Htd & Gilmer Belts
HTD and Gilmer belts are toothed timing belts used to drive oil pumps, water pumps and other accessories off the crank or cam in race engine setups. They work by positive tooth engagement rather than friction, so they don't slip like a V-belt can under load.
Belts here are specified by width, length and tooth pitch, so you'll need to match your current belt or pulley setup rather than swap between sizes. Widths in this range run from around 10mm up to 30mm, with lengths from roughly 225mm through to 640mm, covering common HTD and L-pitch profiles from Peterson, Gates and Aeroflow.
- HTD belts (8mm pitch, various widths and lengths)
- Gilmer/L-pitch belts (240L, 300L, 322L and similar)
- Steel-reinforced timing belts for oil pump and accessory drives
If you're replacing a worn belt, check the markings on the old one or measure tooth count and width before ordering, as a belt that's slightly out on length won't tension correctly.
Frequently asked questions
How do I know what size HTD or Gilmer belt I need?
Check the width and length markings on your existing belt, or measure the belt's width, overall length and tooth pitch before ordering. Getting the length right matters most, since a belt that's too short or too long won't tension properly on the pulleys.
What's the difference between an HTD belt and a Gilmer belt?
Both are toothed timing belts, but they use different tooth profiles and pitches. Gilmer belts are typically specified in the L-pitch system (like 240L or 322L), while HTD belts use a different, deeper tooth profile for higher load applications.
Can I use these belts for accessory drives like oil pumps?
Yes, these belts are commonly used to drive oil pumps, water pumps and similar accessories in race engine applications, as seen with the Gates Gilmer oil pump belt in this range.
