Merc 165 blowing oil

[jam39vw995]

Out the rear seal, I think,. over a litre and a half in 10 minutes came out.<br /><br />This weekend the engine will be pulled and I have a couple questions.<br /><br />Is the rear main oil seal the same as the car/truck engine GM 250? or does it have to be a marine oil seal?<br />Also, while the engine is out and apart would this be a good time to install new crank and rod bearings? If so, are the bearings the same as the GM 250 car engine?<br />thanks

 

[Butch Ammon]

Re: Merc 165 blowing oil

Jeff,<br /><br />With the Merc 165, only the block is the Chevy 250. Everything else (and I mean everything) has been pretty much converted to marine.<br /><br />If you need reference photos of a 165hp Mercruiser, check out the photos of my 165's engine. It still runs like a top after all these years. <br /><br /> http://members.aol.com/ammonc/165engine.jpg <br /><br /> http://members.aol.com/ammonc/165Engine1.jpg <br /><br /> http://members.aol.com/ammonc/165Engine2.jpg <br /><br />Butch A.

 

[jam39vw995]

Re: Merc 165 blowing oil

Thanks. That's what I thought.<br /><br />We do want this to last so we are buying the marine parts.<br />I figure if the pan is off and the main bearing caps loosened to change the rear seal, we might as well do the main bearings and rod bearings while it's apart.<br />To me this seems pretty straight forward and we have a shop manual.<br />If I need to be aware of any weird stuff can someone let me know?<br />thanks

 

[rodbolt]

Re: Merc 165 blowing oil

hello<br /> were it me I would plastigage the bearings rather than replace them. from the factory the bearings were a select fit, the may be .oo1,.oo2 or .oo3 under. cant buy them in that size. check them first. you may find the originals are ok.<br /> good luck and keep posting

 

[xltier]

Re: Merc 165 blowing oil

if ur old bearings are still silver colored and not worn down to the copper coat u can reuse with no problems.u cant make it any better than that.

 

[jam39vw995]

Re: Merc 165 blowing oil

All good advice. thanks!

 

[Rainmaker]

Re: Merc 165 blowing oil

Jam,<br />The seal and bearings are the same as a car engine, unless the engine is reverse-rotation.<br /><br />Plastigaging is a great idea. You can usually get bearings .001" oversize. Shoot for .0025" - .0035" clearance.