Worn Crank Snout

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
327, small journal forged crank with snout drilled for balancer center bolt. Was going to do a leak down test and saw center bolt had come loose and was laying on garage floor. Went to reattach and realized harmonic balancer was wobbly. The keyway in the balancer was wollowed out. Mic'd the crank snout and it ranges from 1.234 at the very front of the crank to 1.246 inside the timing cover. Balancer ID measures 1.245. Balancer was Summit 8" OE Style SUM-161358. Same thing happened April 2018 and replaced balancer without mic'ing either. Probably drove less than 1000 miles since 4/2018.

Crankshaft Coalition says OE snout should range from 1.2460-1.2470. Am I looking at replacing the crank? Thanks.

its a P.I.T.A., but parts wear out, but you have options, a decent machine shop can weld and re-machine the crank snout ,
obviously that requires total engine disassembly , and yes it might be faster and cheaper to buy a replacement crank or use the opportunity to upgrade to a stroker crank assembly,
since you will already be forced to do a total re-assembly/rebuild ,
you can rebuild a 327 or look at this as an opportunity to find a machine shop that can sell you a cheap 350-383 rotating assembly,
yeah, any crank assembly must match your blocks main journal size and rods must match the crank,
and pistons must have the correct deck height,diameter and rods must also match the application.
you can,t randomly interchange components, some thought must go into the selection process.
you could certainly gain a significant boost in performance if you selected a 3.75" stroke crank to replace the 3.25" stroke crank the 327 had,
and matched pistons and connecting rods and the correct journal sizes to match.

750px-crank_snout_-_keyway_dimensions-jpg.196499

why not call a few local machine shops,
lots of old school machine shops have short blocks and cranks that got dropped off and never picked up,
call a few, too see if they have a small journal 327 crank in inventory,
around here I called a few and about $375 is the going price ,on a used 327 crank,
I did not get into the details,
but that certainly seems about right
yeah they might be .010/.010 under size but certainly new bearings and a new crank gets you back running, but if I was potentially going through all that work
a rebuilt 350 short block might be not much more expensive, if you trade in your 327 block,

http://garage.grumpysperformance.com/index.php?threads/damper-tool.223/#post-260

http://garage.grumpysperformance.com/index.php?threads/damper-honing.4975/#post-13912

http://garage.grumpysperformance.com/index.php?threads/scat-cranks-related-info.10930/

http://garage.grumpysperformance.com/index.php?threads/can-i-get-it-polished.9214/#post-91962

http://garage.grumpysperformance.com/index.php?threads/think-thru-your-goals.10606/#post-73288

http://garage.grumpysperformance.com/index.php?threads/repair-or-replace-350-crank.14181/#post-71931

http://garage.grumpysperformance.com/index.php?threads/bits-of-383-info.38/page-2#post-61958

http://garage.grumpysperformance.com/index.php?threads/bearing-clearances.2726/

http://garage.grumpysperformance.com/index.php?threads/bearing-clearances.2726/

http://garage.grumpysperformance.co...ould-you-build-a-350-or-a-383-sbc-combo.8310/


Chevy Smallblock V8 Crankshaft Journal Sizes


Gen.I, "Small Journal"
265...Mains-2.30"-Rods-2.00"
283...Mains-2.30"-Rods-2.00"
302...Mains-2.30"-Rods-2.00"
327...Mains-2.30"-Rods-2.00"




Gen.I, "Medium Journal", includes "Vortec" 305 and 350 thru '98
262...Mains-2.45"-Rods-2.10"
267...Mains-2.45"-Rods-2.10"
302...Mains-2.45"-Rods-2.10"
305...Mains-2.45"-Rods-2.10"
307...Mains-2.45"-Rods-2.10"
327...Mains-2.45"-Rods-2.10"
350...Mains-2.45"-Rods-2.10"
 
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