engine setup

Panhe,

if your motor has the oem heads on it, they are large port (4V) heads, with open combustion chambers & smaller 2V size valves, i.e. 2.04" intake & 1.65" exhaust.

Before anyone can make a head recommendation, it would be best if you discussed your goals for your motor, how you will use the car, if you will stroke it or leave it at 351 cubic inches, what sort of red line you want for the motor, how important is reliability and drivability. How much money you forsee spending on the motor.

Can you fill in the gaps for us?

Your friend on the DTBB, George

thanks george for replying so quickly.My car will not be a daily driver just for sunday drives. Can you explain what does "stroking" involve advantages/disanvantages. As far as redline i would guess 5000-6000 rpm. I dont want a track car but one that will rip the 1/4 mile that will be reliable and that i wouldnt have spend more than 10,00 dollars on!

Panhe,

There are no disadvantages to stroking in my book, other than cost, and the cost of stroking is much less than what it once was. Stroking allows the motor to make more torque at every rpm, since horsepower is torque x rpm / 5252, a horsepower goal can be achieved at a lower rpm since the torque is greater at that rpm. Drivability will also be better for a given horsepower goal. Since the motor is not having to rely upon increased rpm to achieve a horsepower goal, the reliability of the motor will be better. The increased displacement also wakes up the throttle response of the big port 4V heads. In summary stroking provides more power without sacrificing drivability or reliability, and improves throttle response.

Before I recommend a cylinder head & intake system I have 2 more questions if you don't mind. First regarding the intake system. Will you be running a 2 plane manifold, do you want to run a tall single plane manifold for the bad ass looks, or are you planning planning fuel injection, if so which type? Second, will this motor be a stroker or standard displacement?

Your friend on the DTBB, George

George,
I want to mantain the engine screen so ill use a manifold thats fits under it. I will probably stroke the engine and i want to keep the holley 750 double pump it has ,no fuel injection for now, thanks

OK Panhe, thanks for the info.

Here's my thoughts:

Your motor needs aren't much different than mine, but I have the liberty of picking a better set of heads for your motor because you aren't locked into a particular intake manifold like I am, nor have you written anything about keeping the motor looking stock.

The 3.85" stroker kit shall definately be on the menu for your motor. Since your original question was regarding alloy heads, and getting the biggest bang for the buck, I recommend the CHI 3V heads with 218 cc intake ports for your stroker motor. These heads have a 2V size port that is raised 3/8", 2V intake maifolds can be fitted with the use of lifter valley spacers available from CHI.

The only 2V intake that provides the oem height carb mounting pad is the Edelbrock Performer 2V, which is available on e-bay for under $100 USD. There is a new 2 plane manifold for 2V heads, the Edelbrock Performer RPM Air Gap, I'm sure this is a good manifold, it looks really trick on a motor, but I'm not sure exactly how much higher the carb mounting pad sits, at least an inch I'll bet. Finally there is the Weiand X-celerator for 2V heads, which also raises the carb about an inch higher. In general, the 2 plane intakes will make more average horsepower from 2000 to 6000 rpm than the single plane intake, although the "peak" horsepower number will be less "impressive". Since the intake manifold is raised about a 1/4 inch by the CHI spacers, it would be difficult to fit a carb & air filter assembly beneath the engine screen using anything other than a "stock" carb mounting pad height intake manifold, which leads us to the Edelbrock Performer 2V. I have seen dyno data provided by deeb that indicates this manifold can support up to 500 bhp, so I have no worries recommending this manifold for your motor. As I wrote earlier, the 2 plane design will make more average horsepower over the operating range of your motor.

An alternative to the Edelbrock intake will be a 2 plane intake cast specifically for the CHI 3V heads, available from a private individual named Scott Cook. I believe CHI may be able to obtain the manifold for you, or I could help locate Scott, as he lurks on the Cleveland Forum, another web site I hang out on. I have seen a pic of the manifold, it is a good piece, not cheaply made at all. The carb mounting pad is about a half inch higher than the oem intake, and CHI once told me they could machine the carb mounting pad flat for Pantera customers.

You will need a custom ground hydraulic roller cam that matches the characteristics of these heads to the characteristics of your stroker's short block. And finally you'll need all the proper support equipment; i.e. a good ignition, a free flowing exhaust, your 750 Holley, a beefed up fuel supply system, and dyno tuning for the carb & ignition.

With proper assembly and tuning, you'll have yourself a 475 to 500 ft/lb torque monster, making perhaps 475 to 500 bhp, peaking just below 6000 rpm. This is the motor I would recommend to most Pantera owners, and the one I'm tempted to build for myself.

Your friend on the DTBB, George

thanks alot for the info!