5v V12 Fcars

welcome back! stellar picture, dude!!!!

do you have a better snap of it? or other snaps of it?

tia,
doody.

 

5-valve design doesn’t guarantee covering more head area than 4-valver. Nevertheless, if the combustion chamber is in irregular shape like the picture shown, the valves may cover a larger area. The Ferrari F355 makes use of this to enhance high-speed breathing. Is there any disadvantage? Yes, faster breathing also harms low-speed torque if no counter measure is taken. Therefore it is really more suitable to sports cars.

All existing 5-valve engines have 3 intake valves and 2 exhaust valves per cylinder, still arranged as cross-flow. The exhaust valves are larger, but in terms of total area the intake valves are larger. In the F355, by arranging the outer intake valves opening 10° earlier than the center valve, it gets the swirl needed for better air / fuel mixture, hence more efficient burning and cleaner emission.

The advantage of 5-valve engine is still under question. Even the Ferrari F1 cars which was once famous for its 5V engine switched back to 4v design.

 

One way to get around the off idle response and low end torque issues with a 5 valve head is to go with variable cam timing or have 2 of the valves running the hydralic lash adjusters on different oil passages. doing this the engine can use just one valve at idle giving the engine more than ample air. Once the engine comes off idle to about 1750 RPM then open up a valve that let oil to Valve #2 then at about 3500-4000 RPM Open up valve #3. With modern engine fuel and ignition systems, this method would not be hard to acheive. Other than getting the additional oil galleys in place, That could be done on the outside of the engine.