8th May 2016, Glavon Vale of Evesham Run

After hopefully fixing the carburettors, I was interested to find out how the car actually drove so our Glavon TR Register group day out on 8th May was ideal.  Turns out it was the hottest day of the year so far and a proper test. We had a mixed group of 14 cars with TR3,4,5&6 but mine was the only TR7. During the day three of the TR5/6 broke down due to the heat but the TR7 didn't miss a beat.

It was raining at the start!

Driving to the start we had some light rain but the forecast was good so the roof stayed down. This turned out to be the right decision because by 10:00am it was a glorious sunny day.

The route took us from the start at Coombe Hill near Cheltenham across the River Severn at Tirley, to a coffee stop at Clive's Fruit Farm near Upton on Severn. They specialise in pick-your-own fruit, juices and cider, and I can highly recommend their home made cakes.

Coffee stop at Clive's Fruit Farm

Leaving the farm we met quite a lot of traffic at Upton on Severn which seemed to be heading for a Spring show at nearby Malvern. Several of us have CB radios so we were able to keep our small convoy together in the traffic and they came in useful when a couple of the TR5/6 broke down apparently due to the heat. It was now about 25 degrees and I actually decided to put a little sunscreen on my face whilst the cars were restarted.

Lunch was at the Fleece Inn at Bretforton. This is a lovely old 15th century pub owned by the National Trust where they do really nice food.  It is in the middle of a small village but we had arranged to park our cars in their gardens which provided a perfect location for a couple of pictures as well.

Lunch stop at the Fleece Inn, Bretforton

The afternoon run took us up onto the hills and a stop at Broadway Tower before dropping down via Snowshill, Temple Guiting and Kineton to Naunton where we all separated to make our way home.

The TR7 ran perfectly and drove better than it ever has. The engine was smooth with a good spread of power from low revs all through the range.
All in all, a grand day out.

May, 2016. Carburettors

Since I fitted the alloy carb mounts last year I have never been happy with the idling speed.  It never wanted to go much below about 1000 or even 1100 rpm and because there has been stuff going on I have not bothered about it.  The engine runs perfectly, apart from the idle, with good power and reasonable economy so I decided it was time to investigate properly.

All the linkages etc were free and lubricated with no signs of sticking. There was no signs of any air leaks and all the breather hoses are connected and in good condition. Next thing was to put a flow meter on the carbs, and sure enough the front carb was drawing much more air than the rear one. The next thing was to loosen all the links between the carbs and set the idle on each one but even with the throttle stop completely undone the front carb was still drawing way too much air.

Synchrometer, air flow meter I use.

Something was obviously going on with the front carb so I decided the only thing to do was take them both off and have a proper look. First thing I noticed was that the fuel level in the jet of the front carb seemed much higher than the rear one, not an answer to the main problem but something else to sort out as well.  With the carbs off I found that the throttle butterfly on the front one was not closing fully. Holding it up to the light I could see the butterfly was clearly not centered properly in the spindle because light was still visible with it "closed". I was able to slacken off the two screws holding it and get it adjusted so no daylight showed. The butterfly must have been like since the engine went in the car and I think the old suspect rubber mounts had masked the problem.

Next thing to look at was the float levels. The newer types of SU carbs have a one piece plastic float which is non adjustable. Some folks put washers under the needle valve to alter it but I decided I might as well fit the best new ones from Burlen Fuel Systems. These are called StayUp Floats and come complete with a new needle valve and gaskets as well so should be an answer to the fuel level problem. They also have a metal lever so are adjustable as well if needed.

Burlen SU StayUp float kit

Well the new float kits came and are fitted in the car. It was a really easy job to fit them and adjust the floats to the correct setting.

The engine now runs much smoother and I can actually adjust the tickover to a nice 750/800rpm. It also drives nicer and pulls strongly from low revs. I popped into my local garage and checked it on their emissions tester.  CO2 levels were a little high so I set them down to a comfortable 4.5% .

We are out on a little Sunday tour with our GLAVON TR Register group tomorrow so it will be interesting to see how it goes in normal driving.