jos51700
Green Bearing thread connoisseur
So over the last week, I went out to visit my dad. He's hardcore into the Chevy third-gen 6 cylinders of the '60s. I know, this is Mopar land but he's not online and I'm not about to sign up on a Chevy page just for this question.
His primary truck is a '66 4wd with a 292 that was rebuilt two years ago. I'm going to guess about 10k on the rebuild, 90% of that is highway miles at 55mph. It's got a Clifford intake, headers, and some kind of truck cam. Cranking compression is 185 across the board.
After going to Minnesota, this thing turned into an oil-burner. This was probably 5000 miles after the rebuild. It may have burned oil before that. No smoke, it's all going out the breather. So we did a leakdown test, and ALL the air is lost out the breather.
Cylinder 6 was the only normal cylinder at 5% leakdown.
Cylinder 2 and 4 were about 70-75%
Cylinders 1, 3, and 5, all started at 75%, but as the air increased (as I opened the regulator to push up to 100psi), they'd 'jump' to 25% and hold there.
When cross-examined about it, pops said simply, "I installed the rings with the dots up. Isn't that how they're supposed to be oriented?"
I don't do a lot of rebuilds and am wondering if maybe he got a set racing rings that only seat at WFO, if he's installed some upside down, or if they're breaking or something? Block was bored .060 over by a Longmont Colorado machinist. He's looking for the receipt, once the anger subsides.
What sayeth FABO?
His primary truck is a '66 4wd with a 292 that was rebuilt two years ago. I'm going to guess about 10k on the rebuild, 90% of that is highway miles at 55mph. It's got a Clifford intake, headers, and some kind of truck cam. Cranking compression is 185 across the board.
After going to Minnesota, this thing turned into an oil-burner. This was probably 5000 miles after the rebuild. It may have burned oil before that. No smoke, it's all going out the breather. So we did a leakdown test, and ALL the air is lost out the breather.
Cylinder 6 was the only normal cylinder at 5% leakdown.
Cylinder 2 and 4 were about 70-75%
Cylinders 1, 3, and 5, all started at 75%, but as the air increased (as I opened the regulator to push up to 100psi), they'd 'jump' to 25% and hold there.
When cross-examined about it, pops said simply, "I installed the rings with the dots up. Isn't that how they're supposed to be oriented?"
I don't do a lot of rebuilds and am wondering if maybe he got a set racing rings that only seat at WFO, if he's installed some upside down, or if they're breaking or something? Block was bored .060 over by a Longmont Colorado machinist. He's looking for the receipt, once the anger subsides.
What sayeth FABO?
