Four-Stroke Engine Specification Example for City Buses: Racing Spec
Four-Stroke Engine Specification Example for City Buses: Racing Spec
This is a worked specification for four-stroke engine in a racing spec 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 racing spec version exists because the duty cycle on city buses is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually documentation that arrived after the container shipped.
Example specification
| Item | Four-Stroke Engine |
|---|---|
| Application | City Buses |
| Version | Racing Spec |
| Base material | Bronze |
| Controlled dimensions | 3 key dimensions, recorded per lot |
| Tolerance band | ±0.05 mm |
| Finish | as machined |
| MOQ | 1,000 pieces per specification |
| Sampling | 14 working days, 5 days per revision |
| Compliance | CCC |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Bronze, 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
- anodising
- robot welding
- precision stamping
- ultrasonic cleaning
- powder coating
- gravity casting
Where this example applies
Programmes that run racing spec most often specify this build for city buses. Related applications include boat trailers, dealership service, delivery vans, workshop replacements, trailer axles.
Checks before packing
- Dimensional report against the approved drawing.
- AQL 2.5 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
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.
How long does sampling take?
Samples leave the factory in 14 working days, and each revision round adds about 5 days once you have seen the first piece.
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.
Do you handle mixed containers?
Yes. Most programmes consolidate several part numbers into one container to keep freight sensible at 1000 pieces per line.
Tell us the model, the fitment and the quantity and we will hold a production slot for you.
