RULE #1
to consistently win races you need to finish races with the engine still fully functional, and that generally means keeping piston speeds UNDER 4500 Feet Per Minute even with good aftermarket components and 4000fpm-to-4200fpm with stock or factory high performance parts
just for discussion sake here.....
lets discuss why you factor in piston speeds
Ill point out that the probable strength limitations,
in the 355 block and rotating assembly
(assuming good forged components and ARP main studs are used)
yes as pointed out earlier, both engines below would be pushing well past the limitations imposed by a STOCK, O.E.M. production block
but assuming that the O.E.M block will hold up at least for a hundred 1/4 mile passes,before it comes violently apart at peak rpm, that stress limitation,
will be imposed by both common valve spring limitations and piston speed on the rotating assembly and block,
on a 355 chevy with its 3.48" stroke , (assuming a 4200 fpm max reasonable piston speed)
has a peak rpm near 6700-7200 engine rpm, selecting a cam that peaks below about 6700 rpm-7000 rpm,)
leaves the potential advantage of that shorter stroke the 355 sbc on the table.
this is one reason that the 383 with its longer 3.75" stroke is currently the most popular combo with a 4.30 bore block.
if your going to build a 355, then you may as well take full advantage of the engines potential strong points.
a similar longer stroke 383 would be limited to about 6300 rpm-6700 rpm but the trade off is about 40 ft lbs more torque over most of the potential power band
the formula for hp is
torque x rpm/5252= hp
if both engines make about 1.2 hp per cubic inch
the 383 will peak about 400 rpm lower than the 355 if both are built to maximize the engines potential strong points
just for giggles and to point out
why you maximize a RACE ENGINE potential RPM LIMITS
lets assume the 355 power peak is at about 6800 rpm and,
the similar 383 would be peaking nearer 6400 rpm
if you have 1.2 x 355=426 ft lbs x 6800 rpm /5252=551 hp
if you have 1.2 x 383=460 ft lbs x 6400 rpm /5252=560 hp
Chevy V8 bore & stroke chart
I saw this online and figured I would post it..I am going to add the popular lsx strokers soon
CID BORE STROKE
262 = 3.671" x 3.10" (Gen. I, 5.7" rod)
265 = 3.750" x 3.00" ('55-'57 Gen.I, 5.7" rod)
265 = 3.750" x 3.00" ('94-'96 Gen.II, 4.3 liter V-8 "L99", 5.94" rod)
267 = 3.500" x 3.48" (Gen.I, 5.7" rod)
283 = 3.875" x 3.00" (Gen.I, 5.7" rod)
293 = 3.779" x 3.27" ('99-later, Gen.III, "LR4" 4.8 Liter Vortec, 6.278" rod)
302 = 4.000" x 3.00" (Gen.I, 5.7" rod)
305 = 3.736" x 3.48" (Gen.I, 5.7" rod)
307 = 3.875" x 3.25" (Gen.I, 5.7" rod)
325 = 3.779" x 3.622" ('99-later, Gen.III, "LM7", "LS4 front wheel drive V-8" 5.3 Liter Vortec, 6.098" rod)
327 = 4.000" x 3.25" (Gen.I, 5.7" rod)
345 = 3.893" x 3.622" ('97-later, Gen.III, "LS1", 6.098" rod)
350 = 4.000" x 3.48" (Gen.I, 5.7" rod)
350 = 4.000" x 3.48" ('96-'01, Gen. I, Vortec, 5.7" rod)
350 = 3.900" x 3.66" ('89-'95, "LT5", in "ZR1" Corvette 32-valve DOHC, 5.74" rod)
364 = 4.000" x 3.622" ('99-later, Gen.III, "LS2", "LQ4" 6.0 Liter Vortec, 6.098" rod)
376 = 4.065" x 3.622" (2007-later, Gen. IV, "L92", Cadillac Escalade, GMC Yukon)
383 = 4.000" x 3.80" ('00, "HT 383", Gen.I truck crate motor, 5.7" rod)
400 = 4.125" x 3.75" (Gen.I, 5.565" rod)
427 = 4.125" x 4.00" (2006 Gen.IV, LS7 SBC, titanium rods)
Two common, non-factory smallblock combinations:
377 = 4.155" x 3.48" (5.7" or 6.00" rod)
400 block and a 350 crank with "spacer" main bearings
383 = 4.030" x 3.75" (5.565" or 5.7" or 6.0" rod)
350 block and a 400 crank, main bearing crank journals
cut to 350 size
ALL production big blocks used a 6.135" length rod.
