Richard Grindland
New member
At what temperature should pop up be tested? Does the rod grow when it hotter than cool? What about the oil film between the rod and crank bearing?
At what temperature should pop up be tested? Does the rod grow when it hotter than cool? What about the oil film between the rod and crank bearing?
I would disagree first very little of the rod is in oil, the length of the rod will grow from ambient temps to operating temps, though the amount of growth will be marginal. If you got an engine which was at the max of the pop up spec, and you got it dismantled and measured when at full temp there would be a measurable difference. That difference would likely quickly change as you check your work and verify the measure. I feel when we get this close the inspector had better start remeasuring and verifying, the benefit of doubt should always go to the competitor.The rod is not growing at temp, it's in an oil bath and just doesn't get that hot. The head grows because it is operating at significantly more heat.
As for oil film between rod and crank, this is why when I am teching pop-up, I roll the piston up and past TDC than rotate through one cycle and take the "official measurement" the next time it comes to TDC. While it currently doesn't call out this procedure in the official rule set, I think it addresses this possible issue.
At what temperature should pop up be tested? Does the rod grow when it hotter than cool? What about the oil film between the rod and crank bearing?
Going back three years ; to start an argument is counter productive .there are no "serious racers" in lo206 racing is ridiculous
Neither bar that I got with my tech kits are perfect...I've been pushing to make the POP UP rule more descriptive. The professional tech person probably doesn't need it but the more help the mom and pop tracks have the better.
I would like to see something in there about the type of bar you use to lay across the piston.
I would like it to define the length, width and height of the bar as well as surface finish.
I also would like it to say that if it fails you should turn the bar upside down and re test.
No hot or cold rolled steel etc.