Machine tuning matters

If there’s any wonder about the importance of machine service and its impact on the quality of espresso, look no further than the home version of the espresso making game.

Over the past several weeks, my home espresso machine was showing the telltale signs of failing gaskets and seals, which need replacement about once a year with regular use. The water pressure through the group head gradually went from a heavy flow to a trickle and then to a drip. Over time, though almost too subtle to notice, I was pulling my espresso shots differently to adjust to these pressurization changes.

I was taking more and more time to force sufficient water flow in the group head — compensating so I could generate the proper water pressure through the puck of ground coffee that I inserted into the portafilter. Because of this, hot water came into contact with the surface coffee for longer periods of time, changing the extraction of my shots to something much more than desired, and resulting in an uneven shot that contained more water-soluble, bitter elements in the cup.

The answer, of course, was to open up my machine and replace a number of seals and gaskets. This was my project yesterday. While a few gaskets were still in good shape (my machine contains nine different gaskets, six of which are in the group head assembly), the main pair of gaskets around the group head piston showed serious wear.

These seals were worn down from regular use and no longer held the tight pressure seal needed to properly control the water flow. In the photographs below, you can see the difference between the old, smoothed-down pair of rubber gaskets on the piston and what a new pair looks like in their place. The new gaskets “poke out” from the circumference of the piston, gripping the cylindrical piston wall with a much tighter seal.

Breaking out the wrenches, universal retaining ring pliers, and food-safe lubricant, it’s enough to make you feel like you’re rebuilding a car engine. But the bottom line is that my home machine makes a far better espresso once it has been serviced like this. Even so, such a fix still requires me to greatly adjust my espresso shot pulls to account for the improved pressure control.

So whether your favorite café uses a super-automatic, semi-automatic, or manual lever espresso machine, regular, professional machine service can make a huge difference in the quality of the espresso they produce. And if your home machine is making espresso that’s a lot worse off than it was a year ago, it’s probably time for a tune-up.

Honda Clutch Line Installation - Steel Braided Bling

There are a few reasons why you might want to swap your Civic's rigid, steel hydraulic clutch line for something else: It's difficult to get the OEM line and fitting assembly to cooperate with certain engine swaps, if you're going for that shaved-bay look then an ugly steel line running across the firewall simply won't cut it, and even if you're not going for that shaved-bay look a bit of steel braided bling is enough to spice up just about any engine bay. Although going overboard with the bling is never a good thing, the most important thing to keep in mind when working with hydraulic clutch and brake systems is the pressure involved. A typical automotive hydraulic clutch or brake line exhibits upwards of 1,500 psi internally. As the clutch or brake pedal is depressed, fluid pressurizes within the system causing the line to squirm around on its own. Imagine a garden hose that flings around by itself once the water is turned on-the principle is similar.

Flexible, steel braided lines are exactly that-flexible. As such, eliminating too much of the OEM rigid line or selecting too large of a line can result in a soggy pedal and/or poor braking or clutch engagement. An ideal clutch or braking system consists entirely of rigid line but that's simply impossible because of engine vibration and suspension travel. This is where flexible rubber or steel braided lines come into play. Use them sparingly though-like Honda did. A hydraulic clutch or brake system constructed entirely of steel braided hose isn't always the best idea.

