A good example of "group think" is embodied in the before version of this Mercedes 560 SL engine. Previously, a well known specialist shop did their engine modifications package on this engine using old technology. The disappointed owner brought the engine to us and said "I want 350 horsepower." We dyno'd the engine in the state that was in when it arrived and only found 252-hp. While this was an improvement over stock (227-hp), the power just wasn't good enough.
After a scientific analysis of the intake tract the decision was made to fabricate a custom made intake manifold from an earlier Mercedes V8. Additionally, high compression pistons that were 2-mm oversize boosted the displacement to 5,775-cc. Using the existing camshaft, exhaust system and stock heads (which were ported), this EFI controlled engine put out the power the customer wanted.
Click on thumbnails for larger images.
Power: 350-hp @ 5,300-rpm, 392 lb-ft of torque @ 4,000-rpm
Type: M117, SOHC 2v, V8
Bore: 98.5-mm Razzo Rosso forged pistons, 22-mm pin size
Compression Ratio: 10.5:1
Cylinder heads: stock
Camshafts: 237/243 duration (@.050") and 10.7/11.1-mm lift (in/exh)
Induction: Razzo Rosso custom EFI on early V8 manifold. Extrude honed to 40-mm
Exhaust: Factory cast iron Tri-Y manifolds with custom down pipes
Ignition: Bosch electronic ignition with ECU control