Inline Engine Specification Example for Aftermarket Retail: Sealed Unit
Inline Engine Specification Example for Aftermarket Retail: Sealed Unit
This is a worked specification for inline engine in a sealed unit 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 sealed unit version exists because the duty cycle on aftermarket retail is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually warranty claims traced back to a single lot.

Example specification
| Item | Inline Engine |
|---|---|
| Application | Aftermarket Retail |
| Version | Sealed Unit |
| Base material | PVC Coated Fabric |
| Controlled dimensions | 6 key dimensions, recorded per lot |
| Tolerance band | ±0.2 mm |
| Finish | painted |
| MOQ | 500 pieces per specification |
| Sampling | 14 working days, 5 days per revision |
| Compliance | RoHS |
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
- surface grinding
- rubber vulcanisation
- cold forging
- laser cutting
- powder coating
- robot welding
Where this example applies
Programmes that run sealed unit most often specify this build for aftermarket retail. Related applications include scooter fleets, municipal fleets, passenger cars, aftermarket retail, utility trailers.
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 is the minimum order quantity?
The standard MOQ is 500 pieces per specification. Mixed sizes inside one shipment are accepted once the total reaches that figure.
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 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.
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.
Send the part number, the annual volume and the target market, and we will come back with a specification and a sampling plan.



