When it comes to Modular Engine blocks, you'll find there are as many as 12 different castings, but the basic architecture is the same so any heads will bolt up.
For performance applications i recommend finding a 1996-up block because these (Romeo and Windsor) have cross-bolts used on all five main caps.
Windsor blocks use dowels, and most Romeo blocks use jackscrews, neither have proven to be stronger than the other.
Most have found about 10 different cast numbers for blocks (from 1991-present), some are better than others. The Romeo plant built the first block, which was the F1AE, and it was used through early 1992. It was replaced by the F2VE casting at the same time Ford released the AODE transmission in RWD cars. This block was superseded by the F4VE, which is identical to the F2VE. All three blocks are virtually the same and have hollow dowels to align the transmission.
The next block in the long lineup is the Romeo-built F65E, but Ford also cast the F6VE and the F7VE. All three blocks are visually and dimensionally the same, have cross-bolts on all five main caps, and were used from 1996-98. There is a threaded hole in the cylinder valley for a knock sensor. These blocks are preferred over earlier blocks and will work in all RWD cars. The Romeo plant also built engines with a F7AE and XW7E casting number. They were primarily used in trucks from 1997-99 but can be used in passenger cars.
Production of the Windsor blocks began in 1996 with the F65E-BB and the F75E. Windsor blocks have cross-bolts on all five main caps and the bolt pattern on the front of the blocks is the same as earlier Romeo blocks. However, some of the holes may be 10 mm instead of 8 mm. This is important if you are purchasing a blower because the compressor bracket attaches to the front cover.
The stock crank in 1991-95 Romeo-built SOHC engines is the F1AE casting that is made from nodular iron. It has six, knife-edged counterweights (the front one measuring .960 to .980 inch), and the flywheel flange has six holes.
Beginning in 1996, Romeo engines used a similar crank that carries cast No. F65E. This crank also has a six-bolt flange, but the front counterweight measures .920 to .940 inch. Therefore, you may find an interference problem when installing an F1AE crank in a 1996-up block.
All Windsor engines came with the F65E crank, but some had a six-bolt flange, and some came with eight. The most desirable crankshaft is the forged steel unit found in 1996-03 Cobra engines (cast No. F2LE-AG). The Cobra crank can be used in iron-block SOHC engines as long as the eight-bolt flywheel is used (SOHC passenger-car cranks have a six-bolt pattern). Note: Windsor engines may have a different crank (cast No. F65E), which has a smaller front counterweight (.920 inch thick versus .940 inch on the F1AE) so any Windsor engines must be built using the F65E crankshaft or an interference problem may occur between the counterweight and the main area in the block.
-Connecting Rods
All 4.6 engines (except the 2003 Cobra) were fitted with powdered metal rods that have cracked caps. Generally, passenger car engines from the Romeo plant got press-fit piston pins, while Windsor engines got floating pins. Rods can be interchanged, but we recommend using aftermarket steel rods in any performance applications.
-Pistons
Ford used three different pistons in the 4.6 engines. The 1991-99 Romeo pistons have a 10.5cc dish and a 1.5mm/1.5mm/3.0mm ring package, and the pin was press fit to the connecting rod. The 1996-99 Windsor (non-Power Improved) pistons have the same dish and ring dimensions but are of the floating type with circlips holding the pins in place. Lastly, Windsor PI engines have different pistons with a larger (18.5cc) dish to reduce compression, on the PI engines, due to the closed chamber heads.
Therefore, it must be noted that a rise in compression (to about 10.5:1) will result when PI heads are installed on a 1991-98 engine.
For performance applications i recommend finding a 1996-up block because these (Romeo and Windsor) have cross-bolts used on all five main caps.
Windsor blocks use dowels, and most Romeo blocks use jackscrews, neither have proven to be stronger than the other.
Most have found about 10 different cast numbers for blocks (from 1991-present), some are better than others. The Romeo plant built the first block, which was the F1AE, and it was used through early 1992. It was replaced by the F2VE casting at the same time Ford released the AODE transmission in RWD cars. This block was superseded by the F4VE, which is identical to the F2VE. All three blocks are virtually the same and have hollow dowels to align the transmission.
The next block in the long lineup is the Romeo-built F65E, but Ford also cast the F6VE and the F7VE. All three blocks are visually and dimensionally the same, have cross-bolts on all five main caps, and were used from 1996-98. There is a threaded hole in the cylinder valley for a knock sensor. These blocks are preferred over earlier blocks and will work in all RWD cars. The Romeo plant also built engines with a F7AE and XW7E casting number. They were primarily used in trucks from 1997-99 but can be used in passenger cars.
Production of the Windsor blocks began in 1996 with the F65E-BB and the F75E. Windsor blocks have cross-bolts on all five main caps and the bolt pattern on the front of the blocks is the same as earlier Romeo blocks. However, some of the holes may be 10 mm instead of 8 mm. This is important if you are purchasing a blower because the compressor bracket attaches to the front cover.
The stock crank in 1991-95 Romeo-built SOHC engines is the F1AE casting that is made from nodular iron. It has six, knife-edged counterweights (the front one measuring .960 to .980 inch), and the flywheel flange has six holes.
Beginning in 1996, Romeo engines used a similar crank that carries cast No. F65E. This crank also has a six-bolt flange, but the front counterweight measures .920 to .940 inch. Therefore, you may find an interference problem when installing an F1AE crank in a 1996-up block.
All Windsor engines came with the F65E crank, but some had a six-bolt flange, and some came with eight. The most desirable crankshaft is the forged steel unit found in 1996-03 Cobra engines (cast No. F2LE-AG). The Cobra crank can be used in iron-block SOHC engines as long as the eight-bolt flywheel is used (SOHC passenger-car cranks have a six-bolt pattern). Note: Windsor engines may have a different crank (cast No. F65E), which has a smaller front counterweight (.920 inch thick versus .940 inch on the F1AE) so any Windsor engines must be built using the F65E crankshaft or an interference problem may occur between the counterweight and the main area in the block.
-Connecting Rods
All 4.6 engines (except the 2003 Cobra) were fitted with powdered metal rods that have cracked caps. Generally, passenger car engines from the Romeo plant got press-fit piston pins, while Windsor engines got floating pins. Rods can be interchanged, but we recommend using aftermarket steel rods in any performance applications.
-Pistons
Ford used three different pistons in the 4.6 engines. The 1991-99 Romeo pistons have a 10.5cc dish and a 1.5mm/1.5mm/3.0mm ring package, and the pin was press fit to the connecting rod. The 1996-99 Windsor (non-Power Improved) pistons have the same dish and ring dimensions but are of the floating type with circlips holding the pins in place. Lastly, Windsor PI engines have different pistons with a larger (18.5cc) dish to reduce compression, on the PI engines, due to the closed chamber heads.
Therefore, it must be noted that a rise in compression (to about 10.5:1) will result when PI heads are installed on a 1991-98 engine.
