Difference between 8v and 16v

[Laine_16v]

Ive sorta got a project to detail into the main differences between the two, why one is more powerful e.t.c

If anyone could give any main points i could write about i would be very appreciative but i cant really think of much to write about lol.

[stan]

why 4v head produces more power (in brief..im sure you can elaborate!):

more valve area for piston area,

increased peak flow, whilst retaining good velocities,

better in cylinder movement as air enters chamber,

more even cylinder filling, so burn can propogate faster/better,

reduced time for flame front to reach cylinder walls (due to positon of spark plug in relation to inlet valves), so end-gas has less exposure to peak pressures and temps...so more ign advance can be run with reduced risk of detonation,

they will rev higher also.

Americans will tell you the inherent hemi-head design is bad for combustion..in terms of reduced squish, poor piston crown design due to larger valve cut -outs etc...they may have a point on certain aspects, but as always its a comprimise.

[Laine_16v]

This is perfect, thank you

[Laine_16v]

Stan i want to put down some flashy calculation eventually.

What ar ethe size of inlet/outlet valves as standard on F7P

Also the maximum lift they endure (via Cam shaft), and the duration of the camshaft e.t.c

Thanks.

[Laine_16v]

And stroke/bore of the cylinder e.t.c

[MAXIBOY]

30mm/28.5mm sizes

[stan]

bore=82.7mm, stroke=93mm

what course/level are you doing...im unsure of how in-depth you are trying to make this.

you could run computer simulations for example and compare theoretical data on both engines.

or calculations wise, you could determine airflow into the cylinder, and from that calculate potential power which could be made, given the fuel type (calorific value).

[Joel]

He does Mechincal Engineering.. i think

I do electrical engineering

[BenR]

why 4v head produces more power (in brief..im sure you can elaborate!):

more valve area for piston area,

increased peak flow, whilst retaining good velocities,

better in cylinder movement as air enters chamber,

more even cylinder filling, so burn can propogate faster/better,

reduced time for flame front to reach cylinder walls (due to positon of spark plug in relation to inlet valves), so end-gas has less exposure to peak pressures and temps...so more ign advance can be run with reduced risk of detonation,

they will rev higher also.

Americans will tell you the inherent hemi-head design is bad for combustion..in terms of reduced squish, poor piston crown design due to larger valve cut -outs etc...they may have a point on certain aspects, but as always its a comprimise.

Pent roof.

Yanks were very pro - hemi.

[stan]

yup my bad..u know what i meant lol