Get the 4th cylinder cool modification done for only $65 (thermostat version), $50 (heater version), or $35 (adapter + oring only) shipped, with no drilling, tapping, or modification of the head required.
This kit creates a path for stagnant, hot coolant on the #4 cylinder side of the engine to flow. The stock design locates the thermostat housing between cylinders 3 and 4, so hot coolant around the #4 cylinder has to change direction in order to reach the radiator, which causes poor flow and allows hot spots to form. By connecting a tube from the #4 cylinder side of the head to the thermostat housing, or the heater bypass, that coolant can flow continuosly in one direction through the head, greatly improving cooling ability.
There are some things you should check before buying this kit:
- The surface of your head around the freeze plug hole must be clean, flat, and free of any nicks, pits, scratches, or other physical imperfections. If you see some kind of blemish, the oring may still seal if its not in the oring sealing zone, which starts approximately 0.050" from the edge of the freeze plug hole, and extends out to approximately 0.19" from the edge of the freeze plug hole. However, you will still need to remove any protruding burs from the surface of the head so that the adapter can sit flush with the head.
- The bolt holes must be clean and have strong threads in them still. If your threads are eaten away or stripped, then you wont be able to tighten the bolts enough to seal the oring properly.
There are TWO versions of the kit, one which connects to the thermostat housing, and one which connects to the heater bypass.
Installation of the thermostat version is:
Remove bleeder plug on top of thermostat housing.
Drain coolant.
Remove valve cover.
Install 90 degree fitting into bleeder plug hole.
Install other 90 degree fitting into adapter.
Remove bigger freeze plug from #4 side of head.
Loosely install adapter in freeze plug hole.
Figure out the angle both fittings will need to be rotated to so that the hose will fit without kinking, to your liking.
Remove adapter.
Clean and remove any burs from oring mating surface on head around freeze plug.
Install oring in adapter, and install adapter onto head.
Figure out length braided hose should be cut to, and cut it.
Install hose fittings onto braided hose.
Install hose onto adapter fitting only.
Refill coolant, keeping hose above level of head (otherwise coolant will come out of it).
Install hose onto thermostat fitting.
Reinstall valve cover.
Installation of the heater bypass version:
Drain coolant.
Install brass 5/8 barb to 3/8 npt fitting into adapter, pointing towards the front of the vehicle at approximately 45 degree from level.
Remove bigger freeze plug from #4 side of head.
Clean and remove any burs from oring mating surface on head around freeze plug.
Install oring in adapter, and install adapter onto head.
Remove large fitting and/or pipe on bottom of thermostat housing, which heater bypass hose is connected to.
Tape and install included plug into the hole on bottom of thermostate fitting.
If needed, cut a short amount off the end of the heater bypass hose to get to fresh undistorted hose.
Connect hose to brass fitting in adapter, and secure it with a hose clamp.
Refill coolant and bleed system properly.
The kit requires an intermediate level of skill and tools to install. The ability to do the following are required:
-remove and reinstall the valve cover (for thermostat version)
-remove the freeze plug from the side of the head without scratching the surface of the head
-correctly install AN and/or NPT fittings, which requires the ability to torque, tape, and rotate them correctly as required
-figure out the correct angles and hose lengths for your particular setup
-cut a piece of braided hose correctly, twice (for thermostat version)
-install a piece of cut braided hose into hose fittings (for thermostat version)
-carefully locate the adapter onto the freeze plug hole without damaging the oring or head surface, and making sure the adapter boss is seated in the freeze plug hole
-drain and refill the coolant, and bleed the system of air
The parts included in the thermostat version of the kit are:
-one foot of uncut 8AN size stainless steel braided hose
-two straight female 8 AN to hose fittings (black)
-two 90 degree male 3/8 NPT to male 8 AN fittings (blue)
-one machined 6061-T6511 aluminum adapter plate with 3/8 NPT threaded port and oring groove
-two viton fluorelastomer orings (one extra)
-two black oxide flange head bolts with extra thick washers
The parts included in the heater version of the kit are:
-one brass 5/8 hose barb to 3/8 npt elbow fitting
-one machined 6061-T6511 aluminum adapter plate with 3/8 NPT threaded port and oring groove
-one galvanized steel 3/4 NPT plug
-two viton fluorelastomer orings (one extra)
-two black oxide flange head bolts with extra thick washers
The price for the thermostat version is $65 shipped.
The price for the heater version is $50 shipped.
The price for just the adapter plate and an oring is $35 shipped.
Just PM me and I'll send you my paypal info. You can also pay by money order if you like.
If you have any questions please feel free to ask!