Notes from Windward: #69


GEK Projects

Opalyn gets a start on spring

     As our days start to lengthen we are getting a head start on a few GEK related spring projects.

     Scott, the senior member of our Away Team, recently decided that he no longer needed his 1991 Chevrolet Blazer, and decided to donate it to Windward to further the woodgas project. So, Walt and I took advantage of a break in the weather to drive into Portland and bring it home. It needs some minor repairs and maintenance, and we did have some trouble getting out of town because the onboard computer wanted to advance the spark too much, but it will make an excellent test bed for our experiments this year. Since acquiring the Blazer, we've purchased a diagnostic computer and are looking forward to learning how to read the car's control computer so that we can fix whatever it is that's causing it to advance the spark too much. Then we'll look at learning how to reprogram the car's control computer.

[Walt: Thirty years ago, car engines used direct mechanical linkage to control things like spark timing, but in the early 90's, auto manufacturers started using on-board computers to control the engine. The primary purpose was to reduce exhaust emissions, but as in most things, computers are a mixed blessing. When they work, they offer low maintenance and high efficiency--when they don't, the owner usually has to take the car to a dealer to have the error codes downloaded in order to figure out what's wrong.

     We shopped around on the internet and were able to get a very good deal on a system that will allow us to not only read any error codes generated, but to also look at the engine data in real time, or store a run for later review. That's going to be a real help as we tune the Blazer to run on woodgas.

     It used to be that a car's distributor ran off a gear driven by the camshaft that opened and closed the valves. That was then; now there's no actual mechanical connetion between a car's crankshaft and its distributor. Instead sensors read the position of the crankshaft, and other variables such as RPM, manifold vacuum and engine temperature, and using a look-up table, the onboard computer calculates the spark timing needed.

     Being able to access and change that timing table is important because woodgas burns differently than either gasoline or propane--for maximum efficiency, the computer needs a table for each type of fuel. The old Model-T cars had levers on the steering column that allowed the driver to manually set the spark timing--reprograming the control computer will allow us to tell the computer which table to use when.]

Our new wood gas test vehicle


     Our Work Truck is bi-fueled and able to run on either propane or gasoline--which ever is cheaper at the time. We are working out the details of converting the Blazer into a bi-fueled vehicle as well but it would run on either gasoline or wood-gas.

     One of our neighbors has a cache of small Toyota pickup trucks. While visiting with him last week and making arrangements to bring home another steel fuel tank which we will use for the methanol project, we got to talking about the little trucks. In exchange for some labor and a return of the engine and cab parts, I'm going to get to practice converting a pick-up truck into a GEK Trailer.

     We returned later in the week to load the tank and tow the pickup home. Oana, Lindsay, and I rolled the tank out of the woods and over to the truck. First we stood it on its end, and then tipped and pushed it into the bed of the Work Truck.

Opalyn, Oana and Lindsay get the tank rolling

     Next we maneuvered the Work Truck over in-front of the little truck we wanted to tow back to Windward. Walt and I hooked up the tow rope while Lindsay and Oana wandered through the orchard with the owner checking out his latest work on his fruit trees. By the time they returned, laden with mulberry trees and rose plants, we were ready to head out.

     The Work Truck had no problem towing the little truck the eight miles back to Windward. My job was to steer the little truck, and use the brake to control the tension in the tow rope. It was the first time I'd driven one of these miniature pickups, so I appreciated Walt driving home slowly and accelerating even slower. The road was mostly up hill which made my job easier because at every slight down hill slope I had to rely on brakes that were sketchy after having sat unused for a few years. There was one steep downhill close to home where we unhooked the little truck, drove the Work Truck on ahead, and I coasted down to the bottom of that hill. Turning onto Windward Lane, I rolled safely to a stop. We rehooked up the tow strap, and moments later we had the little truck parked within air compressor range of the garage.

the little pickup truck safely tucked away near
the workshop to await conversion into a woodgas trailer

     The plan is to remove the engine and transmission as one unit and then remove the cab, returning these parts to our benefactor. With these “extra” parts out of the way, we'll modify the front half of the frame into a trailer hitch and a place to mount the GEK just forward of the pickup bed. A little body work and paint on the truck bed and we will have a nice trailer to haul the GEK and the wood chips it gasifies to produce fuel for wood-gas vehicles.

Notes From Windward - Index - Vol. 69