20V Auxilaries PT! – Cooling 1


AE101-RWD-CoolantThe whole personality of my car has changed.  I’m basically sick of wrenching and not driving.  Elegance and common methods be damned.  If this car turns out looking like OG Nishida’s… then I won’t be sad.  I really do plan on having something new in the near future.  Lots of guys convert to 16V water pumps when swapping 20V 4AG into AE86 or other RWD chassis.  That’s what I’ve done.  It is arguable that this has some performance disadvantages (i.e. inadequate cooling) at higher HP levels.  I’ll probably never break 200hp, and had no problem justifying the 16V set up.

coolant-outletThe tricky parts of the 16V pump set up are fabricating a coolant outlet pipe exiting the head, as well as a coolant by-pass that allows flow to continue when the thermostat is closed.  I fabricated my coolant outlet by chopping up and piecing the original 20V outlet pipe back together so that it only has one 90 degree bend (rather than two).  And then I brazed a 1/2″ 90 degree copper fitting on for the coolant bypass.

waterpump-housingOn the waterpump housing, it’s pretty easy to orient another 90 degree bend in such a way that it lines up with that on the outlet pipe.  I connected them with a chunk of heater hose, which is not that pretty, but it was very easy to fabricate and assemble.  Note that some recommend blocking off the original coolant bypass on the 16V pump housing, and T’ing into the heater core outlet.  IMO this was not a satisfactory solution.  The original bypass location is actually blocked off when the thermostat opens, where as the heater core gets flow ALL THE TIME.  Therefore, if you use the heater core outlet for your bypass, your bypass will be open ALL THE TIME.  My set up might be ugly… but it is right.

I actually blocked off the heater core outlet on my waterpump housing because I don’t have a heater anymore.  It makes the swap simpler, as well as saves over 40lbs and makes my car super simple under the dash.  We had an AE86 in the late 90’s that also had the core removed… and it didn’t bother me at all.  It’s not like I’m driving this car in the winter, or I can’t wear a sweater in the spring and fall.  The only concern is actually defrost… but I’ll show you how I’m going to look after that later.

sameng-bypass-and-block-offAnd as I said before… I cleaned up the mess on the back of the head with a Sam Engineering block off and bypass plate.   Total cost for EVERYTHING here:  $200


Leave a comment

Your email address will not be published. Required fields are marked *

One thought on “20V Auxilaries PT! – Cooling

  • Q Osborne Post author

    In hindsight this was one of the dumbest things I ever did to a car. I don’t mind that I blocked off and removed the heater core… but copper and brazing was stupid. The whole thing should have been aluminum.