isnt that the point? if they didnt open at the same time where would that get you? every multi valve motor opens the intake valves at the same time and the exhaust valves at the same time

 

The caddy northstar motor has 32 valves and is only 4.8liters i think

 

Northstar 32v = 4.6L of fury.

 

*** yes they are

 

it's also DOCH.

if i remember right, these heads are designed for engines with at least 4" bore or more

 

for $4500.....just add FI and be done with it. too many moving parts anyway...lots of surface area on the moving parts....no gracias compadre

 

Does anyone remember the Ford SHO. It was a 5 valve per cylinder(3 intake and 2 exhaust). It used forked rocker arms to open either 2 or 3 valves at a time. Yamaha made the motor for Ford and the prototype was 7 valves per cylinder which was lowered to 5 because it was thought to be overly complicated for a production engine. I too am having trouble seeing clearly from the photos how this thing works. There is no good overhead view. You would think the intakes and exhaust valves would be on the same side so the pushrod could open them as a pair, but that doesn't appear to be the case. The rockers are billet so that has something to do with the high price. It would be nice to see some flow numbers to be able to do a comparison with a good set of CNCed 2 valve heads.

 

If you take a look at the photos again and pay close attention to the space under the exhaust rocker shaft assembly you will see the tops of the intake valve springs and retainers. It looks to me like they use stock length intake valves and XXTRA long exhaust valves to get all of the components to fit in the small space. Looks like the exhaust push-rod will be longer as well.

As for how they perform? Well, I don't see how they could be too much better than a set of worked over LS3/L92/L76 heads. Design limitation being a single camshaft that you cannot alter LSA dynamically between intake and exhaust lobes, which is the feature where you could gain width in the torque curve (Hint Hint GM!)

 

Damn, with all that billet think of the weight. That's some serious inertia being thrown around. Ill pass.

 

Uh....usually the main benefit to billet is it's weight or lack there of.