AMTuned Audi S4 B6 B7 4.2L 40V BHF BBK Engine Rebuild Program

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  • Regular price $6,999.95
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We are proud to offer AMTuned engine rebuilds in our facility here at Tweetler Performance. Not able to make a trip out to Florida? We will be your trusted "Source Up North" for AMTuned products and 4.2L related services! 

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"Customers now have a trusted source to get their 4.2's rebuilt to extract new life out of them. We have numerous engines which went through our rebuild program bringing back smiles per gallon. Not thrilled about pulling your engine? We can take in your entire car into our facility for a turn key solution, contact us for more information and pricing. Send your long block to us for a complete disassembly and inspection to ensure the engine is a good candidate for rebuilding.

We believe this complete professional rebuild is a comparable cost with what a skilled home enthusiast would pay when considering equivalent parts and a 3rd party machine shop. We offer inspections free of charge for engines that are rebuilt. In the unfortunate event that your engine is not able to be rebuilt, we can source core parts for purchase. If you would like a basic inspection and tear down, our charge is $500.00

Customers MUST establish contact prior to shipping and purchase the desired engine rebuild stage in full before work begins. Shipping to or from our facility is not included. Local drop off and pick-up is available free of charge. Never shipped an engine? Let us help guide you through the process! We typically see shipping rates between $175-$500 one way within the continental United States.

Long blocks are to be delivered to us without accessories. Accessories include: Oil Filter Housing, Water Pump & Pump Shaft, Power Steering Pump, A/C Compressor, Alternator & Bracket, Oil Cooler, Exhaust Manifolds, Knock Sensors, Intake Manifold, Coil Packs, and Cam Sensors. Spark plugs can be left in the engine, but rebuilds will not include spark plugs." 

AMTuned Engine STAGE 0: 
Refreshed BHF / BBK 4.2L Long Block with 20k mile warranty on Stage 0 engine option only. TURN AROUND TIME IS CURRENTLY 8-9 WEEKS AFTER PASSED INSPECTION. 

  • Complete timing service including updated RS4 guides, chains, tensioners, and rebuilt re-machined mechanical adjusters.
  • New electronic adjusters will be installed. The electronic adjusters we use do not have a pigtail lead on them. Customers will need to slightly open the sheathing on their wire harness so the connector on the wire harness can reach the new electronic adjuster. Hydraulic roller rocket tappets are fully disassembled to free seized tappets, cleaned, and reassembled.  
  • Cylinder head refresh including cleaning and inspection. Replacement items include AMTuned upgraded solid core valve set, upgraded guides, upgraded valve guide seals, and gaskets. Cylinder head mating surface will be skimmed to ensure optimal sealing during install. Valve seats will be cut, and assembled heads are pressure tested. 
  • Engine block refresh including cleaning, bore measuring and cylinder bore preparation. Replacement items include main bearings, connecting rod bearings, piston rings, lower engine o-rings, valley pan gasket, valley pan check valves and cylinder head gaskets. Blocks with severe bore damage which cannot be reconditioned, will not pass our inspection process.


AMTuned Engine STAGE 1: Rated for up to 600whp & 7200 rpm. Turn around time is about 5 - 6 weeks. Turn around time is about 8-9 weeks after inspection. All items in Stage 0 package with the addition of:

  • AMTuned 4340 forged H-Beam with tapered end connecting rod package.


AMTuned Engine Stage 1+: Rated for up to 600whp & 8000 rpm for those looking to push higher boost. Turn around time is about 8-9 weeks after inspection. All items in Stage 0 package with the addition of:

  • AMTuned 4340 forged H-Beam with tapered end connecting rod package.
  • Upgraded HD Valve spring package. 65lb Intake seat pressure. 75lb Exhaust seat pressure. Titanium retainers.

AMTuned Engine STAGE 2: Rated for 900+whp & 8000rpm. Turn around time is about 12-16 weeks. All items in Stage 0 package with the addition of:

  • Sleeved engine block using LA Sleeve flanged sleeves
  • Balanced rotating assembly
  • AMTuned design JE Pistons w/93 series pins
  • AMTuned Schwerlast H-Beam connecting rods
  • Supertech 1mm Oversize Upgraded Valves
  • Supertech valve spring kit with titanium retainers.
  • ARP head studs