sign of the times

[Cobb]

Mines is an i-VTEC with i-Dsi.

Love the prius, shame its only true for stop n go driving.

[pgfpro]

Back when I was a teenager late 70's early 80's there was a bunch of useless phrases when describing performance parts.

1/4 race cam
1/2 race cam
3/4 race cam
and of course full race cam
double pumper
power pack heads
camel hump heads
max wedge heads
magnum heads
1.94 heads
2.02 heads
rec port heads
oval heads
angle plug heads
roller cam when all they had was roller rockers
pop up pistons
hi po rods
hi po crank
race fuel
race gears
ported and polished
etc...

But my all time favorite was the "Balanced and Blue Printed Engine". Every kid in town had a "Balanced and Blue Printed Engine"

[screaming_bmwe30]

Originally Posted by darcane

Regardless of marketing, VTEC really only exists for fuel economy.

The same peak power can be made by just using the high cam profile at all times, rather than just at certain RPMs. VTEC simply allows an economical cam profile at low RPMs and high profile at high RPMs

The ricer kids don't like it when you point that out though...

Not completely true. Running the aggressive lift/overlap cam at low revs would lower torque in that "below VTEC range" region...and also make the volumetric efficiency poor, thereby also decreasing FE. The only performance reason to remove VTEC switchover is if you are racing and are always going to be in the torque sweet spot or above on the "high lift" cam. High hp fast revving motors have also been known to have VTEC crossover issues because the oil pressures can not switch the cam fast enough causing wear to the valvetrain . BMW and basically every manufacturer has their version of variable valve lift or timing, and its usually a low rpm/high rpm performance benefit, with a FE benefit being an equally important effect.

[cRiPpLe_rOoStEr]

VTEC, VVT-i, Double VANOS, Ti-VCT, doesn't matter how each manufacturer calls it, the problem is all about the ricers

[Cobb]

Dont forget single and double. Many cars that have some form of valve timing only have it on the intake.

The machine shop I worked in the early 90s when in high school was all about stroking. The owner had a technique for grinding the inner surface of the rod journals and decking pistons making it an interference engine.

You could have one nice sleeper with a plain jane looking outside.

[cRiPpLe_rOoStEr]

Originally Posted by Cobb

Dont forget single and double. Many cars that have some form of valve timing only have it on the intake.

I used to think every VVT system worked for both intake and exhaust (which would actually make more sense), until Toyota released the Dual VVT-i engine in the local version of the Corolla fitted with a 2.0L engine...

[Cobb]

Yeah, toy recently released the dual vvt engine in the scion xd/carolla and man, thats way nicer than just vvt on the intake side.

[cRiPpLe_rOoStEr]

I gotta admit that I never really cared so much about VVT.

[Cobb]

Good point, wished the auto industry felt the same. The valve technology allows the broader power band. Instead the engine should be designed to run low at the higher power output at a fix rpm and a cvt should be used to get the car moving.

Originally Posted by cRiPpLe_rOoStEr

I gotta admit that I never really cared so much about VVT.

[War_Wagon]

Originally Posted by pgfpro

Back when I was a teenager late 70's early 80's there was a bunch of useless phrases when describing performance parts.

1/4 race cam
1/2 race cam
3/4 race cam
and of course full race cam
double pumper
power pack heads
camel hump heads
max wedge heads
magnum heads
1.94 heads
2.02 heads
rec port heads
oval heads
angle plug heads
roller cam when all they had was roller rockers
pop up pistons
hi po rods
hi po crank
race fuel
race gears
ported and polished
etc...

But my all time favorite was the "Balanced and Blue Printed Engine". Every kid in town had a "Balanced and Blue Printed Engine"

You forgot the one thing that every car with a V8 in my high school parking lot had (according to the owner anyway) - a 4 bolt main! Good thing too, those bone stock 200 hp 350s wouldn't live with just a 2 bolt block after all ha ha