Cam Specs & Overview

Recommended applications for S&S Cams:

HP103: For the rider who really wants the most top end horsepower. Easily make 100 horses from a stock engine with S&S intake and exhaust. Ideal for lighter bikes and racing applications where getting the most horsepower from a stock engine is imperative.

MR103: These bolt in-cams are for the rider who wants more of everything without giving up low end torque for high rpm horsepower, or vice versa. More power all across the wide power band, from idle to red line.

475: A bolt-in replacement cam designed for riders with stock engines that want to eliminate the factory chain drive system, but are not necessarily looking for more power. Does not require tuning. Bolt-in stock.

509: Designed as a bolt-in, high torque cam for 1999-'06 models. 180 psi cranking compression, no need for compression releases. For 88 CID engines with stock compression ratio. Idle-4500 rpm. Bolt-in torque.

510: Designed as a bolt-in cam for 88, 95, and 96 CID engines with compression ratios below 9.7:1, it is primarily intended for use with stock, un-ported heads. 3000-5500 rpm. Bolt-in overall.

551: Designed for engines with 96 to 106 CID and 9:1 to 9:9 compression. This is a bolt-in cam set designed for stock or mildly modified touring bikes. 551 cams are not recommended for compression ratios of 10:1 or greater. Greatly improves low-end and midrange torque, strongest from idle-4000rpm. 

557: Designed for Tri-Glide® models, this bolt-in cam, with it’s short duration, produces lots of useable torque. The camshaft’s stock base circle permits the use of stock pushrods. However, we recommend S&S Quickee pushrods for easy installation. 557 camshafts are available in chain or gear driven versions. Both come with our Easy Start automatic compression release feature for quick starts. Fits all 2009-2012 Harley-Davidson®Tri-Glide® models. Bolt-in.

570: Designed for 88 to 96 CID engines with compression ratios between 9:1 and 10:1 this cam will provide a nice power increase across the entire power band. 3200-5700 rpm. Excellent bolt-in for overall power on a 103". Bolt-in overall.

583: Optimized for use in the Softail®/Dyna® lines, this cam makes horsepower and torque that you can feel all the way through the rpm range, making the most power right where you need it:1500–5000rpm. Bolt-in.

585: Designed for 88 to 95 CID engines with compression ratios from 9.7:1 to 10.5:1 and 100 to 124 CID engines from 9:1 to 10:1 compression. Provides massive horsepower and torque increases starting at 3000rpm and holds steady all the way to redline. 3500-6000 rpm for 88" - 103" engines and 2500-5500 for larger engines. 

625: Cam set designed for 95” or larger engines with compression ratios between 10.0 and 10.75:1. 3000-6000 rpm. 

635HO: This is the cam set for the rider looking for maximum horsepower. With .635" lift, your engine can really breath. They’ll work even better when you have your cylinder heads CNC ported in Step 4. High lift S&S valve springs are required.

640: Used in S&S T124 engines, this cam makes horsepower! Intended for engines of 95 CID or more w/compression ratios between 10.5:1 and 11.5:1. 3000-6000 rpm. 

675: A high lift monster, this cam set is designed for 120” or larger engines with at least 11:1 compression ratio. 4500-6500 rpm. 

Note: Stock valve springs in 1999-’04 big twin models can handle cams with valve lifts as high as .515”. Stock valve springs in 2005-up engines can accommodate valve lifts up to .590”.

S&S® offers a variety of cam grinds for 1999-up big twin engines in both chain drive and gear drive versions. Cams that exceed the limits of the stock valve springs require the use of special high lift springs. Most S&S cams have higher lift than stock and are designed to take advantage of the extra flow of ported stock heads or S&S Super Stock® heads. Due to the high lift of these cams, S&S adjustable pushrods are recommended. Not all grinds are available in the chain drive version. To get the best performance from a performance cam installation, a high flow intake and exhaust system is also recommended.


Start any engine regardless of displacement or compression ratio, with a stock starter. The most innovative S&S product since the electric compression release system, these cams will revolutionize the starting of late model big twins. These cams also install just as easily as non compression release versions and require no extra parts or machining! Available in both economical chain drive and rock-solid gear drive. Don't get caught "dead" without them!

How do Easy Start Cams Works

The heart of our Easy Start cams is a centrifugally retracted, spring loaded, compression release lobe milled into the heel of each exhaust lobe. At cranking speeds, the lobe bumps the exhaust valve open slightly during the compression stroke, making the engine much easier to turn over. Once the engine fires and reaches 800 RPM, the lobe swings out of the tappet roller path, allowing the engine to run normally and with full compression.

