page_title: Fiat 128 SOHC engine
section_title: Design and production
hierarchical_section_title: Fiat 128 SOHC engine / Design and production
caption_attribution_description: English: A cut up Fiat 1,581cc SOHC engine in the Rahmi M. Koç Museum of Transportation.
context_page_description: Designed by Aurelio Lampredi, the Fiat SOHC engine first appeared in the front-wheel drive Fiat 128 of 1969. The in-line four-cylinder engine comprised an iron block with an aluminium cylinder-head containing a single overhead camshaft operating directly on both the inlet and exhaust valves in a reverse-flow cylinder-head configuration. The camshaft was driven by a belt rather than chain. The engine remained in production until about 2010 and grew in capacity over the years from 1100 cc to an eventual 1900 cc. The Fiat 130 2.9 L V6 engine, also appearing in 1969, although having crossflow cylinder head, is directly related to the 128 SOHC engine, but with a 1.20 upscale in bore and stroke. It was gradually replaced by the Pratola Serra engine series starting from 1995, although it was also converted to use a multivalve DOHC head, giving birth to the Torque engine, used until 2005.
context_section_description: The engine was designed as a transversely-mounted FWD-only power-plant being the second engine/gearbox combination to exhibit the now standard transverse engine-next-to-gearbox layout with unequal length driveshafts (the first was the Autobianchi Primula, the Mini had its gearbox in the sump of the engine). The exception to the engines FWD-only design is its revolutionary use as a mid-engine drive-train in the Fiat X1/9. Also Tofaş has adapted 128 engines into its Fiat 131 based longitudinally-mounted, front-engine, rear-wheel-drive layout platform. Unusual for the time was the electrically driven fan, rather than it being powered directly by the engine. The 128 engine has five crankshaft bearings.
  A prominent feature of the Fiat SOHC engine is its massively over-square proportions. This over-square design allows large (within the constrains of a reverse-flow configuration) valve sizes relative to engine capacity. A secondary benefit is the short crank throw reduces the accelerative forces on the con-rod allowing the engine to operate at significantly increased engine-speeds. The original engine's limit was only reached at 8000 rpm.
  The 1.3 L (1,301 cc) version was turbocharged and used in the Fiat Uno Turbo. The 1.4 L (1,372 cc) unit was also turbocharged and first used in the MkII Uno Turbo, then in the Punto GT.
  As with its bigger brother the famous Fiat DOHC (aka Fiat/Lancia Twincam) engine, the Fiat SOHC engine was shared with the Fiat subsidiary Lancia (appearing in 1,500 cc guise in the Lancia Delta/Prisma of the 1980s) as well as being used in the Fiat 128 derived Yugo.
  The final incarnation of the 128 SOHC engine was modified to use 16 valves and double overhead camshafts. The engine (using the designation "Torque") initially featured the bore-spacing, bore and stroke of the 1.6 L (1,581 cc) 159/160 series engine with a new 16 valve DOHC crossflow cylinder-head. To incorporate the extra oil-return-paths and symmetrical head (as opposed to the asymmetrical SOHC head) the cylinder-block was slightly revised making the DOHC head non-interchangeable with the previous incarnations of the 128 engine. It powered the Brava/Bravo, Marea and Multipla Fiat automobiles as well as the second-generation Lancia Delta. It was then replaced with a version based on the 1372 block with a longer stroke, displacing 1.6 L (1,596 cc), ending production in 2005. The same stroke of the later version was also used in Brazil with the earlier Torque block, giving birth to an 1.8 L (1,839 cc) version, used in the Linea.
caption: Cut apart 1,581 cc version of the 128 engine
exif: {"Image Make": "Canon", "Image Model": "Canon EOS DIGITAL REBEL XT", "Image Orientation": "Horizontal (normal)", "Image XResolution": "240", "Image YResolution": "240", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop CS5.1 Macintosh", "Image DateTime": "2013:03:03 02:34:31", "Image Artist": "Mr Choppers", "Image ExifOffset": "248", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "878", "Thumbnail JPEGInterchangeFormatLength": "12335", "EXIF ExposureTime": "1/4", "EXIF FNumber": "5", "EXIF ExposureProgram": "Program Normal", "EXIF ISOSpeedRatings": "400", "EXIF SensitivityType": "Unknown", "EXIF ExifVersion": "0221", "EXIF DateTimeOriginal": "2013:02:19 05:29:02", "EXIF DateTimeDigitized": "2013:02:19 05:29:02", "EXIF ShutterSpeedValue": "2", "EXIF ApertureValue": "290241/62500", "EXIF ExposureBiasValue": "-2/3", "EXIF MaxApertureValue": "139/32", "EXIF MeteringMode": "Pattern", "EXIF Flash": "Flash did not fire, compulsory flash mode", "EXIF FocalLength": "39", "EXIF ColorSpace": "Uncalibrated", "EXIF ExifImageWidth": "3051", "EXIF ExifImageLength": "2118", "EXIF FocalPlaneXResolution": "1728000/437", "EXIF FocalPlaneYResolution": "384000/97", "EXIF FocalPlaneResolutionUnit": "2", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF SceneCaptureType": "Standard", "EXIF CameraOwnerName": "Mr Choppers", "EXIF BodySerialNumber": "2020718684", "EXIF LensSpecification": "[18, 55, 0/0, 0/0]", "EXIF LensModel": "18.0-55.0 mm"}