Highest OIl Temps that are safe
05-26-2017, 12:16 PM
#21
artselectricinc.com
Platinum Member
05-26-2017, 02:23 PM
#22
Registered
Caster oil?
The question is what is the highest oil temps that oil can take before issues start?
To start with had a 18 inch long 2 inch diameter cooler and had no idea what the oil temp was. After a short time I wondered why the oil was so black and was running 20W50 Caster oil. Also had 3/8 ID oil lines and standard Merc oil filter block adapter.
This year, installed 10-AN oil lines and oil adapter, along with 525 oil cooler, using Brad Penn straight 50W. Pressure after getting to or above 220 degrees I'm seeing 70 to 80 psi oil pressure. My 530 HP motor is at 220 degrees running 3400 rpm's and gets to 240 degrees at 3600 rpm. When I go higher and at WOT it just keeps climbing. Did not do a lot of running so this was just initial readings with a 18 mile round trip. This was 9 miles up, stop swim and later come back. Water temp is around 85 degrees so its still a bit cool.
Plan to install AFR meters to check ratio, and also water pressure gauge in the block to make sure water is flowing. Also plan to go back to 20W50 Castor oil. Have brand new impeller and Hardin Marine SS water pump housing for this season
To start with had a 18 inch long 2 inch diameter cooler and had no idea what the oil temp was. After a short time I wondered why the oil was so black and was running 20W50 Caster oil. Also had 3/8 ID oil lines and standard Merc oil filter block adapter.
This year, installed 10-AN oil lines and oil adapter, along with 525 oil cooler, using Brad Penn straight 50W. Pressure after getting to or above 220 degrees I'm seeing 70 to 80 psi oil pressure. My 530 HP motor is at 220 degrees running 3400 rpm's and gets to 240 degrees at 3600 rpm. When I go higher and at WOT it just keeps climbing. Did not do a lot of running so this was just initial readings with a 18 mile round trip. This was 9 miles up, stop swim and later come back. Water temp is around 85 degrees so its still a bit cool.
Plan to install AFR meters to check ratio, and also water pressure gauge in the block to make sure water is flowing. Also plan to go back to 20W50 Castor oil. Have brand new impeller and Hardin Marine SS water pump housing for this season
05-26-2017, 04:34 PM
#23
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Not sure if that was for OP or me, but My info came from Eddie Young just so I don't get bashed for posting what I was informed . In my case in past I would see 150-200 after cooler, but had a hard time in coolerbwater after a richer tube, so I added stats this season now see too much temp, 230 after cooler and climbing... so yesterday inremived them, hence why I asked Eddie his opinion just one of many.
Eddie is much smarter than me, and does this for a living. 230 AFTER the cooler, seems pretty darn hot to me. But again, he is a pro, I am not.
I'd imagine that if the oil AFTER the cooler, is 230, it has to be quite a bit hotter BEFORE the cooler. How much, IDK, prob depends on the cooler and rest of system.
All i know, is that the hotter the oil gets, the viscosity plummets. A 20w50 at 230-240 degrees, is prob like running a 5w30 at 180-190 degrees.
05-26-2017, 07:05 PM
#24
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not one Merc small blocks and down run a motor oil cooler ever for a stock app. Even the small block HO MAGS do not use oil coolers. Their oil temps after hard runs are over 220 degrees without any problems and some of the 350 small bocks have 1500 hours on them and or tow skiers around all day long every weekend in the summer.
Texas has very high water temps and high air temps for summer boating. The inboard ski boats - that totally enclosed engine box in the middle of the hull allows no air period to any part of the engine including the oil pan Zero. They get hot running and their oil temps can get very high from lugging skiers around all day long. They do not have motor oil coolers either. Just saying and live very long. The motor oil has to reach 212 at some point to burn off condensation from combustion.
230 MAXED oil temps is not too hot
also other factors turn oil black as well - fuel mixed in to the motor oil, vacuum leaks, and lean conditions all can turn motor oil black as well.
Texas has very high water temps and high air temps for summer boating. The inboard ski boats - that totally enclosed engine box in the middle of the hull allows no air period to any part of the engine including the oil pan Zero. They get hot running and their oil temps can get very high from lugging skiers around all day long. They do not have motor oil coolers either. Just saying and live very long. The motor oil has to reach 212 at some point to burn off condensation from combustion.
230 MAXED oil temps is not too hot
also other factors turn oil black as well - fuel mixed in to the motor oil, vacuum leaks, and lean conditions all can turn motor oil black as well.
Last edited by BUP; 05-26-2017 at 07:18 PM.
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Cap'm Kurt (09-17-2021)
05-26-2017, 07:28 PM
#25
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Maybe your motor oil cooler has a form of restriction impeding waterflow Or your water circ pump is not up to par. Seen many of both
how about your t stat and if applicable the check balls and or check valves at any location in the cooling system.
I really do not even know what your app is but throwing the norms out there
how about your t stat and if applicable the check balls and or check valves at any location in the cooling system.
I really do not even know what your app is but throwing the norms out there
05-26-2017, 07:54 PM
#26
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383 stroker Mercruiser and I think 400 hp and does not use an motor oil cooler - This is from their repower division
http://www.marineengine.com/parts/me...-3-point-drain
At one time Merc had a 383 - 6000 rpm engine with 450 hp and it had no motor oil cooler on it if I stand corrected.
http://www.marineengine.com/parts/me...-3-point-drain
At one time Merc had a 383 - 6000 rpm engine with 450 hp and it had no motor oil cooler on it if I stand corrected.
Last edited by BUP; 05-26-2017 at 07:59 PM.
05-26-2017, 09:15 PM
#29
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I knew someone would bring that up like us old timers.
That is correct on all 80 of them that they sold back in 1987 thru 1989. haha
It was a combo power steering cooler and motor oil cooler in one unit === Half and half. and not very large either,
Also they used the oil pressure sender on the oil filter adapter mount and the old 2 wire version if I recall correctly for the 320.
That is correct on all 80 of them that they sold back in 1987 thru 1989. haha
It was a combo power steering cooler and motor oil cooler in one unit === Half and half. and not very large either,
Also they used the oil pressure sender on the oil filter adapter mount and the old 2 wire version if I recall correctly for the 320.
05-26-2017, 09:34 PM
#30
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300 Tempest had an oil cooler.
https://www.marineengine.com/parts/m...er-and-adaptor
https://www.marineengine.com/parts/m...er-and-adaptor
Merc tracks its warranty claims per sections of the USA and other countries. What issues take place in AZ might not be the same in Canada or Maine or very Northern Michigan and so on. And vice versa.
To add these can be the hottest running engines - the marine gas CAT engines --- because the cat need to have 650 to 800 degrees to be effective and operate correctly. So lack of cooling and heat soak can cause very high heat. These do not have motor oil coolers either. Just saying
http://www.marineengine.com/parts/me...g-system-bravo
Last edited by BUP; 05-26-2017 at 09:50 PM.
