"Project Caprice"

General Motors Holden

1981 WB Statesman Carpice

I originally purchased this car in 1995 with 114,000 km's on the clock, for the grand sum of AUD$8,200.

The car was in average condition externally, but the interior was A1. Mechanically, the car was also in very good condition, with major work on the auto, power steering and motor previously performed by the seller of the vehicle. The previous owner had also spent considerable money fitting Koni/Lovell suspension and modifying the transmission and motor. Unfortunately, he had fitted flat-top pistons raising the engine static compression ratio to 10:1, far too high for the poor quality super fuel available in 1995... Included in the purchase price were a set of new cast heads with hardened valve inserts fitted. The new heads were fitted two weeks after purchasing the car.

Running pure Av-Gas at $1.30 per litre, the car performed well down the quarter mile drag strip. She pulled a consistant 16.40 seconds and could keep up with standard Commodores, weighing in 200 kg less than the Caprice! Running standard pump super, this car put a dent in my wallet on a weekly basis, her 96 litre tank took around $75 per fill! There had to be a cheaper way...

Within six months, the car was taken off the road for major rust repairs and a total respray. The car was then converted to LPG single fuel, with the original factory motor still serving me well. The next 5 years saw the gradual overhaul, conversion and modification of brakes, transmission, exhaust, cooling and rear end.

In 2000, the old factory motor started to exhibit signs of extreme thrust bearing wear, when the ring gear began wearing on the starter housing... The quest for a new purpose built LPG engine began! Gary Chapman performed the skilled and meticulous machine work, Gary's machine skills ensured the new motor was prepared to perform as well as last long. A full engine balance is the key.

Today, the Caprice runs that "dream" motor, a large valve, LPG motor with dished pistons, LPG specific camshaft and roller tipped rockers. I have fabricated a custom inlet manifold and injection computer and also heavily modified the orginal LPG throttle body, converting it to annular discharge. All of these modifications are now available to the general public, just bring an open cheque book with you!

In 2002, the old girl was treated to another Birthday spruce in the panel shop, with rust under both the front and rear windows removed, and also in the drivers door. The front end was removed for restoration and a new stone tray was fitted, replacing the badly damaged original unit. The rear end bumper and trim was not re-chromed, as these items were re-plated during the 1996 re-build and were still in very good condition.

Most of the images in these pages show the car being re-assembled in 2002 following the completion of panel and paint work.

Vehicle Dimensions & Weights

Engine & Mechanical Data

This is the front end, with new stone tray fitted, waiting for the lights, grill and bumper to be fitted.

The original factory grill is a chrome plated casting, with 41 individual anodised aluminium slats, each fastened in place with two screws. Holden never made a grill like this again...

The surround and each of the vertical aluminium slats have been hand restored and polished.

The headlights are now fitted.
Both high and low beam are now fitted with "Artic Blue" halogen lamps.

Next came the grill. The original factory gasket is neither listed or stocked... The original gasket is in very poor condition and must be replaced, with a replacement fabricated from nylon or rubber.

Factory replacement bumperettes are now in place below the headlights. These items are still available as factory spares.

Re-chromed steel bumper and restored rubbers complete the front end re-build.

The front end restoration is now complete. Alibaster white duco and chromium... Oh I am in Holden Heaven.

Dash viewed from the passengers side. The drivers door leather trim is yet to be fitted. A brand spanking new front windsheild was fitted, courtesy of my Insurance Company. The original factory glass was extremely pitted and a nasty crack in front of the driver was getting bigger!

Wallnut dash, leather and velour trim with sheepskin seat covers. The door trim is now in place. The custom fuel injection computer can be seen above the T-bar shift. A "temporary" (read 5 years) engine vacuum gauge lurkes on the dash, just above the computer.

All standard features still function ok, electric windows, door locks, and air work a dream. Well actually, the air conditioner is at the moment out of service, but thats due to the compressor not being fitted following an engine transplant. The original cruise control system was not functioning when I aquired the car, and it now lives in a box, in my shed. RIP cruise control.

The rear compartment is very roomy. Leather and velour from top to bottom. They called this model a "Saloon".

The rear seat is very comfortable, you kinda sink into it...

LPG Tank situated high in the boot, right were the two 12" sub-woofers used to live :( The under-trunk mounted 96 litre petrol tank has been removed. This is one HUGE boot and the tank does take up a reasonable amount of room, but you can still fit around 6 dead bodies in here, so no great loss. :D

Trim is by me, completed around 4 years ago.

Fully custom engine bay! The cast iron block V8 is similar to the original factory motor, Peter Brock "B" cast heads top the "HQ" cast iron block and are fed a pure propane fuel via tuned length 19" ram-resonant manifold with computer controlled ancilliary vapour injection. A modified Gas Research (tm) LPG throttle body provides 440 CFM flow and an annular discharge venturii ensures an homogenous fuel/air mixture for maximum power and efficiency.

The equal length manifold runners were each hand fitted using mandrel bend 1.5" aluminium pipe. The total runner length from plennum to valve is 19", and provides maximum cylinder filling between 2000 and 3500 RPM. The dual-plane plennum chamber was designed to provide constant swirl in each chamber and avoids all the problems experienced with traditional dual-plane designs. The total engine/fuel package delivers axel twisting, transmission smashing torque figures and gets the 4000 lb vehicle moving off the line quite nicely.

Picture yet to be scanned:- Original factory engine bay

This is the final result, the car restored to its former glory!

Dont you just love all that chrome?

Classis NOT plastic!

The original ride height was some 7 inches higher at the front, and 4 inches higher at the rear. This is definately a much nicer look for the car, and handling is way improved as well. You just have to avoid all speed humps and some drive ways... :rolleyes:

Sparkle!

Fat bottom?

My next modification, is to replace the 2 x mufflers / 2 x resonators with 2 very large truck mufflers. I am looking for slightly more noise, but with a much deeper note. The existing exhaust combination sounds good, but most of the engines aggression is lost. hehehe.

Quit Mortorplex, burn-out prior to 1/4 mile race. :)