4.2 BHF AM Tuned Stage 1+ Engine

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  • Regular price $13,195.95
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Tweetler is starting our in stock engine series with this AM Tuned Stage 1+ spec engine. This engine was intended for in house use. We since changed gears in utilizing our ported heads and cams, so we no longer need this engine.

Please note this block had a very minor vertical scratch at the top of one cylinder only. After honing the block 90% of that scratch cleaned up. This is why the block price is reduced by $500. It will run perfectly performance is not impacted, but we are compelled to be completely transparent.

Onto the fun stuff!

If you send your long block to us after your purchase we are willing to give you $1500 off an engine with a passed inspection.

AMTuned Engine Stage 1+:
Rated for up to 600whp & 8000 rpm for those looking to push higher boost. 

Turn around time is 1 week with in stock, built engines:

  • 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 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.