trying to get oil up to 180F + when in very cold water is freakin tough with a crossover cooling system.
Remember, your block and cooling system is a very large and important oil cooler / heater also.
Everyone -
Okay, I just brought up some bad and tough memories with crossovers and there resultant f*king with oil temp and water psi.
People running in colder waters really are doing themselves a disservice with running crossovers (even with t-stats but of course more so without) and not having a oil temp guage nor water psi guage.
The water psi is a whole nother issue for other threads - but note worthy to get a guage since these systems can f*k with that.
Back to oil temp.
Crossovers do not have the capability to recirculate water coming out of the engine back into the engine. Therefore, the engine cannot help warm itself up - both water and oil. Remember, the engine is a large factor for heating up / cooling down oil.
Again, for those with crossovers and no oil temp guage - especially in colder waters - you would absolutely cream your pants on how long it can take to get oil up to temp and also how fast it will cool down when slowing down...even after a long run.
I ran a crossover for a year and could not get a satisfactory oil temp vs time, no matter what i did, when our lake got colder. When it (lake) was 70F+ (a very short time for us) is when I could get close to satisfactory results.
I'll make up a number, but will probably be very close, that 95%+ of people using crossovers do so over the bling factor and that's it.....and 95% of those have absolutely no idea what it's doing with their oil temps (and water psi) and thus, can truely get themselves into trouble with there oiling system.
Summary - for those that have a crossover system and don't have an oil temp guage and water psi guage - do yourself a favor and get those now. Like, right now.
10-30-2014 | 09:06 PM
#187
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From: chicago
Oil coolers are overrated. I suggest removing the oil cooler, installing 210* water thermostats, running a 0w5 oil, and holding it at 95% throttle opening and once the oil warms up to 350 degrees, feel free to go all in. This way youll be sure to boil off the contaminants 
10-30-2014 | 09:20 PM
#188
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From: Ft. Worth TX
^^^^ very funny and you change the pic up and its redline for now ? Huh I liked the past couple of pics better than a gallon jug here.
And you forgot about the power steering coolers as well.
And you forgot about the power steering coolers as well.
Last edited by BUP; 10-30-2014 at 09:56 PM.
10-30-2014 | 09:33 PM
#189
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From: AZ
Personally I'm not a fan of crossovers at all. That said, it is my opinion that if someone wants to run a 20w-50 even when it's for example 70-80 ambient temperature, they should have an oil heating pad running several hours prior to startup. Most will bring your oil up to 180 degrees in a couple of hours. This helps these more viscous oils flow during that crucial few seconds during startup. Obviously the better choice would be to buy a 5w or 10w oil, however keep in mind that some oils have a low viscosity index and as such are laden with a ton of VII's which only last so long.
Some people criticize my choice of "boutique" Ester oils, however I didn't just spin the bottle if you will, when trying to find a well rounded lubricant. And by nature these oils have a high natural viscosity index eliminating the VII's all together. Shearing is just one ugly side effect brought about from the overuse of these additives. Piston rings stick, causing loss of compression, and in some severe cases ring breakage. And the beauty of a ester based synthetic with a winter (W) rating of 5 or 10 is that a pan heater is not needed. It wouldn't hurt, however these oils flow very well in the cold vs any conventional or group III synthetic motor oil.
Coupled with the above, oil thermostats are critical as mentioned earlier. Guys get it in their heads that "cooler" oil is better... Couldn't be a worse case scenario than an engine already running cold with a crossover and then the guy decides to leave out the oil thermostat. Ends up throwing a rod bearing and scratches his head wondering how that happened!?
SB- to be honest I don't think there is a product or oil for that matter that would help these folks encountering what you did while running a crossover. You can help the very first start up with the above tips, however the rest of the day out on the lake low coolant/oil tenps will persist. No oil will handle the moisture and non activation of additives from the overall low temps that come with this combination.
Some people criticize my choice of "boutique" Ester oils, however I didn't just spin the bottle if you will, when trying to find a well rounded lubricant. And by nature these oils have a high natural viscosity index eliminating the VII's all together. Shearing is just one ugly side effect brought about from the overuse of these additives. Piston rings stick, causing loss of compression, and in some severe cases ring breakage. And the beauty of a ester based synthetic with a winter (W) rating of 5 or 10 is that a pan heater is not needed. It wouldn't hurt, however these oils flow very well in the cold vs any conventional or group III synthetic motor oil.
Coupled with the above, oil thermostats are critical as mentioned earlier. Guys get it in their heads that "cooler" oil is better... Couldn't be a worse case scenario than an engine already running cold with a crossover and then the guy decides to leave out the oil thermostat. Ends up throwing a rod bearing and scratches his head wondering how that happened!?
SB- to be honest I don't think there is a product or oil for that matter that would help these folks encountering what you did while running a crossover. You can help the very first start up with the above tips, however the rest of the day out on the lake low coolant/oil tenps will persist. No oil will handle the moisture and non activation of additives from the overall low temps that come with this combination.
Last edited by Borgie; 10-30-2014 at 09:37 PM.
10-30-2014 | 09:46 PM
#190
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From: On A Dirt Floor
The oil cooling issues with crossovers still happens with oil coolers with t-stats. Did testing with a HP500 also.
Any how, was not asking for an oil as a fix - that won't hppen. Asking for an oil to help in the meantime while some sorts out there cooling/heating oil issues.
Any how, was not asking for an oil as a fix - that won't hppen. Asking for an oil to help in the meantime while some sorts out there cooling/heating oil issues.