CHEVY BIG BLOCK V-8 BORE AND STROKE
366T = 3.935" x 3.76"
396 = 4.096" x 3.76"
402 = 4.125" x 3.76"
427 = 4.250" x 3.76"
427T = 4.250" x 3.76"
454 = 4.250" x 4.00"
477= 4.5" bore x 3.76" stroke
496 = 4.250" x 4.37" (2001 Vortec 8100, 8.1 liter)
502 = 4.466" x 4.00"
557T= 4.5 bore 4.375" stroke
572T = 4.560" x 4.375" (2003 "ZZ572" crate motors)
T = Tall Deck
ALL production big blocks used a 6.135" length rod.
http://forum.grumpysperformance.com/viewtopic.php?f=53&t=510&hilit=redline
http://forum.grumpysperformance.com/viewtopic.php?f=53&t=343&p=1170&hilit=redline#p1170
RULE #2
OIL PRESSURE AND VOLUME and REASONABLE TEMPS MUST BE CONSISTENTLY MAINTAINED
most moving parts failures are related to lack of consistently maintained pressurized lubrication by oil at reasonable temperatures
viewtopic.php?f=54&t=2187
viewtopic.php?f=54&t=1800
viewtopic.php?f=54&t=64
viewtopic.php?f=54&t=8966
viewtopic.php?f=54&t=6327
viewtopic.php?f=54&t=2294
viewtopic.php?f=54&t=615
RULE #3
to consistently perform well a car must have a high power to weight ratio and be geared to match the engines power curve
viewtopic.php?f=71&t=741
viewtopic.php?f=71&t=7082
viewtopic.php?f=71&t=555
viewtopic.php?f=87&t=9731&p=37718&hilit=take+fast+weight#p37718
viewtopic.php?f=87&t=3404&p=33377&hilit=take+fast+weight#p33377
RULE #4
THINK THRU WHAT YOUR BUDGET AND GOALS , AND PERSONAL SKILLS ARE GOING TO SUPPORT
viewtopic.php?f=50&t=10363&p=42683&hilit=what+makes+good+engine#p42683
viewtopic.php?f=69&t=9930&p=38054&hilit=what+makes+good+engine#p38054
viewtopic.php?f=50&t=9040&p=32309&hilit=what+makes+good+engine#p32309
viewtopic.php?f=69&t=7722&p=26314&hilit=what+makes+good+engine#p26314
viewtopic.php?f=87&t=10408
to consistently win races you need to finish races with the engine still fully functional, and that generally means keeping piston speeds UNDER 4500 Feet Per Minute even with good aftermarket components and 4000fpm-to-4200fpm with stock or factory high performance parts
just for discussion sake here.....
lets discuss why you factor in piston speeds
Ill point out that the probable strength limitations,
in the 355 block and rotating assembly
(assuming good forged components and ARP main studs are used)
yes as pointed out earlier, both engines below would be pushing well past the limitations imposed by a STOCK, O.E.M. production block
but assuming that the O.E.M block will hold up at least for a hundred 1/4 mile passes,before it comes violently apart at peak rpm, that stress limitation,
will be imposed by both common valve spring limitations and piston speed on the rotating assembly and block,
on a 355 chevy with its 3.48" stroke , (assuming a 4200 fpm max reasonable piston speed)
has a peak rpm near 6700-7200 engine rpm, selecting a cam that peaks below about 6700 rpm-7000 rpm,)
leaves the potential advantage of that shorter stroke the 355 sbc on the table.
this is one reason that the 383 with its longer 3.75" stroke is currently the most popular combo with a 4.30 bore block.
if your going to build a 355, then you may as well take full advantage of the engines potential strong points.
