View Full Version : ka24de rod bearing problem. need advice
puerkone
03-20-2011, 10:02 PM
So I looked on the 240sx fsm and could not find an answer to how to fix this problem. I bought an engine from a guy and looks like he did not told me that his engine was knocking. I dissasseambled the engine and found 1 destroyed rod bearing. Now to fix it, do I just buy a new set of rod bearings and it will be good to drive? or should I also replace the entire crankshaft. let me know what you think, thanks.
By the way on the left, the journal feels smooth compared to the journal on the right that has a good rod bearing.
http://i71.photobucket.com/albums/i135/puerkone/Mobile%20Uploads/0320011440.jpg
http://i71.photobucket.com/albums/i135/puerkone/Mobile%20Uploads/0320011439.jpg
http://i71.photobucket.com/albums/i135/puerkone/Mobile%20Uploads/0319012023.jpg
ZenKi_373
03-20-2011, 10:58 PM
take it to your machinist to inspect to see if it needs to be cut. then buy the appropriate sized bearings. if its not harmed at least get the crank rotated/polished :D
Schassis707
03-20-2011, 11:01 PM
Yes like what he said, take it to the machine shop have them rotate it and balance it now, or you will be doing it again later on down the road.
puerkone
03-21-2011, 02:29 AM
sounds good. The goal with this engine is to make it my pass smog engine. I have to pass smog this oncoming november and I wanted to know if I also have to replace the entire connecting rod and cap that was used on destroyed rod bearing. The rod cap still looks and feels good in the wall. Also, since I am completely rebuilding it, I am thinking to make it completely stock internals. I pulled the head off and the cylinder walls still feel pretty smooth. Should I buy new connecting rods, pistons, rings and rod caps brand new? or can i just buy the piston rings and rod bearings and reuse my stock pistons and rods? the valves look good as well as the piston surfaces. let me know thanks. oh and I will remove the crankshaft and get it measured and fixed. thanks for the replies everyone =D
Hashiriya415
03-21-2011, 03:04 AM
A real good suggestion is don't do it yourself please don't. Seriously, you seem to be clueless of engines. People that build engine like you for first time usually have 90% failure rate. Just from seeing other people in class do rebuilds, even with all the books and homework, it seriously takes a lot more then what you think. Just listening to you I could tell this engine might go to crap. "the rod cap feels good" (you measure and resurface if needed) "cylinder walls feel pretty smooth" (again measure and determine necessary work).
There are things you will not find in FSM and are really important.
Do you know why it spun the bearing. If you don't you might spend $1000 building up and same thing might happen. Some stuff you should leave to professional.
And people that are giving advice, seriously think about the situation. You are telling him get the crank resurfaced and some new bearings and put it back together. I see a 10% chance this engine will make it past 1000 miles. It's not just about a damn crank and bearings. Could the whole block gotten distorted and might need a line hone? How will he find out if he never checks?
puerkone
03-21-2011, 03:39 PM
you are right man. The best way is to start measuring everything like the cylinder walls and journals. I repaired major parts in a KA24de before. I replaced the piston rings and head gasket as well with the rod bearings and that engine ran great. Those things were an easy fix because that engine never had a rod knock. Now with this engine, i bought it with a rod knock and now I am stuck in rebuilding everything on this engine. I tried to check for broken parts but it was all asseambled. the weird thing is that the compression is 180 in all of the cylinders even with a bad rod bearing. but well I talked to some proffessionals and they said that I need to get that crank regrounded or replaced. Also since the engine is going to be torn apart, might as well install new oversized piston rings and rebore the cylinders. I appreciate everyones replies. looks like I will end up spending about 800 bux to fix this engine.
A real good suggestion is don't do it yourself please don't. Seriously, you seem to be clueless of engines. People that build engine like you for first time usually have 90% failure rate. Just from seeing other people in class do rebuilds, even with all the books and homework, it seriously takes a lot more then what you think. Just listening to you I could tell this engine might go to crap. "the rod cap feels good" (you measure and resurface if needed) "cylinder walls feel pretty smooth" (again measure and determine necessary work).
There are things you will not find in FSM and are really important.
Do you know why it spun the bearing. If you don't you might spend $1000 building up and same thing might happen. Some stuff you should leave to professional.
And people that are giving advice, seriously think about the situation. You are telling him get the crank resurfaced and some new bearings and put it back together. I see a 10% chance this engine will make it past 1000 miles. It's not just about a damn crank and bearings. Could the whole block gotten distorted and might need a line hone? How will he find out if he never checks?
MONEY! This guys knows whats up!
PM me for help broseff
http://i613.photobucket.com/albums/tt212/ilov3apples/SR20%20Build/IMG_0232.jpg
http://i613.photobucket.com/albums/tt212/ilov3apples/SR20%20Build/IMG_0226.jpg
http://i613.photobucket.com/albums/tt212/ilov3apples/SR20%20Build/IMG_0247.jpg
http://i613.photobucket.com/albums/tt212/ilov3apples/SR20%20Build/IMG_0261.jpg
MEASURE! do it right or dont it at all bro
http://i613.photobucket.com/albums/tt212/ilov3apples/SR20%20Build/IMG_0313.jpg
-Andrew
9k Racing
puerkone
03-22-2011, 05:33 PM
sweet this is what I been looking for. thanks for the pix. I just finished taking my engine apart and now I am sending the block to get resurfaced, bored, and cleaned or honed. I am buying a remanufactured crankshaft and it is coming with oversized main and rod bearings. Also, I am going to buy new stock connecting rods and pistons with rings. seems like this engine rebuild is coming along. I will post pictures too so you can see the progress. =D
vBulletin® v3.8.11, Copyright ©2000-2021, vBulletin Solutions Inc.