Making a TA Go Faster!

4 Sep

When I was with Derry Dickson in July we talked about his ownership of MGs which dates back as far as 1950. It was then that he bought a rusty wreck of a TA which he had to ‘make do and mend’ to keep it on the road. Money being in short supply meant that anything that needed doing on the car had to be done by himself. It was a steep learning curve but thankfully eased somewhat by the help and understanding of his local garage from whom he learnt a lot. Improvisation was the order of the day for there was not the abundance of technical know how and help to which we are now accustomed. It is against this backdrop that Derry apologises in advance for some statements and facts which might make today’s experts cringe!

Over to Derry…………..

“In 1960, having owned a TA for 10 years, I decided that the TA’s only fault was that it had a virtually ‘untunable’ engine. The obvious answer was to fit a ‘tunable’ one, and it didn’t take me long to decide on the XPEG unit.

My reasoning at the time was that the TA’s suspension is that little bit superior to the TC’s (no arguments please, it’s a fact!) and that 1466cc give just a little more urge than 1250cc. Finally, it was the only conversion that wasn’t going to offend my strong feelings about other engines being installed in classic cars. This way I was not going to have to alter either engine or gearbox mounting points.

Bugatti is quoted once as having said in reply to criticisms of his great cars’ brakes I build my cars to go, not to stop. All very well in pre-traffic congestion days, but I like to be able to stop when I have to, and anyway M.G.s have a motto to live up to. Thus, I approached conversion to greater power with some caution and in three separate stages:

First Stage was to improve the trunnion suspension even further by fitting Woodhead Monroe dampers; these were obtained from the makers with simple and very rugged adapter brackets.

Second Stage was to improve the braking: this was carried out expertly by Bowden Engineering Company, which fitted TD brake parts to my existing back-plates. Fitting the hydraulic piping presented the only difficulty, as it meant juggling underneath the car with varying connections so that the modern narrow gauge pipes could link up with the existing ¼” copper pipe going to the unchanged rear brakes.

Note: The marked increase in efficiency of the front brakes necessitates even more care when braking in the wet than is normally required).

Third Stage. Having tested the car thoroughly and found the road holding and braking to my satisfaction, I set about the final stage of fitting a new XPEG unit (number F3282), obtainable at that time from Abingdon.

This operation is best divided into III phases:

Phase I. Assembly of the necessary parts which are:

XPEG engine unit (un-staged) complete with clutch and distributor. (XPAG engine unit complete with clutch and distributor may, of course be used instead, and is indeed easier to fit – see gearbox section)

TF bell housing (TC housing retained of course, if using XPAG unit)

TC gearbox complete with remote control gear lever and with the TA speedo reduction gears fitted (the two ratios are interchangeable);

TC engine front mounting plate;

TC dynamo pulley – fits TA dynamo;

TF starter motor;

2 x 1 ½” SU carburettors – each float chamber must be in front of its carburettor to enable the existing TA throttle linkage to be used;

Rear mounting bracket for dynamo (TC, TD or TF will do).

“Y” water pipe for connecting bottom of radiator with pump and crankcase water gallery.

Remove the TF front engine mounting plate and replace it with the TC plate – no additional holes require to be drilled, it bolts straight on. The only machining in the whole venture now has to be done: the front bearing of the 1st motion shaft protrudes beyond the body of the gearbox and therefore the opposing face of the bell housing must be machined out to a depth of approximately 3/32” to receive this. There must be no space between the bell housing and bearing: should the recess be machined too deep, then make shims to fill the gap – the shallower the recess and the fewer shims required then the stronger the bell housing will be at this potentially weak point.

A TC bell housing could of course be used, but the clutch actuating shaft and fork are less robust than that on the TF housing and might wear excessively because of the heavier duty clutch springs incorporated in the TF clutch.

Phase II

Having bolted the front mounting plate, clutch housing and gearbox together, the assembly is ready to mount into the car having removed the bulkhead and steering column. No alteration to the engine mountings is necessary and there is plenty of room for all – even the starting handle dog lines up with the handle “tunnel” (a very different story if you try to fit an MGA unit).

The steering column must have ¼” removed from the outer surface of the steering box body at the mounting bolt, to allow the column to move ¼” nearer to the chassis; if this is not done then the column itself fouls the front edge of the starter motor.

(Note: the TC column sits higher than that of the TA and therefore provides ample clearance).

Phase III

Now, all that remains is to make all the connections necessary for the engine to function; I shall deal with these under the following headings:

Electrical

Starter motor requires to be worked electrically, this means a push-button on the dash and the appropriate solenoid instead of Bowden cable and switch.

Earth braided cable from engine to chassis

Distributor – no change

Mechanical linkages

Choke – no change

Clutch – direct linkage provided by a chain comprising 3 x 1” links (see drawing).

Accelerator – the lever for actuating the “butterflies” must be situated at the rear end of the shaft if the existing pedal and lever are to be used (this is why the rear carburettor must have its float chamber to the front; compare the TF which has its chamber to the rear).

Water Hoses

Blank off existing header tank flange and braze in another one of 1 ½” diameter to a suitable position and at an appropriate angle to take a simple L-shape hose from the thermostat.

Instruments

Rev counter, a reduction box as used on a TB, TC, TD, or TF is essential because the TA box has too long a driven spindle, which causes the box to foul the distributor body.

Speedo cable – connects direct.

Notes

A little ingenuity is required when attaching the rev counter cable to the output drive of the reduction box, as the coupling varies between early and later T Types.

The TA back axle and 19” wheels all round have been retained.

Conclusions

Some may say “Is all this trouble worth it?” All I can say is that the proof of the motor’s in the driving and here are some facts to prove it:

The fuel consumption was 33.5 miles per gallon over 24,000 miles of very varied motoring.

The oil consumption still stands at 1 pint per 500 miles.

The car achieved a maximum indicated speed of 95 m.p.h.

The oil pressure after 24,000 miles is 55 pounds per square inch at 3,000 rpm, hot.

The maximum thermostat temperature was 95 degrees centigrade, obtained on the Italian Autostrada del Sole at midday in June 1963.

Acceleration is embarrassing to most other road users.

The car has completed three summer Continental camping holidays complete with wife, self and camping gear, without a mishap. The longest holiday being a 5,000 mile trip to Pompeii (via Spain!) which included the Autostrada del Sole down whose 130 miles the speedo needle was kept between 70 and 80 m.p.h. In fact, during the 24,000 miles of fairly brisk motoring, I have only had to renew the spark plugs 3 times, oil filter element 5 times and one radiator hose.

All this and am I satisfied or am I? Come to think of it, one or two of the hotter Minis are hanging on to my tail, so maybe I’d better do some Stage Tuning now!

Post Script

Since setting out to write this article, I have fitted a Laystall Lucas head (Compression Ratio 9.3:1 costing £61-5-0d) and an extractor exhaust. Only two comments after 2,000 miles; Firstly, the m.p.g. now stands at 35.5 and secondly, where are all those Minis?

Ed’s Note: A Laystall Lucas head for £61.25!

Here are some period photos:

The arrow pointing to the n/side of the dash reads “Also glove box with St Christopher – very necessary!” (I should think so at 95 m.p.h. Ed). The Note: reads “Birds eye walnut dash; Oil pressure, RPM, speedo, oil & water temperature all grouped together and lit by one bulb externally placed in the middle, throwing a red light (good for night vision) direct on to the B/W dials.

A Mews somewhere in the west end of Edinburgh – TA2243 with other T-Types.

Town of Nevers: camp site on the river Loire – according to Google, the site is still there.


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