rebuilt 5.7 mercruser spun bearing

[NYTransplant]

Hi Im new here so Ill give as much info as I can I just had my 1986 mercruser 5.7 rebuilt it was boared 30 over reground crank new cam oil pump hoil pressure heads redone new pistions other words toatal rebuild I took the engine out of the boat and installed my self. I turned the engine over with out the coil wire on until oil pumped out of the heads installed coil wire and fired it up ran nice I ran it at my house for about 2 hours with a water hose hooked up temp stayed at 175 took boat to lake ran for about 2 hr and it devoped a knock down low. took moter back out turns out it spun the #1 bearing the shop is trying to say it had no oil for a short time and it overheated. I know it had oil and never got over 175 HELP any thoughts

 

[Coors]

Re: rebuilt 5.7 mercruser spun bearing

Were the rods re-sized? If not, that could be the problem;if yes-problem points to them. If not re-sized, they should have.

 

[NYTransplant]

Re: rebuilt 5.7 mercruser spun bearing

they say they did I asked if they plastic gaged them and they said that they mic everything and don't use plastic gauge

 

[NYTransplant]

Re: rebuilt 5.7 mercruser spun bearing

Question if #1 spun than # 5 should show signs of major wear no?

 

[mkast]

Re: rebuilt 5.7 mercruser spun bearing

Question if #1 spun than # 5 should show signs of major wear no?

Why?

 

[NYTransplant]

Re: rebuilt 5.7 mercruser spun bearing

they are suppled by the same oil passage no?

 

[rodbolt]

Re: rebuilt 5.7 mercruser spun bearing

1 and 2 rod journals share a common passage.
could have been a non correctly resized rod big end, improper bearing clearence, plasiguage beats micrometers and math any day, or it was most likly your improper oil pump priming method, you may wish to also check each cam lobe and lifter base for galling now due to lack of oil.
I have seen way to many cam failures due to excessive cranking at start up, if the engine rolls over more than 4 times before fire off something was not assembled correctly.

 

[NYTransplant]

Re: rebuilt 5.7 mercruser spun bearing

why do you say it was most likely your improper oil pump priming method I was told by the shop to crank it over until oil was pumping out heads to make sure oil was getting every ware.

 

[Don S]

Re: rebuilt 5.7 mercruser spun bearing

plasiguage beats micrometers and math any day,

I agree with that about %1000.
I plastigauge EVERY rod and main bearing. Then you can take the crankshaft back to the machinist and say the journal is too big, Long before a spun bearing.

 

[Don S]

Re: rebuilt 5.7 mercruser spun bearing

why do you say it was most likely your improper oil pump priming method I was told by the shop to crank it over until oil was pumping out heads to make sure oil was getting every ware.

An oil pump priming tool is the proper method of priming the oil system.
It fits in place of the distributor. Turns the oil pump and when the sysem is charged that way, you have oil pressure long before the engine turns over the first time with the starter.

 

[rodbolt]

Re: rebuilt 5.7 mercruser spun bearing

find another shop
I probably have over 50 service manuals on various V and inline configured marine and automotive engines.
not one says crank the engine until the oil system is primed, priming has to be done way before cranking.
various methods can be used but what your looking to do is spin the pump drive BEFORE ever cranking to insure the pump and oil passages are full with no air locks.
I watched a guy at Cleburne Ford tear the crank out of a 460.
they did an in frame bearing job with a new oil pump and did not so much as submerge the pump in oil much less spin it.
bearings failed within 10 miles.

 

[NYTransplant]

Re: rebuilt 5.7 mercruser spun bearing

Well its funny because the engine was done by 2 shops one did the machine work and the other did the assembly neither one had a problem with what I did I mean that is what I was told to do

 

[NYTransplant]

Re: rebuilt 5.7 mercruser spun bearing

not to get off on the wrong foot what you said does sound to be the best way of ensuring oil to every ware I think I just picked the wrong shop to do this work and now im married to them untill they fix it or i eat 1300 bucks and bring it to a different shop

 

[Don S]

Re: rebuilt 5.7 mercruser spun bearing

Well its funny because the engine was done by 2 shops one did the machine work and the other did the assembly neither one had a problem with what I did I mean that is what I was told to do

That doesn't make it right now, does it? Besides, it did spin the bearings. Something is wrong. And what "They" said is only the start of the chain of events that leads to your quesion in this forum.

 

[Silvertip]

Re: rebuilt 5.7 mercruser spun bearing

You must be a Ford guy. On a small block Chevy, cylinders 1, 3, 5, and 7 are on one side of the block -- 2, 4, 6, and 8 on the other. Therefore Cylinders 1 and 2 share the front journal and are oiled through separate passages.

 

[NYTransplant]

Re: rebuilt 5.7 mercruser spun bearing

bottom line is they are trying to place blame on me for something I did wrong and I don't think I did anything wrong I put the engine in the boat primed it how I was told and it failed in a matter of 4 hrs running time with that said do you feel that it was my fault? or was the shop to blame? If I ran the boat with no oil I would not post anywhere it would be my bad and I can accept that lord knows we all have made mistakes but iv never had a bearing spin in that short time frame on a total rebuild I can assume the shop primed the oil pump befor it left
there shop

 

[Coors]

Re: rebuilt 5.7 mercruser spun bearing

It boils down to: they didn't pre-lube it, and he did what they told him to do.
the shop is at fault.

 

[Don S]

Re: rebuilt 5.7 mercruser spun bearing

And now for the real fun.
Somebody prove any of it to me. I hear one side of the story and haven't seen the engine or any of the parts or have I heard anything from the ones that either machined or put together the engine. Nor did I see how clean anything was when the engine was put back together.

Basically without the facts from all sides, there is absolutely no way in the world anyone can determine the blame for your engine problems.

 

[Coors]

Re: rebuilt 5.7 mercruser spun bearing

Right, it can't be proven. If I build an engine, that I won't be around when it is started: all bearings, etc coated with a mix of oil, stp and camlube, and prelubed.

 

[Uraijit]

Re: rebuilt 5.7 mercruser spun bearing

Most reputable shops will start the rebuilt engine on the stand. They check oil pressure, etc. While they're at it, they'll usually go ahead and break in the cam as well. This way there's no question when that engine goes in, that it's in running condition. If something gets messed up at that point, it's a pretty safe bet who's fault it is...