slick1851

Im just wondering with better flowing heads on a stock cam could you see a gas milage gain?

Steve Bryant

iTrader: (1)

You might see a slight reduction in milage with a pair of typically ported heads because the stock heads have swirl ramps on the intake ports which improve efficiency slightly. Also, if the exhaust ports are enlarged very much, you'll dump the pressure out of the cylinder sooner and loose some torque. When I hand-ported my stock cast iron heads, I specifically tried to leave the swirl ramps in tact and avoid hogging out the exhausts too much for this very reason.

slick1851

thanks

1989GTA

It would seem to me that if the heads were ported correctly you would get better cylinder filling at all rpms. That should equal more horsepower. So I would think you should get somewhat better gas milage.

3.4camaro

iTrader: (1)

More horsepower means you would be able to burn more fuel. Burning more fuel =/= better gas mileage.

I vote no in theory, although I went from 24mpg to 26(highway) from a trickflow head swap

Drew04GTO

iTrader: (1)

EPA found afr heads on c5 z06 during CARB certification tests gained 2mpg on an otherwise stock car.....

1989GTA

"More horsepower means you would be able to burn more fuel. Burning more fuel =/= better gas mileage."

I would think it would mean less throttle is required for the same horsepower. Better VE.

kgkern01

iTrader: (10)

I gained a little better mileage when I went with ported heads about 11.1 CR, and 1.7RR on my stock LT1 cam 155k engine.

Viper

iTrader: (6)

I gained when I went H/C AFR 205's milled .018. I'm getting 28-30 on the highway when it's over a 1/2 hour long and I'm not at high RPM's.

2002_Z28_Six_Speed

iTrader: (19)

Let us not forget you can get a camshaft that will give more fuel econ than stock.

Stock is designed for emissions.

gun5l1ng3r

You mean a cam along the lines of 150/135 .500/.500 right?

That would be so much fun, I can hardly wait

2002_Z28_Six_Speed

iTrader: (19)

Bump up the exhaust alot and use it for nitrous or FI?

Possible to get power that way?

Boost with a small intake tract and no head work is typically acceptable. Maybe the cam doesn't matter either. Just the exhuast side work and cam.