GMC MOTORHOME PROJECT
1973 GMC CANYON LANDS 26’ MOTORHOME
The purpose of this project is to restore this classic and build a hot rod with a bathroom and kitchen at the same time!!
The vehicle was purchased January 2000. It was driven from the East Coast to northern California in 4 days at 70+ mph. Despite its poor condition, it averaged 12 mpg, with no major problems!!
It was sold “new” in New York and lived on the East Coast most of its life. Although it had only 62,000 original miles, this coach had been poorly maintained and left to deteriorate. The frame and chassis were extremely rusty and structurally unsound. The engine ran, but was not rebuildable.
A total frame-off restoration of major proportions was started in July 2000, concentrating on the frame and rolling chassis first. The original chassis, engine, and transmission were scrapped, and a new rolling chassis was created!
All rebuilding, fabrication, and machining (except engine block machining) have been performed in-house. The new engine was designed as low compression, high torque, and “bulletproof,” for future twin turbocharger installation. Performance is currently estimated at 320 HP and 560 ft. lbs. torque at 3000 RPM.
GMC Project
Restoration cost to date: More than $ 50,000.00
Estimated cost to complete: $ WAY TOO MUCH
Completed engine and chassis modifications to date are:
1. ENGINE: 1968 Oldsmobile 455 ci
Blueprinted.
Bored .060 over to 467 ci.
ARP main studs.
Oil restrictors.
Drilled and modified main bearings.
Custom fabricated oil windage baffles.
Melling high-volume oil pump.
Turned, chamfered, and polished crankshaft.
Eagle 4340 steel H-beam rods with full floating pins.
Keith Black pistons.Speed Pro rings.
Complete rotating assembly balanced.
Comp Cam (manufactured to my specs.)
Comp Cam Pro Magnum 7/16 Steel full roller rocker arms.
Holley programmable ECU muli-port fuel injection.
Accel high-performance injectors.
K&N air filter with fabricated cold air intake (flows 1000 cfm).
Edelbrock Torker intake manifold modified for injectors.
Edelbrock aluminum heads.
ARP head bolts.
HEI ignition controlled by ECU engine management system.
Doug Thorley headers.
Flowmaster series 50 mufflers.
3” exhaust.
Larger oil cooler.
2. TRANSMISSION:
Valve body modification.
Various internal case modifications.
H.D. Kevlar clutches.
34-unit sprag.
Variable pitch converter (creates a 6-speed transmission.)
Larger oil cooler and lines.
Transmission is now controlled by ECU engine management system.
3. FINAL DRIVE:
1966 Toronado, rebuilt and machined to correctly fit GMC axles.
3.21 ratio (original 3.08)
4. CHASSIS:
Main frame rails were replaced with 6” x 3” x 3/16” channels. Fabricated from high-strength low-alloy ASTM A-572 steel. (Originals were 6” x 2.50” x 1/8” SAE 950 steel.)
5. REAR SUSPENSION:
Redesigned and machined bogie pivot pins, bushings, thrust washers, and seals. Made bushings and thrust washers of bronze, and used O-rings for seals. Fabricated special retainer for maintaining “zero” endplay. (Original bushings were brass, and had steel shims for endplay.)
6. FRONT SUSPENSION:
Front hubs machined and modified for better bearing life.
New upper control arms.
New reinforced lower control arms.
All other steering and front suspension components rebuilt or replaced.
7. WET HUBS:
Designed and fabricated retainers and windows for “wet hubs.” (Uses 80/90 gear lube for rear wheel bearing lubrication, instead of grease.)
8. FASTENERS:
All fasteners replaced with:
Structural – Grade 8.
Non-structural – stainless steel.
9. DESIGN AND FABRICATION OF SEWER DUMP SYSTEM.
Electric dump valve.
Macerator pump.
10. MODIFICATION TO THE FUEL SYSTEM, AND FUEL TANK SENDING UNITS:
2 electric low-pressure 75 gph fuel circulation pumps (one for each tank).
Fuel accumulator/filter.
6-way electric fuel selector valve.
Electric high-pressure fuel pump to feed fuel injection.
10-micron high-pressure fuel filter.
Pumps are controlled by ECU engine management system.
Addition of fuel injection return lines to sending units.
11. BRAKES:
Front – Larger 80 mm calipers.
EBC yellowstuff pads.
Rear – Larger 1-1/16” wheel cylinders.
Ceramic lining.
12. Misc. chassis brackets and braces were fabricated from stainless steel.
UNFORTUNATELY, MANY PHOTOS OF ENGINE BUILD AND CHASSIS WORK ARE LIVING FOREVER IN A CRASHED HARD DRIVE.
SEE PHOTO GALLERY LINK ABOVE FOR PICTURES THAT SURVIVED.
