American Rail vs International Rail Engine Mounts: How to Tell What You Have (and Buy the Right Mount)
Buyer Guide: If you’ve ever ordered an engine mount and it “almost fits,” this is why. The difference is simple: rail spacing. Measure once, buy once.
Toigo Motor Mount (American Rail) | Toigo Motor Mount (International Rail) | Shop Engines & Motor Parts
Quick answer
The difference between American rail and International rail motor mounts is the center-to-center distance between the two engine rails on the chassis. Many sources summarize it like this: American is ~3" and International is ~3 5/8" (92mm). (PMC guide (PDF); Comet Kart Sales explanation)
On Toigo’s product page, the American rail mount is listed as 2 7/8" c/c. (Toigo American Rail mount) The Toigo International mounts are listed as International rail mounts with a sliding top plate assembly. (Toigo International Rail mount)
What “rail spacing” means (in plain English)
Look at the two parallel rails/tubes where your engine mount clamps onto the chassis. The only measurement that matters for “American vs International” is the distance from the center of one rail to the center of the other rail.
Why the confusion? Because the engine can be American (GX/Clone/Animal style) while the chassis rails might be international spacing. The mount must match the chassis rails, not just the engine family.
How to measure your chassis in 60 seconds
- Grab a tape measure or calipers.
- Measure center-to-center of the two engine rails where the mount sits (not edge-to-edge).
- If you’re around 3" (or Toigo’s listed 2 7/8" c/c for American rail), buy an American rail mount.
- If you’re around 3 5/8" (92mm), buy an International rail mount. (Common standard explained in multiple kart sources: Comet Kart Sales; PMC PDF)
Tip: If you’re between measurements or your chassis has unusual tubing, measure twice and look at where the clamps actually land.
Which Toigo mount should you buy?
Buy American Rail if your rails match American spacing
Toigo’s American rail option is listed with American clamps and 2 7/8" c/c rail spacing. It includes a slider plate assembly. Motor Mount with Slider Assembly (American Rail)
Buy International Rail if your rails match International spacing
Toigo’s International rail mounts are listed as 15 degree International rail with a sliding top plate assembly. Stealth Motor Mount (International Rail) (You’ll also see the same International rail description on other Toigo mount listings, like Wraith.) Wraith Motor Mount (International Rail)
Common mistakes (and how to avoid them)
- Measuring edge-to-edge instead of center-to-center: center-to-center is the standard described by kart mount suppliers.
- Assuming “American engine” = “American rails”: the chassis rail spacing is what matters for the mount.
- Not checking slide/adjustment needs: slider plates help with chain alignment and gearing changes.
FAQ
What’s the standard spacing difference?
Many kart suppliers describe it as American being around 3" and International around 3 5/8" (92mm). (Source)
What does Toigo list for American rail?
Toigo’s American rail mount listing states Engine Rail 2 7/8" c/c. (Source)