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VCT/OCV questions


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  • Dropping a turd
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  • Member For: 16y 5m 2d
  • Gender: Male
  • Location: Perth

Brad not telling ALL the truth.

 

Dual Independent Variable Cam Timing (DI-VCT)

The Barra 195 engine had a vane-type VCT phaser – produced by Aisin – on each camshaft that provided continual variable adjustment within a 60 degree range (10 degrees advanced or 50 degrees retarded from the initial pin lock position). Each camshaft phaser was hydraulically controlled via an oil control valve that was mounted on top of it.

The variable cam timing system for the Barra 195 engine was Ford’s ‘Dual Independent Phase Shifting’ (DIPS) which enabled the intake and exhaust camshafts to be varied independently of each other. In contrast, the Barra 182 engine had Dual Equal Phase Shifting (DEPS) in which the intake and exhaust camshafts could only be advanced or retarded by the same degree synchronously such that valve overlap was a constant 25 degrees.

Valve timing for the Barra 195 engine is understood to be the same as the Barra 190 engine and is given in the tables below. From these, valve overlap could be varied from -35 degrees to 85 degrees, intake duration was 256 degrees and exhaust duration was 256 degrees. Furthermore,
  • On low throttle openings, timing would be retarded by up to 50 degrees to improve fuel economy;
  • At idle, the intake camshaft was retarded by 18 degrees for improved combustion and a stable idle; and,
  • At higher loads, timing would be advanced for greater power.

 

 

Barra 195 engine - valve timing: pin lock position
Intake Open 27.5° BTDC
Close 48.5° ABDC
Exhaust Open 78.5° BBDC
Close 2.5° BTDC
Barra 195 engine - valve timing: 10 degrees advanced
Intake Open 37.5° BTDC
Close 38.5° ABDC
Exhaust Open 88.5° BBDC
Close 12.5° BTDC
Barra 195 engine - valve timing: 50 degrees retarded
Intake Open 22.5° ATDC
Close 98.5° ABDC
Exhaust Open 28.5° BBDC
Close 47.5° ATDC
Edited by arronm
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  • 2 weeks later...
  • New Member
  • Member For: 6y 6m 25d

Nope, intake manifold gaskets are all new and tested no vacuum leaks

 

the only thing I’ve got my fingers pointing at atm is the pcm/tune

looks like someone has played or tampered with the tune to make it more fuel efficient as timing is pulled quite a fair bit

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