3.50" SBC crankshaft

[cmus10]

Would someone please school me on the 3.50" crankshaft vs. the 3.48".
Advantage/Disadvantage?
Thanks

 

[grumpyvette]

yes there's a difference , in that the 3.50" stroke is generally an aftermarket crank, in theory adds a tiny extra stroke ,going from a stock chevy crank throw of 1.74" to the aftermarket 1.75"
but given that the stock block deck height tends to vary from 9.023 to 9.020 , and piston pin heights easily vary .001-.002 or more between manufacturers, and theres a wide variation in combustion chambers volumes, and head gasket, thickness and bore diameters , I don,t think your worrying about anything that maters much.

Id also ask why anyone would use a 350 chevy when components to build a 383 (3.75" stroke) or 396 (3.875" stroke) displacement engine combo
just don,t add a huge tab to the cost of the engine build?
Id also point out that the material the cranks made from and the quality of the machine work would concern me far more than the minor stroke differences.

rebuilt or new chevy 383 crank
http://www.superchevy.com/how-to/project-cars/sucp-0706-small-block-chevy-stroker-kit/

I generally just use SCAT cranks in my builds as Ive yet to have one fail in use
READ THRU THESE LINKS

viewtopic.php?f=53&t=204

viewtopic.php?f=53&t=5064

http://www.mre-books.com/chevy/engines/parts_interchange/crankshaft.html

http://www.chevydiy.com/1955-1996-chevy-small-block-performance-guide-crankshafts-manual-part-2/#

viewtopic.php?f=53&t=8310

viewtopic.php?f=53&t=9955

viewtopic.php?f=53&t=9527

http://scatenterprises.com/

http://adperformance.com/index.php?main ... ath=71_231

http://www.summitracing.com/search?Sort ... %20asembly

 

[cmus10]

Didn't plan on using one, just was asking for the head knowledge.

 

[grumpyvette]

Didn't plan on using one, just was asking for the head knowledge.

I,m generally curious about what effects the engines build quality also, so I understand where your coming from!
Chevy V8 bore & stroke chart


CHEVY SMALLBLOCK V-8 BORE AND 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

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"
496 = 4.250" x 4.37" (2001 Vortec 8100, 8.1 liter)
502 = 4.466" x 4.00"
572T = 4.560" x 4.375" (2003 "ZZ572" crate motors)

T = Tall Deck

ALL production big blocks used a 6.135" length rod.


CHEVY 348-409 V-8 BORE AND STROKE


348 = 4.125" x 3.25" (6.125" rod)
409 = 4.312" x 3.50" (6.010" rod)
427 = 4.312" x 3.65" (6.135" rod) 1963 "Z11" SHP drag race