Diesel Engine Parts Specification Example for City Buses: Lightweight Version
Diesel Engine Parts Specification Example for City Buses: Lightweight Version
This is a worked specification for diesel engine parts in a lightweight version 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 lightweight version 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 a supplier who changed material without saying so.
Example specification
| Item | Diesel Engine Parts |
|---|---|
| Application | City Buses |
| Version | Lightweight Version |
| Base material | PVC Coated Fabric |
| Controlled dimensions | 3 key dimensions, recorded per lot |
| Tolerance band | ±0.5 mm |
| Finish | zinc plated |
| MOQ | 3,000 pieces per specification |
| Sampling | 14 working days, 3 days per revision |
| Compliance | SAE J431 |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — PVC Coated Fabric, 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
- precision stamping
- gravity casting
- powder coating
- heat treatment
- shot blasting
- anodising
Where this example applies
Programmes that run lightweight version most often specify this build for city buses. Related applications include three-wheelers, delivery vans, passenger cars, camper conversions, export programmes.
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
What testing is included?
Standard lots ship with dimensional and hardness reports. SAE J431 documentation is issued with the shipment when your market requires it.
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.
Can you match an existing sample?
Send a sample and we will reverse-engineer the specification, then produce a counter sample for approval before any bulk starts.
How long does sampling take?
Samples leave the factory in 14 working days, and each revision round adds about 3 days once you have seen the first piece.
Send the part number, the annual volume and the target market, and we will come back with a specification and a sampling plan.
