Four-Stroke Engine Specification Example for Assembly Programmes: Folding Type
Four-Stroke Engine Specification Example for Assembly Programmes: Folding Type
This is a worked specification for four-stroke engine in a folding type programme. It is the document we would send a buyer who asks what exactly they are getting: the material, the dimensions that are actually controlled, the finish, and the checks that happen before anything is packed.
The folding type version exists because the duty cycle on assembly programmes is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually premature wear on the first batch.

Example specification
| Item | Four-Stroke Engine |
|---|---|
| Application | Assembly Programmes |
| Version | Folding Type |
| Base material | Chromed Steel |
| Controlled dimensions | 4 key dimensions, recorded per lot |
| Tolerance band | ±0.05 mm |
| Finish | as machined |
| MOQ | 500 pieces per specification |
| Sampling | 10 working days, 3 days per revision |
| Compliance | ECE R90 |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Chromed Steel, in this example.
- List the dimensions that are actually controlled and the tolerance on each.
- Name the finish and what it has to survive.
- State the inspection level and who pays when a lot fails.

Processes involved
- sintering
- shot blasting
- surface grinding
- ultrasonic cleaning
- die casting
- robot welding
Where this example applies
Programmes that run folding type most often specify this build for assembly programmes. Related applications include workshop replacements, dealership service, aftermarket retail, long-haul trucks, off-road bikes.
Checks before packing
- Dimensional report against the approved drawing.
- AQL 4.0 sampling on the finished lot.
- Finish inspection under agreed lighting.
- Carton drop test on the first lot of a new packing specification.
Questions buyers ask
Can the specification be held on file?
Yes. Once approved, the specification is recorded against your part number so a reorder reproduces the ECE R90-compliant build instead of a fresh interpretation.
Do you handle mixed containers?
Yes. Most programmes consolidate several part numbers into one container to keep freight sensible at 500 pieces per line.
What happens if a lot fails inspection?
The lot is re-inspected against the golden sample, and replacement pieces ship on the next available booking at our cost.
How is packing specified?
Individual packing, inner box quantity and carton marking are confirmed at quotation stage so the cartons arrive ready for your warehouse.
Ask for the current catalogue and the specification sheet for this line.



