11/12/13/15 "degree" heads?

JFM-jr · 10-09-2009, 08:27 AM

What extaly is the relationship of a "degree" of a head? Is it the valve angle relative to the heads deck surface? I know the less degree the more PTV so it's going flusher to the piston in that aspect.

Gordon0652 · 10-09-2009, 09:10 AM

I believe its the valve to deck surface angle.

beast69camaro · 10-09-2009, 01:21 PM

it is the relative angle between the valve stem axis and the cylinder bore axis.

it is also the relative angle between the valve face and the deck face.

both numbers are equivalent.

DREAMZ28 · 11-07-2009, 03:18 AM

So what are the benifits of each?
Disadvantages?

Edit: I chose my words wrong, what are the effects of a higher/lower degree head. I've been hearing this term for a while and my guess on what it was was right.

It seems the lower the degree of the head, the more direct the air flow into the cylinder, but depending on the head design the air velocity might be slowed by having to go around a sharper bend. Also fluid dynamics take places with the air flow riding against the wall in the port, etc.

If anyone with knowledge on this subject is reading, please chime in. This is VERY interesting..