M20

[Kroki]

Както си търсех информация попаднах на един текст, който до сега не бях срещал.


2.8, 2.9, 3.0 and 3.15

All of these options will require custom pistons except for the 2.8 which uses regular 325i pistons with eta rods. Mild build may be able to run factory fuel injection system with larger injectors, but for high power builds some sort of computer upgrade is required. With the exception of the 2.8, all should use 135 mm (5.3 in) rods sourced from a 325i. A much better option is to use the lighter weight rods from M52B28, S52B32 or M54B30 (these are the same part number) without any additional modification. Aftermarket rods are also available but not necessary for naturally aspirated builds. The stock rods have been proven over 7500 rpms and hundreds of horsepower.

Non-Eta-based strokers use the forged crankshafts from an M52, S50US, S52US, or M54 engines. These cranks all fit neatly into the M20 block with little modification. Block clearance should be checked and adjusted accordingly especially if using E30 325i rods. The installation of a spacer on the front of the crankshaft is needed to accommodate the front crank seal on the M20 and a different front crank bolt must be used. Sometimes a modified intermediate shaft is used where block clearance issues arise. All of these extra parts should come with any stroker kit sold by a reputable vendor.

Performance will vary depending on what other mods, if any, are made (cams, porting, exhausts etc.)and the quality of tuning.

2.8

Option 1: Eta-based (81mm stroke). Same as 2.7 options above except that the block gets bored out to 86 mm (3.4 in) and custom pistons are used

Option 2: m52 84mm crank (casting number 1748751 or part numbers [not found on crankshaft]11211433026 or 11211709059) with 325i pistons and ETA rods. This is the only stroker other than the 2.7 to use all stock parts. Using the m52 crank, 130 mm (5.1 in) ETA rods and 325i pistons results in the same compression height as a stock 325i, plus the increased displacement results in 9.7:1 compression ratio. Some have commented that this is a less than ideal rod stroke ratio of 1.54, but in fact the s52 is even worse at 1.51.

am e block or extensive modification to the bottom of the cylinder in order to clear the counterweights/connecting rods during a rotation though the pistons will require modification in order to clear the counterweights of the crank, or the crank needs to be lightened by removing surface from the outer radius of the crank in order to clear the pistons. Тhis nets about a 50 horsepower and 65 torque gain over stock do to the massive increase in stroke.

2.9

Same as 2.8 Option 2 but block bored to 86 mm (3.4 in) for 2.9 liters of displacement.

3.0

Option 1: Block bored to 86mm, 85.8 mm (3.4 in) S50B30US crank used for 3.0 liters of displacement.

Option 2: Bore unchanged (84mm), Install 89.6 mm (3.5 in) crank from S52US or M54B30 for 3.0 liters.

3.15/3.2

In this option, the block is bored to 86 mm (3.4 in) and the 89.6 mm (3.5 in) crank is used for 3.15 liters. It has been reported that engine-builders have bored out as far as 86.4 for an even 3.2 liters but this is beyond the generally accepted design limitations of the M20 block.

Някой в БГ да е правил повече от 2.8 ? Заслужава ли си да се разпилва толкова? Надявам се да стане една приятна дискусия

[Bavarcho]

Един прожект 331is
друго четиво

[bum_bum]

Тия текстове е желателно да се превеждат, ако се пускат във форума.

[climbernoob1 Профил]

Някой в БГ да е правил повече от 2.8 ? Заслужава ли си да се разпилва толкова? Надявам се да стане една приятна дискусия

Много пара искат сетъп-ите след 2.8..
Заслужава си, ако ти се кара атмосферка, а ефекта ще е учудващ..

[slavianko Профил Уеб-сайт]

Някой в БГ да е правил повече от 2.8 ? Заслужава ли си да се разпилва толкова? Надявам се да стане една приятна дискусия

Много пара искат сетъп-ите след 2.8..
Заслужава си, ако ти се кара атмосферка, а ефекта ще е учудващ..

Никога не си заслужава да правиш атмосверка. Не и ако не си червив с пари и не те бърка колко ще дадеш и искаш да си направиш експеримент.

[smurf4o Профил]

това е извадено от wikipedia....
дайте нещо което не се намира чак толкова лесно и е бъкано с полезна информация която да се чудиш от къде да почнеш да я помниш

[tuningfena Профил]

интересно , но като има вече достъпни по големи двигатели май не си струва