I have overcome one problem with the oil jets, but now have another major problem. I put the new main bearing shells in plonked in the crankshaft turned nice and free. Then fitted the cradle torqued them up in 3 stages to 74 Nm and now the crank will not turn freely.It binds firm and the crank will not spin. I released all the bolts and checked if it turned ok which it did. Re torqued the main bolts up again and she is not turning freely again. There is no flywheel attached at this stage. When I rebuilt the last engine it turned over freely and although it did take a bit of effort there were no tight spots. I put another crankshaft in to check if it did the same and it also binds. Is this another buggered motor that needs the main bearing bores re aligned? Or could I have 2 bent cranks on my hands? There was some copper showing through on one of the old main shells (N02) that indicated a wear point but nothing unexpected from a used motor. All measurements are within tolerances. I am getting a bit frustrated here, surely there is an answer to this?. "O knowledgeable ones your input is really needed here"
sounds like your rear thrust bearing is too tight. pull crank and look at thrust face of the rear thrust bearing. You may have contact there between the face of the last main journal fillet area and the bearing itself. Easy fix if that is where you are binding up. you also need to ensure you DO NOT tq down the main bolts before checking end play on the crankshaft. This is very vital. if you have contact on the thrust face of the rear bearing get yourself some high grit sand paper 1000-1500 and put a little oil on the sand paper. Then take the bearing and work the thrust face on the oil in a figure 8 motion. this will evenly reduce the thickness of the trust face giving you the clearance you need. you may have to install and uninstall a few times to check the clearance but in most cases, this is where the binding is occuring. Good luck
Please dont use sand paper, Wet & dry is the way to go. Also what bearings are you fitting? standard and what brand? I have a new set of standard main bearings here if you want to try them. No way have you got two bad cranks. You are using the same main bearing cradle arent you, these cradles are matched the the block!! Cheers Martin
Good stuff guys. I was a little suspect with the end float so after the replies I checked the clearance and it has no clearance to speak of, so that is where the problem is. Martin I think our American friend is talking about wet & dry and it may just be lost in the translation. You know Yank to OZ. I have torqued the bridle down several times so what damage could be done to the thrust face bearing?
You should be able to see any damage and where it is binding. These will be the high points, but I have never had this problem and dont like rubbing down bearings. What brand are OEM, ACL?
Removed the bearings this morning and no real high spots so I just linished the thrust faces clean. When I mount the rear main bearings directly to the crank journal there is plenty of end float. Bearings are aftermarket, Ex Bursons. I will see how it goes this morning.
Tech@EPR has the answer. I lightly linished, several times, the thrust faces and made sure that the bridle was fitted correctly and now the crank spins freely. Now I can get onto finishing the block assembly and then just the heads to be offered up and then the bling and then heaps of other stuff before I get to putting the engine back in. I believe this is called one step forward.
that is the racing industry standard in gaining clearance. The face of the thrust bearing is designed to be that way. Sand paper...whatever you want to call it..it must be a fine abrasive cloth/paper with oil on it so you can lightly thin the material in that area. Its not uncommon at all to do this procedure to gain clearance and shouldn't be shunned upon. Good luck
Totally agree with this. This was often necessary "back in the Day". We're talking fine Wet'n'Dry etc, not an Angle Grinder.:rofl:
Agree totally. I should have done this and remembered this technique in the first place. "As I age I feel I have more gray hair than gray matter" But who cares at least I am still playing with cars!
