Last time around we took a look at the awesome K20 top end magic performed by the crew at 4Piston Racing and, not surprising, it's as good as their reputation suggests. With most of the aftermarket internals already in hand, I should have already started assembling the engine but I'm short on quite a few OEM parts and I'm currently digging around, making calls and trying to track them down.
Meanwhile, I pulled the Civic back out of storage because I found a set of del Sol Si rear disc brakes and trailing arms to replace the original VX drums. I also sourced a pair of Civic EX front knuckles from a wrecked coupe so that I could freshen up the front end at the same time. A rear disc conversion will make a serious impact on braking performance, and with so many cross-platform options available and junkyards stocked up on the parts needed for this process, it should be at the top of your to-do list.
Prior to getting the car on the lift I decided to pick up a new set of bearings for the EX knuckles, and since it was all going to be apart anyway, it was an ideal time to add a set of ARP extended studs. These use the factory thread size but add well over an inch of thread. Each one is made of heat treated, 8740 chrome moly and cadmium plated so they're ultra-strong and won't corrode on you over time with constant wheel removal and replacement. With a tensile strength of 200,000psi, they're built to last and this is about the fifth or sixth project car that I've used ARP studs on and I've never been let down.
Due to scheduling conflicts I wasn't able to get to the Motor Trend tech center so that I could borrow the press for the new bearings and studs, so instead I relied on a local machine shop just a few miles from my house. They're relatively cheap but they do charge to remove the old bearings, ball joints, and studs, so I did those at home to save a few bucks. Note: If using EX or Si non-ABS brakes, you'll need ABS wheel bearings. The non-ABS bearings are too small for the knuckle.
For wheel bearings, there are a number of inexpensive tools to help with removal. I don't own any of them. So, I just grab a socket large enough to match diameter with the hub, bridge the knuckle across a step or curb, and give it a few whacks with a 6lb. hammer until it pops through. Sometimes I get lucky and the bearing's inner race lets go, but it's rare. Fortunately my local machine shop doesn't charge to cut the race off. For the rest of the wheel bearing, the outer seal is pried off with a flathead and a slightly larger socket is used to pound it through and send bearings all over your garage. The ball joint is much simpler; just remove the retaining clip and give it a few hits to pop it through. Note: the ball joint won't come out if the outer seal for the bearing is still in place. Remove it to clear the ball joint's path.
For wheel studs I use the same abused socket to sit under the stud I'm working on to prop up the hub firmly, drop the hammer a few times, and out it comes.
I gave the hubs a little elbow grease but they were rougher than I expected and I wasn't making much progress. The Lowrider Magazine group, who work in the same office, mentioned trying Evapo-Rust since it had worked well for some of their projects. I ordered a jug from Amazon Prime, poured it in a bucket without diluting and let the hubs sit for 48 hours (label calls for less than a day but the weather was below 50, so I gave it more time). I came back to find them in great shape, not needing any additional work other than drying them off.
In the same bucket of Evapo-Rust, I submerged the front calipers since they were corroded and heavily discolored. A little bit of sandpaper to even them out and a few coats of high-heat paint and they looked much better.
Having drained the brake fluid when I pulled the VX engine out previously, I removed the brake line entirely without any mess. Remove the nuts that secure the lower ball joint, outer tie-rod and upper control arm and the knuckle can be pulled out and replaced.
For new rotors and pads, I went with a set of EBC Brakes' USR Ultimax Series sport rotors. You've definitely seen these before with their distinct black finish, called GEOMET, which actually helps resist corrosion. The narrow, uniform slot pattern helps to cool and "de-gas" under braking load, lends a hand in quieting things down, and lets the brake pads remain flat for even wear so you don't run into groove and galling issues.
And speaking of pads, I opted for EBC's "Red Stuff" fast street pads. I've used these on a few different projects previously and they bite nicely on the street and handle weekend track days without issue. They put up with plenty of abuse without noticeable fall off and, as a bonus; they don't produce much brake dust at all. Each of the pads, both front and rear, also feature their "brake-in" surface coating to make things even easier. If you're in the market for a more aggressive pad, intended for more track time, EBC's "Yellow Stuff" pads might be an ideal fit for you. On the flip side, if you just want a quality OEM replacement, they've got that covered with their Ultimax line up and they offer a ton of vehicle-specific fitment options.
