• Mazworx inline-six long block, front angled view. Customer-core service example; pictured hardware varies.
  • Mazworx long block side view. Customer-core service example; pictured hardware varies.
  • Mazworx long block rear-face view. Customer-core service example; pictured hardware varies.
  • Mazworx long block opposite side view. Customer-core service example; pictured hardware varies.
  • Mazworx timing belt and front accessories. Customer-core service example; pictured hardware varies.
  • Mazworx valve-cover and front upper detail. Customer-core service example; pictured hardware varies.
  • Mazworx cylinder-head port close-up. Customer-core service example; pictured hardware varies.
  • Mazworx cylinder-head port exterior detail. Customer-core service example; pictured hardware varies.
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MazWorx Authorized Dealer

Mazworx RB25DET Long Block Stage 2 Service

Mazworx RB25DET Long Block Stage 2 Service

$14,061.57
$14,061.57
Sale Sold out
Configuration

Out of stock

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Shipping & returns

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Shipping details

In-stock orders are processed within 48 hours; transit time is additional.

International orders include export processing and customs clearance. Duties, taxes and brokerage are extra; final freight charges may change after remeasurement.

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Returns

Need help with a return? Request authorization within 30 days of delivery for eligible unused, uninstalled items. See details for exclusions and applicable fees.

Read the full return policy
Return details & how to start

Request return authorization (RMA) within 30 days of delivery for eligible items. Keep items unused and uninstalled, with original packaging and accessories. Electronics, liquids, special orders and other categories are excluded.

Email sales@frsport.com with RETURN and your order number in the subject to request an RMA. Please wait for return authorization before sending your item back.

Wrong part/size or change of mind: a 20% return processing fee applies, plus applicable shipping costs.

Original shipping is non-refundable. For orders shipped free, the actual outbound shipping cost is deducted from the refund. Return shipping is prepaid by the customer.

After payment capture, cancellations and refunds generally incur a 5% processing fee, except for our error, confirmed defects or confirmed carrier loss. The 5% and 20% fees do not stack; only the greater applicable fee applies. Store credit waives the 5% fee, but applicable return fees remain.

Missing, incorrect or transit-damaged items: report within 3 business days of receipt with photos of the product and packaging.

For defective items, contact us for help with the manufacturer's warranty process. The manufacturer decides the claim.

Specifications

Product details shared across all variants.

Category
Car Repair & Maintenance

This service uses customer-provided engine components. A replacement core is not included.

Provide RB25 core long block. Confirm compatibility and condition before ordering.

Service work and components

  • Complete disassembly of the short block
  • Hot tank cleaning and sand blasting of the iron block, followed by painting
  • Machining processes including threaded oil and freeze plug installations, RB26 oil groove modifications, head stud preparations, block resurfacing, resizing the cylinder with torque plate, and line boring with honing
  • Oil pump collar installation on the crankshaft
  • Crankshaft cleaning, inspection, polishing, and balancing
  • Reassembly of the short block
  • CP Pistons sized at 86.5mm with 9:1 compression ratio
  • Upgraded 9310 wrist pins with .250″ wall thickness
  • Manley Turbo Tuff connecting rods
  • ACL RB26 race bearings
  • ARP main studs
  • Mazworx RB oil pump collar, and threaded/O-ring sealed small and freeze plugs
  • Disassembly and sand blasting of the cylinder head
  • Removal, drilling, tapping, and replacement of oil port plugs
  • Stage 3 CNC port and combustion chamber work
  • Machining for threaded freeze plugs and RB26 head studs
  • Valve guide removal, reinstallation, reaming, and race-quality valve job with resurfacing
  • Final assembly of the head
  • Kelford Cams 246-B with cam profiles of 264/272 degrees at 10mm lift
  • Supertech intake valves (+1mm), Inconel exhaust valves (+1mm), bronze valve guides
  • Supertech single valve spring kit rated at 85 lbs, titanium retainers, and valve seals
  • Mazworx threaded freeze plugs and miscellaneous plugs
  • ATI street damper for crankshaft vibration control
  • Tomei upgraded oil pump
  • Gates racing timing belt and Kelford adjustable cam gear for precise timing control
  • Tomei 88mm x 1.2mm head gasket
  • OEM water pump and gasket kit
  • ARP RB26 head studs
  • Powder-coated valve cover and timing cover
  • Mazworx bolt kit
  • Engine break-in oil and filter included
  • Engine supplied spun and primed

Confirm delivery arrangements before sending parts. Work starts only after the individual intake is approved.

Additional work and replacement parts need approval. Core credit requests require individual approval. No automatic core credit is included.

Photos show manufacturer work examples. The service uses customer-provided cores. Selected options and listed components define the supplied work.

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Vehicle fitment