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TracTuff RBB/ RBC Rear Wheel Drive K Swap Water Neck Kit


I have combined three popular products into a single kit for quick and easy purchasing!

Products shown are also available individually at each of these links. You can either go to each of the pages and read the product descriptions or read them all below.

Water Neck 

Thermostat Cover

Water Bypass Adapter

Water Neck

The RWD upper water neck addresses a few concerns with the growing popularity of the k swapping a number of front engine rear drive chassis. Now fabricated with a one piece tube!!!

Normally, the water neck is pretty much right in front of the radiator and the two points are pretty much equal in height... and even then, the K is notorious for being a real bitch to bleed! Rotate the motor 90° and now you have make the radiator hose either go up and over or down and under the intake manifold. Both will present problems, but one is uglier than the other, so down and under it is. Lucky for you, I have created a fixture based off of the S2000 outlet, had custom tubes bent, and have welded them to my billet RWD housing... essentially mimicking the geometry of the factory S2000 intake manifold/ water neck assembly.

This option has allowed K swapped S2000's to reuse the factory upper hose and I'm starting to see more and more Non-Honda swaps going to that hose to solve there unique swaps connection issue. The only short coming of this design, is that when taking the cooling systems highest point and ask it do dive down under the intake manifold, you are creating a HUGE pocket for air to collect! For this reason, I highly recommend a swirl pot, a fill pot, a filler neck, or at the very least... a vent (pictured) (listed in order of best, better, good). Each of those product offers a way to eliminate the air on initial fill up where the best option constantly deaerates the coolant (read more).

NOTE: Made to Order - Contact for ETA - If you are interested in a running AN lines or a specific design, please email sales@tractuff.com. The tube is welded so that it sits similarly to the OEM S2000 water neck outlet position when the engine sits at its original 15° lean to the passenger side (exhaust side). The billet neck has a 1/2" NPT heater port and the hardware kit includes a 90° hose fitting and a plug in the event you don't plan on connecting a heater hose. The Skunk2 Ultra Street and Ultra Race intake manifolds require a small change to the outlet position in order to avoid the plenum flange but the end of the tube is still VERY similar to the OEM S2000 water necks outlet position.

Thermostat Cover

Originally offered as a configuration option but due to customers complaining that the options were confusing, I have decided to give the common RWD selection its own spot. No cool features, no weaknesses, no bullshit! What you see is a simple Billet Thermostat Cover that bolts to the OEM plastic housing, uses the OEM shoulder bolts, the OEM thermostat, and OEM gasket for pretty much any RWD k swap. I chose the original thermostat because it is unique to this engines configuration and is related to many of customers number once concern. You wont find any sensor ports because they don't belong here and you wont find a swivel because it doesn't work for everyone anyway. What you do get is, a straight forward, refreshing design that allows the end-user to chose whichever fitting he/ she needs to plumb the lower hose.

Machined from US milled 6061 aluminum; the flange incorporates an OEM o-ring grove and the front (originally threaded for -16 ORB) has been machined to remove the material beyond the thermostats locating pin, reducing the overall length and welding a straight section of 1-1/4" tube or a -16 male flare. The Billet Thermostat Cover uniquely receives the K20a2/ K20a3/ k20z1 thermostat for the most reliable function and retains the quick warm up feature of the water bypass circuit. 

NOTE: The TracTuff K Series Billet Thermostat Cover is designed to be a direct replacement for the 2002-2006 Acura RSX or 2002-2005 Civic Si thermostat cover. In order to run this product, you MUST use the thermostat (not included) and thermostat case (back-half that bolts to the water pump housing (P/N 19320-PNA-003)) from a 2002-2006 Acura RSX or 2002-2005 Civic Si. The water pump housing bolt pattern is common between all the k series engines I have touched, so if you do not have the correct thermostat case to use my cover... you can simply swap it out. The S2000 and Miata k swap benefits from this configuration the most, but as more and more chassis are being k swapped, I imagine others will as well. I strongly suggest measuring the space you have BEFORE ordering any configuration! Some RWD swaps may have enough room to use an unmodified cover with a screw in fitting and save a few bucks.

Water Bypass Adapter

The OG water bypass adapter! Imitated but not duplicated. Still the best looking, best fitting (leak free!), and now the least expensive!

My water bypass allows RAA, RBB, RBC, and RSP cylinder head owners to run the more popular aftermarket intake manifold options that were designed for the earlier PRB/ PRC flange. The PRB/ PRC style manifolds do not have an integrated coolant passage so the coolant bypass hole is left open when used together. Even if you don't plan on running a PRB/ PRC style manifold... there are plenty of benefits that make this product a smart purchase! Benefits such as a reduction of intake manifold temps by eliminating the heat transfer/ heat soak associated with hot coolant running through the manifold. By simply modifying the manifolds flange (cutting off coolant portion) and running this adapter, the coolant is kept away from the manifold completely, just like what you would find on the earlier PRB/ PRC heads. NOW your Hondata IM gasket will really work!! I've personally seen drops in temp as much as 18°!! Not to mention, the additional benefit of no longer having to drain the coolant when removing the intake manifold for maintenance or swaps! It makes that job a real SNAP.

NOTE: Starting 4/16/20 ALL water bypass adapter sales will include a 90° 1/2" NPT to 5/8" hose fitting as STANDARD. You no longer have the option of buying a plug... if you are interested in deleting the water bypass hose and its function, please check out my new dedicated Water Bypass Block-Off.