The Resurrection of TA0844 (Part 6)

1 Jul

In this article I have illustrated the rest of the extras for TA0844. I hope to cover the lighting arrangements in a later article I have been asked where I had purchased the BX44 fan belt. This and many bearings came from Bearing Boys Tel: 01233 822150.

A speedometer cable square drive to Yeager Tube

I had a new speedometer cable with a square drive at the instrument end which is for a later T- Type. A converter from square drive to Yeager tube would eliminate the need to purchase another cable. This is illustrated in the drawing and photo. I used some thin wall brass tube of 5mm OD having an inside diameter such that it could be tapped square around the square cable inner and then soldered into a hole in the Yeager tube drive inner part. The protruding brass was turned to finish the end. The outer part was threaded to accept the cable outer cap. The inner part is a sliding fit in the outer. Both parts were made from stainless steel. The brass tube can be found at most model components suppliers.

Cable End Converter Drawing
Drawing 1 – cable end converter drawing

Cable End Converter Photo
Photo 1 – Cable End Converter

Modified petrol change-over tap

The petrol feed change-over tap is a potential source for a fuel leak because of its cork seal. In an article in the MGOCC Bulletin for December 2011, J.E.Harris illustrates in detail how to modify this tap to incorporate a PTFE seal. The external appearance of the tap is unchanged. A short piece of PTFE rod is not easy to obtain but I was successful on eBay.

An alternative to this arrangement has been suggested by Keith Gordon in a letter to the MGOCC Bulletin, February 2012.

The oil pressure switch

I purchased an oil pressure switch from GL autos: E-mail glautos ‘at’ hotmail.com (Item No.140740000053). It operates at 17.4 to 23.2 psi and switches to earth for ‘on’. An operating pressure of about 50 psi may have been more desirable but one could not be found at a reasonable cost.

I made an adaptor from 5/8inch square brass bar to fit the oil gauge exit on the engine block (1/8 BSP). The switch is screwed into the top (M10x1) and the oil gauge feed screws on the end (1/8 BSP) The switch was supplied with a sealing washer. The washer for the adapter to block was selected for thickness for the adapter to arrive in an appropriate position for the switch connection.

The switch is open circuit for no oil pressure and short circuit when the pressure is above the operating point. The open circuit state is converted to 12v to drive a warning light and the same buzzer as is used for the indicators.

MG TA Oil Pressure Switch
Photo 2 – oil pressure switch and adapter (see photo 4 to view the switch in position)

Brake lamps switch

The idea for this came from an article in the MGOCC Bulletin by Ernie Preston.

The brake lamp switch is fitted to a banjo bolt on the back of the master cylinder. The original banjo bolt is not big enough to accommodate the thread for the switch so I used a banjo adapter bolt from a TD no. 27H167, which is also the Moss number. I used a hydraulic switch Lucas 34765 as used for the TD which I obtained at autojumble. There is a later switch with a similar shape but with push on connectors which is probably more easily found.

The Lucas switch has a 1/8 NPT thread. I did not have this size of tap so I turned down the thread and rethreaded it M8x1. I drilled out the thread from the new banjo bolt and silver soldered in a steel plug. I drilled this and tapped M8x1 to fit the switch. The original bolt has two exit holes but the TD bolt only has one, therefore drilling is necessary.

Also required are three copper washers. The banjo washers are Moss No. 324-908 (unfortunately only sold by Moss as a car set of twelve), and one for the switch. I used one from my spares bin.

MG TA Brake Switch
Photo 3 – from left to right, the original banjo bolt, the TD banjo bolt, the modified union, the modified switch (see photo 5 to view it in position)

Indicators

As stated in my last article I have converted to negative earth to enable the installation of LED lighting, except for the indicators. Having decided to use LEDs for all lighting (except the headlights) I have now replaced the indicators relay for conventional bulbs with an electronic indicators relay. The relay was supplied by Vehicle Wiring Products. It was a three pin relay no. LED02 rated at 10watts. As it is silent in operation an audible warning is desirable. I used the circuit shown to isolate the 12 v from the indicators relay to drive the buzzer. A feed from this circuit connects to the green 30mph led warning lamp.