Features & Benefits of S&S Easy Start Cams:

  • Start any engine with a stock starter
  • Save your starter and battery!
  • Reliable – tested for 100,000 accumulative starts and over 150,000 road miles
    without breakage or compression release failure!
  • Automatic – no buttons to push

Compare S&S Cams To Other Popular Cams

Application Cross Reference Chart  

S&S H D® Screamin' Eagle®   A ndrews®   M ost Fitting Application
551 SE-203/255 21H/26H Touring Models
570 54H All Big Twin Models
583 SE-203/255 21H/26H Softail®/Dyna® Models
585 SE-211/251/257  31H/32H/50H/55H/67H All Big Twin Models   
625 SE-258/260 60H All Big Twin Models   
640 SE-264 59H All Big Twin Models   
675 64H All Big Twin Models   
All reference to H-D® and Andrews® part numbers is for identification purposes only. We in no way are implying that any of S&S Cycle’s products are original equipment parts or that they are equivalent to the corresponding H-D® part number shown. Use of brand names such as Harley-Davidson® Sportster® are also for reference only.
Specs for S&S® Chain Drive & Gear Drive Camshafts for 1999-Up Big Twins
Cam  Valve Timing (open/close)Valve DurationValve Lift  CenterlineLift @ TDC
IntakeExhaustIntake Exhaust Intake Exhaust Intake Exhaust 

Open BTDC/Close ABDC

Open BBDC/Close ATDC

Note: Although several cam grinds were used in stock engines from 1999-’06, the timing specs of the 475G cams is most similar to cams used in 1999-’03 EFI engines. **551 cams are not recommended with compression ratio of 10:1 or higher.

NOTE: Stock valve springs in 1999-’04 big twin models can handle cams with valve lifts as high as .515". Stock valve springs in 2005-up engines can accommodate valve lifts up to .590".

Recommended applications for S&S Cams: 1984-1999

508: Bolt-in cam intended for stock engines with less than 10:1 compression ratio. Quiet valvetrain with excellent low/mid range torque for touring and 2 up riding.

510V: Bolt-in cam that works well with stock or ported heads. Improved ramp design results in low valve train noise. Meant for engines up to 96" and 10:1 compression ratio. 3000-5000 rpm.

520: A replacement part for S&S emissions certified engines, this is a short duration emissions cam with very little overlap to reduce emissions of unburned hydrocarbons. Requires high lift springs and normal clearance checks. 1000-4500 rpm (80"-96").

543: A replacement cam for newer S&S 4-1/8" bore V-series emissions certified engines for OE and custom applications. High lift, short duration and no overlap. Requires high lift springs and normal clearance checks. 1000-4000 rpm (111"-124").

546: A replacement cam for older S&S V-Series emissions certified engines, this is a short duration emissions cam with very little overlap to reduce emissions of unburned hydrocarbons. Requires high lift springs and normal clearance checks. 1000-4000 rpm (111"-124").
561: For 80"–96" engines at 9.5:1–10.5:1 compression ratio. Provides strong midrange power. 3000-5500 rpm.

585V: A versatile cam for 80" to 96" engines with 10:1-10.5:1 compression, and larger engines with 9.5:1-10:1 compression ratios. 3500-6000 rpm.

600: An exceptional cam in any large displacement engine with 9.5:1 to 10.5:1 compression. 3500-6000 rpm.

631: For high rpm applications, an excellent choice for all street and racing engines with 11:1 and higher compression ratios. Great performance cam, but expect more "wear and tear" on valve train components. Valve spring spacing and other normal clearancing checks required. 4500-6500 rpm

640: For large displacement motors with compression ratios of 10.5 - 11.5:1, or smaller motors with 11:1-12:1 compression ratio. Does not require as much compression as the 631 and provides a more linear power delivery. 3000-6000 rpm.

675: Designed for use with S&S special application cylinder heads, but can be used with other cylinder heads with appropriate valve springs. Intended for large displacement competition engines of 120 cubic inches or more, and 11:1 or greater compression. 4500-6500 rpm.

Specs for S&S® Gear Drive Camshafts for 1984-1999 Big Twins

Cam Name Valve Timing Open/Close Valve Duration Valve Lift Center Line Lift @ TDC
Intake Exhaust Intake Exhaust Intake Exhaust Intake Exhaust
Open BTDC/Close ABDC Open BBDC/Close ATDC
508 11°/25° 50°/5° 217° 235° .508"  97˚ 112.5˚ .141" .110"
510V 20°/38° 52°/20° 238° 252° .510" 99° 106° .187" .178"
520 0°/40° 50°/2° 220° 232° .520" 110° 114° .086" .094"
543* Front -26°/52° 49°/-1° 206° 228° .543" 129˚  115˚  .017" .083"
543* Rear -25°/44° 33°/-10° 199° 203° .543" 124.5˚ 111.5˚ .018" .053"
546 5°/55° 52°/5° 240° 237° .546" 115° 113.5° .126" .106"
561 32°/40° 50°/26° 252° 256° .561" 94° 102° .252" .210"
585 20°/45° 60°/20° 245° 260° .585" 102.5° 110° .186" .180"
600 20°/55° 60°/20° 255° 260° .600" 107.5° 110° .192" .184"
631 34°/61° 66°/29° 275° 275° .630" 103.5° 108.5° .281" .221"
640 25°/60° 65°/20° 265° 265° .640" 107.5° 112.5° .222" .192"
675 25°/64° 70°/25° 269° 275° .675" 109.5° 112.5° .235" .209"
*Emissions cams front and rear do not have identical timing. Negative values are due to special timing for reduced emissions.
Notes: S&S can do a special order cam. Contact your S&S Customer Service Representative for more information.
Not legal for sale or use on CA or EPA pollution controlled motorcycles.