a similar longer stroke 383 would be limited to about 6300 rpm-6700 rpm but the trade off is about 40 ft lbs more torque over most of the potential power band
the formula for hp is
torque x rpm/5252= hp
if both engines make about 1.2 hp per cubic inch
the 383 will peak about 400 rpm lower than the 355 if both are built to maximize the engines potential strong points
just for giggles and to point out
why you maximize a RACE ENGINE potential RPM LIMITS
lets assume the 355 power peak is at about 6800 rpm and,
the similar 383 would be peaking nearer 6400 rpm
if you have 1.2 x 355=426 ft lbs x 6800 rpm /5252=551 hp
if you have 1.2 x 383=460 ft lbs x 6400 rpm /5252=560 hp
Chevy V8 bore & stroke chart
I saw this online and figured I would post it..I am going to add the popular lsx strokers soon
CID BORE STROKE
262 = 3.671" x 3.10" (Gen. I, 5.7" rod)
265 = 3.750" x 3.00" ('55-'57 Gen.I, 5.7" rod)
265 = 3.750" x 3.00" ('94-'96 Gen.II, 4.3 liter V-8 "L99", 5.94" rod)
267 = 3.500" x 3.48" (Gen.I, 5.7" rod)
283 = 3.875" x 3.00" (Gen.I, 5.7" rod)
293 = 3.779" x 3.27" ('99-later, Gen.III, "LR4" 4.8 Liter Vortec, 6.278" rod)
302 = 4.000" x 3.00" (Gen.I, 5.7" rod)
305 = 3.736" x 3.48" (Gen.I, 5.7" rod)
307 = 3.875" x 3.25" (Gen.I, 5.7" rod)
325 = 3.779" x 3.622" ('99-later, Gen.III, "LM7", "LS4 front wheel drive V-8" 5.3 Liter Vortec, 6.098" rod)
327 = 4.000" x 3.25" (Gen.I, 5.7" rod)
345 = 3.893" x 3.622" ('97-later, Gen.III, "LS1", 6.098" rod)
350 = 4.000" x 3.48" (Gen.I, 5.7" rod)
350 = 4.000" x 3.48" ('96-'01, Gen. I, Vortec, 5.7" rod)
350 = 3.900" x 3.66" ('89-'95, "LT5", in "ZR1" Corvette 32-valve DOHC, 5.74" rod)
364 = 4.000" x 3.622" ('99-later, Gen.III, "LS2", "LQ4" 6.0 Liter Vortec, 6.098" rod)
376 = 4.065" x 3.622" (2007-later, Gen. IV, "L92", Cadillac Escalade, GMC Yukon)
383 = 4.000" x 3.80" ('00, "HT 383", Gen.I truck crate motor, 5.7" rod)
400 = 4.125" x 3.75" (Gen.I, 5.565" rod)
427 = 4.125" x 4.00" (2006 Gen.IV, LS7 SBC, titanium rods)
Two common, non-factory smallblock combinations:
377 = 4.155" x 3.48" (5.7" or 6.00" rod)
400 block and a 350 crank with "spacer" main bearings
383 = 4.030" x 3.75" (5.565" or 5.7" or 6.0" rod)
350 block and a 400 crank, main bearing crank journals
cut to 350 size
ALL production big blocks used a 6.135" length rod.
CHEVY BIG BLOCK V-8 BORE AND STROKE
366T = 3.935" x 3.76"
396 = 4.096" x 3.76"
402 = 4.125" x 3.76"
427 = 4.250" x 3.76"
427T = 4.250" x 3.76"
454 = 4.250" x 4.00"
477= 4.5" bore x 3.76" stroke
496 = 4.250" x 4.37" (2001 Vortec 8100, 8.1 liter)
502 = 4.466" x 4.00"
557T= 4.5 bore 4.375" stroke
572T = 4.560" x 4.375" (2003 "ZZ572" crate motors)
T = Tall Deck
ALL production big blocks used a 6.135" length rod.
http://forum.grumpysperformance.com/viewtopic.php?f=53&t=510&hilit=redline
http://forum.grumpysperformance.com/viewtopic.php?f=53&t=343&p=1170&hilit=redline#p1170
RULE #2
OIL PRESSURE AND VOLUME and REASONABLE TEMPS MUST BE CONSISTENTLY MAINTAINED
most moving parts failures are related to lack of consistently maintained pressurized lubrication by oil at reasonable temperatures
viewtopic.php?f=54&t=2187
viewtopic.php?f=54&t=1800
viewtopic.php?f=54&t=64
viewtopic.php?f=54&t=8966
viewtopic.php?f=54&t=6327
viewtopic.php?f=54&t=2294
viewtopic.php?f=54&t=615
RULE #3
to consistently perform well a car must have a high power to weight ratio and be geared to match the engines power curve
viewtopic.php?f=71&t=741
viewtopic.php?f=71&t=7082
viewtopic.php?f=71&t=555
viewtopic.php?f=87&t=9731&p=37718&hilit=take+fast+weight#p37718
viewtopic.php?f=87&t=3404&p=33377&hilit=take+fast+weight#p33377
RULE #4
THINK THRU WHAT YOUR BUDGET AND GOALS , AND PERSONAL SKILLS ARE GOING TO SUPPORT
viewtopic.php?f=50&t=10363&p=42683&hilit=what+makes+good+engine#p42683
viewtopic.php?f=69&t=9930&p=38054&hilit=what+makes+good+engine#p38054
viewtopic.php?f=50&t=9040&p=32309&hilit=what+makes+good+engine#p32309
viewtopic.php?f=69&t=7722&p=26314&hilit=what+makes+good+engine#p26314
viewtopic.php?f=87&t=10408
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