the piston and rods are always in compression. however the crank is in tension/torsional. and tensional force is always harder on materials and torsional is the hardest on metal. this is why the crank MUST be forged. on low spin engines cast rods are fine because they are lighter but weaker. for all high power or high spin engines the rods must be forged. forged pistons are incredibly rare.
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Originally posted by kronus View PostPretty sure rods are in tension on at least one of the four cycles...
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Originally posted by Danny View PostThe pistons. Then the rods. It doesn't matter. The low boost setup you're talking about running but will never actually be running won't hurt anything. Mostly due to the fact you won't be running it ;)
but yeah. don't worry about the bottom end parts. difference between cast and forged comes into play at 1+bar/above 7000rpm.
also: the M20 is also a "tiny" engine, just a heavier one with shitty head cfm numbers that's a pain in the ass to work on because it's shoehorned into a space designed for M/S1* derivatives. compare M42 (or the last 4 cylinders of an M50) vs. M20 flow bench sometime.past:
1989 325is (learner shitbox)
1986 325e (turbo dorito)
1991 318ic (5-lug ITB)
1985 323i baur
current:
1995 M3 (suspension, 17x9/255-40, borla)
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Originally posted by RUFFLZsomeone hop on this like yesterday!
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Originally posted by dk View Postzing!
but yeah. don't worry about the bottom end parts. difference between cast and forged comes into play at 1+bar/above 7000rpm.
also: the M20 is also a "tiny" engine, just a heavier one with shitty head cfm numbers that's a pain in the ass to work on because it's shoehorned into a space designed for M/S1* derivatives. compare M42 (or the last 4 cylinders of an M50) vs. M20 flow bench sometime.
Originally posted by Danny View PostThe pistons. Then the rods. It doesn't matter. The low boost setup you're talking about running but will never actually be running won't hurt anything. Mostly due to the fact you won't be running it ;)
Originally posted by ohthejosh View PostThinking of reverting my car back to DBs and justing waiting for an opportunity to snatch me a set of euro bumpers.
Some opinions would be much appreciated.The first car I ever rode in was an e30
Originally posted by Cabriolet
Wish you the best and hope you don't remember anything after 10pm.
1992 Mauritiusblau Vert
2011 Alpinweiss 335is coupe
2002 540i/6 Black/Black
2003 GSX-R 750 (RIP)
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Originally posted by Vivek View PostDo it. Euro bumpers are better than plastics on an early model especially without a rear valance. And powdercoat them matte black when you paint your car it'll look amazing.
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Originally posted by Cabriolet View Postonly if the engine is not free flowing. the exhaust should be pulling the air into the cylinders on the intake stroke. but either way is very very low tension in compared to the 2 major compression strokes.
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Originally posted by Vivek View PostIsn't someone in SoCal selling a set for like $350?
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