Engine Oil Cooler

[Brooksie]

This may be of interest to others, I don't know. But for what it's worth:
Two weeks ago I decided to change out my transmission and engine oil coolers due to their age. The engine oil cooler on my horizontal Perkins 6 is in the oil pan/tank & in my installation the tube bundle can't be removed without hoisting the engine, a replacement tube bundle is $1800, and if it leaks seawater enters the oilpan. So instead of the "in-tank" cooler I ordered a 3" x 9" high pressure, cu-ni, external cooler. A homemade bracket, some hi temp oil hose, and a "sandwich" adapter completed the installation. The "sandwich" adapter goes under the oil filter and allows 1/2" in & out oil lines easily to the cooler. The the water was blown out of the old oil cooler & it was capped off.

Now with water and oil passing through the new cooler instead of tubes of water just sitting partly in the oil, my oil pressure is greatly improved from 30 to 40 at cruise and 35 @ hot idle instead of 15 as b/4. I did not change my oil during this conversion. It is now removable and servicable. If it leaks oil will go into the seawater and I will loose the oil but water will not go into the oil pan.

Moral of story: A properly sized & working engine oil cooler can make a big difference in oil pressure.

 

[psneeld]

I'm actually thinking of getting rid of my oil cooler on the Lehman..but I have 80psi down to 60 when warm and the engine really never get's to 180...thinking it's just another point of failure.

Glad your fix worked for you...

 

[Brooksie]

The Perkins is in my lobsterboat not my trawler (pictured) It gets pushed pretty hard and well maintained but old and it is a turbo. I now know it could not do without an oil cooler. Maybe your Lehman can, I don't know. If you do change it get the cu-ni tubes they are worth the price difference for sure.

You have a 20 PSI drop at hot idle just as I did. Starting with 80 you can afford it whereas I could not. 80 would indicate a stuck relief valve to me because I doubt if Lehman sets their max pressure to 80 but then I have never had one myself.

 

[sabaru350]

oil cooler

This may be of interest to others, I don't know. But for what it's worth:
Two weeks ago I decided to change out my transmission and engine oil coolers due to their age. The engine oil cooler on my horizontal Perkins 6 is in the oil pan/tank & in my installation the tube bundle can't be removed without hoisting the engine, a replacement tube bundle is $1800, and if it leaks seawater enters the oilpan. So instead of the "in-tank" cooler I ordered a 3" x 9" high pressure, cu-ni, external cooler. A homemade bracket, some hi temp oil hose, and a "sandwich" adapter completed the installation. The "sandwich" adapter goes under the oil filter and allows 1/2" in & out oil lines easily to the cooler. The the water was blown out of the old oil cooler & it was capped off.

Now with water and oil passing through the new cooler instead of tubes of water just sitting partly in the oil, my oil pressure is greatly improved from 30 to 40 at cruise and 35 @ hot idle instead of 15 as b/4. I did not change my oil during this conversion. It is now removable and servicable. If it leaks oil will go into the seawater and I will loose the oil but water will not go into the oil pan.

Moral of story: A properly sized & working engine oil cooler can make a big difference in oil pressure.

Do have the part # for that external oil cooler, I would like to make that one of my projects when I go back to Florida.
Sincerely
Marty

 

[Xsbank]

Brooksie, that is the thing I most like about owning my own boat, my inventions and innovations are few, but when I tackle one and it works, the feeling can't be beat!

When I had my GB, I changed the transmission and engine oil coolers as they are a point of serious failure. If one of them failed, the consequences would be dire. On my Cummins, I have been less concerned as I am dry-stacked and have no salt water in the system.

 

[psneeld]

I wonder what all the "oh no, the manufacturer's know best" crowd will point out on this one.

 

[Ski in NC]

Sea water oil coolers are used on Lehman, Volvo, Yanmar and Perkins- various models. I consider them second rate engineering. All diesels at high load need some sort of oil cooling. But size the cooler for high load and high sea temp, and it will then overcool the oil down at low load and low sea temp. First rate engineering has the oil cooled by coolant, specifically at the discharge of the circ pump. This has the benefit of having somewhat a constant oil temp across the load range. At low load, tstat is closed and coolant going out of circ pump is almost all bypass flow, nearly normal engine temp. At high load, tstat is open and the coolant temp coming out of circ pump is lower, and thats when you want oil cooling. Cat, Detroit, Cummins and all the larger engines use coolant to cool oil.

On a couple custom engine builds, I used the oil filter sandwich cooler adapter to divert oil to a sea water cooler. The sandwich has a bimetal thermostat that only diverts flow once oil gets hot. The thing looked a bit like chicken sh!t engineering when I bought it, but in three installs, they worked perfectly. Oil temps kept controlled, albeit at a lower temp than I liked. Good oil temp is around a constant 200-220, these kept around 180F.

Lehmans running hull speed tend to overcool the oil, often just around 150F. The pancake adapter might be an option there.

Another option is to elimate the cooler entirely as posted by PSN above, that should be fine at low load, but sort of closes the window on running high power if needed. Worth a try and just monitor with IR gun at oil pan or oil filter skin.

 

[Ben]

On a couple custom engine builds, I used the oil filter sandwich cooler adapter to divert oil to a sea water cooler. The sandwich has a bimetal thermostat that only diverts flow once oil gets hot. The thing looked a bit like chicken sh!t engineering when I bought it, but in three installs, they worked perfectly. Oil temps kept controlled, albeit at a lower temp than I liked. Good oil temp is around a constant 200-220, these kept around 180F.

Lehmans running hull speed tend to overcool the oil, often just around 150F. The pancake adapter might be an option there.

I have an oil cooler on my Lehman I have been planning to replace (age). I run water temp around 170-175. I am also planning to pull my heat exchanger and de-scale. All of these will be my rookie first-effort*, but seem reasonably straight-forward. Now you have me thinking about an oil temp sensor...

(*I work slowly, anxiously, and methodically, remembering Murphy!)

We're in the same town. Any time you might need a free apprentice, send me an IM. Happy to pay tuition in labor or beer.