Imperial Timing Chains


RM Fowler Limited can supply imperial inverted tooth and roller type timing chains. We also have stock of a limited range of 10mm Pitch metric inverted tooth chain.

RM Fowler cannot supply timing chains for any modern vehicles. We specialise in pre-1960 vehicles.

Roller Chain

RM Fowler can supply simplex, duplex and triplex type roller chains from a number of manufacturers including IWIS and Morse.

To supply customers with roller type chain we will need to know the following details:

  • Roller chain type – simplex, duplex or triplex
  • Chain pitch – distance between the pins
  • Chain roller diameter – the diameter of the rollers that engage with the sprocket
  • Distance between the inner plates

For more information on roller chain measurements please go to our Roller Chain page.

Inverted Tooth Chain

For 10 mm Pitch metric chain please see our Metric Timing Chain page.

For imperial inverted tooth chain also known as silent tooth timing chain we supply Ramsey chain.

Ramsey Products are located in North Carolina USA and have been manufacturing inverted tooth chain for 85 years - visit www.ramseychain.com for more information.

Ramsey chains utilize efficient, quiet, two-pin roller bearing joints; technology which has been shown to outperform conventional, round pin joints. Ramsey is an excellent alternative to pin joint chains from obsolete makes shown in the below pictures.

Ramsey chains are suitable as replacements for many obsolete makes such as Morse, The Coventry and Brampton chains.

Imperial Chain 1
Imperial Chain 2

In circumstances where the sprockets run on both sides of the chain we can supply duplex chain.

Chain Pitch and Guides

The two most commonly used inverted tooth chains have either a centre or side guide. Other variations are available such as non-guided chain.

Ramsey centre guided chain SC

Ramsey side guided chain SC

To supply the correct chain we need to know the following details:

  • Pitch = Distance between pins
  • Length = Total length of chain measured in the number of pins or 'pitches'
  • WBG = Width Between guides (on side guided chains)
  • WL = Total width not including pins (centre guided chains)

For a full list of the available sizes of centre guided chains from Ramsey please visit www.ramseychain.com/products/power-transmission-chains/sc/.

Please see below list for available sizes of Ramsey Side guided chain.

Nominal Width - The nominal width of a chain is not an exact measurement but it is used by Ramsey and RM Fowler as an approximate width of the chain.

Pitch Part no Nominal width WBG
3/8 SSG302 1/2 3/8
3/8 SSG302.5 5/8 1/2
3/8 SSG303 3/4 5/8
3/8 SSG303.5 7/8 3/4
3/8 SSG304 1 7/8
3/8 SSG304.5 1 1/8 1
3/8 SSG305 1 1/4 1 1/8
3/8 SSG305.5 1 3/8 1 1/4
3/8 SSG306 1 1/2 1 3/8
3/8 SSG306.5 1 5/8 1 1/2
3/8 SSG307 1 3/4 1 5/8
3/8 SSG307.5 1 7/8 1 3/4
3/8 SSG308 2 1 7/8
1/2 SSG402 1/2 3/8
1/2 SSG402.5 5/8 1/2
1/2 SSG403 3/4 5/8
1/2 SSG403.5 7/8 3/4
1/2 SSG404 1 7/8
1/2 SSG404.5 1 1/8 1
1/2 SSG405 1 1/4 1 1/8
1/2 SSG405.5 1 3/8 1 1/4
1/2 SSG406 1 1/2 1 3/8
1/2 SSG406.5 1 5/8 1 1/2
1/2 SSG407 1 3/4 1 5/8
1/2 SSG407.5 1 7/8 1 3/4
1/2 SSG408 2 1 7/8

When replacing timing chain it is also advisable to check the condition of the sprockets as these are just as important to the running of an engine as the timing chain. RM Fowler have close ties with a number of specialists who can manufacture high quality sprockets to suit all the chains we supply.

For a quote go to our Contact Us page and fill in our online form, email info@chain-drive.co.uk or call 01565 651 051.