Last summer i did a cheap rebuild on a 350. not much performance holley intake, edelbrock carb, and summit low end cam. my question is my bearings went bad right away, my rod bearings where kinda black and had little chunks out of them and the main bearings had a record disc feel and look to it. Is this an oil pump issue? because i never replaced my oil pump with a new one. and could this happen from not using assembly lube?
03-25-2011 12:49 PM
Black w/chunks missing could have been caused by a lack of lubrication that caused the bearing surface to overheat and begin to weld itself to the crank journal. The lack of assembly lube might have played a part in this, as could a lack of pre lubing the engine by spinning the oil pump w/a drill prior to first start up.
The "record disc" feeling is likely caused by grit or metal shavings and particulates left from machining or insufficient cleaning.
03-25-2011 12:50 PM
You mean you didn`t lube the bearings upon assembly? What did you expect them to do without lube? The oil from the pump has to travel a good ways before it gets to all points in the engine, especially the crank, by the time it got there you had already cooked it. The clearance between the bearing and the crank is very very close, the crank NEVER touches the bearings because they are riding on oil, oil is a liquid and it, like all liquids cannot be compressed. I see your only 16 but please by all means LEARN before you try anything like this again.
03-25-2011 09:35 PM
Yes i do have alot to learn from every mistake is something you learn and i definetly learned from this. :spank: the reason for rebuilding was because a bearing went out and i cleaned it myself so this time im gona have a machine shop clean it. should you always prime the pump even with assembly lube?
03-26-2011 12:54 AM
Originally Posted by Linez35
should you always prime the pump even with assembly lube?
Sure. It gives the engine just that much better of a chance to start up w/o being starved for lubrication for even a couple seconds.
You want to rotate the engine about 1/4 turn at a time as you prime the pump so all the lifters get oiled. You'll know the lifters are oiled when oil comes out the tops of the pushrods at the rocker arms.
When you use a tool to prime the pump, be sure it has the section that connects the two sides of the lifter galleries (that's the blue piece at the right side, in the photo below). Some auto parts stores will loan this tool after you leave them a deposit. Using an old distributor w/the teeth ground off the distributor gear also works fine for this (shown in the thumbnail below). http://static.summitracing.com/globa...sum-901010.jpg
03-26-2011 02:38 AM
Hey man, don't beat yourself up. I built an engine two years ago and have beat it to heck. We had a hard winter, I did a cam and carb swap and got it hot quick a few times. I now have a knock, and know it's time I flip the motor over and see what the bearings look like. I hope that I can put some emery cloth to the crank, change the bearings and be good to go. When I built the engine, I took my time and made sure to take every precaution. I raced it a few times, and ran it very hard. You will learn everyday, but if you quit on the hobby it will never grow. Take it in stride and try again, don't let these old timers get to you, they have made plenty of mistakes of their own and wouldn't be the mechanics they are without them. I've been building helicopters for five solid years and learn every single day. I encourage you to build it again, but do it better.
03-26-2011 10:38 AM
Hi,i keep hearing about assembly lube,ive built probably 100 to 150 engines,the ONLY thing i have used for lube is STP,i put it on with a 1 inch paint brush,bearings,cam,lifters,and rocker arms.never had a problem.......... :)
03-26-2011 11:29 AM
I`ve used all kinds of stuff for lube, this, came from the very same reason for me picking up wrenches as well as for many others. When your poor you use what works and when your poor you can`t afford to let someone else do it so you have to do it yourself. To this day, I don`t like to use that stuff many call "Cherry lube" it`s too thin and it runs off far too easy. I perfer to use moly lube, but I will use white lube, which I`ve heard about a 100 guys tell me not to and I haven`t had a failure yet. I started turning wrenches when I was six as I was forced to do so by my father. Over the years my older brother who was 10 years older than me and very much a natural at it, taught me from there. I did my first complete rebuild at 12 which was a 140 cubic inch Ford 4 cylinder out of a 1979 Mustang. The biggest goof that I can say I am guilty of was not cleaning the bore of the block enough to get all the hone grit out. And to this day, I`ve seen many do rebuilds, and I look at the bore and can tell it`s not clean, I tell them and they blow it off, telling me it won`t hurt nothing. So I just say okay, have it your way and move on.
That`s why I urge so many newbies on here that are doing a build to clean it, clean it and clean it some more as it`s so easy to be overlooked.
03-26-2011 09:52 PM
Originally Posted by boatbob2
Hi,i keep hearing about assembly lube,ive built probably 100 to 150 engines,the ONLY thing i have used for lube is STP...
While I wouldn't use straight STP, in this case STP IS "assembly lube". It doesn't have to be something marketed as such- it can be 'whatever', as long as it has enough viscosity to stay put for however long the engine will remain stored before it's started. I got a 12-pack of assembly lube from Cleveite a long time ago, I still use it on crank and cam bearings/journals.
I have zero problem using Lubriplate as an assembly lube. I DO have a problem w/using Lubriplate on cam lobes and lifter bottoms to break in a performance cam and lifters. And I wouldn't use moly lube (the thick, black lube often used to break in cams) on crank or cam bearings and journals. But that's me.
03-26-2011 10:10 PM
using straight motor oil is a practice used by vehicle manufacturers for many years.
the big difference is the cleanliness of the internals and the working area even dust and lint are the enemy.
stp is ok but it attracts dirt like crazy you would need to be a brain surgeon to use it effectively and not make a huge mess.
but if you pre oil, pressure test and rotate every engine like you should before lighting it up all those fancy lubes end up in the oilpan before she fires for the first time anyway.
03-27-2011 12:41 AM
Thanks guys for all the helpfull tips i will consider all of them and i will not quit this hobby i love working on engines im one of those people if its not good the first time ill make it better so ill get this motor done as soon as i can thanks again for all the help :D