Cooling Systems - Thermostat Housings

Polished Stainless Thermostat Kit For Chevy, 455 Olds

This thermostat kit fits small and big block Chevy, 455 Olds.  We found the majority of marine engines run far to cold to obtain proper combustion temperature.  This results in lower power output, economy and engine life.  Most engines are designed to run at a minimum water temperature of 160 degrees to achieve peak performance.  This thermostat system is designed for use on cold water source cooling systems.  It will keep the engine temperature between 140 and 160 degrees which is the most desirable range.  The temperature will cycle up to 30 degrees within this range, due to cold water entering the system when the thermostat opens.  We do not recommend this system be used on supercharged or turbocharged engines which run for long periods of time at maximum or near maximum power output.  We do not recommend this system be used in extremely sandy areas - sand build up can interfere with proper operation of the thermostat.

460 Ford Thermostat Kit

Well you asked for it, and the folks at Hardin Marine once again delivered. The frustrations of trying to manage the engine temperature on you B/B Ford 460 engine have left many a boater near insane. It seemed that without a thermostat styled cooling system the engines just either ran too hot or too cold. The problem was that without having the ability to bypass water to the exhaust system to keep it cool there was just no way to use a thermostat. So Hardin Marine looked at the problem discussed it with their engineering team and developed this attractive and functional cooling system package. They cast an all new thermostat housing and front cover featuring integral water bypass ports. This allows the thermostat to retain the water in the engine block as it warms up while still providing water flow to the engines exhaust system. The perfect answer the a long awaited problem. This kit comes complete with the new thermostat housing, thermostat, front cover, bolts, gaskets.

Bypass style thermostat housings are required whenever a thermostat is being used in the cooling system to provide water to the engines exhaust system during the time that the thermostat is warming up. This is the unit used in crossover cooling system #620-300100. It features (3) 1" push-on discharge connections. A key factor not found in most other thermostat housings. Many thermostat housing do "NOT" provide adequate water to the exhaust system during warm up due to too small of a bypass port.

Big Block Chevy with Circulating Pump

This beautiful cast stainless steel thermostat housing is designed to replace that ugly black factory cast iron unit that is original equipment on most MerCruiser applications.  It's gleaming polished finish adds sparkle to any engine Designed to work in conjunction with the factory circulating pump.

These highly polished handcrafted stainless steel water dividers are available in many configurations to fit a number of plumbing applications. Designed to fit Chevrolet engines. Bypass hole can also be used for temperature sender.

These highly polished handcrafted stainless steel water dividers are available in many configurations to fit a number of plumbing applications. Designed to fit Chevrolet engines. Bypass hole can also be used for temperature sender.

These highly polished handcrafted stainless steel water dividers are available in many configurations to fit a number of plumbing applications. Designed to fit Chevrolet engines. Bypass hole can also be used for temperature sender.

Polished Stainless Steel Water Outlet Divider With Bypass Hole & 1" Slip-on Hose Outlets

These highly polished handcrafted stainless steel water dividers are available in many configurations to fit a number of plumbing applications. These dividers are designed to fit Chevrolet engines and cannot be used with a thermostat unless ordered with the bypass hole in the top. Bypass hole can also be used for temperature sender.

This highly polished handcrafted stainless steel thermostat water outlet dividers is used in the Hardin Marine custom fabricated stainless steel closed cooling system. It is designed to fit a B/B Chevrolet engine application. It is only specific to the Hardin Marine kit and may require plumbing modifications in other applications. It features (1) 1-3/4",(2) 1",(1) 1-1/4" push on hose connections as well as (2) alternate 1/8"npt steam or bypass ports.

These beautiful cast stainless steel thermostat housings are designed to replace that ugly black factory cast iron unit that is original equipment on most Mercruiser applications. It’s gleaming polished finish adds sparkle to any engine. Designed to work in conjunction with the factory circulating pump and available in both standard height and low profile applications such as EFI engines etc.

Stainless Steel Water Outlet For Supercharged Engine Applications
1" Slip-on Divider With Bypass - Fits 8-71 thru 14-71 TBS and B&M 250 and 420 Superchargers

This all stainless steel divider has been specially designed for Chevrolet engine applications using superchargers. The unique size and shape makes it much easier to work with than standard dividers.

These all stainless steel dividers have been specially designed for Chevrolet engine applications using superchargers. Their unique size and shapes make them much easier to work with than standard dividers.

These all stainless steel dividers have been specially designed for Chevrolet engine applications using superchargers. Their unique size and shapes make them much easier to work with than standard dividers.

Replacement Plastic Bypass Valve

Replacement Retainer Ring

Replacement Valve Seat

Replacement Spring