Oil Pump

[ceasefire49Z]

I have an 88 Rienell 18.5 that I just put a new transom in along with stringers and deck. I am changing some items like fuel pump and thermostat ,impeller, Raw water pump etc since the engine is out and the boat sat for two years. I am looking for the oil pump replacement, is this a different oil pump then what a standard auto GM 5.7 uses or is it the same? Is there a better one to use? Thanks in advance.

 

[Scott Danforth]

if your oil pump is bad, your motor needs a full rebuild. generally the oil pump is never a problem.

same goes for the circulating pump. the raw water pump is in the outdrive if its a mercruiser or OMC, and bolted to the motor if its a volvo.

however its your money, get a melling from your local machine shop. the boat motors use truck blocks and the heavier truck oil pump.

 

[alldodge]

It is the standard GM oil pump, and there are higher flow ones, but like Scott said, if it has low pressure there is usually something else wrong.

What are you finding which gives you this impression, and have you put a mechanical gauge on it to verify?

 

[ceasefire49Z]

As I said the engine is out of the boat and while it's out I am replacing items. Nothing wrong with it but it is 30 years old and who knows.

 

[Scott Danforth]

timing chain set would be a better spend of your money than an oil pump.

 

[Bondo]

Ayuh,..... Only time I've ever changed an oil pump, is when rebuildin' a motor,.....

 

[ceasefire49Z]

Good point on timing chain.

 

[Silvertip]

My two cents worth is as long as the engine is out, pull the oil pan and pull the main and rod caps to have a peak at the bearings. If they look good reassemble. If they look questionable, then now would be decision time. 1) have the crank refinished and install new bearings or 2) slip in a new set and call it good. Check the back side of the old bearings to make sure the crank had not been reworked at some earlier date and undersize bearings installed. The bearing will be marked with the size. You went through the trouble of replacing a transom and stringers, why not start knowing you have a good bottom end in the motor.