• Diamond Marine, World-Renowned Outboard Racing Engine Specialists to Retire Company

    An Incredible History of Mercury V6 Engine Innovation

    Notice to all Diamond Marine customers,

    We would like tell you some bitter sweet news, after serving the Mercury high performance outboard industry for 33 years we have decided that it was time to close up shop and retire. Through the years we had created an amazing customer base with many friendships along the way. It is hard to put a number how many boats we were instrumental in putting in the winners circle all over the world, those were the Monday morning phone calls that we always enjoyed. We want to thank all of our customers for their loyalty and support they have given us through the years it has been truly appreciated.

    Now I would like to let everyone what is next for us, simply at this time we are in the process of liquidating all machinery equipment as well as a vast inventory of used parts, because of the quantity of items we have we will not be making any kind of list. If you are looking for a certain item just call us at 954-525-2600 and we will see if we can find it. For anyone that would like to come to the shop and look at our equipment and inventory all is welcome, everything must go. We plan on a total liquidation of the property March 22 so please be aware that this is happening right now. Thanks again to all our customers I am sure we will still be in touch in the future.

    Joe and Marty Signorelli

    For all sales inquiries, please email us at speed@diamondmarine.com




    Closing thoughts by Greg Terzian

    They were at the cutting edge of the art of creating horsepower for decades. Joe and Marty Signorelli have worked together since they were teenagers, having opened their first shop in Farmingdale, Long Island in 1978. It will be the end of an era, and it does not matter what brand of engine or boat you own, because Joe and Marty's influence has likely touched all of us in some way.

    I grew up in Massapequa, which is a neighboring town to Farmingdale, so my early days at the boat ramps in Lindenhurst and Massapequa are filled with memories of early STVs and screaming Bridgeport Mercury engines. Once in a while I would see one of those STVs, and that beautiful aroma of aviation fuel. The Diamond Marine logo on the deck cowl of that Pro Comp made clear what it was. And what was it? I am not even sure, because Joe and Marty are the mad scientists of the high performance boating world, and they developed parts that were not only effective, but simply exotic and beautiful to behold.


    Diamond Race Cars Camaro at the 1983 N.H.R.A. Nationals, Indianapolis.

    The Signorelli brothers established Diamond Race Cars building custom tubular drag race car frames and engines, and their exquisite attention to detail and exacting quality of their work rapidly made them very well known in the early 1980s. Of course, being from Long Island, having an interest in boating is only natural, and the then-new STV boats and accelerating interest in fast, outboard-powered boats added to an inspiration to direct their talents to race boat development.


    Back then, the Mercury 2.0 and 2.4-Litre V6 engines were new and cutting-edge, and presented a very inviting platform for Joe and Marty's unique style of innovation and precision, and their work would go far beyond simple engine modifications. The development of their now famous lightweight flywheels, dual-spark plug heads, the very first programmable digital EFI ECU, custom intakes, and an endless catalog of custom-made parts designed and manufactured by them would become legendary.


    Testing Mercury EFI Bridgeport in the late-1980s at Tanner Park in Lindenhurst, Long Island.

    To know Joe and Marty is to understand exactly what Diamond Marine is - or now, sadly - was. These two guys were irreplaceable for the sum of the whole that was Diamond Marine. Marty has often been the voice of Diamond, who communicated with customers in his unique style of a person that speaks from tremendous experience, yet always makes the most technical points both easy to understand and humorous with typical Long Island cynicism and flair. Joe is more reserved and to the point, a technical razor that always gives the impression that his mind is never resting. Their unique talents complimented each other perfectly, resulting in creations of power and precision that became legendary.

    Joe and Marty never stopped developing new products for their customer's needs, which were often professional race teams. I remember the first time I came to visit Diamond Marine in Fort Lauderdale and seeing that immense CNC, with Joe Signorelli beside it on his computer workstation designing a new lower unit adapter plate. These guys did it all, start to finish.


    Dennis Vitolo's STV is the last in a line of many STVs that Diamond Marine engines powered, as well as numerous custom fabricated parts for rigging. Note Diamond Marine lightweight race flywheel.

    I felt the need to add my thoughts to the official press release of their retirement because I feel that this is not only the retirement of an unparalleled team of two brothers that shaped our sport in so many ways, but just two great people that always placed their customer first, regardless of whether they were having a race engine built, or just asking advice.

    Diamond Marine's company history encompassed nearly the entire development life of the racing versions of Mercury V6 from the 2.4-liter Bridgeport to the latest 2.5-liter Mercury Drag engines, and their influence will very likely be present for as long as we are all using those engines.


    Comments 11 Comments
    1. tux974's Avatar
      tux974 -
      Well deserved for 2 amazing guys and friends!
    1. Frank Molé's Avatar
      Frank Molé -
      Good luck guys,you should have a lot of fun...congrats.....
    1. Zukiride's Avatar
      Zukiride -
      Amazing shop, amazing innovators, sad to see the shop close, but wish you the best in a long, happy, healthy retirement!
    1. stokernick's Avatar
      stokernick -
      Quite a journey ! Best wishes and thanks for all you did, Marty and Joe ! You'll be missed but well earned !
    1. AZMIDLYF's Avatar
      AZMIDLYF -
      Icons of the industry...times are changing too fast for this old guy. All the best in the next phase of your lives.
    1. wetsetmarine's Avatar
      wetsetmarine -
      Best of luck in the future! Thank you for the past!!!
    1. Markus's Avatar
      Markus -
      Joe and Marty,

      Thank you for the helpfulness, the great products, and the enjoyable conversations!

      Enjoy retirement!__PRESENT
    1. 89LASER's Avatar
      89LASER -
      Best of luck to both of you and your families. Enjoy your retirement, you both deserve it.
    1. GRH's Avatar
      GRH -
      Best wishes on your retirement.... many happy memories of our Diamond Prepared STV Euro....
    1. LOSTINJ's Avatar
      LOSTINJ -
      What's next ? I hope not hopping up larks @ Shady Acres!
    1. Bodhi's Avatar
      Bodhi -
      So now that the legend of diamond marine has come to an end. Anyone know where quality high performance motors are built now? I hear of many builders but they all seem to come with the same tale from customers that communication is poor, blocks get switched, and/or work is crap.
      I had always planned on bringing my powerhead over to diamond when that day eventually comes.
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