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I'm a former mechanic/engine builder/parts house owner of 28yrs and was just pulling legs to see what kind of answer would pop up.
Basically a REDLINE is the MFG highest recommended RPM a stock engine should be run. Limited short bursts over the REDLINE will not damage a engine whereas continued use over this REDLINE will bring a sooner then later breakdown. (Ask me how I know)
Decades ago GM had a Pontiac that had a RED line indictor in the spedo that could be adjusted so that when the two line indicators lined up together a BUZZER would sound. THis let you know your car had reached the max speed you desired (NO speeding tickets).
To bad that the same method could not or has not been designed into the TACH to let us know the safe RPM be it a stock or modified performance engine.
I do know that there is a REV Limiter for some Race engines but not sure if available on stock assembly cars. (some sure to let me know)
I'm a former mechanic/engine builder/parts house owner of 28yrs and was just pulling legs to see what kind of answer would pop up.
Basically a REDLINE is the MFG highest recommended RPM a stock engine should be run. Limited short bursts over the REDLINE will not damage a engine whereas continued use over this REDLINE will bring a sooner then later breakdown. (Ask me how I know)
Decades ago GM had a Pontiac that had a RED line indictor in the spedo that could be adjusted so that when the two line indicators lined up together a BUZZER would sound. THis let you know your car had reached the max speed you desired (NO speeding tickets).
To bad that the same method could not or has not been designed into the TACH to let us know the safe RPM be it a stock or modified performance engine.
I do know that there is a REV Limiter for some Race engines but not sure if available on stock assembly cars. (some sure to let me know)
My SHO has a rev limiter. In "Park" it wont go past 4K RPMs even though the redline is at 5500 or 6500 (cant remember off hand)
I'm a former mechanic/engine builder/parts house owner of 28yrs and was just pulling legs to see what kind of answer would pop up.
Basically a REDLINE is the MFG highest recommended RPM a stock engine should be run. Limited short bursts over the REDLINE will not damage a engine whereas continued use over this REDLINE will bring a sooner then later breakdown. (Ask me how I know)
Decades ago GM had a Pontiac that had a RED line indictor in the spedo that could be adjusted so that when the two line indicators lined up together a BUZZER would sound. THis let you know your car had reached the max speed you desired (NO speeding tickets).
To bad that the same method could not or has not been designed into the TACH to let us know the safe RPM be it a stock or modified performance engine.
I do know that there is a REV Limiter for some Race engines but not sure if available on stock assembly cars. (some sure to let me know)
Regarding the bolded:
So, are you saying that if I exceed the red line while shifting (lets assume just poor shifting timing) my manual transmission car briefly once a year, I DON'T need to re-ring my pistons ?
This is something I was concerned about... Some people believe redlining once is bad, and requires re-ringing your pistons immediately.
Makes me feel a little better about my 'missed' shifts in the past... Of course, my car still runs, and runs well, but long term, I don't know if problems can pop up.
There's also things like imposed limiters, fuel cuts or "soft limiters", shift notifications (beeps or lights), limp modes (which don't allow the car to rev after usually a code is thrown)
You can also over rev an engine in a manual transmission which, among other things can bend valves.
When an engine is cold you want to make sure you aren't reving too high.
RPMs at idle and other times can also aide in diagnosing engine problems. Shaky idle, higher/lower than normal idle speed etc.
Also self imposed shift points at certain RPMs can aide in saving gas as well, i.e. not shifting over 3k.
Regarding the bolded:
So, are you saying that if I exceed the red line while shifting (lets assume just poor shifting timing) my manual transmission car briefly once a year, I DON'T need to re-ring my pistons ?
This is something I was concerned about... Some people believe redlining once is bad, and requires re-ringing your pistons immediately.
Makes me feel a little better about my 'missed' shifts in the past... Of course, my car still runs, and runs well, but long term, I don't know if problems can pop up.
Occasionally hitting or exceeding the redline in a well maintained engine should cause no harm. Remember - the manufacturer doesn't expect you to be perfect. I regularly reach 8000 rpm on my NSX just for fun. Ocasionally I hit the rev limiter (around 8200-8300 rpm).
Occasionally hitting or exceeding the redline in a well maintained engine should cause no harm. Remember - the manufacturer doesn't expect you to be perfect. I regularly reach 8000 rpm on my NSX just for fun. Ocasionally I hit the rev limiter (around 8200-8300 rpm).
Yes, redlining does not hurt the engine in the slightest. Especially in those types of Honda engines; they were meant to be "rung out."
However, misshifting from, say, 4th to 2nd while redlining (or driving hard) will cause the engine to mechanically overrev and that's bad.
I'd like to add that in many cases the manufacturer specified redline is very much on the safe side and has a bit more room for relatively safe operation. My car has it's rev limiter raised to 7400 which can be done for many reasons. One is to give some breathing room when shifting at the factory redline without bouncing off the limiter another is to allow a larger turbo enough rev range to build proper spool and maximize output. I stare at my rpm gauge religiously because putting down 330wtq+ below 3200rpm in a higher gear (5th/6th) would be catastrophic for my stock internals four banger and the turbo spools fast enough to actually pose a danger.
Jensen Healey had a distributor with a centrifically driven cut off that kicked in around 8000 R.P.M. I am not sure if that is called a rev limiter or not. They were expensive to replace, so no one did (most people just switched to electronic ignition anyway).
My Camaro seems to use the ASR when you redline it (applies the brakes and advances the timing).
4 cylinder cars seem to have much higher redlines than V-8s (e.g. Jensen 7800; Camaro around 5500 or 5800).
Jensen Healey had a distributor with a centrifically driven cut off that kicked in around 8000 R.P.M. I am not sure if that is called a rev limiter or not. They were expensive to replace, so no one did (most people just switched to electronic ignition anyway).
My Camaro seems to use the ASR when you redline it (applies the brakes and advances the timing).
4 cylinder cars seem to have much higher redlines than V-8s (e.g. Jensen 7800; Camaro around 5500 or 5800).
V8's (along with V10's, V12's, etc) can be built for extremely high rev range operation but are rarely done so from the factory in mainstream applications. Most V8's (particularly from domestic makes) tend to be a bit lazy due to the cost involved in making them sing.
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