The Triumph Dolomite Club - Discussion Forum

Hi I bought my Dolomite 1300 last June and she has generally been running fine.
I bought a timing light to check the timing. I blocked off the tube that comes out of the distributor. I got a reading of 16 btdc. I notice another thread this week that said that 12 btdc is the maximum because of detonation damaging the pistons. Should I adjust my timing to this figure?

The timing could well be spot on as it is as long as it isn't pinking. If it is pinking you should retard it until it stops pinking.

A 1300 is very different from a Sprint....which was the car in question that is liable to piston damage.

Even so 16 BTDC at idle is too far I think. I would be happier at 10-12.

Jonners

Jonners, the book figures were developed for 4-star petrol. Modern unleaded burns differently. The book figures are a good place to start if the timing is being set from scratch. It might need retarding a bit if there's any pinking.

If it ain't broke...

Try setting it back to the factory figure of 10°BTDC and see how the car runs with it set to that. If it doesn't run properly you can always re-set it back to 16°BTDC!

16 seems a bit too far off even allowing for modern fuels. Jonners recently set the ignition on my Spitfire's 1300 engine which IIRC was pretty close to if not the same as the factory figure.

Also make sure you are taking the reading at idle 800-900 RPM.

Hi thanks for your advice. The problem that I have is that the 1300 does not have a rev counter so I don't know if she is running between 800-900 rpm when I am checking the timing. Is there a bit of kit that you know of that would enable me to know the rpm or is fitting a rev counter my best option?

Just do it statically...

Set the engine to the 10-12BTDC position on the pointers on the timing chain cover and then turn the dissie to the point
of spark...
You can get it spot on with a bit of practice.

Then check it with the timing light...

Jonners

Hi Larry

My 1300 Dolly was also set at around 16 degrees to run on standard unleaded when I got it two years ago. It was running well but occasionally it would get pre-ignition under load and running on even after the mixture had been set with a colour tune and an exhaust gas analyser. The mixture was difficult to set and kept varying and a worn waxstat was diagnosed so this was changed for a red jet but the pinking persisted. I decided to take it back to the original settings to start again, and reset it to 10 degrees and use super unleaded 97 Ron which is the leaded rating the car was designed to use. It now runs much better, very smoothly, and pulls better than it ever did with no pinking. If the V Power you are using is the super unleaded type then I would suggest you try it at 10 degrees you may get the same results I do.

I haven't got a rev counter and having electronic ignition fitted I set the idle at a "normal" smooth tick over by ear but after setting the mixture first with the colour tune and checking the plug gaps. If you are running on points I would suggest you check the points gap also. Once the timing was set I then rechecked the mixture.

Bob

Hi thanks for your help. I will reset the timing and let you know how I get on.

Hi thanks for your help with the timing. I adjusted it to 12 this afternoon just by moving the distributor slightly. Then checked the points which only needed a slight adjustment.
She was idling fine but the revs seemed to be down so will see how it goes.

Sorry but if you adjusted the points then you will have altered the timing....
Open the points and the timing advances...close them and it retards.

Set the points gap to 15 thou and then set the timing to 12BTDC static. Then you can check it with the strobe
light and see how it advances under vacuum and revs.

The tickover will drop about 200 rpm if you back off the timing by 4 degrees.

Jonners

Hi thanks. I thought that when I adjusted the timing that this would effect the points.
Please let me know what you mean by setting the points to 15 thou.
Is this right by static timing adjustment: take out plugs, turn engine till marks line up with 12 BTDC. loosen dizzy nut. put test light on coil and earth to engine.(where on the coil?) turn dizzy until light goes out, tighten nut. Start engine and check timing with strobe light.
When should I set the points to 0.38mm?
Sorry to ask these questions but I have never done this before. This is my first car with points and which the timing can be altered and I would like to learn how to do it properly. Thanks for your help.

To set the gap on the points, you will need a set of feeler gauges. Turn the engine so the points are at their maximum opening and make the adjustment. With the correct size feeler gauge, adjust the gap until you can feel it dragging slightly. Another problem with points is timing scatter which is caused by a worn distributor shaft. The points gap will be all over the place. It might be worth considering fitting electronic ignition. This would eliminate the points and condenser and is generally unaffected by the timing scatter problem I've mentioned. The Britpart kit is one I'd recommend and is a direct replacement for the points and condenser. You can use your existing coil with the Britpart kit.

the order in which you make adjustments is just as important as how accurately you make them. First set the points gap and the sparkplug gaps, then the timing. If you are making carb adjustments make sure the whole ignition system is spot on first. Carbs are the most sensetive component - even the weather affects the state of tune, so make sure any settings that have no dependencies on other settings are done first to reduce the number of variables affecting mixture settings. If you set the fuel mixture then change the timing the mixture will no longer be correct.

Hi thanks for your help. I set the points to 15 thou and checked the timing which was 10 btdc. The car is running fine, no stalling or kangarooing and she is idling smoothly.