Closed December 25th. - January 1st.
  • TracTuff K24Z Water Bypass Adapter


    On Back Order as of 11/20/20. Out of a small component and should be back in stock in about 7-10 days.

    Our K24AZ water bypass adapter allows R40 cylinder head owners to run the more popular aftermarket intake manifold options that were designed for the early 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 must have! The biggest benefit is in the reduction of intake manifold temps by eliminating the heat transfer/ heat soak associated with hot coolant running through the manifold. By modifying the manifolds flange (cutting off coolant portion) and running our adapter the coolant is kept away from the manifold completely, just like what you would find on the earlier PRB/ PRC heads, so NOW your Hondata IM gasket will really work!! We've seen drops 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... makes things a real SNAP!

    NOTE: The water bypass adapter has a 1/2" NPT water bypass port; the hardware kit includes a 90° hose fitting and a plug.

    Installation Guide

    The manifold shown is JUST AN EXAMPLE... I'm not going to re shoot instructions for every manifold out there! As long as the aftermarket manifold you own has the same shape as the PRB/ PRC manifold shown and they did a good job of holding to Honda's tolerance, my adapter will fit perfectly! This was the first product on the market and its been flawless since 2012.

    Start by installing the o-ring into the recess on the adapter’s backside. Set the adapter aside.



    Grab the stainless steel link and longer 40mm Genuine Honda flanged bolt and install the bolt into the smooth hole in the link.



    Install the bolt and stainless link into the right-most intake manifold flange bolt hole. Tighten lightly with the link facing upward.



    Grab the shorter 28mm Genuine Honda flange bolt and adapter and install the bolt into the lower bolt hole.



    Take the bolt and adapter and install it over the exposed water & egr ports. Thread the bolt into the cylinder head until it is hand tight. Do NOT install the adapter over a gasket


    Grab the stainless steel set screw and thread it into the stainless link. The pointed set screw will tighten into the hole well but in some extreme cases it may be a good idea to use some medium grade Loctite.

    Swing the stainless link and set screw down until it lines up with the pilot hole of your choice.


    Tighten the 8mm intake manifold and Water Bypass bolts to 18 lb. ft. of torque and tighten the set screw until you have sufficient crush on the adapters o-ring. The thin 8mm jamb nut is not shown here but it would either go on the exposed threads of the set screw (face of the link) if there were enough threads OR in between the link and the bypass adapter (shown) and tightened to lock the set screw in place. Congratulations! You're done.