Swartz Racing Manifolds


*Billet Manifolds:* Complete billet manifolds are available for engine builders who want several identical manifolds. The extensive design and CNC programming resources consumed by this method can only be recovered by a limited production run of several manifolds with minimal or no changes. This is a good fit for multi-car teams or race engine leasing shops. The main manifold components are machined from 6061 or 7050 aircraft aluminum plate. Assorted HDPE plastic spacers are also included for plenum volume tuning. All of the components are doweled and bolted together using #10 socket head cap screws. There is NO welding or epoxy used in this type of manifold. This allows for precise repeatability from manifold-to-manifold and engine-to-engine. The quality and performance never disappoints. They are guaranteed to fit with only minor port matching required (0.02” maximum). In order to protect the particular plenum details of my customer’s internal R&D, we can only show partial pictures of this type of manifold.
	*Bottom view of runner assembly with no valley tray installed.* A complete manifold weighs just over 20 pounds, but it starts as over 300 pounds of aluminum billet.

	*Front view, showing bolt-in valley tray, contoured billet aluminum top, plastic volume-tuning spacer, and double-flanged vibration isolation plastic spacer.* The top bolts are separate from the base bolts, thus reducing vibrations transmitted to the carburetors through the top fasteners. Most sheet metal manifolds use wood or rubber isolator spacers, but the steel bolts still transmit harmonics. Other features and benefits include:
No welding distortion - exact runner lengths and minimal variation from cylinder-to-cylinder. CAD designed runners – a true extension of your intake ports. Planned runner layout – optimized runner openings for carburetor arrangement. Rigid billet construction – more power due to less energy losses from plenum and runner pulsations and resonance in sheet metal manifolds. Turn-key upon delivery – final port matching and light runner surface preparation is all that is required for optimum results.
*A word about “modular” manifolds…* I get many requests for “modular” manifolds from my customers. All forward-thinking engine builders would like to have a manifold with interchangeable parts. They would like the runners to be “inserts” that can be altered and replaced. This is my opinion. Nothing is impossible, but a modular manifold is not as easy as it sounds. The main thing you would want to change is runner length or taper. When you change the runner length, the plenum width has to change accordingly. Therefore, you must start with a plenum that is wide enough to accommodate the shortest runners that you’ll ever want to test. And then as you make the runners longer, they have to be “bowed” or tilted in order to attach to the same point on the plenum. In other words, all of the features of manifold geometry are related to each other. Changing one dimension without changing the rest of the design requires some geometric compromises to make it all fit. This “less than optimum” size and shape always hurts performance. The test results will probably tell you how well that particular combination of parts fit together rather than what runner length works best. For my solution, see *Billet Runners*.