Diesel Engine Cylinder Head Casting RFQ Checklist: Cores, Machining, Leak Test, and PPAP

# Diesel Engine Cylinder Head Casting RFQ Checklist: Cores, Machining, Leak Test, and PPAP

An aluminum cylinder head RFQ is one of the easiest places for sourcing assumptions to drift. The drawing may show the part, but the quote depends on core package difficulty, coolant and oil passage risk, machining datums, heat treatment, leak or pressure-test scope, and approval records.

This checklist helps engine, aftermarket, and industrial equipment buyers send a package that casting suppliers can review without guessing.

Helpful Bohua routes:

• •Diesel engine cylinder head aluminum casting RFQ page
• •Casting drawing requirements
• •A356 aluminum casting manufacturer
• •Request quote + drawing upload

1) Send the core and passage information clearly

Cylinder heads have internal geometry that cannot be understood from outside surfaces alone.

Include:

• •2D drawing with revision status
• •3D STEP model
• •coolant and oil passage notes
• •core package or core-box information if available
• •wall thickness and minimum section notes
• •areas where internal passage cleanliness matters

If a passage is critical but not obvious, mark it in the drawing package or add a short note in the RFQ email.

2) Define the machined interfaces

The supplier needs to know what will be cast, what will be machined, and which surfaces control assembly.

Call out:

• •combustion face machining stock
• •valve seat or guide related requirements
• •cam or bore datum relationships
• •gasket faces and flatness targets
• •bolt holes, threaded features, and dowel locations
• •CMM or layout report expectations

This keeps the quote from treating machining as a vague add-on.

3) State alloy, heat treatment, and mechanical expectations

If the program specifies A356, ZL114, or another alloy, include the exact specification. If the alloy is open, state the performance context and ask for a recommendation.

Useful RFQ lines:

• •alloy and temper
• •heat treatment requirement
• •hardness or mechanical property target
• •corrosion, coolant, or temperature exposure
• •accepted equivalent standard, if engineering permits substitution

Do not force a material assumption simply because a previous supplier used it. Ask for process and alloy reasoning if the new part geometry differs.

4) Make leak or pressure-test criteria quotable

For cylinder heads, "test required" is not enough.

Define:

• •test medium
• •pressure or vacuum level
• •hold time
• •acceptance threshold
• •sampling plan
• •whether records need serial, batch, or sample traceability

If the test method is not fixed, ask the supplier to propose a test plan after reviewing the drawing.

5) Match documentation to the buyer's approval path

Engine-related programs may need more documentation than a standard industrial casting.

Ask for the records your team actually needs:

• •material certificate
• •heat-treatment record if required
• •CMM or dimensional report
• •X-ray or CT review if risk requires it
• •leak or pressure-test record
• •PPAP Level 3 or other customer-specific submission if applicable

See certifications and quality control for supplier evidence before final approval.

Copy-paste RFQ starter

> Part: diesel engine aluminum cylinder head casting RFQ

> Files: 2D PDF rev __, 3D STEP __

> Alloy/temper: __; heat treatment: __

> Core/passages: coolant __; oil __; critical zones __

> Machining: combustion face __; valve/cam/bore datums __; gasket face __

> Testing: medium __; pressure __; hold time __; acceptance __; sampling __

> Inspection: CMM __; X-ray/CT __; material cert __; PPAP/FAI __

> Volume: prototype __; annual __; destination __; approval timing __

> Questions: confirm process route, tooling approach, inspection plan, and quote assumptions

FAQ

Can Bohua review diesel engine cylinder head RFQs?

Bohua can review cylinder head drawings, internal passage requirements, alloy and heat-treatment targets, machining scope, inspection records, annual volume, and PPAP expectations before confirming quotation fit.

Is a 3D model required?

For cylinder heads, a 3D model is strongly preferred because internal passages, cores, and machining relationships affect both tooling and inspection assumptions.

Where should a drawing-ready buyer start?

Use the diesel engine cylinder head casting RFQ page, then submit drawings through Request Quote.