"Shillelagh"    1930s Retro-roadster
by CARCENTRIC

1935 Triumph Dolomite Straight Eight=  BACKGROUND  =  
This project started when I discovered a picture of this beautiful, red 1935 Dolomite Straight Eight (left). According to Motorbase, Triumph built a grand total of three, so it's highly unlikely I'll ever drive one, let alone find one for sale in my price range. Its rakish long hood (bonnet), seats almost between the rear wheels, and fold-down windscreen, however, are very appealing - I couldn't get it out of my mind.

Burlington ArrowIn late 2003, I won an eBay auction for an original set of plans for a Burlington Arrow (brown roadster shown right) - a doorless British home-built based on the Triumph Herald (or Spitfire) chassis and drivetrain. The Arrow plans have had a substantial effect on my assembly methods, and are once again available (now on CD) from the original designer in the UK at www.turn-the-crank.com (no financial interest).

I chose the name Shillelagh (pronounced shuh-LAY-lee) for mine because of my Irish heritage.  Most commonly seen now in the hands of cartoon Leprechauns, a shillelagh is a combination walking stick and fighting stick.

=  GATHERING THE PARTS  =  
I think I now have enough parts to hand-build my own "classic" Triumph roadster . . .

  <>   TRIUMPH PARTS
Shillelagh concept
 I have a Triumph Spitfire Mk.IV that will contribute its 1.3-liter "Straight Four" engine, four speed transmission and electric overdrive (unless I sell the OD separately), chassis with front suspension and disc brakes, and fuel tank with latched filler cap.
 An additional section of frame from a Triumph GT6+ will move the front wheels out forward of the engine and provide mounts for a GT6 radiator (taller and narrower than the Spitfire radiator).
 Instead of 13" Spitfire wheels, I'll be using a set of old-timey 48-spoke TR3 wire wheels (with narrow 165R15 tires on 4" rims). The front pair of TR3 splined hub adapters will be fit to the Spitfire suspension via a pair of 1" thick T-6061 alloy wheel adapters I inherited.
 An early model Spitfire "banjo-spoke" steering wheel and a pair of those perky pre-1971 "round tail" tail lights were found on eBay.

  <>   NON-TRIUMPH PARTS  
Gazelle kit car body  I know several ways* to make the flat body panels, but a pair of gracefully flared front fenders (wings in the UK) such as the Straight Eight had would be very difficult for me to make from scratch. Fortunately, I found and bought a complete but unassembled Gazelle
kit car (very loosely based on the 1929 Mercedes Benz SSK, right). The Gazelle headlights will also be used, and I'll make an Arrow-style radiator shell and shorten the Gazelle's boot (trunk) length to look more like the Arrow's rear end.
Early Morris Minor differential
 I'm thinking, too, about using the 4.56:1 live rear axle (left) from my 1950 Morris Minor instead of the Spitfire's 4.11:1 swing axle differential.  The shorter ratio, when combined with the TR3 wire wheels' larger diameter, will keep the overall gearing** within 0.2% of the stock Spitfire's (both the TR3 splined hubs and Morris Minor rear axle assembly use a 4-on-4.5" bolt pattern). I don't yet know if I can somehow use the Spitfire's transverse leaf spring rear suspension with the live rear axle, but that would surely produce authentically peculiar 1930's handling!  And how about a few degrees of positive camber in front for that old-time look?
 I'll fabricate a fold-down windscreen frame that will use flat safety glass - either a single Locost*** roadster-style, or as a pair of Brooklands-style windscreens.
 To let people know I'm coming, how about a '50s-style glasspak muffler whose sound will "ripen" with age?
 No radio, wipers, or soft top . . . this'll be a sassy, no-frills, fair-weather-only runabout.

SPECIFICATIONS

1935 Triumph
Straight Eight

"SHILLELAGH"
by CARCENTRIC

Burlington
Arrow

Wheelbase
Track
Engine Size
Weight
Total Production

104"
54"
1990cc
2128 lbs.
Three

98"
51" front, 50.3" rear
1296cc
Under 1700 lbs.
One, eventually

96"
49" front, 48" rear
1147cc (typ.)
unknown
unknown

 

=  CONSTRUCTION SCHEDULE  =  
Don't expect to see my Shillelagh on the road in the next few months - I'm still sorting through the options and removing the unneeded body and other parts from the Triumph Spitfire that will be the primary donor vehicle. Cogent observations and suggestions would be timely, therefore - and appreciated.

   Return to CARCENTRIC home page

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* Three ways:
Fiberglass book Sheet metal book How to Build a Locost (click on a picture to order the book)  

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** Overall gearing takes into account both the drive wheels' tire diameter and the differential (ring/pinion) ratio.

 

tire W

tire A%

wheel D

tire D

 

ring/pinion

 

  OVERALL

Triumph Spitfire

155mm

80

13

22.76"

 D

4.11:1

 D

DIFFERENCE

Shillelagh

165mm

80

15

25.39"

10.4%

4.56:1

-9.9%

0.2% higher

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*** The top photo below shows how a Spitfire chassis has been modified for a Locust build (clicking on the picture will take you to the builder's web page).  The three black and white Spitfire photos that follow are from Triumph Spitfire and GT6 by Graham Robson (available at Amazon):

John Jones' Spitfire-based Locust
Spitfire chassis
Front suspension
Swing spring