quote:
Originally posted by ttam23:
... Will just changing the head to the older stye closed chamber heads give me a 10to 1 compression ratio ...
Factory flat top pistons & 1970 (D0AE) heads are nominal 10:1, factory flat top pistons & 1971 heads (D1AE) are nominal 9.7:1.
quote:
Originally posted by PanteraDoug:
... Georges cam is pretty mild. That's why he says advance it ... It's going to have a short rpm range. All done by about 6200rpm or so ... That's ok if you're not racing, etc. It will certainly turn more rpm but you will feel "the nose of the car drop" at around 6,000 ... stock 4v cj balancer ...
The cam is not that "mild", the engine will lope at idle and accelerate hard anywhere in its powerband. But the engine will have usable manifold vacuum, low rpm power and a willingness to rev to high rpm (wide power band). Its a good hydraulic version of the Boss 351 cam. The intake duration reinforces the natural power band built into the heads (peak bhp at about 6000 rpm), as does the design of the Blue Thunder intake manifold.
I advise advancing the cam to place the exhaust valve opening and intake valve closing events where I believe they should be, thus improving low rpm power, raising dynamic compression, avoiding low rpm reversion and improving high rpm over-rev. As with any 351C equipped with 4V heads, the top end pull shall hinge upon the size of the carburetor, the exhaust system, the ignition, the valve springs and the push rods ... not so much upon the camshaft. I've seen engines equipped with the cobra jet cam rev to 7000 rpm (only 205 degrees duration at 0.050).
I agree with Doug the new crank damper needs to be a heavy one designed to contend with the torque trying to twist the crank in the 6000 to 7000 range. There's a big harmonic somewhere above 6000 rpm that needs to be dampened.
quote:
Originally posted by PanteraDoug:
... Don't pick one because it's prettier. Big fat and ugly is better ...
Reminds me of an old song ... If you want to be happy for the rest of your life ...