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2.0 pinto distributer tapping on low revs
maximus1 - 25/8/13 at 10:08 PM

Hi there I'm running 2.0 pinto on 40 side drafts on very low revs distributer
Starts making a taping noise and sometimes slight miss fire .
Rev it and its fine any ideas if I cut off vacuum pipe tapping stops will it be ok with out that on
What's best distributer to run engines had work, pistons, rods but its fairly standerd ? V thanks barry

austin man - 25/8/13 at 10:18 PM

sounds like the advance and retard mechanism should be okay may need oiling

Dusty - 25/8/13 at 10:49 PM

Where have you taken the vacuum advance from? If from a single inlet you can get pulsations at a frequency that is audible and has the baseplate rattling to and fro and the timing all over the place. Either tap all four inlet runners and lead to a small plenum and then from that to the dizzy or don't use vacuum advance.

britishtrident - 26/8/13 at 06:03 AM

I would say the distributor bob weights need a tiny amount of oil.

mcerd1 - 26/8/13 at 08:36 AM

as above have you still got a Vac. advance and how is it connected ?

quote:
Originally posted by maximus1
What's best distributer to run engines

the best dizzy is no dizzy at all
(well nearly no dizzy - you need to keep the bottom half of it on a pinto to drive the oil pump...)

megajolt is probably still the cheapest setup, but thats still going to be ~£150 all in

maximus1 - 26/8/13 at 01:04 PM

Both pipes from distributer vacuum go in to tee pice and then one
Pipe goes in to air in take manifold !!!

mcerd1 - 26/8/13 at 02:20 PM

quote:
Originally posted by maximus1
Both pipes from distributer vacuum go in to tee pice and then one
Pipe goes in to air in take manifold !!!


so thats only connected to 1 cylinder out of the 4 then ?

maximus1 - 26/8/13 at 02:32 PM

Yes found out that's not good I have lifted tick over to 1000 rpm
And seems much better no tapping. What should tick over ball park be when running delorto 40s

mcerd1 - 26/8/13 at 02:49 PM

as above - have you tried a little drop of oil inside the dizzy yet?




what some of as are trying to get at is: part of the problem could be to do with the vacuum advance...


your twin 40's effectively have 4 separate manifolds (1 per cylinder)


the intake pressure at each individual cylinder varies as that cylinder goes through one complete cycle (i.e. 2 full revolutions of the crank) in that time the vacuum is being generated for only ~1/2 a turn of the crank while your valves are open

so by taking a vacuum signal from only one cylinder you get a lot of pulses or a 'lumpy' signal for lack of a better word


the dizzy's with vacuum advance are designed to be connected to a single common manifold for all 4 cylinders - this has lets the vacuum from all 4 cylinders mix in a large enough volume that it effectively averages out the vacuum signal to a nice smooth signal for the dizzy to 'read'



you either need to disconnect the vacuum advance (a modified dizzy would be best in this case)

or connect a vacuum line to all 4 cylinders - but this must be via a small expansion chamber to allow the signal to be smoothed out.

[Edited on 26/8/2013 by mcerd1]

[Edited on 26/8/2013 by mcerd1]

britishtrident - 26/8/13 at 05:41 PM

quote:
Originally posted by maximus1
Yes found out that's not good I have lifted tick over to 1000 rpm
And seems much better no tapping. What should tick over ball park be when running delorto 40s



Oil the distributor before doing anything, this type of noise used to be a very common symptom back in the days of centrifugal advance distributors.
Two or at most three drops of oil, two on two the centrifugal mechanism under the base plate, then remove the rotor arm and place a single drop on the screw exposed by removing the rotor arm. Allow the oil to soak in for 20minutes or so before starting the engine.