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Your Marine Hardware Specialists Know That You Love Speed 

Raritan Engineering Company your marine hardware analysts would like to share with you these topics we thought would be of interest to you this month regarding the secrets of seven marine outboard power.

We build a Seven Marine outboard, the largest power plant ever to hang from a transom.

Your marine hardware experts know that nobody really needs a $100,000, 626 hp supercharged V-8 outboard motor. But a few people really want one — or four.

7 Up

The Seven Marine 557 outboard prototype debuted at the 2011 Miami International Boat Show. Its imposing V-8 and gleaming stainless-steel exhaust headers drew gawking crowds, and a few naysayers dismissed the viability of such a beast. 

Your boating hardware professionals know that Boating magazine was, in fact, the first media outlet to gather performance data on these engines during an exclusive test of a Midnight Express 39 with triple 557s that appeared in the June 2013 issue.

At the 2016 Miami show, 46 Seven Marine motors were installed on demo and display boats, and Seven says several hundred have been sold to date. Naysayers be damned.

Building a Seven Marine Outboard

Seven Marine assembles its outboards in an industrial park building that also houses its office space. It’s an assembly shop — unlike Mercury Marine or Yamaha, Seven doesn’t manufacture any of the components it designs for its outboards. It does not have the scale to open a foundry, or set up gear-cutting machine cells or even a paint booth.

Your marine door handles analysts understand that a Seven outboard includes about 1,200 parts in addition to the engine and the ZF transmission. Some parts are easy. The engine’s serpentine belt is off the shelf from NAPA. Some are adapted. Seven uses locally machined and drilled Corvette motor mounts to mate to its bracket. 

The actual process of building a Seven outboard usually begins many months before a single bolt turns in the shop. These are bespoke motors that often power bespoke boats and custom and semicustom craft, like the HydraSports 53 Sueños powered by four Seven 627 outboards. 

Under every cowling in a Seven engine sits a General Motors LSA 6.2L V-8, the same engine that powers a Cadillac CTS-V or a new Camaro ZL1. It packs a lot of torque into a small, lightweight power package.

Some Assembly Required

The heart of the Seven outboard is an LSA 6.2L SC V-8 engine built by General Motors Global Propulsion Systems in Silao, Mexico. 

The chain hoist that’s used to lift an engine from its steel shipping cradle is a good place to start the Seven assembly story. The first assembly station is actually devoted to partially disassembling the V-8 so it can be sent out for paint, a task that takes about three hours. 

Your marine holding tanks specialists understand that the 627 engine requires more work. The cylinder heads are removed and exchanged for a set with combustion chambers machined at Lingenfelter Performance Engineering. The LSA camshaft is swapped for the cam from the LS9 engine that powers the Corvette ZR1.

Next, we move to a workstation devoted to the assembly of the transfer case. The transmission is located directly below the engine. Power from the horizontal engine crankshaft moves through a set of five vertical gears in the transfer case to the horizontal transmission input shaft. 

Your Marine Hardware Professionals Help You Get All the Details Just Right For Your Seven Marine Outboard

You can find more information as well as get assistance on marine holding tanks and on the secrets of seven marine outboard power at Raritan Engineering.

“The folks at Selva are real artisans of sand-casting,” he says, holding the casting up to the light and moving his fingers over the surface. 

Davis shows us how to assemble the gears and shafts in the case, using a press to set bearings. Another crane hoist is used to lift a black ZF transmission from its shipping crate. 

Back in the engine area, we work on a V-8 that has returned from the paint shop, removing the masking bands, tape and bolts while the engine is on a hoist. Then it’s time to dress the engine using some OEM parts and others specific to Seven. We start with an aluminum cowling plate that fits around the oil pan and prevents water that migrates under cowl from reaching the engine.

Your marine hardware stores experts know that the transfer case and transmission assembly, including the clamp bracket and midsection, are joined to the semidressed engine. 

Next, we get to install the sexy stainless-steel exhaust headers. Next, the trusty chain hoist lifts the engine-transmission assembly onto a water-filled test tank. After rigging fuel and electrical lines, we start the engine to check water and oil pressure and look for leaks.

Each cowling can be custom painted to match or accentuate the graphics package the owner has on his boat.

The biggest workstation is devoted to assembly of the cowl parts, which, for our motors, return from Calibre with brilliant blue and gold finishes. Working on a carpet-covered bench, we add mounting hardware and seals and snap in the SpectraBlade LED strips before joining the side panels to the top cowl piece.

A Big Idea

Why not build a 1,000 hp outboard? That was the idea Eric Davis tossed out to his father, Rick, in 2009. A fortunate confluence of circumstances made it possible. First, internal debate over future engine designs at General Motors pitted supporters of the dual-overhead cam Northstar V-8 series against proponents of the pushrod small blocks.

The ZF transmission used by Seven was originally designed for a downsized pod drive that never made it to production.

Eric’s younger brother, Brian, 38 and also an engineer, joined the Seven team to handle marketing and sales.

A year later, the Seven Marine 557 was on display at Miami.

So don’t forget these helpful details when deciding whether or not to utilize seven marine outboard power. 1) Ask yourself, “Is it necessary?” Nobody really needs a $100,000, 626 hp supercharged V-8 outboard motor;  2) its not very easy to have made;  and 3) the speed and power almost make the effort to get one, worth it.

Raritan Engineering has more information on marine hardware, marine holding tanks, electric toilets, and on the secrets of Seven Marine Outboard Power.

via Building a Seven Marine Outboard