"Oblio"    1930s Retro-roadster
by CARCENTRIC

NOTE
This page has been superceded by http://www.carcentric.com/Shillelagh.htm - where there are differences in content, that other page is definitive.

1935 Triumph Dolomite Straight Eight=  BACKGROUND  =  
This project started when I found a picture of this beautiful 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.

Midge kit carIn another internet search, I discovered the Classic Midge (red roadster shown right) - a British kit car (no longer manufactured) with cycle-style fenders. Not as grand as the Straight Eight, but the same general theme and - more important to me - Midges were built on extended wheelbase Triumph Spitfire/Herald chasses (I have several Spitfire parts cars in my back yard, and I bought a rare-in-the-US Herald chassis last winter)!

Burlington ArrowIn late 2003, I won an eBay auction for a set of Burlington Arrow (brown roadster shown right) plans - a doorless British home built car also based on the Triumph Herald chassis. I'm sure that the Arrow plans will have a substantial effect on my final design and on assembly methods as well. The Arrow was also the inspiration for Oblio's name (Oblio was the character who sang "Me and My Arrow" in Nilsson's animated musical, The Point).

=  GATHERING THE PARTS  =  
From what I've gathered so far, it looks like I'll be able to hand-build my own "classic" Triumph roadster:
  
<>   SPITFIRE PARTS  - 1.3-liter "Straight Four" engine, four speed transmission and electric overdrive, late model "swing spring" rear suspension, complete front suspension and brakes, fuel tank with latched filler cap, early model "banjo-spoke" steering wheel, a pair of those perky pre-1971 "round tail" tail lights mounted low on the Gazelle rear fenders, and the all-important Certificate of Title for registration and licensing
  
<>   OTHER TRIUMPH PARTS  - a Herald frame (shown below right, but with a GT6 front suspension frame section added to the front), a GT6 radiator and seats (with headrests removed), a set of refinished TR3 wire wheels (48-spoke, 15" x 4") with narrow 165R15 tires, TR2 knockoff spinners, and TR4A splined adapters that'll need to be "double drilled" with the Spitfire's four-on-3.75" bolt circleBottom view of the Herald frame
  
<>   JUST FOR FUN  -   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 set of fiberglass fenders from an unassembled Gazelle kit car (loosely based on those of the 1929 Mercedes Benz SSK, the Gazelle kit carfenders are highlighted below in white) - they're close enough to the Straight Eight's fenders for my purposes.   I bought a pair of tarnished 7" headlight nacelles at the last All British Field Meet, (I have no idea what car they may have been separated from).  I'll have flat safety glass cut to fit a fold-down windscreen frame I'll fabricate and, if I build doors, they will be rear-hinged (commonly referred to as "suicide" doors).  To let people know I'm coming, I'm thinking about a '50s-style glasspak muffler whose sound will "ripen" with age. No radio, wipers, or soft top . . . this'll be a no-frills fair-weather-only runabout.

SPECIFICATIONS

1935 Triumph
Straight Eight

"OBLIO"
by CARCENTRIC

Burlington
Arrow

Wheelbase
Track
Engine Size
Weight
Total Production

104"
54"
1990cc
2128 lbs.
Three

101"
51" (est.)
1296cc
Under 1700 lbs.
One, eventually

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

=  TECHNICAL STUFF  =  
According to the Midge instructions (portions of which were shared with me by
Dave Everall), the "usual" way to extend the Spitfire wheelbase is to cut the chassis behind the front suspension towers and insert a section of channel between the front section and rearward remainder of the frame. Frame extension planCustom engine mounts are then fabricated and installed where the stock ones were originally (relative to the rear part of the frame), and front brake lines and the steering shaft are extended.

Always the shadetree engineer, I'm exploring a different idea that involves cutting the frontmost section from a spare Triumph GT6 frame (with a second set of front suspension towers) and welding them to overlap the front of the Herald frame (see drawing to the left - the Herald frame is white outlined in black, and the front of the GT6 frame is red).  

This would relocate the front suspension forward so the axles and coil springs would be in line with the center of the radiator and 2" higher than the main frame rails (so the engine would effectively become lower than usual relative to the front suspension). The two pairs of front suspension towers would then be modified as follows:
1. Only the suspension mount parts of the FRONT tower pair would be used - the motor mount parts would be removed and discarded.
2. Only the motor mount parts of the REAR tower pair would be used - the suspension mount parts would be cut away and discarded.
The primary advantage to this frame extension method is that no custom parts would have to be fabricated - this should ensure that all necessary mounting points would be in their (new) proper places.

Oblio's wheelbase would be 101" (5" longer than the Burlington Arrow and 2" shorter than the Triumph Dolomite Straight Eight).  This would result in a 5" longer bonnet than the standard Arrow design.  And for that slightly awkward 1930's look, I'm also thinking about setting the front wheels to a few degrees of positive camber!

=  CONSTRUCTION SCHEDULE  =  Oblio concept
Don't expect to see Oblio on the road in the next few months - I'm still sorting through the options, collecting parts, and removing the unneeded body and other parts from the '71 Triumph Spitfire that will be the primary donor vehicle. Cogent observations and suggestions would be timely, therefore - and appreciated.

   Return to CARCENTRIC home page

______________________________________________
* Two ways:
Fiberglass book Sheet metal book
(click on either picture to order the book)  

 

=  REFERENCE  =  

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
Chassis
Front suspension
Swing spring