S&S CYCLE SKU: T14-663804

S&S Cycle Crankcases — 1999-2006 Harley-Davidson

$2,155.95
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S&S Cycle crankcase for 1999-2006 Harley Twin Cam 88A engines, designed with reinforced construction and larger bearing surfaces to handle high-performance builds. Cast in 4-1/8" wrinkle black finish with oversized front motor mount and clearance for aggressive cam profiles up to .675" lift.

Features

  • S&S breather reed valve eliminates oil carry-over
  • Large cam chest for up to .675" cam lift without clearancing
  • Timken-style sprocket shaft bearings
  • Extra-large front motor mount for increased strength
  • Pinion and bearing hardware included

Specifications

  • Brand: S&S Cycle
  • Manufacturer Part #: 31-0178A
  • Finish: Wrinkle black
  • Stud Pattern: 4-1/8"
  • Weight: 40 lb
  • Category: Engine Components / Crankshafts

Fitment

Fits 1999-2006 Harley-Davidson Twin Cam 88A engines. Will not fit 2006 Dyna models.

Frequently Asked Questions

Does this fit my 2006 Dyna?

No — this crankcase is not compatible with 2006 Dyna models. Check the specific year and model before ordering.

What's included in the kit?

The S&S crankcase, S&S breather reed valve, pinion, Timken bearing, and all mounting hardware.

Can I use this with a big-lift cam?

Yes — the large cam chest allows cam lift up to .675" without requiring port clearancing.

Does this eliminate oil scavenging problems?

The S&S breather reed valve design reduces oil carry-over and scavenging issues common with stock crankcases.

BRANDS&S Cycle
TYPECrankshafts
SKUT14-663804
WEIGHT40.0 lb
Please contact us to confirm fitment for your specific motorcycle, or check the product title for compatibility notes.
CUSTOMER REVIEWS
4.88
16 RATINGS
5★ 14
4★ 2
3★ 0
2★ 0
1★ 0
✓ VERIFIED
Aug 9, 2021

Started with stock TC88 in a 2006 Road King Custom with 55k on the odo.<br />We massaged the twin cam stock heads, Andrews 26G, S&S Lifters, Crane Adjustable Pushrods, S&S Cam Gear drive in a Delkron Backing Plate, Feuling Oil Pressure Relief Spring and Piston, stock headers running into the 2006 Screaming Eagle Slip-ons and tuned the fuel delivery with a Power Commander 20% + across the entire RPM range. Way more power than I was expecting. Clutch slipping so we rebuilt with extra clutch disc's and heavy duty spring - still won't hold! Installing a Barnett High Performance Assembly soon. Excited to see the dynamometer report when we can get all that power to the ground. Super happy.

— Anonymous
✓ VERIFIED
Jul 5, 2022

Love everything about this upgrade for my twin cam 88

— Anonymous
✓ VERIFIED
Jul 5, 2021

Real nice set. Very complete.

— Anonymous
✓ VERIFIED
May 31, 2020

I haven't installed it yet but I was impressed with how fast it came in on standard shipping. These people wasn't messing around. Hope to have on soon so I can try it out. I know it will be great tho. I've never been let down by an s&s product

— Anonymous
✓ VERIFIED
Mar 25, 2020

Went from 72 hp to 86.5 hp. Big difference very happy!

— Anonymous
✓ VERIFIED
Jul 29, 2015

Just an update on my last review,<br />I'm so pleased with how much power this kit produces, on a 2000 FLHTCUI twin cam 88 that is now a twin cam 97-10.0:1 compression roller rockers adjustable push rods and a 3 angle valve job and some pocket porting done with STOCK CAMS, and a dyno jet tuner, let's just say even in 5th gear I have no need to down shift ridding 2up with two heavy people on it going from about 30 mph back up to 55+ mph like a breeze and as of now I have about 500 miles on the kit and love it. And I'm going to go with the 551g gear drive came kit to get the max power out of this kit

— Anonymous