Hardine Marine Polished Bypass Thermostat Kit         Complete  $165


Note - Some water pump cover plates may have to be drilled out

and taped for a 1/2" NPT to accommodate the inlet tees.

Set of Four Hose Fittings, 1/2"  NPT x5/8" Hose    $16


Chevy Water Inlet Blocks     $41


When using the bypass thermostat kit for the Chevy and Olds motors, you

may need to enlarge the fitting size on the water inlet plates and blocks.  In early

applications, the Chevy inlet blocks and the Old water pump cover plates were

 tapped with 3/8" NPT pipe thread.  These thermostat kits use water tees with

1/2" NPT threads.  With the Olds, you will have to drill out the 3/8" thread in

the inlet plate and re-tap to 1/2" NPT thread.  With the small and big block Chevys,

you can save yourself the hassle by using these billet inlet blocks.  These new inlet blocks

are already set up with 1/2" NPT threads and come with bolts and gaskets.




As most of you Ford lovers know, the bypass thermostat kits available for Chevy and Olds do not fit the 460 Ford engines.  Jim at Performance Jet has a 460 Ford engine in his 21-foot Eliminator.  The engine temp was always running cold, so we figured a way to control the temperature without breaking the budget.  This system has been working nicely for our customers for many years, so Performance Jet decided to offer this setup as a kit.


The kit includes a new thermostat housing with the divider milled out to accept a 160-degree marine thermostat that is specially drilled for this setup.  In conjunction with the thermostat and housing, the Performance Jet water pressure relief kit MUST be used and is included as part of this kit.


Note:  Performance Jet recommends that both outlets on the

thermostat housing be plumbed to dump overboard, and they do if

you have thru Transom exhaust.  If your boat runs headers, it is

recommended that you find another water source for your headers

and dump both thermostat outlets overboard.

NOTE:  This kit would no longer be needed for the 460 ford with the advent of the new Ford four port T stat kit.  But, this set up still works just fine and may be used on jet boats with unusual engine combinations where temperature control systems are not available. This set up can still be used on Fords or Chevy’s if you choose to do so. This kit is Just gives you another option.

Ford 460 Jet boat Owners   **ALERT**   New Product for 2014


Up until 2014 Ford jet boat owners had only a few ways to manage engine temperature in their engines, a pricey re-circulation kit or the pressure relief thermostat assembly developed by Jim at Performance Jet.


Jim got together with Scott at Hardin Marine and suggested they develop a four port by-pass T stat kit and housing that would fit the Ford engine with the front mount distributor.  This kit is the same as the GM by-pass T stat kit but is designed with an offset to clear distributors and to fit the Ford intake manifold flange.  The four fitting ports were also “re clocked” to allow for the hoses to route properly.


Some computer specs were drawn up and Scott had a prototype made up out of plastic on a 3 D printer.  The part was sent to Performance Jet for fit testing and analysis.  ( See pics 1& 2, below.)


It turns out that most distributors will fit and a few will not.  In pic #1 the mock up shows an OEM Prestolite distributor and pic#2 shows with a marine MSD billet distributor. Distributors with a 4.750 inch diameter body at the cap hold down screws will fit just fine.  You could even rotate the distributor on set up to get the rotor cap hold downs away from the T stat housing for more clearance if desired.


Standard Mallory, Accel and Pro Tronix distributors will fit as well.  The only distributors that were found to not fit were the larger body distributors that have the coil in the rotor cap and the Mallory 9000 as far as I could tell.  It would be wise to double check and measure your distributor to make sure the cap diameter is 4.750 inches if you have any doubts.  Shown below is the new 460 Ford four port T sat kit.  


Kit price $195


Reduce pressure in your engine block for

improved realiability and temperature control.

As shown  $149

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