valves?

[fredk]

I got an old 87 at the shop with a 4af and on the head right where the intake goes onto it is this rod running along it that turns a pivot on each intake port operated by a vacuum motor, when intake vacuum drops it moves this rod

[Flashmn]

Got a picture?

[retiredat44]

another method of rotating the valves, so the valves don't wear unevenly,,, there are several weays of keep valaves rotating. if they were not rotated you would get fried valves warped and burned much faster.

[fredk]

im not talking about the valves in the head, these things are in the intake ports just past the manifold mating surface

[Pineapple]

TVIS on a 4AF?

[Flashmn]

Never heard of it.

[retiredat44]

a pre-combustion chamber, or pre-mixing, this makes the fuel mix and mileage more efficient burning of the fuel. That is probably what you see. Different car makers do this in differetn ways..

[fredk]

its a rod with 4 pivots in the head that runs along the side of the valve cover under the air filter housing and the vacuum actuator is right beside the timing belt cover, its real neat, when its idling and you pop open the throttle it moves

[Flashmn]

a pre-combustion chamber, or pre-mixing, this makes the fuel mix and mileage more efficient burning of the fuel

This isnt a diesel...

[freakinbox]

1... PICS
2... you sure it's an 87? Wouldn't it have the 4ac not the 4af..

And yeah sounds like he's talking about tvis... Possibly a 4age?

[Flashmn]

And yeah sounds like he's talking about tvis... Possibly a 4age?

Yes I thought about this option too...

you sure it's an 87? Wouldn't it have the 4ac not the 4af..

AE92 was introduced in 87, thus you'd have a 4A-F.

[fredk]

its an f head on a 4a block with a carb