Ok thanks to u guys i figured out that it was my number 3 cylinder rod bearing that was bad causeing a knocking noise. I bought a new bearing and stuff.

But question is do i gotta dissassemble the block and have it honed and all?? Thats what a local shop told me today!

I was just gonna drop the oil pan , windage tray , and oil pick up and do it from there.

Oh yeah can some one please tell me the Torque Specs for the rods (B18a)]

Again Thanks alot for your guys help , i really appreciate it

 

that's like saying you need new piston rings cause you're valve cover seal is bad. No, you don't need to hone the cylinders unless you're putting in new rings. You should be able to replace it fine from underneath the car. If there is damage to the crank journal, then you might need to get it grinded, but you'll find out when you get there

 

If your rod bearing was damaged enough to knock, chances are that the bearing journal on the crankshaft is damaged. Be prepared for some serious downtime if this is the case. A machine shop may be able to repair the crank for you, but the crank will have to be out of the block. You might as well do all of the rod and main bearings while you are at it. Thrust washers too. Good luck.

 

Make sure you measure all journals on that crank for out-of-round and taper before buying any bearings.

 

It sounds like you spun the rod bearing. Is the crank discolored and scratched there?

Regardless, I would at least drop the crank out and inspect it.

Sonny

 

you cant check bearing clearances with the engine in hte car... unless you tip the car onto its roof...

t..

 

Ok today i pulled out the rod bearings, and boom, both bearings were spun, no more tabs on both of them, i really dont have time to pull out the crank due to school and work. The Actual crank journal looks like it has some small Knicks in it and the rod has a lil scratch. How are the surfaces supposed to look???? like a mirror??

You guys think i can just replace the bearing and have it run nomal???
I also got some green plastigage stuff , dont know how to use it though

 

ummm........i'm afraid your gonna have to pull the engine out and have the crank machined and balanced........you CAN put a new bearing on that journal but i would say there is a 98% chance of that new bearing getting spun again.......

 

Also with the spun bearing, the rod will probably need to be reconditioned.

 

i reccomend a full disassembly. There is no telling what kinda crap your pumping though you engine now. Check the oil filter first and see if your pumping any little peices of metal through the engine. If so id also take head to a machine shop and have them clean it really good. also your probably gonna want to refinish the cylinder walls might just want to bore it. I suggest finding another b20 crank rather than it refinsihed. I forgot to look and see what part of the country you lived in but i'd say unless its cali there probably arent any good machine shops around that can do it perfectly again. Your engine would have blow if you drove it much longer or the rod would have got so hot it would have welded itself to the piston and your car would never start or you would have thrown a rd if this had happened while driving. so thats basicly what you a working with a engine that is about to blow. Might just want to get a new b20 and salvage the head

 

man, you in bad shape!

not much to say except www.helminc.com

and that you will have to take it to a shop at the very least for inspection and resurface and will need to have the bearing sized correctly for the newly resurfaced crank journal...

the problem with plastigauge is that it is generally used to measure oil clearance between surfaces which doesnt INCLUDE gravity.

if you are testing for cleanace, upside down, you have the crank pushing down on hte journal due to gravity and you will get a bad reading,

i dont know how erroneous this effect actually is (because i have never tried it) but i would assume it must affect it in some way...

t..

PS why DID your bearing go bad?

 

Gravity won't have much affect , if any, on measuring rod bearing clearances with plastiguage. The weight of the crank does not come in to play, nor the weight of the rod, since it is on the top side of the crank. You should be able to get a pretty accurate plastiguage reading on the bottom rod bearing with the engine in the vehicle. I am not even sure if gravity would have that much of an affect on plastiguage readings of the main bearings in the car. I might just check it out when I pull my motor the next time (in car versus on the stand).

 

that would be good, i have always wondered...

i have always thought that this would be the reason why you shouldnt do any bearing work with an engine in a car...

t..

 

The journals and bearings won't be mirror polished and pristine, but the wear should be even and fairly uniform across the entire journal and bearing.

I also recommend rebuilding it from top to bottom.

 

While you are deciding how deep to go into the beast, cut your oil filter can open and see how much (if any) metal flakes got circulated in the oil. That will be another piece of data to judge the risk by.

Tough call when you are on a tight schedule and budget. Some good high reliability advice above though.

Regards,
BigMoose

 

Please save yourself an extra overhaul and get it done right like b19coupe's quote: "Do it right the first time. It's cheaper in the long run. "

 

To tell u guys the truth , i have no idea how the bearings spun, my lsvtec was a complete rebuid by Fastrak Performance, but i guess they dick me and bent me over. I just bought another b18a shortblock and try to rebuild my other b18a the RIGHT way

 

oh yeah anothr factor my motor had 5700 miles on it clost to 6000

 

where you low on oil? low on coolint? car running really hot? reving really high? those would probably be the most likely reasons you would spin a bearing. Was the bottom end stock?