oil filter/cooler modification by PO

[southcarolinaf150]

Working on my Lund that has a 1960 BB70 mated to an Aquamatic outdrive unit, but this might be more of a general q based on other cooling system setups. PO did a fair amount of 'modification' to the rest of the boat but not the engine so I overlooked this. The cooling water line, which is supposed to run scoop/strainer/filter/water pump/oil filter & cooler/exhaust manifold/etc has been modified to bypass the oil filter & cooler and directly connect the water pump and exhaust manifold. The inlet and outlet on the oil cooler were then looped with a short piece of hose.

Will this have an observable effect on engine temp? If so why did the PO delete this part of the system?

I've only run on land (max maybe 30 min because of complementary 'alternator delete') and haven't noticed any issues with overheating. I also haven't changed the oil yet so I havent opened the oil filter/cooler housing yet.

Cooling lines diagram for ref:
imgur: the simple image sharer

 

[Alan Lloys]

Re: oil filter/cooler modification by PO

Just guessing here - but probably a leak in the oil cooler.
By looping the water side together the oil is not leaking out and you are not putting any water in. Sounds like a plausible short term fix that was never corrected.

You can test it by opening the looped water line and see if you are getting oil out.
In many cases the oil cooler is actually just bolted on below the oil filter and may be able to be removed completely.

What impact it will have on operating temperatures are dependent on your use of the engine.
Rarely do the spend the money and engineering on putting on parts that are not beneficial but if you are just cruising around on a river you may be OK.

 

[Scott Danforth]

Re: oil filter/cooler modification by PO

I agree that the oil cooler probably had developed a leak due to poor winterization or age, and the PO simply "bypassed" it.