Black Hawk Engineering - Deserter GS Build and Development

Deserter GS Build and Development

I had wanted to build a car for some time and after I graduated from college in 1973, I researched the available car kits. I had originally planned on a FiberFab coupe, but eventually decided in favor of performance over style and chose a Deserter GS. This was a mid-engined chassis in a dune buggy style body developed originally by Alex Dearborn and later sold by Autodynamics. Autodynamics was a racecar fabricator in Marblehead, Massachusetts that had done the design work and fabrication for Alex. I placed an order and after several months of waiting, my wife and I flew to Boston in December, rented a truck and picked up the kit components from Autodynamics.

Fiberglass parts in the yard at Autodynamics.

Several key parts were missing, but I was assured that they would be shipped soon, so we left for Ohio where I was working at the time for BF Goodrich Tire Company. The first artificial gasoline shortage was on so we had to adjust the schedule according to which days gasoline was available.

I placed an ad in the local newspaper for a “1967 to 1971 Karmann Ghia or VW, body condition not important, engine not necessary”. This really brought the characters out of the woodwork, but eventually I found a ratty but usable donor car, a 1967 Karmann Ghia coupe.

I removed the transaxle, suspension, instruments and some trim parts. I sold the engine and wheels and then had the remains carted off for scrap. In retrospect, it would have been much better to buy a nicer car for more money and sell the extra parts to recover the added cost. I spent a lot of time cleaning and rebuilding parts.

The Ghia carcass is hauled away.

The birthplace. I was working in a rented garage behind the apartment building where we lived. The only power came through 125 feet of extension cords from the only outside electrical outlet.

Trial fitting the transaxle

Test fitting the floor and seat pan. The 4 original Rochester carburetors would not fit under the engine cover even without the tall air filters.

I reluctantly converted to a center mounted 4-barrel carburetor.

Installing the body

The car ready to drive. It is still missing the side tanks and a number of other parts which Autodynamics never delivered. Autodynamics went out of business about the time the car was licensed in July, 1974.

Rear view

With the top, side curtains and airdam installed

I actually won FTD (Fast Time of the Day) at the first autocross in which I drove the car. It was a very tight course set up by an MG club. It was another 2 years of development before I won another FTD on an open track.

I made my own Z-bar since Autodynamics never delivered the Z-bar I paid for. This version is mounted on rear chassis extensions and the links are attached directly to the swing axles. This transformed the handling of the car by reducing swing axle jacking.

I crashed the car during an autocross on a paved oval in Ohio after the throttle stuck open. I did not have a kill switch and did not have the presence of mind to disengage the clutch. A blown engine would have been a lot cheaper than rebuilding the whole car. I did take the opportunity during the rebuild to stiffen the chassis.

Crash damage photos

The frame after the crash. The original Autodynamics front engine support is still on the car. This was made of thin gauge square tubing welded to a heavy (3/8") angle. It broke at the joints many times - on both sides - despite reinforcement.

The crumpled floor pan.

Front torsion beams welded to the frame rails

Repaired frame with some support added for the seat pan, shifter and steering column.

New front suspension assembly welded to the frame rails instead of the narrow bolted joint.

Steering column support

The chassis rebuilt after the crash.

I found a vendor who had taken a splash of the Deserter GT body and was able to supply a front corner and the side pods. The frame has already been repaired in this photo. The front suspension beams folded in the center (at the height adjuster) and the wheel was back to the windshield post.

Attempting to mate the new fender with the rest of the body

Hydraulic clutch slave cylinder

Neal dual master cylinder brake and hydraulic clutch pedals.

I installed a hydraulic throttle on the theory that if it failed, it would fail closed since the throttle return springs would close the throttle blades.

The engine with the hydraulic throttle slave cylinder

The light steel tubing truss I made weighed less than half as much as the original front engine support and never broke.

Back together

Racing on a paved oval in Pennsylvania while on street tires

Then I got greedy and had a turbocharger installed by the local turbocharger hero in a search for more power for hill climbs.

The only photo I have found so far with the turbocharger still installed on the car. The Holley 4 barrel carburetor was mounted on a stub manifold welded to the compressor housing.

The turbocharger blew into an adapter on top of the center mount manifold.

