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Points dwell angle


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Changed my points as they looked worn and going to do a lot of miles at weekend. - I know dont fix wot aint broken !!!

Changed rotor arm for quality red one. Will fitting new points have altered timing? -as now not running and picking up as well as it did before.

What is correct Dwell angle for late tr6?,( typical cant find my manual !)I have got a Gunsons unit for checking.

I am running an Aldon ignitor coil which may be too much for points (gap different a for high power coil?) but has been fine for three years.Car running on triple weber 40 DCOE.

Any thoughts please! .

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You dont mention you have set the gap on the new points. If the gap is right so will be the dwell.

Make sure there is smear of grease on the cam. Plastic points wear badly especially initially, and if fitted dry can stop the engine runnning in a couple of hundred miles.

Take the feeler gauge with you on your trip!

14 to 16 thou IIRC

 

Peter

Edited by Peter Cobbold
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Hi Mark,

put the original rotor arm back in and see what happens.?

The points either work or don;t if put back wrong.

If the gap is OK then so should be the dwell angle .

 

In fiddling with the electrics have you knocked off any pipe work for the carbs, vacuum etc.

 

Roger

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Depends on dizzy,

22d6 ...41319......35 degrees +/- 3 degrees

The other Lucas dizzy's I Assume for carb cars ate all 25 degrees +/- 3 degrees.

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Hi Peter - points set at 15 thou. Old set had been in the car for about 5 years. I should have checked the gap of the old ones which also had not been altered at all. I wonder if I have altered the timing to suit the points Gap in the past and now I have set the points correctly it has upset the timing slightly.Or am I talking rubbish?

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Yes, check the serial number pm the side, stamped into, the dizzy for the 41319 number. This is the standard dizzy for PI cars.

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Points gap will affect timing so if you had the old set in for a while before setting the timing it would be as well to get a strobe on it and be certain it's right.

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Hi Peter - points set at 15 thou. Old set had been in the car for about 5 years. I should have checked the gap of the old ones which also had not been altered at all. I wonder if I have altered the timing to suit the points Gap in the past and now I have set the points correctly it has upset the timing slightly.Or am I talking rubbish?

Hi Mark, If the gap on the old ones was different from 15 thou then the timing will be different now.

Easiest way to set the timing is to run the enigne at tickover and slowly turn the disy to and for, a few mm no more, until you get the fastest tickover. then retighten the disy clamp. If it really speeds up, keep rpm below 1000 by slowing the tickover to stop centrigugal advance coming in.

Reason for using this method is the timing mark on the pulley may no longer be at TDC as the rubber in the crank damper distorts with age. Finding the new TDC needs a little more work....

Peter

Edited by Peter Cobbold
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Haven't checked dwell since way, way back in the 1900s on mine ( late '70s ). Gap at 0.015" is the target value but should do OK close to that. More likely your timing has been retarded a bit; I find on mine ( TR250 with P.I. head, cam and 3X40DCOE ) a couple of degrees makes a surprising difference. Set to ping point and back off with your handy vernier; 2 degrees per 1/2 turn ;). If gap is OK then just advance it a half turn and see how it does.

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Hi Peter - points set at 15 thou. Old set had been in the car for about 5 years. I should have checked the gap of the old ones which also had not been altered at all. I wonder if I have altered the timing to suit the points Gap in the past and now I have set the points correctly it has upset the timing slightly.Or am I talking rubbish?

Mark

Not at all,dwell is also the duration of the points gap, the gap can vary,check your timing.

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