DIYEFI.org Forum

. . . I _must_ be missing something truly fundamental here. I don't see the additional hardware costs as being prohibitively more than current engine technology (and as mentioned above, there are SOME savings that help to offset them!) It all seems so easy that I cannot believe _someone_ hasn't alr...

Maybe I'm being a little naive here, but it's my 'understanding' that the primary issue at 'race revs' is valve springs (and thus the ensuing valve float). In order to increase the intake valve lift from the original 10.5mm to 12mm in the "pattakon Honda VTEC B16A2" prototype engine (deta...

The entire camshaft subsystem including timing chain 'disappears'. (This would probably necessitate a redesign of the primary oil pumping system since many of the engines I've seen run the oil pump from a gear on the camshaft). Perhaps I should re-stress at this point that my thought process is cen...

During 'outgoing air control' which crank angles are the fuel and spark? It depends on the engine. Direct injection? Port injection? The PatAir can operate with all the available modes / strategies ("Ingoing Air Control") of the MultiAir of FIAT and with an infinity of additional "Ou...

MotoFab wrote: Pushing a piston up against closed valves, is the same as a pulling a piston down against closed valves. Think the following case: You keep the intake valves of a cylinder open from the overlap TDC to 30 degrees after the overlap TDC. Then you close the intake valves. The volume of t...

What's stopping them using another such solenoid on a pressurised fluid supply to OPEN the valve too? It is more easy than this. You don't need a second solenoid electromagnetic valve. Take a look at the HyDesm (Hydraulic Desmodromic) at http://www.pattakon.com/pattakonHyDesmo.htm EXTREMELY interes...

For others who, like me, might be somewhat intrigued, here's a semi decent description of MultiAir / Pattakon that has just HELPED my understanding a lot: http://www.pattakon.com/pattakonHydro.htm (And yes, the valves do INDEED seem to 'snap shut' a lot more than with a traditional cam profile.) Ed...