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Dart block oil temp

Old 11-17-2016, 08:44 AM
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Originally Posted by minxguy
Way too cold for oil, You probably increase you oil level in your sump because you dont burn off the water from condensation.

180 is probably the coolest oil should get 210 is what it is tested at for viscosity.

Keep it under 300.

Ken
IJust because water "boils" at 212, doesn't mean that if you fail to get your oil to 212*, its gonna be ridden with water in it. The ONLY time my oil gauge goes over 200 , is on a long wot run down in LOTO where the water is warmer. Most normal days of boating, it never goes above 170-180 on Lake Michigan. I do have mercury racing oil thermostats. I do not run any water stats, so my water temp is cold. I never have foam on my dipstick, valve covers, or any of that. I mean maybe the slightest bit I have seen over the years, but nothing thats hurting anything. Now, if your seeing milkshake on your rocker arms, springs, etc, you have an issue.

I think theres alot of guys who get milky chit in their engines, and think hotter oil is the cure. There are a thousand places for water to get into an engine. Oil cooler, head bolt in water jacket, slightest leak at headgasket, intake gasket , and so on.

While sure, you're oil might withstand 230+ degrees, oil not only lubes parts, it cools them. I personally, would rather drizzle 180 degree oil on my valvesprings, than 230+ oil, same on the pistons. The other factor, is hot oil gets thin. Most are running hydraulic lifters. The lifter is nothing more than a hydraulic piston. It will be more suceptible to bleeding down, with water in it at high rpm, than oil. Go take an oil filled shock absorber, and try to compress it by hand when its 30 degrees outside. Then, heat it up to 150 degrees after driving down a bumpy road, and repeat. kinda the same thing.

SO, with hot oil temps, your losing valve spring pressure, you're breaking down friction modifiers in the oil, (which if running a conventional mulitgrade, there usually is quite a bit of friction modifiers in the oil), and possibly losing the effectiveness of the lifters bleed rate. Alot of guys have done dyno testing on hydraulic roller bbc's , and found heavier grade oils usually made more power, which contradicts what you would think.

I think it be interesting to do a dyno test with a bbc, varying oil temps, and oil viscosities. We all dyno with fresh oil. What about a 20w50 oil, that has 25 hours of 230+ oil temps, some fuel dilution, and what not in it. It prob has the viscosity rating of a 20 or 30 grade oil when hot at that point in its life.

Look at the open load psi when temperature of the valvespring gets hot. By 200* spring temp, youre down about 25lbs , by 250*, 40 lbs, by 300* its down 60lbs. IMO, anything you can do to keep the springs cool, is a bonus. If your oil is 250*, theres just no way your valvesprings will be cooler than 250*. Valvespring oilers help keep the spring temps from getting out of hand by keeping them flooded with oil. Heat of the spring has a direct effect on the springs rate. We all know what happens when you don't have enough spring pressure to keep the valvetrain stable.
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Old 11-17-2016, 08:52 AM
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Originally Posted by MILD THUNDER
IJust because water "boils" at 212, doesn't mean that if you fail to get your oil to 212*, its gonna be ridden with water in it. The ONLY time my oil gauge goes over 200 , is on a long wot run down in LOTO where the water is warmer. Most normal days of boating, it never goes above 170-180 on Lake Michigan. I do have mercury racing oil thermostats. I do not run any water stats, so my water temp is cold. I never have foam on my dipstick, valve covers, or any of that. I mean maybe the slightest bit I have seen over the years, but nothing thats hurting anything. Now, if your seeing milkshake on your rocker arms, springs, etc, you have an issue.

I think theres alot of guys who get milky chit in their engines, and think hotter oil is the cure. There are a thousand places for water to get into an engine. Oil cooler, head bolt in water jacket, slightest leak at headgasket, intake gasket , and so on.

While sure, you're oil might withstand 230+ degrees, oil not only lubes parts, it cools them. I personally, would rather drizzle 180 degree oil on my valvesprings, than 230+ oil, same on the pistons. The other factor, is hot oil gets thin. Most are running hydraulic lifters. The lifter is nothing more than a hydraulic piston. It will be more suceptible to bleeding down, with water in it at high rpm, than oil. Go take an oil filled shock absorber, and try to compress it by hand when its 30 degrees outside. Then, heat it up to 150 degrees after driving down a bumpy road, and repeat. kinda the same thing.

SO, with hot oil temps, your losing valve spring pressure, you're breaking down friction modifiers in the oil, (which if running a conventional mulitgrade, there usually is quite a bit of friction modifiers in the oil), and possibly losing the effectiveness of the lifters bleed rate. Alot of guys have done dyno testing on hydraulic roller bbc's , and found heavier grade oils usually made more power, which contradicts what you would think.

