Rebuilding engine, ran into a problem.

[defrag010]

hey guys im rebuilding my engine right now from my 90 tsi. i have all new stock equipment and im doing a stock rebuild. i got the crank in and my problem is with the connecting rods. the chiltons book i have says 14 ftlbs plus 1/4 turn. whenever i torque the rod caps to that spec i can not even rotate the crank. i plastigauged everything and its perfect. i had the crank polished and am using standard bearings. im stumped because ive built motors before and they all rotate easily when everything is torqued down. could i have the wrong rod bearings? could the tq from the chiltons be wrong?

 

[RoasT BeeF]

This sounds more like a piston/cylinder bore problem than a bearing one. Do the pistons fit in the cylinders pretty tight? Make sure you are using a good assembly lube as well.

 

[defrag010]

im using redline assembly lube and plenty of it. the pistons are stock bore and all the block got was a standard hone. everything spins fine with about 20 ftlbs on it all but whenever i torque everything to spec it locks up. i used my torque wrench on the crank sprocket and it was holding 75 ftlbs before i gave up and decided not to mess something up.

 

[MrDee]

It is the connecting rod caps...loosen all of them and start working from 1 end.Remove cap from cylinder 1 and rotate/spin it then tighten is..try turning crank and see if it moves..it should solve your problem.

When i did mine..i labelled them very clear and took them to the local shop..and told the man how i want the rods faced with the pistons..but i guess he was listernin with his buttt.He connected them so that either i have my pistns facin backwards or the caps..so dicided to let te caps face back.It worked good.

 

[defrag010]

thanks. ill try that and let you guys know!
i noticed that when i took the rodcaps off that the bearing tangs are on the same side unlike the mainbearings.

 

[RoasT BeeF]

Hm. Maybe they gave you the wrong size bearings.

 

[pinknuggit]

Take your rod caps off and check the bearing tangs. The rod cap should bolt onto the rod with the tangs on each side being on the same side of the rod. If the tangs are on the opposite side of each other, then they're on backwards.
You can also take a rodcap off, rotate the crank so that the selected piston is at the bottom of the stroke, tap the piston up in the bore so you have room, and take off the rod side of the rod bearing. There is a bi-circular pattern that extends around the entirety of the bearing surface that can only be "matched up" one way. Make sure yours are lined up.

I've built a motor before where I wasn't paying attention. I had 2G pistons that were on the rods backwards. I installed the rods backwards but I forgot to put the caps on backwards. It didn't cause it to lock up, but I could hear the cap rubbing the crank when it would turn.

 

[Lancer14]

Hm. Maybe they gave you the wrong size bearings.

That's what I was thinking.
When I rebuilt my motor the shop gave me the wrong size rod bearings. It didn't take very long to realize that, so I'm guessing that's probably not your problem.

Chris

 

[MrDee]

it is not a wrong size..these things are made for prescision fitting. put themon wrong and they lock..put them on right they fit perfect and you get no slack and just the intended oil clearance...follow the lines i gave you and tell us how it went...i actually experinced the exact thing when rebuilding mine.