Vct And The Differences Between Ba, Bf And Fg Engines

[Woznaldo]

Evening All,

I've done a bit of a search but have had trouble finding anything concrete on what level of VCT exists on the Barra Engine.

I know that it's the infinitely variable type, but does work on both Intake and Exhaust Camshafts or just one?

Also, I read a little about how it's all controlled but not how the PCM knows what position the Camshaft is in?

Woz

[Ralph Wiggum]

Ba XR both cams advance/retard together

BA Fpv Cams Advance/retard independently

BF XR/FPV as per BA FPV

FG XR/FPV as per BA FPV/BF,but FG FPV's also have duo-phased inlet cams (lobes are offset so one intake valve opens before the other for better offboost performance/fuel econ) I am unsure if this also applies ot FG xr's

All engines have a Cam angle sensor for each cam at the back of the cyl head.

[Mr_4.0]

I didn't think the independent timing came in until the bf ?? I thought all BA models advanced/retarded cams together.

Yes the duo phased cams in FG are great. Allows more lift and duration for the same engine vacuum and creates swirl in the chamber for a cleaner burn.

[Mr_4.0]

Also should add, pretty sure from base model NA to FPV typhoon, the FG cams are all identical. All got duo phased.

[JETURBO]

Its all about the swirl baby

I believe 50degrees is the max rotation from the phasors

[Ralph Wiggum]

I'm 99% sure ba typhoons got independent valves timing, will hunt around to see if I can back this up.

[Woznaldo]

Thanks for the responses Guys.

What do the Cam Angle Sensors read? If it's some kind of toothed wheel, does anyone know the wheel pattern?

[Ralph Wiggum]

It's a toothed wheel. I have some cams in my workshop I can grab some photos when I get home tonight, if somebody doesn't post some sooner

[Woznaldo]

Awesome, thanks Ralph.

[Ninka]

This may help if you look at top right of engine, you can see the cam sensor pickup 'gears'

This is the first engine built for me by Xtreme in about 2005