The acceleration was impressive, but it was very difficult to drive. It was bad in Ohio, but much worse at altitude in Colorado. After the move to Colorado in 1978, I decided to get serious about autocrossing. I removed the turbocharger and put the 4 barrel Holley carburetor back on the center-mount manifold.

I bought an oxyacetylene welding outfit and built my first set of headers - long tube and equal length.

First race tires with my brother John visiting.

With race tires and more chassis development, I was able to set FTD 85 times out of 147 events.

I ran at every location and every type of event that I was able to enter.

An autocross at Golden, Colorado

An autocross at the Moby Gym parking lot at Colorado State University in Fort Collins, Colorado

An autocross on Englewood Speedway in Colorado (now replaced by a subdivision).

A track event at Pueblo International Raceway, Pueblo, Colorado

An autocross at shopping center parking lot in Westminster, Colorado (now covered by more stores).

An autocross on the Longmont Go Cart track in Colorado (now replaced by a subdivision and stores).

The 1981 SCCA Solo II Nationals in Salinas, Kansas

Time trials at Second Creek Race Track in Colorado (soon to be replaced by subdivisions).

The Black Otter Hill Climb in Billings, Montana

In the pits at the Black Otter Hill Climb

The Black Otter Hill Climb another year setting a class record.

An autocross through the streets of Bayfield, Colorado

New Engine in 2003 – I had stopped competing in the early 90s after the car was bumped into a class with tiny lightweight Formula cars. A move to California for job reasons brought even stiffer competition. After fooling with alternative engine concepts for a few years, I decided to refurbish the car and return it to street use. Steve Goodman of Rear Engine Specialists in Golden, Colorado built the new reverse rotation engine. Transform of Long Beach, California built the transaxle with longer gears.

I replaced the front engine support with an aluminum truss at less than half the weight of the previous steel truss. A few welds are still missing in these photos. My first serious project welding aluminum with the TIG welder. Note the rod end for the shift linkage.

Side view

The latest header arrangement (still in need of refurbishing). The next set will be made from stainless steel.

Straightened and reinforced frame

Test fitting the aluminum front engine support with through-bolt mounts. The original rubber mounts failed in tension.

Light weight reduction gear starter

The battery box is now in the right side pod to improve the side-to-side weight distribution.

Reverse rotation belt guide prototype attached to the oil cooler. The final version is powdercoated.

Reverse rotation deep alternator pulley

I completed the rebuild after a lay off led to early retirement and a return to Colorado.

Driving the van through a blizzard in Wyoming with the car on an open trailer wasn't that much fun. The car required a lot of cleaning afterwards.

The new shop and garage - house attached.

The shop with mill/drill, NC mill, NC lathe, drill press, hydraulic press and manual lathe

Removing the engine one more time to fix an oil leak at the engine adapter. This is much easier with the electric hoist.

A new steering box tightened up the steering

A new shift linkage U-joint that was machined on the NC milling machine. The original shift linkage design had a joint well behind the shifter nose. This multiplied the lateral load on the sleeve bushing which wore out quickly. The new design wraps the U-joint around the bushing transmitting the force directly to the bushing. The blue yoke was an early experiment with DIY anodizing.

The linkage passes through a hole in the frame reducing the joint angularity.

The middle shift linkage joint is attached to the transaxle with a machined bracket. The drive train moves a little relative to the frame. Attaching all of the shift linkage except the shifter to the drivetrain made it much easier to find gears.

There is another rod end attached to the front engine support barely visible here. The U-joint in front of the engine support allows the center linkage tube to pass close to the engine. The extra joint allows much smaller angles at each joint reducing wear and improving precision.

More fun with the NC milling machine: an engraved air filter top plate giving credit to the engine builder Steve Goodman's shop.

The updated car at a car show in Golden, Colorado in 2006.

A kit car is never finished of course. Planned projects include a MegaSquirt fuel injection system, alloy wheels with up to date tires and top and bottom channels connecting the windshield posts to create a full windshield frame. This is at least the 4th windshield broken from flexing due to incomplete support.

e-mail Address: sales at blackhawkengr dot com

Last Up Date: May 26, 2009 10:09 AM