Modified Mustangs & FordsHow To Engine
Turbocharged Six Cylinder Ford Mustang - Inline Is Real Fine
McLearran Racing And Classic Inlines Build A Turbocharged, Intercooled, Six-Cylinder Powerhouse
Ford six-cylinder heads didn't change much over the long production life of these engines. In fact, all heads are interchange-able. For the engine to perform properly, however, you must con-sider chamber size as well as valve and port size. It gets even more complex with Ford South America and Ford Australia head castings, which are better than North America's. Because these engines remained in production longer Down Under than they did in North America, there are some pretty terrific head castings available if you know where to look. There are composite castings with removable intake manifolds as well as a crossflow head. Classic Inlines can give you insight on where to find them.
The greatest shortcoming of the North American head is an integral, log-style intake manifold. Ford did this for cost reasons, but this head breathes poorly, and fuel-droplet distribution is horrid. Some heads, as a matter of luck and casting irregularity only, do better than others. Most of them cause poor idle quality and stumble-both difficult issues to overcome.
If you're going to stick with a North American head, base your choice on casting number and dimensions. Check chamber size and design. Are the valves shrouded or unshrouded? What happens if you machine the deck and wind up with a smaller chamber? Which head should you choose for your six-cylinder project? We discourage the use of early Ford 144ci and 170ci head castings because there's nothing to be gained from them. Chamber size will help compression and theoretically gain power, but valve sizing and shrouding will hurt performance-in short, no gain.
According to The Ford Falcon Six Cylinder Performance Handbook, the best heads to use are '77-and-later 200/250ci castings as they have the largest valves (1.76/1.38 inches intake/exhaust). They also have hardened exhaust valve seats from the factory and don't require modification. Chamber size is ideal at 60-62 cc. The book suggests checking chamber size before committing to a casting. Intake manifold volume is also larger with this head.
For more information on this book or to order one, contact Dave Schjeldahl at 582 Safstrom Pl., Idaho Falls, ID 83401; (208) 523-2763; or check out www.falconperformance.sundog.net.
|Classic Inlines Head Facts|
|Chamber Size||56 cc|
|Intake Valve Size||1.840 inches|
|Intake Port Volume||52 cfm at 0.100-inch lift|
|99 cfm at 0.200-inch lift|
|143 cfm at 0.300-inch lift|
|180 cfm at 0.400-inch lift|
|201 cfm at 0.500-inch lift|
|210 cfm at 0.600-inch lift|
|Exhaust Valve Size||1.500 inches|
|Exhaust Port Volume||40 cfm at 0.100-inch lift|
|79 cfm at 0.200-inch lift|
|111 cfm at 0.300-inch lift|
|144 cfm at 0.400-inch lift|
|164 cfm at 0.500-inch lift|
|174 cfm at 0.600-inch lift|
|Manufacturer PN||Lobe Center||Intake Lift||Exhaust Lift||Intake Duration||Exhaust Duration|
|Clay Smith S294-112||112||0.528 inch||0.528 inch||240 at 0.050||240 at 0.050|
|Note: This camshaft grind is designed for turbocharging. Talk to a Clay Smith expert or Classic Inlines about a camshaft grind suitable for your application.|
Building a Turbo-Six ScreamerYou've got to love inline-sixes to fully appreciate why Winterboer and the McLearrans possess such a serious commitment to these engines.
The McLearrans cracked the 10-second barrier by understanding how inline Ford sixes make power. Kelly's automatic turbo Falcon has been the acid test with blown engines, painful setbacks, and learning the hard way what works and what doesn't.
The McLearrans will show us how to build a solid, reliable Ford six that will make upwards of 350-400 hp using a carburetor, and Winterboer would like to do it with electronic fuel injection.