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Old 05-04-2019, 12:39 PM   #5 (permalink)
JSH
AKA - Jason
 
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Join Date: May 2009
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Adventure Seeker - '04 Chevy Astro - Campervan
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Quote:
Originally Posted by hayden55 View Post
Odd thought as my googling was unsuccessful. With a lot of real world experience with friends running Hondas basically tractoring down the road with one dead cylinder, two dead cylinders, and one time an amazing three cylinders down. What would killing one cylinder do? I assume if you killed the injector to keep the fuel from pumping instead of just killing the spark like what typically happens... Could you three cylinder it and get better mileage? DIYactivecylindermanagement?
For cylinder deactivation to work you need to keep the valves closed on the deactivated cylinder. If you don't close the valves you increase the pumping losses of the engine. (You are essentially using that dead cylinder as an air compressor.) Pumping air also causes all kinds of problems with the engine management as noted by RedDevil



Quote:
Originally Posted by oil pan 4 View Post
It only works in engines with hydraulic lifters.
Plenty of overhead cam engines have cylinder deactivation. They use two piece rocker arms with a pin connecting them. When the cylinder is in use oil pressure keeps the two pieces pinned together allowing the valve to open in close. When the cylinder is deactivated the pin is disconnected so the cam is not longer connected to the valve.

EDIT: Eaton's overhead cam cylinder deactivation
http://videos.eaton.com/detail/video...tion-with-lash

Last edited by JSH; 05-05-2019 at 12:29 AM..
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