Well, we finally raced our Honda. Let me set the stage. The Mini-Stock rules at East Bay Raceway are rather liberal. This is basically a Pinto-based 2300cc Ford class. Based is the operative word. Suspension points on the chassis must be in stock position. The sheet aluminum/plastic nose bodies hide a tube frame. Car weight is 1 pound per cubic centimeter, and a Holley two-barrel carb is required on an engine that must be in stock location.
These cars are not inexpensive. A front-running car may very well be in the $14,000 range. I recently heard of a season-old car offered for sale for $12,000 less engine. Our Honda, on the other hand, was built for a real-world cost of $3,500. This cost does not reflect any of our labor.
The premise of our Honda project was to do all the work we wanted but spend as few dollars as possible. There is not a lot of Honda left under the skin. The firewall and front suspension areas remain in the front. At the rear, the crossmember with its suspension points remains intact. The centersection of the car is all tube frame. Tubes also support the front and rear areas of the car. When finished, the car weighed only 1,082 pounds, with water and oil. Had I known it would be this light, I would have built it much stronger. Remember at 1 pound per cubic centimeter the car must weigh 1,500 pounds with the driver.
I used 225 pounds of A&A Manufacturing's lead weights. These clamp-on weights are easily moved for chassis weight adjustments. With the car sitting on the Intercomp wheel scales, I spent the better part of a day placing and moving weights. As the weight was shifted, the spacers under the AFCO springs as well as the springs themselves were changed. In the case of the Honda, which is not a strut but an A-frame car, AFCO's coilover springs are the same diameter as the Honda springs.
After overheating the engine,...
After overheating the engine, it was wise to take it all apart. Even though torqued to spec, the flywheel bolts had loosened up. Loctite is the recommended cure. When you need to loosen it, heat the bolt with a propane torch to weaken the Loctite.
As far as missteps go on this project, let's start with the intake manifold. I think I've been sent to school on these things. The rules specify a Holley two-barrel carb. Also a stock manifold may be modified to fit the carb. Easy enough. The stock throttle-body fuel injection manifold just needed some grinding and drilling-or so we thought. The long runners in the manifold set up a reverse pulse. This pulse caused such a rich condition that the engine would flood down and not run over 5,000 rpm sitting in the shop.
With the long runners diagnosed as the problem, I cut down a stock manifold so the runners were only 3 inches long coming out of the head. Then a plenum about the size of two cigar boxes was fabricated and attached to it. Better, but not right. I worked on the carb using a spring and steel ball in place of the needle under the accelerator pump squirters. This worked but was a very critical adjustment. The first night's racing was done with this setup. Still, it would go rich and flatten out about the flagstand. Not too bad, though, because we went from 17th to 6th in the feature that night.
One reader, whose name I lost in a computer glitch, suggested using an EW-1 manifold from an '86 Honda. Ah, salvation at last. Consid- erable work must be done with a grinder and J-B Weld (a two-part epoxy compound) to make a home for the carb. The ports lined up, but the bolt holes needed some die grinder realignment.
The oval hole in the EW-1 is aligned parallel to the direction the car travels. Don't put the carb on this way. If you do, the engine will only run on two cylinders. Those cylinders are in the direction of the opening of the throttle plates. Mount the carb with the float bowl facing forward. This may take some more J-B Weld to seal around the openings.
For a carb mounting/spacer, I purchased a 1x6x36-inch piece of maple. I cut the pieces to size and used a hole saw for the internal sizes. Carb attachment bolts were installed from the bottom of the spacer. The spacer was then bolted and put in place with epoxy.