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534 SEAMASTER, Ford Super Duty gas truck motor marine conversion from the 1960s

March 15 2010 at 9:24 PM
Paul  (no login)

Response to * Chris Craft Power

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Several years before Janet and I bought our 427 powered 38, we looked at one on Tims Ford Lake that had a pair of 545 Ford Seamasters, and ladies and gentlemen, they were georgeous!

The 534, in case people are not familiar with this particular motor, is the "ROYALTY of the gasoline workhorse V8 world". It was used in fire engines, large busses, and lots of other heavy industrial uses. I have no idea how this motor got into a Chris Craft, but I suspect it was a custom order. We would have bought the boat, but it had been used as a dive boat in Florida, and that scared us off.

Since then I have always looked for another Seamaster installation, and so far I have never seen another one. This has to be the strongest and most durable gas motor ever installed in a Chris Craft boat, now, then, ever, with no close seconds.

534 cubic inches of pure industrial strength, it's a LOT of motor, and I suspect it was very expensive too.

Here is a SEAMASTER installation in the 1965 Commander 38, FFA-38-0022-H . I suspect this was the original power for this boat, arranged through the dealer. I have seen one of these in very good condition and the copper exhaust manifold was all polished up and the motors sounded fabulous. This setup here has obviously been used many hours and neglected, however, these motors are tanker truck strong and may well have outlasted their previous owners. One only wonders if they would start with a little coaxing.
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The 534 Seamaster conversions were offered in many large gas powered cruisers, including Egg Harbor and Hatteras, just to name a few. Here is a little history on how the "Seamaster" name disappeared (the company was purchased by OSCO) !!

The SEAMASTER 534 engines are still out there in lots of boats, as I don't think they're very easily worn out. I suspect they'll last as long or longer than the wood hulls they were installed in. I think Chris Craft would install an owner specified motor in their boats if the owner required this at the time the order was placed. I know of One (1) Chris Craft Commander powered by a pair of 534 SEAMASTER's. It would be very interesting to know the circumstances as to how many of these were done, etc.

Here's the history on the OSCO connection:

The name OSCO is derived from the OSCAR SMITH COMPANY. Oscar Smith was the grandfather of Robertson F. Smith who actually started the company. History has it that Oscar loaned the seed money to Robertson, so Robertson named the company after him. The current owner, Tom Cooper, has worked for OSCO since 1965, and purchased the company in 1995.

In addition to the original marine engines, which were based on Model A Ford 4 and 8 cylinder engines, OSCO sold conversion kits, which provided the marine parts for a customer to convert his own engine obtained from a car or truck. During the 1970s a full range of conversion kits was offered, covering every commonly available American car block, and several industrial diesels.

During their developing years, OSCO was called upon to make production marine parts for many familiar marine engine companies such as Glastron, Johnson and Towers, Holman & Moody, American Diesel, Noreast Ford, Commander Marine, KAAMA, Universal Motors, ONAN, Kohler, KEM Equipment, GM Overseas Operations, and others. At the same time OSCO produced and offered for sale a marine engine line, gas and diesel, from 14 to 180 HP. OSCO Marine engines were used by Pacemaker, US Coast Guard, Wayfarer, Newporter, Pearson, Columbia, Chris Craft, in addition to thousands of individual re-power installations by boat owners.

While busy enough with the above production, OSCO also manufactured an extensive line of hydraulic powered fishing deck machinery such as crab and lobster trap haulers, net takers, capstans and almost anything fishing related that could be turned hydraulically.

In the late 1960s, OSCO purchased the SEAMASTER Marine Engine Co. and added to their existing product line a Seamaster "300" six cylinder gasoline engine, and two V8 gasoline models based on the 534 cu. In. Ford industrial engine. The most powerful Seamaster model boasted twin turbo chargers and inter-cooling way back in the early 1970s.

Due to difficulties in obtaining base engines, OSCO discontinued their engine product line in 1983 and began the production of after-market manifolds in earnest.

Switching from earlier conversion type manifolds to after-market style manifolds required virtually all-new tooling. From the mid 1980s OSCOs in-house pattern shop facility has built the required patterns, and working with only the best American foundries continues to produce large volumes of marine manifolds and risers that have become the quality standard of the industry for the broadest range of Original Equipment Engines.

In 1990, OSCO began marketing their product to the large volume marine distributors, and today is recognized as the leader in quality, 100% built in the USA, manifolds, risers and accessory parts. OSCO manifolds and parts are available throughout the boating world through distributors, local marinas, marine engine repair shops, and the Internet.



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