Project Honda Civic EJ: Staying Cool with Koyo and HPS
By Annie Sam
Photos By Chuck Johnson
The last time project Civic was at the racetrack, it overheated and blew a head gasket, warping the head along the way. Since then, Chuck Johnson took apart the motor and filled it up with all sorts of goodies that you can read about here in the last installment of Project Honda Civic EJ.
Now that the motor was back in the car ready to be buttoned up, we decided to give it a little bit of a cooling upgrade to avoid another Buttonwillow incident. Naturally, the next logical step was to replace the stock Civic radiator with the biggest, baddest one we could find. Ok, maybe not the biggest, but we were definitely looking for the baddest. Although the stock radiator was reliable for over a decade for daily driving, our beefed up Civic would also need a beefed up cooling system.
The radiator we opted for was the Koyo All Aluminum Racing radiator for the Honda Civic SI. The inlet/outlet diameters between the B16 and B18 motors were the same at 1 1/4″, whereas the outlets for the D16 were 1 1/8″. So, what we did was order the radiator meant for the Civic SI which ran the B16. Not only is this critical for consistency in the diameter of the openings, it eliminated the bottleneck which occurs when you use the stock Civic's radiator with the B18. It may sound like common sense but there are a lot of people that run this set up with the B18 swap. Hey it worked for over 100,000 miles for me and would have ran even longer if I didn't abuse it at the racetrack the way that I did.
|Right off the bat you could see the huge difference in width between the two radiators. The Koyo full race radiator was more than three times the width of the factory Civic radiator.|
Because we had ordered the Civic SI radiator for my Civic EX, my stock radiator fan wasn't an exact fit. The lower brackets to the fan had to be modified because the threaded holes to the radiator were in a slightly different location. It might not look pretty but I didn't have to buy a whole new radiator fan and it got the job done.
|Not the prettiest modification but it gets the job done.|
|Aside from the bottom brackets, the rest of the radiator fan bolted right in place.|