Fresh rebuild troubleshooting

[dsm-junkie]

Hey guys I got my motor installed last night and now I have a couple things that I cannot get straight! First I started my car and it drives! I do hear a small knock sound around 2000 RPMS. A buddy of mine said it could of been lifters??? I did have fresh new bearings on a stock crank and a fresh honed block with new rings and stock rods and pistons! I am using a 6 bolt shortblock with a 2g head! After driving for a bit in the city my idle will stick around 1400 RPMS then drop sometimes. I have DSMlink V3 and tried to hook it up but my computer cannot connect to the ECU. The light on the usb cable does not light up either. I am in the process of using reinstalling my oil pan because of a small leak! Should I continue with running the car??? Im really confused on where to go from here!

 

[black_eclipse96]

If i recall it was just the bottom bearing (rod cap) that was like that. Everythimg looked to be clean.

 

[turboglenn]

you may have deformed the rod caps by overtightening, i know torque on my eagles with arp bolts is only 40 lb/ft, i think stock is less. ACl tri metal are usually the tightest fit bearing there is when checking clearances with several sets, mine all came out to .0025, and according to my machnist .003 is loose for what these engines need to llive properly on the street with the way we treat them...what oil were you using? My machinist also won't cover anything on my engine unless i run 10-30, nothing thicker because he said it's too hard to get picked up and lubrcating the engine on cold starts and some other things... but i have to also ask did you prime the oiling system and use assembly lube when building it?

there's no other ways about it, if those bearings went bad that fast there's a really large issue lurking in there that just a bearing replacement isn't gonna solve..the shavings in the ics aqbove are WAY too big to be "normal" what people consider normal are light traces of sparkley specs in the first oil change or two, those look like something came apart that shouldn' have.

at this point there's probably metal in the cranks oiling holes that will come out and eat any new bearings put in from this point so i'd have the entire rotating assemble dropped out, flush the block, have machinist check crank, rods, and everything else, I am a machinist by trade now (hobby my whole life) but not an engine machnist as i don't have large enough machies or fine enough measuring tools, its a complete different world between machining or being a mechanic compared to being an engine builder...even when i assemble my own my machinist labels each rod, bearing and piston as to where they go and to what journal each bearing goes in as they are all precisely fit to each other, even the wrist pin to rod small ends are custm fit in a proper build... So although i build the assmebly, he has basically built it himself just not assembled it when i get it and go from there on my own..

there's no roon for error and no room to assume things will go right because it's an "OEM rebuild" i've been the victim and witness to others in these same situations too many times to chance it unless i'm just re-ringing and putting new bearings in an engine that had no problems to start with and i just wanted to freshen it up (and even then i check everything with my measuring tools and plasti-gauge) Also, i file fit EVERY ring in any engine, the tool isnt much money and you can even do it with a fine file in a vice,

best of luck and let us know how it goes

Glenn

 

[black_eclipse96]

I know this is way late, but I did find the problem. I installed the main bearing backwards.