[mbb]

Well what is it Guru?

 

[papajam]

When an intake cam is timed at 114, it means that the intake valve will be at it's maximum opening when the crankshaft is 114 degrees after top dead center (ATDC). If timed to 102 degrees, maximum valve opening will be at 102* ATDC. Since 102 ATDC occurs before 114 ATDC, a cam timed at 102 is more advanced (by 12 crankshaft degrees) than a cam timed at 114.

 

[Grant]

Just an FYI, I'm working with VVT on my 4age 20 valve engine - 1.6 liter, 5 valves, VVT, and ITB's from the factory (like spica, but with EFI).

Anyways, VVT is load based, and it advances the cam to 35 degrees IVO from 2500 rpm to 6000 rpm depending on load. Below that, or above that, cam is back to a baseline of 5 degrees IVO BTDC.

The change is tremendous when it comes on! I have it controlled with a standalone, and before I got it to work with Keith's help (he's on this board), the difference was almost night an day.

VVT is great, I'd try to make it work with higher lift cams if at all possible.

 

[mbb]

Thank you Alfar 7 for pointing out that there was a logic problem and Pappajam for letting me know what the flaw was.

It looks like, when vvt is engaged the valve timing is at the magic 102/102. Correct? (On stock and standard L-jet).

Thanks,

 

[60sRacer]

Valve timing for good performance with most cams is 102/102. Old Shankle catalog pointed that out. VVT reduces the overlap at low rpm for a bit better idle - lower emission and lower fuel consumption, and a bit smoother .

Robert

 

[msiert]

The advantage of VVT isn't really for more HP................ The advantage is to widen the power band when using them for performance.

 

[60sRacer]

Hey, Murray,

Did you put vvt on intake and exhaust?

Robert

 

[mini1071]

For anyone interested these people Baker Electronix - RPM Switches RPM Controlled Devices make an RPM switch that can be used to operate the electric VVT at battery voltage...