Guide To Ford Six-Cylinder Performance

This is the FSP-250-IMC manifold with port fuel injection and a large 70mm throttle body.

You can also adapt the FSP-250-IMW manifold for Weber carburetors or multiple throttle bodies. The manifold flanges are machined from 3-inch aluminum. You can really dial in your level of performance with this setup.

This is the FSP-250-IMC manifold for the 250 iron and aluminum head. It's available three ways: 4V-A with a conventional four-barrel flange for Holley and Autolite 4100 carburetors, 2V-A for two-barrel carburetors such as the Autolite 2100 or a comparable Holley, or 2V-B with the two-barrel flange positioned sideways.

The D.U.I. (Davis Unified Ignition) ignition system is perfect for any Ford six, stock or modified, because it reliably delivers a hotter spark. Live Wires from Performance Distributors provide reliable spark delivery with virtually no chance of crossfire.

Three types of headers are available from Classic Inlines for Ford sixes: two long-tube and one shorty type. High-temperature coatings are available. These are outstanding quality with 3?8-inch-thick flanges and solid welding for exceptional integrity.

Check out these long-tube headers on an Australian Ford 250ci six with a crossflow head.

This is the new Vaporizer 1100 carburetor from Pony Carburetors. Not a rebuild, it's all new from the inside out with annular fuel discharge for better performance and fuel economy. Pony Carburetors took the Autolite 1100 design and went back to the drawing board, conceiving a factory look with better technology inside.

This six sports an FSP-250-IMC intake, an aluminum head with Holley carburetion, and Classic Inlines' finned aluminum valve cover.

Here's another variation of the same thing with the IMC manifold, long-tube headers, and D.U.I. from Performance Distributors. This not only performs well, but also looks terrific.

Check out this Mustang six with the Aussie OZ 250 head and SU carburetion. Motorcraft Dura-Spark lights the fire.

Here's a Paxton supercharged Ford six sporting FSP induction, Holley carburetion, and the Classic Inlines aluminum head.

Classic Inlines' rolling showcase for Ford six performance is a turbocharged, port fuel-injected '69 Mustang SportsRoof with a five-speed, Mustangs Plus suspension, and Baer brakes. The Mustang Shop in Chandler, Arizona, did most of the work along with McLearren Motorsport.

This is an Australian Falcon, but you get the idea. The Aussie 4.0L Intech overhead cam six is based on the 250ci tall-deck six. If you're thinking about a 4.6L SOHC or DOHC V-8, consider the Aussie six for something decidedly different.

If you want to build a six-cylinder Mustang, it's a good idea to have a quick reference book filled with useful information. David and Dennis Schjeldahi wrote and published The Ford Falcon Six Cylinder Performance Handbook to make it easier to sift through fact and fiction regarding Ford sixes. This 91-page handbook is loaded with information for when it's time to build your six-cylinder restomod. It's available from Classic Inlines.

Dyno-Testing Carbs
Classic Inlines took a trip down to Pony Carburetors in Las Cruces, New Mexico, to test its all-aluminum induction and cylinder head package with Autolite 2100 two-barrel and 4100 four-barrel carburetion. The baseline was 177 hp with a 500-cfm Holley two-barrel carburetor, which is pretty darned good. When Pony Carburetors bolted on a 480-cfm Autolite 4100 carburetor, the result was 211 hp, a 34hp gain. Another run netted 222 hp. We're talking excess of 200 hp at the rear wheels.Pony Carburetors also tested a variety of Autolite 2100 two-barrel carburetors, but it got less power regardless of size. The best result was achieved with a 1.02-inch carburetor. This tells us that the 4100, or a comparable Holley 4150 or 4160 four-barrel, makes more power than a two-barrel regardless of size. In normal driving, expect more torque and improved fuel economy as well.