TomR

Ok!
Got the motor back in and dialed out after THE MELTDOWN, and everything is cool except! The operating temp now runs around 160 & 165, about ten degrees hotter than before the rebuild. I am running a little higher compression about 9:00 to 1, same pistons but just had the deck cut to "0"and then installed a .041 head gaskets. The motor runs great stronger than ever, good plug color etc. My bigger concern is the oil pressure about 70lbs cold at idle, 60lbs warmed up cruising but after a WOT run the pressure will drop to 55lbs running along and drop to about to 30lbs at idle. I have been running the oil cooler from the 7.4L that was originally in the boat and I am concerned that it may not be quite enough now. It was doing this before the rebuild but not to this degree. I was thinking of installing a oil temp gauge along with a large Eddie Marine oil/ps cooler but was wondering what other boaters had experienced in this area. Any input appreciated.

Waterfoul

Those oil pressures don't sound bad to me. And get yourself an oil temp gauge, second most important gauge on my dash. Right after the Tachometer. It might be in your best interest to get the gauge first, check the temp of the oil, and then decide if you need a bigger cooler.

I'll bet after a few minutes at idle speeds (say, 1000 rpm) the pressure comes back up a ways???

Tinkerer

Both of mine do just about the same thing.

Turbojack

Last year had same low pressures. This year put big eddie marine cooler & permacool t-stat. Now Oil pressure starts out at 80, & lowest I have ever seen is 70-75 anthing above idle. Do a search on coolers. This has been discussed many times before.

TomR

Once I slow down for a 30 to 45 seconds the pressure comes back. I think I'll try a oil temp gauge. I have a port on the remote oil filter pad, is this a good place to install a temp gauge??

olysan

Last year I had the same problem with my 406. No oil cooler, just power steering cooler. This year I added the eddie marine cooler and permacool stat, and so far no issue with dropping oil pressure.

Mike

traviss

same thing i ran into on my SBC... have a 454 mag cooler on it.. with a perma cool thermostat.. pressure at idle cold is 40 psi.. WOT 58-60 psi.... warmmm i should say hot (280 degrees) its 25 psi at idle and 30 psi at WOT.. So i have the biggest eddie marine cooler coming tommorrow. hopefully that gives me better oil pressure..

mopower

Pressures don't sound bad to me either. My two do just about the same. Mine might go down to 25 pounds after a hard run , but like yours in 30-45 second of idling its back to 40. The bad news is the pan is probably the best place for the oil temp sender.

ursus

I posted this as a question before and did not get an answer to the contrary. Why is the pan a better place than the remote filter when the oil comes directly from the pan, thru the pump out the adapter to the remote oil filter.

Why would the temp be any different at the remote than in the pan other than maybe coolin 1 degree because it goes thru a 2 foot hose to get there

Why I ask you Why

mopower

Because I said so that's why ! Just kidding! Seriously though , the oil filter location would probably be ok. It would show temp variations as you change speed and load on the engine. But since it is sitting out there in the open with a 1/4 inch of aluminum around it acting like a heat sync , I would imagine it would read a little lower than the pan where you have more volume around it. Even if its 10 degrees off its certainly not going to kill you