How to Get More Horsepower Out of a Ford 289by Richard Rowe
If the 221 cubic inch Windsor V8 made waves, then its large-bore 289 successor was a tsunami. The 289 (1963-1968) was a high-revving, pint-sized powerhouse producing 195 and 210 horsepower in base trim (two or four barrel carburetor, respectively), and 271 horsepower in HiPo (High Performance) form. While the displacement-hungry horsepower wars of the 1960s later forced Ford to install a stroker crank (creating the 302), it was the 289 that first brought the joys of a high-revving, small displacement V8 to Ford fans worldwide.
Machine the block to bring it into spec, and bore the cylinders 0.060-inch over to increase displacement to 297 cubic inches. While not an enormous increase in displacement, the large bore will help to better un-shroud (allow air to flow away from) the large valves you'll be using, which will help the heads to work more efficiently. Micro polish the crankshaft and install new camshaft bearings.
Choose a cylinder head before you install the pistons. If you're going to use the stock 289 heads, install 1.84-inch intake valves, then port the intake and exhaust; these mods will net you about 185 cfm of intake port flow at 0.50 lift. Late-model ford GT40 and GT40P heads with 1.84-inch intake valves will also flow 185 cfm at 0.50-inch lift, but flow more than the 289 heads at all other lift ranges. A set of race-ported 351W C5AE heads will net you a whopping 215 cfm. More port flow equals more power, so choose carefully.
Install a set of forged H-beam rods and a set of forged pistons designed to deliver about 10.5:1 compression with whatever cylinder heads you choose. Coat the tops of the pistons, the roof of the combustion chambers and the insides of the intake/exhaust ports with thermally-insulating, ceramic-metallic powdercoating. This will keep combustion heat where it belongs, increasing power, decreasing coolant temps (a problem with over-bored Windsor motors) and increasing octane tolerance so that you can run 91-octane with your high compression pistons.
Install a split-pattern, hydraulic flat-tappet camshaft with about 219/233 (intake exhaust) duration at 0.050 valve lift, 275/283 advertised duration and 0.295" Intake and 0.304" exhaust lift (at the cam lobes). The Dual Energy cam used by Mustang Monthly met this spec, and delivered power in the 2,000-5,500 rpm range on their 331 stroker; expect about 500 rpm higher for your 297. A 270S cam will work if you like a smoother idle, but will cost some top-end power.
Install a high-flowing dual-plane intake, ceramic coated headers (stock 289 HiPo manifolds flow well and will fit nicely on GT40P heads if you opt to use them), a 675-750 cfm carburetor (or a retrofitted 5.0L electronic fuel injection system), and a good HEI-style aftermarket distributor.
- This combo should net you between 340 horsepower (ported 289 heads, smaller cam and carburetor) and 400 horsepower (race-ported heads, big cam and EFI), with a broad powerband from 2,000 rpm to about 6,000.
Richard Rowe has been writing professionally since 2007, specializing in automotive topics. He has worked as a tractor-trailer driver and mechanic, a rigger at a fire engine factory and as a race-car driver and builder. Rowe studied engineering, philosophy and American literature at Central Florida Community College.