Manufacturing Defects - not all parts are equal

AI Thread Summary
Checking all parts before assembly is crucial for racers to avoid issues stemming from manufacturing defects. A case involving a round track driver revealed that a starter failed to turn the engine due to a flex plate with a significant undercut on one half, a manufacturing error that went unnoticed until compared with other plates. The problem was initially misattributed to potential warping from improper storage. This highlights the importance of thorough inspections, as defects can lead to performance failures. Always verify the quality of components to prevent similar issues in racing.
Ranger Mike
Science Advisor
Messages
2,443
Reaction score
427
One of the things all the pros do is to check all parts before assembly..good tip for all racers..my life long round track driver, “ Krash” had a real head scratching problem. The starter he ran for years was now not turning over the engine. It was hanging up at the same point of rotation. We first thought because he stored the engine over the winter letting it rest on the oil pan and “ flywheel” ( actually the torque plate from an automatic transmission ) thinking was be may have bumped into the engine and warped the flex plate. ( stock car class with restricted rules do not address this area in the rules...OPPORTUNITY --- so the hot set up is to run a 5 1/4 inch dual clutch disc package on this ring to cut down rotating weight).
well when we disassembled the whole thing we found the flex plate was perfect over 180 degrees..but..the other 180 degrees was about .100” under cut. This was a manufacturing error when the teeth were being machined. So t he starter engaged the teeth on the starter ring up until the teeth were wore to the pint that the starter could not engage that half of the ring.
We never would have found it unless we compared a few of the other production flex plates. You could feel the perfect alignment over half the diameter but it dramatically dropped off the other half..Let that be a lesson to you..there are manufacturing defects and check, CHECK and Re check..
 

Attachments

  • starter ring.jpg
    starter ring.jpg
    43.5 KB · Views: 499
Posted June 2024 - 15 years after starting this class. I have learned a whole lot. To get to the short course on making your stock car, late model, hobby stock E-mod handle, look at the index below. Read all posts on Roll Center, Jacking effect and Why does car drive straight to the wall when I gas it? Also read You really have two race cars. This will cover 90% of problems you have. Simply put, the car pushes going in and is loose coming out. You do not have enuff downforce on the right...
I'm trying to decide what size and type of galvanized steel I need for 2 cantilever extensions. The cantilever is 5 ft. The space between the two cantilever arms is a 17 ft Gap the center 7 ft of the 17 ft Gap we'll need to Bear approximately 17,000 lb spread evenly from the front of the cantilever to the back of the cantilever over 5 ft. I will put support beams across these cantilever arms to support the load evenly
Thread 'What's the most likely cause for this carbon seal crack?'
We have a molded carbon graphite seal that is used in an inline axial piston, variable displacement hydraulic pump. One of our customers reported that, when using the “A” parts in the past, they only needed to replace them due to normal wear. However, after switching to our parts, the replacement cycle seems to be much shorter due to “broken” or “cracked” failures. This issue was identified after hydraulic fluid leakage was observed. According to their records, the same problem has occurred...
Back
Top