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Rotary Valve Engine Head 99 BMW 328is

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My twin brother and I for the past few years have been working on a rotary valve cylinder head for a 99 BMW 328is.  The cylinder head completely replaces the stock 24 valve cylinder head with a custom head that utilizes 6 axial flow rotary valves to control intake and exhaust.  The car in question is a very beat up e36 generation 3 series coupe with a 2.8L inline 6.  The engine runs on the stock ECU with all of the original emissions equipment in place.  About 100 miles have been put on the car with the modified head.


We have many videos on our YouTube channel of it.  The most recent video shows it running quite well.


Early on it ingested huge amounts of oil due to a poorly contrived PCV setup.



If you're super interested in it, we have a long show and tell video.


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  • 11 months later...

Been a while since I had a minute to work on this project.  I reflashed the ECU today with the factory original BMW tune, turns out it runs very well on that tune.  It might be worth pulling back out of the garage for some driving tests again.


There have been many refinements since the the head was first installed in the car years ago.  The biggest change is changing the port geometry for less aggressive valve timing.  The original timing would have been at home in a NASCAR engine spinning at 9,000 rpm, waaaayy too much overlap.  Other notable refinements was switching from a timing belt to a roller chain to drive the valves, larger hotter spark plugs, sorted cooling system, a breather box from a Cummins X15 for crankcase ventilation, and fixing all of the vacuum leaks in the homemade intake plenum. 



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