| Author | Message | ||
| "The Don" (Mlemus)
Advanced Member Username: Mlemus Post Number: 3491 Registered: 8-2002 |
after  | ||
| TomD (Tifosi)
Advanced Member Username: Tifosi Post Number: 3144 Registered: 9-2001 |
matt, is that before or after adjusting for the tach being off | ||
| "The Don" (Mlemus)
Advanced Member Username: Mlemus Post Number: 3490 Registered: 8-2002 |
Mike, I take mine to 6k and MAYBE 6300K. Our engines are 25 years old and, in my case, has not been taken apart for a rebuild. Has Hans (gezz type that 10 times fast) said, they are rolling museums. Matt | ||
| Mike Procopio (Pupz308)
Junior Member Username: Pupz308 Post Number: 230 Registered: 10-2002 |
Matt, you're serious? I might be able to hold off of redline, but an occasional stint up to 7000 is part of the experience. You're telling me you don't, as a rule, go past 6k? | ||
| "The Don" (Mlemus)
Advanced Member Username: Mlemus Post Number: 3481 Registered: 8-2002 |
Why are you reving so high in the first place? Anything past 6k in a 25 year old car is asking for trouble. | ||
| Hans E. Hansen (4re_gt4)
Intermediate Member Username: 4re_gt4 Post Number: 1020 Registered: 4-2002 |
You're scaring me, Mike. I've never had the guts to rev my rolling museum past 7k. The 180deg crank isn't as smooth as some engines, and all sorts of vibrations can be set up. I get one at about 4k, just sort of a buzz. What you describe does sound like a 'beat frequency oscillation', a combining of two frequencies that have a difference of only 3 hertz. I'd consider maybe belts. Hard mechanical bits should be rotating at the same speed, so shouldn't have a 3 hertz differential. Also, maybe something having to do with air pulses in the intake system. Sorry, no hard info. Just conjecture. | ||
| Mike Procopio (Pupz308)
Junior Member Username: Pupz308 Post Number: 221 Registered: 10-2002 |
As I approach redline, mostly apparent from 7k rpm to 7700 in 2nd gear or above, my acceleration slows down and I begin to hear a "beat frequency" in the engine's sound. I'd say the at about 3 times per second at that RPM, I hear and feel this resonance. Of course, everything in the engine is happening much faster than 3 times per second. I've never experienced this in a car--do any of you have it, or have any of you experienced this? 78 308 GTS. Mike. |