CRX front drum brake conversion

[jrnsr]

Out of all the various forums I posted this question on, you guys are the only ones with intelligent responses. Most others just post stupid insults.

We used to have a carbureted '87 CRX, with the aluminum rear drums & superlight wheels, rated 57 mgp highway. We even ran it successfully on 2 cylinders, but it was a real slug.

Now, I'm setting up another CRX to run on 2 cylinders, but have the 2 center cylinders supercharge the outside cylinders (welding/grinding cam required). Fuel injection will be a vast improvement over the previous one with motorcycle carbs.

The idea of springs is on the right track, but there's no feedback/control to compensate for wear. Too much space will mandate pumping the brakes before they grip. Small springs would be a viable option for short term events. Most of us don't remember that the old mechanical brakes had to be adjusted constantly, so an adjustable spring idea is a viable option for only the most conscientious car owner. Maybe someday Japan will come out with an electric (electro hydraulic even) servo system to clear the pads from the disc, or even incorporate that into the ABS hardware that exists.

When I converted our '50 MG to front disc brakes, a proportioning & compensating valve was a pretty important addition, otherwise, the mismatched behavior between discs/drums leads to spinouts. The fact that disc drag and drum brakes don't is why the compensator valving was developed, to hold the calipers back until the shoes provide resistance. For a car with 4 drum brakes, no proportioning valve is needed.

[Gasoline Fumes]

The front brakes on my 1991 Civic Wagon don't drag. The pads actually rattle around in the caliper brackets with the brakes released. Keep everything in good shape and they won't drag. No mods required.

[arcosine]

I made a 800 cc honda accord, terribly slow, out accelerated by semi-trucks. mpg only 14% better than full 1600 cc engine. Consider putting in a HF transmission in the car first. With 165/80R15 tires on Saturn rims the RPM will be 1630 at 60 mph.

[Ryland]

The front brake calipers don't have return springs, they rely on the O-ring that seals the piston to return it as it has a square profile, if these O-rings are 30 years old they could be dried out and not working like they should, replacing them might give you the results that you are looking for.
The last time I checked my front brakes there were clear gaps between the pads and the disk and my disks are original to the car (220,000 miles) so they have had very little drag over their life time or they would have wore out by now.

The rest of your project sounds interesting, care to tell us more about it? maybe start another thread on the super charging project?