5th May 2015, Carburettor mounts and exhaust clonk

After the St.Roses car show I thought it was time to have a look at the rubber carburettor mountings. These are common to most TR7's and are a well known problem area. The original production items were good quality rubber and lasted for ages but modern replacement parts seem to use inferior rubber and fail quite quickly.  This can cause air leaks and poor running so needs fixing.

Rubber carb mounting on its way to failure.

(There is a similar problem with engine and gearbox mountings where the modern replacements are much too hard and cause noise transmission into the car.  I was lucky enough to be able to re-use some old stock original ones which are much nicer.)

The Triumph Dolomite Club sells some very nicely made solid aluminium mountings to replace the rubber ones and I bought a set of these together with some more replacement spark plug tubes as mentioned in a previous post.

Replacement carburettor mountings

Fitting them was not difficult but I have upset the carb balance so need to re-tune the engine !

Nice and shiny

New mounts in place

Next job on the list was to sort out an annoying clonk from the exhaust. Its a very nice fully stainless system that I got from S & S Preparations and it was touching somewhere at the rear of the car but not all of the time. All the mountings were OK so I checked all the clamps and went out on a test drive - nothing at first then lots of clonks after a few miles.  Looking again I realised that when the system gets hot it was hitting the towing eye on the rear chassis rail.   This was soon sorted out with the angle grinder and it now has plenty of clearance !

Modified towing eye.

2012 Sprint engine update and Oil Pressure gauge

 Running around trying out the Sprint engine was good fun. It is a smooth torquey engine and I just love the way it revs.  The only thing I started to notice when the initial grin started to fade was a few rattles and noises that weren't there before. The exhaust system would knock on the floor sometimes and I had also found a mark on the inside of the bonnet (hood) where the oil filler cap was just touching.

Several attempts to rearrange my cobbled up exhaust system proved useless, and it was too close over the axle area,  so I decided to buy a complete new system that I knew would fit properly.  S&S supplied a very nice complete new stainless system including manifold and mounting rubbers, but at around £500 it was not cheap!
Fitting the system was very easy apart from the manifold.   The new engine has studs in the head instead of bolts which I think is a good idea, but the clearance issue ( see picture ) means there is not enough room to

 Nice new stainless manifold - but close to chassis

get the manifold on/off the studs.  The only way is to undo the engine mounts to tip it over and then it would just go on.  I also used brass nuts on the studs to avoid any sticking problems later.

When I asked S&S about the clearance to the chassis rail they told me that folks tend to use a bit of heat and a hammer to "modify" the manifold.  I thought this was a bit brutal having just paid good money for it but found another way on one of the forums by a small machining job on the right side engine mount - see pictures below.

engine mount before - block side

and after

engine mount before - chassis side

and after

About 5mm is machined off each side of the mounting as shown in the pictures.  The effect of the machining is to make the engine "lean" slightly to the right and away from the chassis rail.




Enquiries about the bonnet clearance revealed that the usual trick is to use TR8 spacers between the subframe and chassis rails.   These are basically just a thick washer (about 10mm) which drops the subframe by the same amount relative to the body. Easy fix and took less than 30mins to do.

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Forgot to mention earlier, somewhere in amongst all these goings on I managed to find time to fit an oil pressure gauge in place of the clock. The car always had a gauge fitted low down by your left knee - a useless place - so I moved it to somewhere you can now see it.. I used a old Smiths classic full scale 0-100 psi capillary. gauge. Quite a simple job, just a bit of fitting/cutting out some plastic in the back of the instrument pod to get it sitting nicely in place..

Oil Pressure now clearly visible.