Table of Contents
Differences between the Mazda and Kia FE3 Engines
For specific information on what vehicles had the FE-DOHC engine, Please see the Where to find a FE3 page.
Both the Mazda and Kia FE-DOHC engines were designed by Mazda, Kia produced them under license for the 1995 - 2003 Sportage. They share the same castings and dimensions for the bottom end of the block. All are 86mm Bore and Stroke with a rod/stroke ratio of 1.74. They have forged connecting rods, large journals, piston oilers, web-stiffened castings and a oil cooler from stock making them ideal for a turbo application. Standard they made between 130 and 162 horsepower with between 8.8:1 and 10.5:1 compression ratio depending on model. When forced induction is applied to the FE-DOHC up to 600hp has been seen on some engines, while it is generally accepted that a stock engine can make as much as 250hp with only uprated head gaskets and studs.
All Mazda variant FE-DOHC motors were mounted in an east/west configuration, because of this they had a distributor with built crank angle sensor. They also had the thermostat mounted on the rear of the cylinder head and head gasket was restricted in a way to allow optimal coolant flow. They have a 6 bolt flywheel and crank that is not interchangeable. They can come with the best variant of the cams available, But the exhaust cam is not interchangeable with the Kia because of the way it drives the distributor. They use standard top feed injectors with a variable intake length system called VICS.
All Kia variant FE-DOHC motors were mounted north/south configuration, because of this they have a cam angle sensor where the mazda has its distributor. They use a Crank angle sensor located in the bell housing of the gearbox and have a wasted spark coil on plug setup. Their thermostat is mounted on the front of the cylinder head and have a different head gasket design to the mazda. They have a 8 bolt flywheel and crankshaft that is not interchangeable. Generally speaking the stock cams on the kia variants is the lower duration variant, and its exhaust cam is different to the mazda so to trigger the cam angle sensor. They use air shrouded top feed injectors and a standard manifold.