Cylinder Head Machining in South Jersey, NJ

Complete cylinder head services for cast iron and aluminum heads: resurfacing, valve seat cutting and replacement, valve guide work, and porting. Precision machining for rebuilds and performance applications.

Head Machining

Cylinder Head Work Done Right in South Jersey

Cylinder head machining is precision work. The flatness of the head gasket surface, the geometry of the valve seats, and the condition of the valve guides directly determine whether an engine seals, runs efficiently, and lasts. A head that isn't machined correctly is a head gasket failure waiting to happen — or power left on the table.

At Nitro Custom Works, we treat cylinder head machining with the same discipline we apply to CNC part production: measure first, machine to spec, measure again. We work on both cast iron and aluminum heads for passenger cars, light trucks, performance builds, and vintage vehicles.

We're located in South Jersey, serving Burlington, Camden, Gloucester, and Salem Counties as well as the Philadelphia metro area. Drop your head off or call us at (856) 207-2495 to discuss your project before you bring it in.

Cylinder head mounted on a milling machine for machining at Nitro Custom Works in South Jersey, NJ
Services

Complete Cylinder Head Services

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Resurfacing / Decking

The head gasket mating surface is machined flat to manufacturer tolerance — typically 0.003" or less across the length. Required after overheating, head gasket failure, or warping. We check flatness before and after.

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Valve Seat Cutting

Intake and exhaust valve seats are recut to the correct angle and contact width. Hardened seats are installed when original seats have receded or when converting to unleaded fuel. Three-angle valve jobs available for performance.

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Valve Guide Replacement

Worn or damaged valve guides are pressed out and replaced with new guides, then reamed to the correct stem clearance. Proper guide clearance is critical for valve sealing, oil control, and valve life.

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Porting & Polishing

Port shape and volume are modified to improve airflow into and out of the combustion chamber. Performance port work increases peak power by reducing restriction. Port matching to intake and exhaust manifolds also available.

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Flatness Inspection

We check head flatness with a precision straightedge before you commit to a resurface. If your head is within spec, we'll tell you — no unnecessary machine work.

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Thread Repair

Damaged spark plug threads, head bolt holes, and other threaded features repaired with Heli-Coil inserts or time-sert type repairs. Stripped threads are not a reason to scrap a head.

Aluminum vs. Cast Iron

We Machine Both Head Materials

Cast iron and aluminum heads require different tooling, speeds, and care to machine correctly. Aluminum is more prone to distortion from improper clamping and requires sharp tooling to avoid a torn surface finish. Cast iron is harder on tooling but more tolerant of heat and clamping variation.

We understand both materials and approach each one correctly. Aluminum heads are inspected for cracks (common after overheating) before we machine them — there's no point resurfacing a cracked head.

  • OHC and OHV aluminum heads — passenger and performance
  • Cast iron heads — domestic V8, V6, and inline engines
  • Diesel heads — iron and aluminum
  • Vintage/classic heads — restoration-correct tolerancing
  • High-performance heads — ported, competition spec
Close-up of a freshly machined cylinder head showing valve seats and combustion chambers
FAQ

Cylinder Head Machining — Questions & Answers

Cylinder head resurfacing (also called decking) is the process of machining the head gasket mating surface to restore it to a flat, smooth condition. A warped or pitted surface causes head gasket failure; resurfacing restores the correct geometry so the head gasket can seal properly. The process removes a small amount of material — typically just enough to achieve flatness within 0.003" across the full length of the head.
Valve seat cutting is the process of machining the angled seating surfaces inside the cylinder head where the intake and exhaust valves close. Over time, seats wear, crack, or recede into the head. Seat cutting restores the correct contact angle and width for proper valve sealing, prevents combustion blow-by, and ensures efficient heat transfer from the valve into the head.
A warped head is typically confirmed by checking it with a precision straightedge and feeler gauges across multiple directions on the gasket surface. Most manufacturers allow 0.003"–0.004" maximum deviation across the length. If your vehicle overheated, had a blown head gasket, or showed coolant mixing with oil, have the head checked before reinstalling it. We can check it for you and give you an honest assessment.
Yes. Aluminum cylinder heads are machined differently than cast iron — they require sharper tooling, different feeds and speeds, and careful clamping to avoid distortion. We have experience with both aluminum and cast iron heads and apply the correct approach to each. Aluminum heads are also inspected for cracks before machining, since overheating commonly causes cracking in aluminum.
Porting is the process of reshaping the intake and exhaust ports inside the cylinder head to improve airflow. A ported head flows more air and fuel mixture into the cylinders and expels exhaust gases more efficiently — both result in increased power and improved throttle response. Polishing the port surfaces further reduces turbulence. This is a proven performance modification for engines built for higher output.
Pricing depends on the services needed and the size and configuration of the head. A basic resurface is straightforward; a full valve job with seat cutting and guide replacement takes more time and material. Contact us with your head type and what services you need for a specific quote. We give you a real number before any work begins.

Ready to Bring In Your Head?

Call (856) 207-2495 or email nitrocwc@gmail.com — we'll discuss your project and what it needs.

Get a Quote