General Category > General Discussion
Worst Case Scenario - Chrome Cylinders?
Greg Field:
Yes, take it out of the frame and check the crank and clean out the sludge trap. You will be happy for many years that you did, even though it seems unnecessary at this time.
Break-in: Warm up the oil as gently as you can as you ride to the steepest, biggest hill available. At the base of the hill, shift up one gear to really load the rings, and roll on hard to seat the rings as quickly as possible. Then, coast down to the base again and repeat, repeatedly. Then, change out the oil.
LonerDave:
Finally picking up where I left off in May. Work on the bikes was suspended as we "enhanced" our garage from a 2-car to a 5-car. Two bays are set off from the others and now form a dedicated shop. Hog heaven.
Removed crank for inspection and cleaning of sludge trap.
Trap is a bit less than a third full. Good, I guess, for a 52k motor. There doesn't appear to be an insert to remove, so I assume I just get the sludge out of there?
I have no experience evaluating crankshafts so can't say much about the condition or usability. Bearing surfaces don't appear burned or gouged. They do appear to have what I'd call "scoring". Not deep, but visible. Surfaces on connecting rods and front and rear bearings is in same condition - scored, but not burnt or deeply scratched.
Rear (flywheel side) crank surface:
Front (timing side):
Crankpin:
Connecting rod big end:
Rear bearing:
I assume I'll need at least the crank polished, maybe ground. And that I'll need new bearings (main - front and rear), con rod shells. Don't know about small ends.
Figure I'll take the crank to the same shop that did the heads and ask them to measure and assess. May also spend $200 for a couple micrometers and a bore gauge (Fowler brand) to at least practice measuring myself.
Will be checking oil pump next.
Would love it if anyone with more crankshaft experience (just about everybody!) cares to weigh in on condition and next steps.
Dave
Don G:
I would suggest that you take your crank, main bearings and rods along with a list of the specs. to a competant engine rebuilding shop, or a decent machinist who knows how to measure something and have the components checked for dimension, possibly you may find that you are still in spec. and may get away with a polish and new rod bearings, check the wrist pin bushings for size and the wrist pins for wear, while your at it check the rocker pins too. Good Luck ;-T DonG
Chuck in Indiana:
^^^^^
Agreed. I've seen worse looking stuff, but you'll know nothing until it's accurately measured.
redrider90:
--- Quote from: Chuck in Indiana on December 13, 2013, 10:51:18 AM ---What the good father says. ;D I *have* heard of chrome bores holding up for a long time if used regularly. I've seen what happens when the chrome lets go. It's not pretty. Takes out the bearings, crank, rocker pins, oil pump... you get the picture. I'm a cheap barstid, too.. but I wouldn't take that roll of the dice. ;)
--- End quote ---
I assume only big block used chrome. What were the years and models that had chrome?
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