As far as Civics go, only '92 and newer models feature hydraulic clutch systems, which makes this process somewhat useless for those with anything older. A typical '92-'95 Civic hydraulic clutch system consists of the ugly rigid steel line, dirty rubber hose, and metal brackets on the right. The steel braided setup on the left is much simpler and just looks better.	The OEM rigid line travels from the clutch master cylinder to the slave cylinder, located on the transmission. The line is intercepted by a short section of high-pressure rubber hose to allow for engine movement. Use a 10mm line wrench to remove the fitting from the clutch slave cylinder and then a 10mm socket to remove the two bolts holding the bracket in place. Set a drain pan underneath the vehicle to catch the residual fluid from the line and allow it to drain thoroughly before moving forward.	92-'95 Civics feature this aluminum clutch line connector located on the firewall directly behind the throttle body. You can either thread a 12x1.0mm to -3 adapter into the connector's left side and run steel braided line from here to the slave cylinder or you can remove this connector altogether and tap directly into the master cylinder. Keep in mind that the more flexible line you add, the greater the chance the clutch pedal may exhibit a soft feel, although this is generally more common with brake systems.
Running a line from the master cylinder to the slave cylinder requires just a few parts: approximately 60 inches of -3, Teflon-lined steel braided line, two 10x1.0mm to -3 inverted flare fittings, two appropriately sized hose clamps, and two -3 steel hose ends-a 180-degree one and a 45- or 30-degree one. Straight hose ends are cheaper and will work, but when working with steel braided plumbing it's best to achieve your bends by means of the fitting not the hose.	Use a 10mm line wrench to remove the fitting from the clutch master cylinder's outlet port and remove the line. Carefully unclip the clutch line from the brake lines along the firewall and remove any brackets connecting it to the chassis using a 10mm socket. Brake fluid is an excellent paint remover so be sure and wrap the line's ends with a rag before pulling it out.	Thread the adapter fitting into the clutch master cylinder's outlet port. Do not use any type of sealant here-that's what the inverted flare is for. Applying Teflon tape or sealant will cause a leak. Assemble both hose ends onto the hose before connecting it to the -3 fitting. Connect the 180-degree end to the clutch master cylinder end, turning it in such a way so as to allow clearance between the tube and the firewall. The hose should route underneath the brake booster and along the firewall.
Use a suitably sized hose clamp to attach the line to the firewall where the factory aluminum connector was. Don't be lazy or cheap here. The line will flex and move every time you step on the clutch if you skimp on clamps.	This clamp is even more important because it will prevent the line from shorting out against the starter's main power wire. Find a suitable location on the transmission or framerail and clamp the line down. This B-series transmission bracket works well.	Thread the remaining fitting and hose end onto the clutch slave cylinder. Be sure to orient the hose the way you want it before making the final turn. Again, stay away from that sealant.
Of course, you'll need to bleed the clutch system of air bubbles since it's been opened. Use a 8mm line wrench to crack open the bleeder fitting and purge away.

whel ofset

If there's one thing hard parkers and road racers can agree upon it's that wheels and fenders should fit flush with one another. Perhaps it's because of how good it looks when the wheels and body surface are in the same plane. Or maybe it's because cars tend to handle better with the wheels positioned farther out. Either way, since wheels travel upward as suspensions compress, the farthest outboard they can go is just about flush with the fender. If the car looks and handles better, then despite what we've been told, maybe we can have our cake and eat it too.

Offset: What the heck is it?
All of this brings us to wheel offset, which is simply the distance between the wheel's hub-mounting surface and its center plane. Positive offset means the hub-mounting surface is closer to the wheel's outboard side. Conversely, negative offset means it's closer to the inboard side. If the mounting surface coincides with the wheel's center plane then offset measures in at zero. In other words, offset determines the lateral, or side to side, position of the wheel. As wheel widths change, the offset combined with the new width must be chosen properly so that the wheel and tire have enough space within the wheelwell to avoid rubbing or unwanted contact with other components.

Front-wheel-drive cars are generally equipped with positive offset wheels. Most manufacturers design cars with a negative scrub radius up front that is made possible by positive offsets. The scrub radius simply refers to the distance between the point where the steering axis intersects the pavement and the center of the tire's contact patch. Since the scrub radius has to do with steering geometry, such positive offset requirements only apply up front. However, since factories typically prefer using similar wheels all around to reduce manufacturing costs, the rear wheels typically get the same positive offset wheels as the front. If we're talking about rear-wheel-drive cars, then most OEMs incorporate a minimal scrub radius up front.

Why should you Care?
The ability to understand wheel offset can help solve a variety of wheel fitment issues. Wheel and tire upsizing often requires altered offsets. The wheel supplier will usually have the information necessary in terms of which offsets will and will not work, and, if that doesn't work, there's probably at least one thread somewhere on the Web with at least one guy who's tried the same wheel combo you're considering, but don't count on it. Sometimes the info just isn't there and the only way to know for sure is to measure and calculate. It all begins with your stock wheels and tires.

The minimum clearances on both sides of the OEM wheel/tire package must be accounted for prior to assuming a potential maximum tire width-this includes the space between the nearest suspension component as well as the fender. Keep in mind that oftentimes when dealing with extreme steering positions, minimal, inner wheelwell tire rubbing might occur. Also, some tires measure differently than others. For example, some 225mm-wide tires measure similar to some that are labeled as much as 245mm. It's best to allow an 1/8-inch of play for potentially wider tires.