oh crap!
Ive been driving my car at 7,000 rpm's constantly it has 510 miles on it. damn damn damn I also red lined it in 1st 4 times oh god my poor poor car.

 

Hamada, I wouldn't worry. The engine will withstand the rpms it was built to run at. Mine is proof.

 

ok phew

 

Not only are the tires different sizes from front to back, but the wheels themselves are different sizes. (width) You should not put the rear wheels on the front! I say should not, but it is possible, as I found out the hard way. But then your wheel has a nasty wobble. See the manual regarding getting a flat on the rear.

 

[QUOTE]Originally posted by Charly
[B]Hamada, I wouldn't worry. The engine will withstand the rpms it was built to run at.

 

Howdoes the engine Vtec?? What really goes on withe cam or lifters to change their profile - can some one explain this in simple terms??
Thanks

 

i'm bored here at work so here goes.

in simple terms, at 6000RPM several things happen. oil pressure and temperature reach a certain level. when the ECU detects that 6000RPM has been reach, it quickly reviews several key readings before it allows the VTEC solenoid to engage VTEC.

-oil pressure must be at the correct level (if you're low on oil.. no VTEC for you)
-temperature must be right (cold engines don't VTEC)
-speed must be correct for the current gear (VTEC doesn't engage if ur rev a motor at a stoplight)

if these simple requirements are met, then the VTEC solenoid receives a go.

before I go on, i'll briefly explain how the valves/cams function. the camshafts have 3 lobes per cylinder per camshaft. it is a "DOHC" aka dual overhead cam design so there are two camshafts: 1 intake and 1 exhaust. Each set of 3 lobes consists of a Primary, Secondary, and Middle profile. Each lobe has a corresponding rocker arm. Of the three rocker arms, only two are directly in contact with the valves. For every cylinder, there are 4 valves. 2 intake and 2 exhaust and 6 total lobes (3 per shaft) that contorl these valves. The Primary and Secondary lobes are on the outside of the triplet and the Mid lobe is in between.When the camdrive spins the cam gears (directly attached to the camshafts), the camshafts spin in place and the lobes hit against the rockers opening and closing the valves. The Mid lobe hits the middle rocker but that rocker is not attached to anything.

on the S2000, each set of 3 rockers contain two small cylindrical pistons that are touching end to end. simply put, when VTEC engages, oil pushes the pistons so that they sit between Primary and Mid rocker and the Mid and Secondary rocker. This forces the Primary and Secondary rocker to follow the motion of the Mid rocker (whose correspond lobe has a greater amount of lift and an longer duration).

This is VTEC.

 

Thanks for the explanation - it will take a little time to sink in - does the cam shaft shift back and forth ??

 

The camshaft stays in place. Here's a crude diagram.

No VTEC=
----------------------------------------- <-
.................................................. . <- camshaft
````---P---```||||M|||```---S---``` <-

....|----A----||----B----||-----C----|.... <- Rockers
.....==Z==.......==Z==................. <-hollow center of rockers w/ pistons
....|----A----||----B----||-----C----|....<-Rockers
......Valve1.........................Valve2

Explanation: (P)rimary & (S)econdary lobes are smaller than the (M)id lobe. P, M, and S hit the valve rockers that correspond to them (A, B, C). When VTEC is OFF, the M-lobe and the B-rocker do nothing because there is no valve underneath the rocker B.

VTEC=
----------------------------------------- <-
.................................................. . <- camshaft
````---P---```||||M|||```---S---``` <-

....|----A----||----B----||-----C----|....<- Rockers
................==Z==......==Z==.................<-hollow center of rockers w/ pistons
....|----A----||----B----||-----C----|....<- Rockers
......Valve1........................Valve2

Explanation: Notice now the two Z pistons are inbetween the gap between A&B and B&C. Since M-lobe is LARGER than P-lobe & S-lobe, and the rockers are now connected together by the pistons, Valve1 and Valve2 are forced to move with the M-lobe profile which forces the valves to open for a longer period of time and create a large gap for air to flow.

Hope that explains it..sorry for the crude diagrams..

 

Thanks - yes it is clear now. has there been any major problems ??