I put the VW engine case together today (temporarily). I lubed & sealed it up, torqued the case, checked for free rotation just like it said in the book. After everything was torqued and done I noticed the crank had a tight spot in it, and I heard a metal squeaking noise while turning it over. Completely and utterly disgusted I took the case back apart and found the center main bearings had pretty substantial rub/wear marks on them while all other bearings were perfectly fine.
The bearings I'm using are Silverline brand made in Mexico, standard case, .020 under crank.
This is the 2nd set of new main bearings I purchased for this project. I replaced the 1st set because the cam gear puller galled up the front thrust bearing when I pulled the cam gears off. The center mains on the 1st set were also kinda buggered up right out of the box. I polished them up, they fit fine, but I figured I'd just use everything from the new set. The center mains on the 2nd set never seemed to fit or seat properly though. I pulled the dowel pins & polished the journals and they seemed to fit fine afterwards.
When I pulled the case back apart I compared each set of center mains. I zip tied the shells together tight to get a rough measurement from each set. The crank is ground to 2.144. The 1st set of bearings measures 2.147 center to center, about .003 over the crank which is fine and should crush to 2.146 -2.1465 when installed. The 2nd set measures 2.145-2.147 center to center (they're ovaled out), .0005-.001 which leaves almost no room for a crush fit and explains the rubbing/wear marks issue. I'm considering using the center mains from the 1st bearing set. I used some oil soaked scotchbrite and 400 grit paper to smooth them and ended up taking off a fair amount of plating in the process. I've done this in the past on other engine builds with no ill effects, but the plating on these particular bearings appears to be very thin. See photos:
Without flash..
With flash..
The case halves are in good shape with no big lips of ridges in the journals..
Studded side..
Non studded side..
So my question is, WTF is going on here!?!?!?!
I've read the crank might be bent, twisted.
I've read the journals may need line bored.
I've also read people have been getting shitty bearings and are having the same issues I'm having.
Have you ever had this problem Chris?
What would you do???
The bearings I'm using are Silverline brand made in Mexico, standard case, .020 under crank.
This is the 2nd set of new main bearings I purchased for this project. I replaced the 1st set because the cam gear puller galled up the front thrust bearing when I pulled the cam gears off. The center mains on the 1st set were also kinda buggered up right out of the box. I polished them up, they fit fine, but I figured I'd just use everything from the new set. The center mains on the 2nd set never seemed to fit or seat properly though. I pulled the dowel pins & polished the journals and they seemed to fit fine afterwards.
When I pulled the case back apart I compared each set of center mains. I zip tied the shells together tight to get a rough measurement from each set. The crank is ground to 2.144. The 1st set of bearings measures 2.147 center to center, about .003 over the crank which is fine and should crush to 2.146 -2.1465 when installed. The 2nd set measures 2.145-2.147 center to center (they're ovaled out), .0005-.001 which leaves almost no room for a crush fit and explains the rubbing/wear marks issue. I'm considering using the center mains from the 1st bearing set. I used some oil soaked scotchbrite and 400 grit paper to smooth them and ended up taking off a fair amount of plating in the process. I've done this in the past on other engine builds with no ill effects, but the plating on these particular bearings appears to be very thin. See photos:
Without flash..
With flash..
The case halves are in good shape with no big lips of ridges in the journals..
Studded side..
Non studded side..
So my question is, WTF is going on here!?!?!?!
I've read the crank might be bent, twisted.
I've read the journals may need line bored.
I've also read people have been getting shitty bearings and are having the same issues I'm having.
Have you ever had this problem Chris?
What would you do???
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