EBC's USR rotor held place with fresh OEM Honda rotor set screws (do yourself a favor and use anti-seize on these screws. Y'welcome) along with the newly installed ARP extended studs.
I wiped down the rotor but didn't use any brake cleaner on the surface as the USR rotors come ready to go and don't require removal of any factory coatings like some others.
CONVERTING TO REAR DISC
As I mentioned, the rear discs are from a del Sol, which means the parking brake cables are too short for the EH chassis, as seen in the photo. Fortunately, I had a set of Civic hatchback cables in my garage (no idea why, but glad they were there) and it's the easiest part of this conversion. Simply unfasten the cotter pin and stay, remove the old cable and run the new one in its place. I prefer doing this while the brakes are off the car so that when the time comes, it's one less thing to worry about and they're stiff enough to stay out of your way while fitting the new brakes.
If you're swapping in rear trailing arms from a '90s Honda, this is what you can expect. This trailing arm bushing is beat—the core completely ripped from its surround, so I used an air hammer to carefully remove the remainder. These bushings are often incredibly stubborn and, lucky me, this was by far the worst I'd ever encountered.
Here tech center guru and fire guy, Christian Arriero, helps me burn the old bushing out. Rather than lighting up the rubber itself and breathing the fumes, the trick is to heat the area around the bushing to loosen it up. Getting the rubber off of the trailing arm pivot requires some intense heat as well, and I did it outdoors since the rubber itself had to be lit up. Immediately after, I scraped off the charred rubber with a flathead. I went back through the bushing opening using an air grinder with a sandpaper bit to clean up any leftover rubber.
Replacing the old, torn OEM bushing is Energy Suspension's HYPERFLEX performance polyurethane. Superior to factory rubber bushings, Energy Suspension helps maintain your car's factory alignment even when things get aggressive on the street or track. You get a noticeable improvement in handling and overall vehicle control and, best of all, they're much less than the cost of just one OEM bushing that won't last nearly as long as Energy's bushing—it's a win-win.
I laced the bushing itself and the inner portion of the trailing arm bushing opening with Energy Suspension Formula 5 and slowly pressed the bushing into place. The pivot arm is done the same way, again using plenty of Formula 5 so that the bushing goes in smooth and can do its job on the road quietly.
Import Tuner used an Energy Suspension bushing when they built the car the first time but I wanted to ditch the drums entirely. The addition of discs in the rear will make a dramatic improvement in braking and I'm more than willing to add a few pounds in order to gain some stopping power. As far as pricing, that's all over the board but I found these del Sol rears, complete, for $100 on a Facebook used parts page and picked them up locally.
Before removing the drum-equipped trailing arm, I disconnected the parking brake cables inside the cabin and fed them through the chassis. I also unbolted the mounting brackets that hold the cables in place under the car and just like the fronts; brake fluid was already drained during my engine removal previously. If you're not draining fluid, most will pinch the brake line in order to complete the job and not lose all of the fluid. Rubber hose fit over the jaws of a set of locking pliers is a good makeshift tourniquet.
Just a few bolts need to be removed from the trailing arm's rear, as well as the bushing pivot arm and the compensator arm. If you have a second set of hands, it'll make things easier. I didn't, so I used an exhaust stand to prop the rear disc while I worked on the compensator arm. After that I ran the parking brake cables inside the cabin, secured them and bolted up their brackets under the car before adjusting the cable to a 4-click hold point.
Like the fronts, the rusty rear rotors and worn pads were replaced by fresh EBC Brakes' USR slotted rotors and Red Stuff pads.
I ran out of time on Christmas Eve and had to get my car off the lift to make way for another group's project but was able to return to the tech center a week later to finish the last brake caliper using a few jack stands.
The finished product and a closer look at the Energy Suspension bushing fully mounted.
The stock VX wheels are too small for the front brakes so I pulled a set of Mugen MF8s out of storage so the Civic could remain a roller. Without any open-end lug nuts on hand, I picked up a set of Muteki SR45R Super Tuner lug nuts. These are produced in cold forged 50BV30 steel and feature an oversized, 60-degree, rotating cone seat at the bottom that make for better contact with the wheel and avoid scratching the surface. The knurled outer edge is a nice touch when removing or replacing, especially if you've got grease or oil on your hands.
The ARP extended stud and Muteki SR45R combo works perfectly together.
The next order of business for braking is a new master cylinder, booster, proper OEM prop valve to match the new rear disc set up and some custom lines.