ok i had a stock rebuilt motor with stock pump new rings and bearings stuck a 306 cam in it and shifter at 6800 for prolly 15k miles over 2 years and changed the oil every 1000 miles or so very frequent

now im considering doing it again with another new motor and im wondering if i just had luck with my last motor or no? should i do it again? this will be a daily driver so it sees about 2 times the amount of miles but 1/8 the racing

also this one ended up with a high volume oil pump(not by choice i went through some1 to dealwith the machine shop and he asked for that i was told after i putting it in the car) i can change this if needed id like to see yalls reccomendations the stock volume in my old motor sucked the pan dry with 5 quarts i ran 6.5 in a stock pan to get it to stop...this one doesnt suck it dry at 6k rpm with 6.5 quarts im just not sure about the 688-6900 i might be turning with it soon

also what causes bearing failure was my real question/wear/heat/crank or rods not staying stabile

 

With 6.5 quarts in a stock pan I would worry about windage causing oiling problems, if the oil get foamed it wont lube right.

Honestly I would use a stock pump with a high pressure spring if using a stock oilpan, make sure the windage tray is in there too.

 

Stock pump should be fine.

Oil starvation, crank flex caused by detonation, walking, etc., are the most common I think.

 

is that the only 3 reasons? anyone got any more info?

 

In my experience, by far the most common cause of lower-end bearing failure is a lack of lubrication. There are several possible circumstances that can contribute to oiling issues but when the oil is cut off, the outcomes are very predictable.

 

Unless there is a gross defect in the materials, machining, or assembly of the bottom end ALL premature bearing failures are ultimately an "oiling failure". They occur due to metal to metal contact. IOW, a lack of oil at the interface between the bearing and the rotating part. This can be from the oiling system per se not delivering enough oil (level too low, pump failure, etc.). A lack of clearance within which the oil film forms, deflection of the crank, coolant getting into the oil from a blown/leaking head gasket, etc.

BTW: there is no reason whatsoever to change your oil every 1000 miles. None, zero, zip, zilch, nada.

Rich

 

You know detonation can be like taking a hammer to the pistons and can damage bearings. Can you post pics of the bearings?

 

Just to elaborate on my theme. Detonation kills bearings by causing crank deflection, which disrupts the oil film - the final common pathway for bearing failure.

Rich

 

Yeah I understand it is a matter of disrupting the oil film.

Just saying that insufficient lubrication is the killer of bearing is sort of like saying lack of oxygen to the brain is the only cause of death. Technically true but there are a lot of ways to arrive at that same common problem.

When I read about engine failures I see A LOT of them that can be potentially blamed on detonation.