lindatr4 Posted August 27, 2019 Report Share Posted August 27, 2019 Old distributor has been consigned to the parts bin and a new one fitted. Wrestling with the timing now and looking for some good advice I understand that the correct position should be 4° BTDC but as there is only the little hole in the pulley to indicate TDC, would I be correct in assuming that by using a strobe light the markings should appear as in the photo? Obviously the engine is not running but is this what I should be seeing as the engine idles? Or should it be showing the other side of the pointer on the cover. Quote Link to post Share on other sites
RogerH Posted August 27, 2019 Report Share Posted August 27, 2019 The triangle pointer is at TDC (in theory) The crank rotates clockwise So the mark on the pulley is 'Before TDC' and that is good. Once in this position you can now very slightly rotate the Dizzy to fine tune any pinking etc. Roger Quote Link to post Share on other sites
bob-menhennett Posted August 27, 2019 Report Share Posted August 27, 2019 (edited) As Roger says . We are assuming you've got No 1 cylinder piston at the top of it's firing compression stroke and the rotor arm pointing at No 1 cylinder ? ( Distributor cap removed of course , if all systems go , replace cap ) Temporarily slacken the distributor clamp at the base of the distributor , so that you can twist it by hand comfortably. Set the micrometer adjusting thumbwheel to it's central position so that once you're reasonably happy with the tickover / running you can " fine adjust it " on the road test , backwards or forwards.This will provide you with the optimum position. If the micro adjustment has already been moved fully , to either extreme , then you will be unable to adjust it in both directions for the final finessing of the timing.Tighten up the Distributor clamp bolt without altering it's position and do a road test. Adjust if necessary. Whilst the Manual says 4 degrees people now suggest , with unleaded petrol , that the figure should be nearer 10 degrees. Bottom line is that your engine will be able to tell you when it's happy.You'll hear the difference ! Usual safety warning … keep you hands and any loose clothing away from the moving parts. Good luck with it. Lets us know how you get on. Bob Edited August 27, 2019 by bob-menhennett Quote Link to post Share on other sites
rogerowen Posted August 27, 2019 Report Share Posted August 27, 2019 That's exactly the position I have recently set my timing to - about 5mm before the bar. Car runs well apart from a little overrun on switch off sometimes. Interested to hear about 10 degree BTDC - might give that a try. I use posh petrol - wonder if that makes a difference. Quote Link to post Share on other sites
Z320 Posted August 27, 2019 Report Share Posted August 27, 2019 the drill it 0°, first notch is 5°, first countersunk is 10°.... 15, 20, 25, 30, 35, 40 Quote Link to post Share on other sites
lindatr4 Posted August 31, 2019 Author Report Share Posted August 31, 2019 So I sets up the timing light and I goes through the motions...now that's odd I says to myself, no mark to be seen! So off comes the rocker cover to make sure No.1 piston is on the compression stroke, out comes the spark plug to witness piston at the top of its stroke only to find that the TDC mark is way off on the pulley. Whosoever fitted the bottom pulley must have installed it incorrectly. Oh dear Quote Link to post Share on other sites
RobTR3 Posted September 1, 2019 Report Share Posted September 1, 2019 'So I sets up the timing light and I goes through the motions...now that's odd I says to myself, no mark to be seen! So off comes the rocker cover to make sure No.1 piston is on the compression stroke, out comes the spark plug to witness piston at the top of its stroke only to find that the TDC mark is way off on the pulley. Whosoever fitted the bottom pulley must have installed it incorrectly. Oh dear' Had this issue myself!. The crankshaft pully must be assembled so that the key on the hub is directly opposite the timing hole (180 degrees)on the inner half of the pully. As there are six fixing bolts it can be assembled in six different positions! You will need to either dis-mantle and re-assemble the pully or put a TDC mark on the pully as accurately as you can, but not easy to get spot on. Rob Quote Link to post Share on other sites
tim hunt Posted September 1, 2019 Report Share Posted September 1, 2019 This mis-assembly is not uncommon Bob, even a BL dealer got it wrong back in the day when rebuilding my engine, at their expense I might add after they had fitted a new steering rack and carelessly trapped an oil cooler hose that chafed through with predictable results on Bodmin Moor during a Club Triumph RBRR. The fixing should have been designed so the pulley will only fit one way on the crank but poka yoke had not been heard of by the UK motor industry back in the 50s. Tim Quote Link to post Share on other sites
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