TracTuff K24A/ K20Z3 Water Bypass Adapter
Imitated but not duplicated! I pioneered the Water Bypass Adapter 16+ years ago, and it is still the best fitting and most problem-free (no leaks) solution available, despite the concept being copied.
I developed this product in 2008 so K20Z3 engine owners could use all the popular intake manifolds that were made for the previous generation cylinder head. The K20Z3's RBC cylinder head and all those like it (RAA, RBB, and RSP) have a water passage incorporated into the intake manifold, and the popular aftermarket options do not. Using an intake manifold that was designed for the PRB/ PRC cylinder head will leave the rightmost portion of the intake manifold's flange exposed, leaving both the coolant bypass and EGR passages exposed. My water bypass adapter allows you to make the water passage connection as well as cover the unused EGR passage.
Even if you don't plan on running an aftermarket intake manifold... you can realize the benefits of reduced intake manifold temps by eliminating the heat transfer associated with hot coolant warming the manifold and no longer needing to drain and bleed the cooling system every time you remove the intake manifold for maintenance or swaps.
NOTE: The sensor port is OPTIONAL. If you don't have a sensor to accommodate, don't select it. I only offer 1/8" NPT or 1/8" BSPT (Honda Single Prong Sensor). If you don't need the water bypass function, please check out my dedicated Water Bypass Block-Off.
Installation Guide
Please understand that the intake manifold shown is JUST AN EXAMPLE. Please also understand that my water bypass adapter was designed and machined for a perfect fit when using the Genuine Honda PRB/ PRC manifold shown. I cannot control how aftermarket intake manifold companies cast or machine their products. If the water bypass adapter does not fit properly, you can decide which of the two products will be modified.
Also, nowhere in this write-up do I mention the use of OR recommend Hondabond or any RTV sealant. This is NOT an oversight or accident. It is NOT needed. The only thing you need to do is apply Teflon tape to the fitting's threads; the O-ring seals directly against the cylinder head. Do NOT install the water bypass adapter on top of a gasket!!
Start by wrapping the threads of the 90° hose fitting with Teflon tape. If you have never applied Teflon tape to a fitting's threads... please watch this video. There is a right and wrong way of applying it. Install the hose fitting in the water bypass adapter, then install the O-ring into the recess on the adapter’s backside and set the adapter aside. If you need assistance with keeping the O-ring in place... use a small dab of Hondabond or grease.
Grab the stainless steel link and the 35mm Genuine Honda flanged bolt and insert the bolt into the unthreaded hole in the link.
Thread the bolt and stainless link into the upper right-most intake manifold flange bolt hole. Tighten lightly with the link facing upward. Depending on the intake manifolds flange thickness, you may need to use a spacer or washers to shim the link out far enough to ensure it goes over the water bypass adapter.
Grab the shorter Genuine Honda flange bolt (now an M8 socket head 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 of any type!
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 (only one now).
Tighten the M8 hex head Honda flange bolt and M8 socked head cap screw to 18 lb. ft. of torque. Tighten the set screw until you have sufficient crush on the adapters o-ring. Thread the thin M8 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.