The buzzer used was a very cheap one from the Maplin Electronics range which will have to be changed if not loud enough. All other components came from my spares bin but can be obtained from any electronic components supplier. I soldered the circuit components to a section of Vero board and remodelled the indicators switches mounting bracket, which was described in the June issue, to include side lugs and to accept the circuit board. Its connector will plug into the six-way connector on the dashboard.

Bob Butson

Ed’s Note: One more diagram and five photos follow:

MG TA Indicators Circuit Diagram
Diagram 2 – oil pressure and indicators circuit

Oil Pressure Switch
Photo 4 – oil pressure switch in position

Brake
Photo 5 – brake light switch in position

Buzzer Circuit Board
Photo 6 – buzzer circuit board, indicators switches

Connectors and Indicators Panel
Photo 7 – connectors and indicators panel

Driver's View
Photo 8 – driver’s view

Ed’s Note: Bob mentioned the BX44 fan belt which he purchased from Bearing Boys. This has reminded me that Brian Rainbow has recently done some research on prices of regular service items for the TA model and the fruits of his labours are as follows:

Part Description Best Price (£) Supplier
Contact breaker points 400415 7.00 JB Vintage Spares
Condenser 400308 6.97 Octagon Car Club
Distributor cap 400135 19.50 JB Vintage Spares
Rotor arm 400051 405468 2.50 London Classics
Top hose 14.00 JB Vintage Spares
Bottom hose set 12.00 MOSS
Core plug 39mm 0.60 Octagon Car Club
Fan belt 44 inch 5.35 Bearing Boys
Oil filter (felt) 13.50 Grove Classic Motorcycles
Thermostat (bellows type) 55.00 Barrie Bishop Scunthorpe
Ignition coil (screw type) 12.50 JB Vintage Spares
Front hub inner bearing 6205 3.47 Bearing Boys
Front hub outer bearing 6304 4.00 Bearing Boys
Rear hub bearing 6208 8.02 Bearing Boys
Front hub oil seal 48 x 62 x 8 3.89 Bearing Boys
Rear hub oil seal 1 1⁄2 x 2 1⁄4 x 0.3 3.61 Bearing Boys
Brake linings and rivets – axle set 35.90 NTG
Brake shoe set (no exchange) 75.00 MG Centre Wrexham

 
Notes:

For the purpose of price comparisons, the advertised prices of four main suppliers were recorded. The four suppliers were:
MOSS Europe, NTG, Brown & Gammons, Octagon Car Club.

The contact details for those suppliers who offered one or more of the best prices are as follows:

JB Vintage Spares – www.jbvintagespares.co.uk
Octagon CC – www.mgcars.org.uk/octclub
London Classics – stores.ebay.co.uk/London-Classics
Bearing Boys – www.bearingboys.co.uk
MOSS Europe – www.moss-europe.co.uk
Barrie Bishop Scunthorpe – www.ebay.com
NTG – www.mgbits.com
MG Centre Wrexham – www.welshmg.co.uk
Grove Classic Motorcycles – www.groveclassicmotorcycles.co.uk

All the prices included VAT, and were like for like. They were obtained via online searches a few weeks ago. For a number of the suppliers, such as JB Vintage Spares, London Classics, Barry Bishop, MG Centre Wrexham, the prices quoted were taken from e-Bay searches, not their websites. Quite a few suppliers sell on e-Bay and sell the same parts a lot cheaper than on their website. You can of course use MG AuctionWatch (the website which lists and categorises by model, all MG parts on eBay). Use the T-Types ‘All Parts’ search facility. The above prices may no longer be applicable, but give an indication of who was the cheapest supplier at a given point in time. The motto is ‘check before you buy’!


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One Response to “The Resurrection of TA0844 (Part 6)”

  1. Tom Kirkland 06. Mar, 2017 at 6:42 pm #

    I have been most impressed — All these hints have been well presented and will be most useful to me. As I have been involved with Restoring MGs since my recent Retirement. I have recently finished an MGTC restoration and an MG YT refurbishment. where I made up a Brake Light Switch very similar to the one you have described. Presently I have a 1933 Morris 10/4, which will be a complete Restoration Job.
    I also enjoy reading through your T-Type 2 Newsletter.
    Keep up the Good Work.

    Best Regards,
    TOM KIRKLAND (South Africa)

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