was in my friend's s2000 just now n he was testin out his new exhaust... n he bouce of 1st gear redline then 2nd gear...

car drove fine after... now he just worrie..


he's thinkin compression test,leakdown test,vavle lash...


anything else he can check or more info ???

 

If all you did was bounce off the rev limiter that is fine that's what its there for.

Over rev is when you make, for example, a 6th to 2 shift at highway speeds when you meant to shift to 4th and thus rev the engine well past the redline. That can potentially be very bad for the engine.

 

Wow, is your keyboard broken?

 

To the OP .................... Both you and your friend really need to do a little reading to find out how an engine and drivetrain works, especially how a rev limiter works, when it works and how it works. Also find out what a mechanical over-rev really is, how it's done and why it happens and what the consequences are. Until you do, you guys are going to give yourselves a mental hernia.

 

 

can you break it down... what does each means.. so i dont have to endlessly search..

s2ki search engine SUCks~!

 

Then go find out somewhere else.

 

Basically if you pull all the way up through a gear when you hit the redline the ECU cuts fuel to the injectors. However if you are at redline in say 3rd and try to shift into 4th, but accidently find 2nd gear instead, then there is nothing the ECU can do to prevent the engine from spinning beyond it's redline. At least I think that is right.

 

youngingz...

 

Don't be so modest. Of course it's right.

I find myself with a little time, so I'll elaborate and save the OP the task of "Googling" this sort of thing.

Under normal operation during acceleration or steady state running, the engine drives the rest of the drivetrain. IE, power goes from the engine through the clutch, thru the tranny, down the propshaft, in and out the rear diff, out the 1/2 shafts and to the wheels and tires, onto the ground. Our engines have a "rev-limiter", which prevents the rpm from going beyond a set point when the engine is driving the rear wheels.
However, when operating during deceleration, as long as the car is in gear and the clutch is engaged, the rear wheels try to "drive" the engine. The power goes backwards. The engine's compression fights this force that's coming back to it. This is called "engine braking". As long as the force going backwards does not exceed what the engine's compression can hold back, the rpm will decline or stay the same, depending upon what gear you are in. In very particular circumstances, the force moving backwards through the drivetrain exceeds the engine's "braking" force (or compression) and the rpm increases. Because this is a "mechanical" force that's making the engine rpm rise, the rev limiter can't help to prevent the rpm from going beyond that set point (or limit).
In the most severe of these cases, the rear wheels can drive the engine speed well beyond the point where the valvetrain and other key components were designed to function at. This would be a situation where you are already high in the rev band and select a gear that would allow the rear wheels to drive the engine to extreme speeds (a much lower gear). If rpm get high enough (about 10,500 rpm for this car), valves begin to "float". IE, they are being pushed down into the cylinder so frequently that the springs do not have enough strength to pull them back up before the piston comes up and smashes into the valve. This results in damaged valves, pistons, valve retainers. In very extreme cases, you can incur damage to the bottom end of the engine as well.

No, you don't have to search S2Ki for this info. Google is your friend.