I was running the boat
under load this weekend for an extended period. The water
temperature was in the mid 70's, so my engine
was essentially being cooled with the warmest water
of the season. As I continued at full load for about 15 minutes, I noticed my oil
pressure dropped by 25 percent. I headed back to the marina, docked, and allowed the engine
to cool for a few minutes (temp dropped to 160 degrees). I then started it again and noticed the oil
pressure back to normal.
I'm guessing taking the engine to 180-190 degrees compromises the viscosity of the oil and causes the pressure to drop. I'm considering two things. First, I want to install a larger heat exchanger
. I have constantly read accounts regarding the original heat exchanger
on it not having enough capacity. Second, I'm considering installing an oil cooler. I notice many sailboats with the Perkins 4.108
do have an oil cooler (for crankcase oil).
I want to install the oil cooler first, as it would be the easiest fix for the oil pressure problem. But I want to eventually upgrade the heat exchanger to one with more capacity.
What has people's experience been with oil pressure dropping on the Perkins 4.108
as engine temperature increases? What capacity oil cooler would be best?
Thanks in advance for your help.