# Automotive Engine Calculator

> Automotive Engine Calculator is a paid API for AI agents from automotive-calc.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-30).

Calculates engine displacement (cc, litres, cubic inches), compression ratio, bore-stroke ratio, and mean piston speed from bore, stroke, cylinders, and optional parameters.

## Facts

- Endpoint: GET https://automotive-calc.x402tookit.com/engine-calc?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/automotive-engine-calculator-faaa069f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_qbWiD_mBhYeefAD1dJMdl

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability automotive-engine-calculator-faaa069f
```

Example prompt: Calculate the engine displacement and compression ratio for a 4-cylinder engine with 86mm bore, 86mm stroke, and a clearance volume of 42cc, also give me the mean piston speed at 6500 RPM.

## When to prefer this

Use this endpoint when you need precise, multi-unit engine displacement calculations, compression ratio, bore-stroke ratio, or mean piston speed from raw engine geometry. Ideal for automotive engineers, tuners, or enthusiasts who have bore, stroke, and cylinder count and need instant derived metrics without manual formula work.

## Known failure modes

- Missing required parameters (bore, stroke, cylinders) returns an error
- Invalid unit value (not 'mm' or 'in') may produce incorrect results
- Cylinders outside 1–16 range may be rejected
- Zero or negative bore/stroke values produce nonsensical results
- Missing clearance volume means no compression ratio is returned
- Missing RPM means no mean piston speed is returned

## How this service works

Engine displacement in cc, litres and cubic inches from bore, stroke and cylinders; compression ratio and mean piston speed.

## Output

Returns a JSON object with engine displacement in cc, litres, and cubic inches (total and per cylinder), bore-stroke ratio, and optionally compression ratio (if clearance volume provided) and mean piston speed in m/s and ft/min (if RPM provided), along with bore and stroke in mm, cylinder count, and a summary.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "bore",
      "stroke",
      "cylinders"
     ],
     "properties": {
      "rpm": {
       "type": "number",
       "description": "Engine speed, for mean piston speed"
      },
      "bore": {
       "type": "number",
       "description": "Cylinder bore diameter"
      },
      "unit": {
       "type": "string",
       "description": "mm (default) or in for bore and stroke"
      },
      "stroke": {
       "type": "number",
       "description": "Piston stroke"
      },
      "cylinders": {
       "type": "integer",
       "description": "Number of cylinders, 1 to 16"
      },
      "clearanceVolumeCc": {
       "type": "number",
       "description": "Combustion chamber volume per cylinder at top dead centre, cc, for the compression ratio"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "boreMm": {
       "type": [
        "null",
        "number"
       ]
      },
      "design": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "strokeMm": {
       "type": [
        "null",
        "number"
       ]
      },
      "cylinders": {
       "type": [
        "null",
        "number"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "notChecked": {
       "type
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/automotive-engine-calculator-faaa069f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from automotive-calc.x402tookit.com](https://www.zero.xyz/host/automotive-calc.x402tookit.com/llms.txt)