Cossie.jack

Hi all,
I need some help here, my collage tutor has told me to research into the advantage and disadvantages between the over head cams and over head values. Try searching google not much there, could any one explain for me?

Thanks Jack

focusv8

Your Google must be having a bad day;

https://www.google.co.uk/search?q=ov...Oqqw0wX7mYDYBQ

Cossie.jack

Lol it was on my iPad I couldn't get much, got on the computer and got loads? Weird, anyway got all my info thanks!

stevieturbo

Or you could always look at each design....and decide for yourself pro's and cons for each design, rather than googling for other peoples ideas.

martysmartie

iTrader: (1)

OHV is an older design, the camshaft is in the block and the valves are actuated by push rods, disadvantage is they have more mass, I think I am right in saying these engines typically do not rev very high for this reason either? I can't think of an advantage off hand.

OHC is a modern design, and as the name suggests, the camshaft is in the head and actuates the valves directly. The advantage is less mass and fewer moving components.

Martin

Karlos G

iTrader: (4)

It's probably because you were searching for over head VALUES and not valve mate?! lol

xr2wishy

iTrader: (2)

advantage of an ohv with pushrods is unlikely to bend valves if belt slips.
disadvantage is more mass and more clearances to take into account of rod to cam and rod to rockers.
ohc is better for power (gains and losses)

Cossie.jack

Lol

Thanks all for your replies

martysmartie

iTrader: (1)

Are you sure? These engines have chains, but regardless if the timing was out a mangled mess would be the result, assuming an interference engine?

Martin

Glenn_

iTrader: (1)

The ohv ford engines had a chain and a tensioner.

martysmartie

iTrader: (1)

Correct, as does every engine of this kind I know of!

The interesting one is Fords 1L Ecoboost which has an integral belt, which supposedly is 'for life'!

Martin