RE: What is Dynamic Skip Fire? PH Explains

[RobM77]

fred bloggs said:

I hired a 6.3 supercharged camero for a long road trip to Europe, and this had cylinder deactivation. this year I took my holden with the 5.7 chev with a big cam, and I got better milage from the holden.

so there, its a load of bks.

Well, for starters the Camaro was supercharged and over half a litre greater in capacity!..

[Jackspistonheadsaccount]

Ok please correct me if I'm wrong, but when deactivating a cylinder, why isn't it best to simply open the inlet valve and just leave it open? Then the piston won't be moving down, pulling against a vacuum which will use energy no?

[The Wookie]

Jackspistonheadsaccount said:

Ok please correct me if I'm wrong, but when deactivating a cylinder, why isn't it best to simply open the inlet valve and just leave it open? Then the piston won't be moving down, pulling against a vacuum which will use energy no?

Because then you’re pumping in and out of the cylinder. Presumably the inlet valves are left open for the first deactivated stroke, then all valves are left shut so the piston is effectively working against an air spring, then the only losses are friction in the bearings and ring pack

ETA, just watched video, all the valves are shut but same difference one stroke less pumping, works against the vacuum which then helps pull the piston back up instead of working to compress the air then the compressed air pushing the piston down

Edited by The Wookie on Tuesday 21st August 20:40