bottom end knock from built engine. please help.

[Logue]

Is powdercoat paint though, it can't come off can it?? and if powdercoat can't be there how do i get it off? I was checking for sand in the bottum of the cover that got left from sandblasting.

 

[half-cocked]

uhh my valve cover was just powdercoated flat textured black.... my built 6 bolt motor is fully assembled and ready for the first start tomm. What plate are you guys talking about? where exactly should i look? Cause i did notice some overspray on the buttom of my cover??

When you sand blast or glass bead blast the valve cover it is vitually impossible to get all of the blast media out of the baffles underneath the valve cover.

But this guys bearings seem like they are 'chunking' off. Are they coming out spun? As in are the tangs in the right place or are they just getting beat to shit and not spinning?

 

[AWD~SLEEPER]

yes it will come off. one of my buddys valve covers was painted on the inside, he used goof off. but if your not carefull it will get on the out side and mess up that paint.

 

[AWD~SLEEPER]

there not spunn but they are beat all to he**

 

[ArticNemesis]

there not spunn but they are beat all to he**

dirty oil. lack of oil. incorrect clearances. incorrect tolerances on the crankshaft / rods... It's one of those.. But we need to see what a bearing looks like... not just described as "beat to hell"

 

[AWD~SLEEPER]

ill do my best to get pics tomarrow. thanks for the help to all.

 

[redbrake]

Say did you check if the failed main bearing is receiving oil. Sometimes if the machine shop is nor careful junk falls into the oilways ang clogs it up. If your can spin the crank by hand with all the bearings installed then its not binding. But it doesnt mean the bearing is getting oil. Just my 2cents.

Red.

 

[Mirage2LTurbo]

Say did you check if the failed main bearing is receiving oil. Sometimes if the machine shop is nor careful junk falls into the oilways ang clogs it up. If your can spin the crank by hand with all the bearings installed then its not binding. But it doesnt mean the bearing is getting oil. Just my 2cents.

Red.

Any machine shop should have hot tanked the block. That would destroy any bearing material, rtv, etc that fell down in the passageways.

 

[Defiant]

Are you going without a harmonic balancer?

 

[half-cocked]

or did the front pully start to separate?

 

[AWD~SLEEPER]

its a 6 bolt. stock harmonic balancer like new.

 

[Logue]

alright i went out and bought a new/used valve cover from junkyard 15 bucks of a 91 gsx.

what the best way to clean it up? i have enginebrite, my airhose, bring to machine shop and have them hottank it, put it in the dishwasher or something.

 

[Mirage2LTurbo]

alright i went out and bought a new/used valve cover from junkyard 15 bucks of a 91 gsx.

what the best way to clean it up? i have enginebrite, my airhose, bring to machine shop and have them hottank it, put it in the dishwasher or something.

Have it hot tanked at the local machine shop. Tell them to bathe it well, mine took 5-6 washes to get clean because they are SOAKED in oil.

 

[ArticNemesis]

I still think you need to find evidence to the source of the problem other than guessing that it was left over residue from the valve cover. I'd hate to put an engine back together a 3rd time, and it do the same thing.

 

[half-cocked]

Paint in the oil doesnt cause chunks of bearings to come off.

 

[Mirage2LTurbo]

Paint in the oil doesnt cause chunks of bearings to come off.

Exactly, we should all add it during our regular oil changes.

 

[heavyD]

ok........

this is going to sound really stupied, but did you ever have your valve cover painted?

i had to replace my damn engine 3 times because of the bearings being torn up in the first 100 miles...... the machine shop always asked if it was ever around sand.......i thought it was sumthin me and my dad did wrong everytime, safe to say lots a fights because of that....anyway it ended up being that the powder coated valve cover was sand blasted and the plate was put back in the back and was never cleaned out....when we took out the plate, sand poured out and made a nice little pile.........needless to say we found the problem.

Happened to me too. Spun a rod bearing and wrecked my turbo seals.

 

[heavyD]

Back to the topic. If the main bearings wear out that fast it is usually due to having too much bearing clearance between the crank & bearing surfaces. I have seen guys get their crank machined 0.010 (for example) and the shop put in standard rather than oversize bearings and same thing would happen within a few thousand miles.

 

[half-cocked]

Exactly, we should all add it during our regular oil changes.

I do it every other fill up.

 

[92redman]

Back to the topic. If the main bearings wear out that fast it is usually due to having too much bearing clearance between the crank & bearing surfaces. I have seen guys get their crank machined 0.010 (for example) and the shop put in standard rather than oversize bearings and same thing would happen within a few thousand miles.

I think you mean undersized bearings, but that wouldn't cause only one bearing to get destroyed.

 

[heavyD]

I think you mean undersized bearings, but that wouldn't cause only one bearing to get destroyed.

No. I meant oversized bearings. I think you don't know what you are talking about.

 

[92redman]

No. I meant oversized bearings. I think you don't know what you are talking about.

"Standardized bearing undersizes vary from SAE, DIV, to ISO measurement systems. Always check the manufacturer or aftermarket supplier for exact undersize bearing information and specifications." Directly from Sunnen's Complete Cylinder Head and Engine Rebuilding Handbook. Copyright 1998 by John G. Edwards, San Buenaventura, CA.

I think I do know what I am talking about. In about six weeks I will have my Performance Machining graduation certificate, I know a thing or two.

 

[half-cocked]

"Standardized bearing undersizes vary from SAE, DIV, to ISO measurement systems. Always check the manufacturer or aftermarket supplier for exact undersize bearing information and specifications." Directly from Sunnen's Complete Cylinder Head and Engine Rebuilding Handbook. Copyright 1998 by John G. Edwards, San Buenaventura, CA.

I think I do know what I am talking about. In about six weeks I will have my Performance Machining graduation certificate, I know a thing or two.

Awesome book, I have read that cover to cover at least twice.

 

[92redman]

Awesome book, I have read that cover to cover at least twice.

Sunnen gave us a real good deal on them too. I got it brand spankin new for $15 US dollars.

 

[half-cocked]

Damn I paid $17 used, very used.