Quote:
|
Originally Posted by jasonlee
Hello,
Could anybody let me know if a rod bearing goes, and the crank gets a bit scratched up. but not too deep.... could it just be smoothed out and replace the bearings, or will machining be necessary? some of the bearing was still there but not alot.
thanks...
j
|
You must measure the crank, buy a vernier caliper from Harbor Freight, $16
http://www.harborfreight.com/cpi/cta...emnumber=47257
Take several measurments, then check another journal. You can buy some "PLASTIGAUGE" and check all the bearings. Take the best bearing set and move to the bad bearing journal, check again.
http://www.plastigauge.co.uk/
Some bearing makers make a .002" undersize bearings, these are their standard for "first overhaul" where the crank is in good condition but just worn through normal wear when doing a rubuild. Until you have measured you don't want to pull the crank when you don't need to. Is the engine out of the car?
A trick I've used when things get .001"-003" out of spec, is to tape a sheet of 1500 grit wet or dry sandpaper to a piece of plate glass, _not_ window glass, "plate glass". You then put the rod cap on the paper and then sand to take the machining marks out of the mating face. Don't go in circles but back and forth and a little side to side. If you take .001" off this will calculate to about .0025" which should bring you back into spec and not have to grind the crank.
Plate Glass is very accurate in 3/8"-1/2" thickness and can be used as a surface plate within reason, you don't need a very big piece for this application. If you want to check a head for warpage then you should go with the 1/2".
Keep us posted, ask questions.
Cheers,
GTM