Failed piston ring?
- Thread starter Kooldino
- Start date
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- Hemi Ram, 71 Plymth Scamp, 71 Plymth Duster 340, 69 Dart 340/4sp
how much do you want for your old, damaged pistons?
Sorry I guess I should look before I post. How do the other bearings look? This one does not look to be wiped from an oil problem. It looks like damage from dirt. I am not talking about oil in your oilpan or by not doing an oil change or two. I mean from when it went together. How is the crankpin surface?Kooldino said:
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- Hemi Ram, 71 Plymth Scamp, 71 Plymth Duster 340, 69 Dart 340/4sp
no thats not from crank walking... defintely some type of foreign material got in there.
I dry first start would cause a bearing to wipe. These have grooves in them. That can only be done by dirt or by nicking the crankshaft. Since our engines do not have rod bolts pressed into the rod them it would be hard to nick the crankshaft when it went together.igdrasil said:
What did the main bearings look like? Are they fine?
no... I was making a related but not direct comment. I'm assuming Dana used stock bearings... I'm just surprised to see the stock rod bearings were apparently both grooved... but the fact that I have a set of Toga High Performance bearings on my desk next to me and the rod bearings are NOT grooved at all..
Dana, putting in stock bearings without them being sized or clearance checked can result in major issues.... Pro5 ran into that this week and his bearings are fried as well after only a few thousand miles. It's really important that you run a good bearing clearance. I'm aiming for about 2.1 to 2.2 thousandths of clerance. I believe stock is just shy of 3 thousandths. (on the mains) If you run a bad clearance you can get oil starvation, low oil pressures, large particles can make it in if the oil isn't filtered well enough and other problems that can add up to be a major problem. I don't know the stock rod clearance but from what I've been told it's pretty close to that of the mains. Make sure if you have your crank reground and so forth that the clearances are checked with a dial bore gauge and if necessary that all the caps (both mains and rod) are hand lapped to the right clearance.
Dana, putting in stock bearings without them being sized or clearance checked can result in major issues.... Pro5 ran into that this week and his bearings are fried as well after only a few thousand miles. It's really important that you run a good bearing clearance. I'm aiming for about 2.1 to 2.2 thousandths of clerance. I believe stock is just shy of 3 thousandths. (on the mains) If you run a bad clearance you can get oil starvation, low oil pressures, large particles can make it in if the oil isn't filtered well enough and other problems that can add up to be a major problem. I don't know the stock rod clearance but from what I've been told it's pretty close to that of the mains. Make sure if you have your crank reground and so forth that the clearances are checked with a dial bore gauge and if necessary that all the caps (both mains and rod) are hand lapped to the right clearance.
