Re: Rod bearing failure whats wrong?
 

Heat,the back of the engine is the last to get water!Oil pan to small,the 7-8 is the closest to the oil pump so first to get oil,also first to starve of oil if all the oil is gone and is up top!Wrist pin clearence,marine engines need to be set up on the loose side because of the cold water going threw!What type of fuel pump? Go with the mechanical,if the voltage isnt right on an electric pump the engine can lean out and overheat the cyclinders,especialy on a single plain manifold,the back two cylinders are last to get fuel and water!Go with holleys at minimum if you can,carter style carbs floats can stick causing a lean condition!No more than 32 degree total advance!Cleandlyness is next to goodlyness,this is a must!

Re: Rod bearing failure whats wrong?
 

For me there is no such thing as "Stupid Suggestion" I'm very pleased for all the help I'm getting from you guys... I will definitely tjek that too. :)

Re: Rod bearing failure whats wrong?
 

I do have mechanical fuel pump. But maby I should go lower on thermostat im 188* freshwater cooling. Any suggest what water temp is best. I know the saltwater cooled is only 142* but thats more to sure the salt not to crystallize than its good for the engine or am I wrong?

Re: Rod bearing failure whats wrong?
 

Non efi engines should all use the 140 degree thermostat.

Re: Rod bearing failure whats wrong?
 

Rob;
I stand corrected. I should have said sometimes some of you guys! I know there are a lot of owners out there who do a great job at building strong motors, there just seem to be more guys like this poor fellow who get in deep!

Ray @ Raylar

Re: Rod bearing failure whats wrong?
 

You are right, I could just by 2 brand new engine and sleep all winter like the bears. But I like making my own engines and see the result in spring. I have build more than 10 engines over the time with no problem at all.This time I failed, and thats why I went here, to ask the real experts. I already got a lot of helpfully info from you guys that posted serious feedback. Thank You Guys....

Re: Rod bearing failure whats wrong?
 

What oil do you run in your motor?

140-160 seems to be a good water temp for most. I think the mercruiser high water temp alarm is set for 190 so you must be setting that off.

Re: Rod bearing failure whats wrong?
 

Castrol GTX 10W-40 synthetic based. The high water temp alarm was hit for very short time at WOT. But shut off again as soon I cruise 3000 RPM. The only reason I was using the 188* was for better fuel atomizing / idle. I will go back to 160* before I try again. But remember the other engine are doing fine and everything are equal but the oil cooler are bigger.
I'm thinking about finding another block? But if bigger oil-hose and bigger oil cooler are the case I should maby give it the last chance by rebuild it again. And high volume oil-pump.
Should I use another oil? :rolleyes:

Re: Rod bearing failure whats wrong?
 

Depends on your weather

I'd break it in easy with an SAE 30 for 5-10 hours then switch to a 20/50. I am a big fan of synthetic so I run the M-1 v-twin. Castrol 20/50 is a good oil also.

Re: Rod bearing failure whats wrong?
 

Yea, I never blow up the same thing twice, (knocking on wood)