I have my engine out of the car on the stand putting fresh head gaskets in. Motor was ready to go back in until I pulled the oil pan today to check for gasket material. I took a flash light to check the timing chain and saw the tensioner broken off just laying in the cover area next to the chain. I thought I told the engine builder to leave out the tensioner since it had a double roller chain. I guess that didnot happen. Has anyone had this happen and were able to get the tensioner out without pulling the front cover. Looks like I could pull the front main cap and get some room to pull it out with the spring. anyone have such luck.
Timing chain tensioner broke in engine
- Thread starter Way2QWK
- Start date
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Well I guess I got lucky. I got the broken tensioner and spring out of the cover area without removing the cover. I took off the first main cap and was able to work it out. Now the bad part. The metal from the tensioner is now in the bearings. This motor only has 10k miles. Oil pressure was fine before the head gasket replacement. I cant decide if I should take it back apart and put fresh bearings in it or just put it back together until i have problem with oil pressure. If I do the bearings it will be without taking the top end of the motor apart.
Is it possible to just replace the bottom main bearings for now.
Is it possible to just replace the bottom main bearings for now.
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- Nov 24, 2001
- Messages
- 11,267
I would take the motor out and beat the engine builder with it and use the wrappers from the new rod and main bearings to help him heal is bleeding wounds :wink:
Good idea on replacing them, id also delete the oil cooler in the rad after looking at the bearings in the last post
BW
Good idea on replacing them, id also delete the oil cooler in the rad after looking at the bearings in the last post
BW
That sucks. I will help you out. Just give me the engine builders address.Oh wait I know where he is
This thread is from March
The crankshaft rides on a very thin oil wedge only about .00005? thick when the engine is running. With tolerances this tight, a properly polished crankshaft is a must. If there are any nodules or burrs poking through the surface of the journal it won't take much to wipe the oil film and cause a bearing failure.
Crankshaft grinding is considered by many to be an art form if you are polishing with a manual belt machine. But with today's OEM finishes being extremely smooth and flat, achieving this level is more and more important. There are some good machines available for polishing and micropolishing, no doubt, but they must be used properly.
Customarily with an aftermarket crankshaft, rebuilders mic the journals and go through a two- or three-step polishing process. If the crank proves salvageable and it doesn't have to be ground, some engine builders start with a #400 grit belt, moving to a finer cork belt or other fine grit micropolishing belt for final finish. Other experts say to start with a #320 belt, then go to the #400 before moving on to the finer belt for a few revolutions.
Micropolishing machines are the high tech way to achieve OEM-like surface finishes, but costs may put these machines out of reach of smaller shops. According to one manufacturer, micropolishing is the most advanced way to achieve OEM-level surface finishes on cranks today. He cautions rebuilders who believe that using a very fine belt won't remove material that this idea is a myth. With micropolishing it is possible to consistently remove the peaks and get down closer to the valleys in the surface creating a finer finish with higher load-carrying ability.
Crankshaft grinding is considered by many to be an art form if you are polishing with a manual belt machine. But with today's OEM finishes being extremely smooth and flat, achieving this level is more and more important. There are some good machines available for polishing and micropolishing, no doubt, but they must be used properly.
Customarily with an aftermarket crankshaft, rebuilders mic the journals and go through a two- or three-step polishing process. If the crank proves salvageable and it doesn't have to be ground, some engine builders start with a #400 grit belt, moving to a finer cork belt or other fine grit micropolishing belt for final finish. Other experts say to start with a #320 belt, then go to the #400 before moving on to the finer belt for a few revolutions.
Micropolishing machines are the high tech way to achieve OEM-like surface finishes, but costs may put these machines out of reach of smaller shops. According to one manufacturer, micropolishing is the most advanced way to achieve OEM-level surface finishes on cranks today. He cautions rebuilders who believe that using a very fine belt won't remove material that this idea is a myth. With micropolishing it is possible to consistently remove the peaks and get down closer to the valleys in the surface creating a finer finish with higher load-carrying ability.