I think it be interesting to do a dyno test with a bbc, varying oil temps, and oil viscosities. We all dyno with fresh oil. What about a 20w50 oil, that has 25 hours of 230+ oil temps, some fuel dilution, and what not in it. It prob has the viscosity rating of a 20 or 30 grade oil when hot at that point in its life.

Look at the open load psi when temperature of the valvespring gets hot. By 200* spring temp, youre down about 25lbs , by 250*, 40 lbs, by 300* its down 60lbs. IMO, anything you can do to keep the springs cool, is a bonus. If your oil is 250*, theres just no way your valvesprings will be cooler than 250*. Valvespring oilers help keep the spring temps from getting out of hand by keeping them flooded with oil. Heat of the spring has a direct effect on the springs rate. We all know what happens when you don't have enough spring pressure to keep the valvetrain stable.
Makes perfect sense to me.
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Old 11-17-2016, 09:06 AM
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525 EFI SPECS

Crankshaft Kilowatts / Horsepower 391 kw (525 hp)
Displacement L / cid 8.2 L / 502 cid
Bore 113.436 mm (4.466 in.)
Stroke 101.6 mm (3.999 in.)
Compression Ratio 8.75 :1
Maximum RPM at Wide-Open-Throttle 5200
RPM Rev Limit 5400
Type of Ignition System Inductive – Digital Control
Oil Pressure @ Idle (HOT) 138 kPa (Min. 20 psi)
Oil Pressure @ WOT (HOT) 241 kPa (Min. 35 psi)
Max. Allowable Engine Oil Temperature 104 °C (220 °F)
Thermostat 71 °C (160 °F)
Electrical System 12-Volt Negative (–) Ground
Alternator Rating 917 Watts (65 Amps)
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Old 11-17-2016, 09:06 AM
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every now and then the oil temp issue comes up.then someone will say they like 150 deg,next guy sais you need ^212 to boil off moisture.i always get a kick out of the[to boil the moisture off you need 212 or above]fact is that is an incorrect statement.i like 190 deg but i have seen marine engines that run 150 deg oil temp for years and have no moisture issues.imo joe is spot on with his post.running the oil above 230 deg in a marine engine is not good imo.
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Old 11-17-2016, 09:18 AM
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Originally Posted by mike tkach
every now and then the oil temp issue comes up.then someone will say they like 150 deg,next guy sais you need ^212 to boil off moisture.i always get a kick out of the[to boil the moisture off you need 212 or above]fact is that is an incorrect statement.i like 190 deg but i have seen marine engines that run 150 deg oil temp for years and have no moisture issues.imo joe is spot on with his post.running the oil above 230 deg in a marine engine is not good imo.
Hugs all around

Last edited by F-2 Speedy; 11-17-2016 at 10:35 AM.
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Old 11-17-2016, 12:35 PM
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All I know is this, in my procharged HP500, with no oil therm always ran about 150 max, after installed a canton therm around 200, but before had the engine out, and after only about 100 hours running rotella 15-40 had a large amount of thick sludge in the bottom of the pan. put a post up on this back then, most think was from oil never getting hot enough...so the 190 and maybe 215-220 after running hard should be good
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Old 11-17-2016, 01:44 PM
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Right - wrong - indifferent... Whatever works for ones specific build is the name of the game. Some guys like to run more bearing clearances while others would say their crazy but again... It's ok. Btw BB I like the fact your not easy on your engines either. I've seen way to many boaters back out of the throttles cause their afraid something is gonna let lose. The way I see it if it's gonna go lets get on with it and move on. Cheers
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Old 11-17-2016, 05:26 PM
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If this is a kind of new build and the have tighter bearing clearance lifter clearance you will have les flow going through the cooler and may have an effect on the temperature of the oil. Also did you use a different oil pan? Make sure the oil is not over full.

BTW I run the oil around 260 with no problems 290 and bearings start to get unhappy.

Last edited by 14 apache; 11-17-2016 at 05:31 PM.
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Old 11-17-2016, 06:22 PM
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Here is my moto ..when we do a build after the first hour of use ,,new build ,,,drive it like u stole it ...if **** going to break get it over with ....just like our 489 did pushed it hard and a valve broke at stem
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Old 11-17-2016, 06:23 PM
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Originally Posted by 14 apache

BTW I run the oil around 260 with no problems 290 and bearings start to get unhappy.
Hydraulic lifters? How many hours do you normally get out of your springs?
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