8. Dobby the Teenager gets Exhausted

(October 2017)

Thirteen may be unlucky for some, but for me it is just another year. Yes, I am officially a teenager so in true rebellious style I decided it was time to force my master’s hand. Well he’d supposedly always intended to put a stainless steel exhaust on me but my mild steel one had always done sterling service, despite being thoroughly abused by sleeping policemen. So after 13 years, enough is enough and I blew a small hole in the back silencer. Not enough to make a noise and make him cross, no, just enough to embarrass him into doing something about it before the MOT came along.

So it was that my master decided to replace the exhaust with a stainless one – but which one? And whether to replace the cast iron manifold with a stainless one as well? The main problem, as most TFs will know, is that the middle “silencer” sits under the central chassis giving very little clearance and is the section which most attracts the attentions of the aforesaid policemen. And what about the clamps? These had been clouted and replaced regularly as they protruded even lower than the silencer.

 

Now, my master had spotted a slimline bomb type SS system in the MGOC accessories catalogue and thought maybe this would give a centimetre or two extra clearance. He also discovered some Mikalor SS clamps which are like beefy jubilee clips, tightened with a bolt rather than a screw. These would be able to be positioned so they didn’t stick below the line of the exhaust. That just left the manifold – sense prevailed (prompted by John Hoyle!) to use the same supplier as the rest of the system. So it was that my master phoned the MGOC and organised a SS “performance” system complete with tubular manifold and the centre box replaced with the slimline bomb type silencer. Result? Well almost.

 

My teenagerishness continued as I felt I had been underused this year (this is in fact true and fully justified) as my Master and his wife had toddled off to Austria in May without me (under the guise of their ruby wedding) and not even taken me on holiday this summer! So up on the ramp and off came the old exhaust. All the nuts came undone without a complaint and it felt good – I had lulled him into a false sense of security.

 

Now my obstinacy was to come to the fore. My master started at the front end (logically) and removed the old cast iron manifold. Armed with a new gasket, the new manifold was tried in place. This was when I threw my first wobbly - the centre branch of the new manifold swept out more than the old cast one. This would not have been a problem for a standard MGB but a common modification for the TF is thinner spacers between the carbs and the inlet manifold bringing the former nearer to the exhaust manifold and the throttle could no longer swivel. The thinner spacers are needed so that slim air filters can just be fitted inside the TF bonnet side. Not to be outdone, my master rummaged his box of bits and found another pair of thinner spacers. By careful measuring he decided that, if he added these, the total thickness would still be less than the original but, more importantly, there would be sufficient room both for the throttle to operate and the air filters to be fitted (albeit only by releasing the bonnet side panel a little).

 

However, I thwarted his plans with my second tantrum. The carb fixing studs on the inlet manifold were not long enough for the added spacers and gaskets. So my master searched the Internet for some imperial studs to replace these and then triumphantly assembled the manifolds.

 

Once the front end was completed, my master proceeded to add each section of exhaust pipe, first assembling dry to make sure it all fitted – it didn’t. Well it almost did but there were two issues. The first was that it was too long overall but this was easy to solve by cutting off bits from the two intervening pipes. The second issue was more of a problem. The diameter of the ends of the centre “slimline” bomb silencer were slightly too small to receive the intervening pipes. So as a result of this third sulk my master had to buy an exhaust pipe expander which sort of worked, although stainless steel is really hard. By slightly extending the side cuts and using the clamp to close up the end once the pipe was in place, a reasonable seal could be made. Incidentally, he was very impressed that his very old tube of Granville exhaust assembly paste was still usable!

 

So all that remained was to replace the mountings, the front one to the gearbox and a new almost standard MGB one at the rear. For the centre one (not able to easily identify a cushioned replacement) he formed a new bracket based on standard exhaust bobbins.

 

Now I’m a proper teenager and make a bit more noise than I did – I think you could say my voice has broken! I think my master actually likes my new growl!

 

Having completed the exhausting work, my master wanted to add some DRLs (daytime running lights) that he purchased at Stoneleigh. These are discreet LED units about 18mm diameter and he made a proper meal of wiring these into my existing cable runs. He has mounted them in small aluminium plates on the badge bar so the cables run straight through the grille and disappear. Using a relay, he has wired them to come on with the ignition but extinguish when the normal lights are on. Quite subtle – like having highlights in your hair.

 

Well, must dash; I’m off to the Peak District next week and I’ve never been there. Looking forward to showing off my new growl and my highlights.

 

Finally, an apology for the abundant technical content. My master said that this was “necessary” as people liked to know these details. What piffle!

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Dobby