[eschaider]

Even with TiVCT the low speed torque of the n/a Coyote is not on par with a large displacement pushrod engine. When you supercharge, it is easily the same or more low speed torque.

Low speed torque translates into responsiveness to the driver's gas pedal commands. High torque means electric vehicle like throttle response. Low torque means Sunday go to meeting like throttle response.

When ford built the Coyote they used a 100mm bore center block. The Coyote has a 3.629" bore that translates into a 92.2mm bore size. With a 100mm bore center that only leaves a 7.8mm web between bores or 0.307".

A web thickness between cylinders of .3" works OK for n/a engines but not so well for s/c engines. The gasket web between cylinders becomes noticeably tender above 15 lbs of boost — particularly in daily driver type usage.

To get the kind of low speed torque the larger pushrod V8's have you will need 16 to 18 psi of boost. That will put you into the uncomfortable gasket leakage between cylinders space. In an aluminum block using a supercharger, that leak across the webbing between cylinders will torch the block and head.

The engine Ford worked hard to kill at the Coyote introduction (the 4.6L SVT Cobra) was a supercharged 100mm bore center block with 90.2mm bores and 9.8mm (0.386") webbing between cylinder bores. Even with the increased web thickness the seal between cylinders became tender above 24 psi.

The Coyote may not be the best pick for what you are trying to do. Someone on the site here had one of Ford's FR500C big bore 5 liter n/a road race engines in his Cobra. For a while he used to promote how his engine would sing at 7000 or 8000 rpm — I forget which anymore. He eventually sold the car and bought a Kirkham with a 482 or so inch FE. He had experience with both the high torque pushrod engine and also the high power high rpm small displacement model. He had to admit the pushrods and big inches were more satisfying.

You can get around the inches issue with a blower but with head gaskets being a tender spot you will quickly tire of the repair / maintenance required by that engine build model.


Ed


p.s. you can get the lumpy idle by just tightening up on the lobe separation angle for the intake and exhaust cams.