AC: don’t really understand vacuum advance. Does the vacuum increase or decrease under heavy throttle applications? Does the vacuum system work with or against mechanical advance? Why doesn’t the S engine have a vacuum advance? If the vacuum advance isn’t there, has the mechanical advance been modified to compensate? I would greatly appreciate your straight-talking advice on all this. I note both the dizzies you were discussing in this video had vacuum advance systems. Would you use these on a Cooper S motor? Cheers, Will
Vacuum advance is used in conjunction with mechanical advance to add additional ignition advance at low throttle openings and light load running. This increases efficiency and resposiveness and is a must for road driven vehicles where economy is required. When the throttle is opened fully, vacuum drops to near zero and the advance unit retards the ignition back to that delivered solely by the centrifugal advance mechanism. Cooper ‘a’ engines never used vacuum advance because it simply was not needed on an engine that is driven at wide open throttle everywhere
Thanks for another great vid. I'm current using an electronic module in a 45D that doesn't have variable dwell. Is there anything to gain by switching it to a variable dwell module that can run a 1.5ohm (or less) coil?
@@ACDodd thank you, yes I understand that. I've always been in the "if it's lit, it's lit" camp but I will experiment with a variable dwell and lower ohm coil to see if there's any improvement in the upper RPMs.
@@user-du8cs8sn2v the real benefit I see is better part throttle torque and the ability to light off leaner mixtures and still generate the same power. Higher rpm should also be noticeable.
I've got a programmable ignition module which can adjust the dwell. Have you got any idea what the dwell curve is like on the 65D from idle to max dwell? For the moment I've updated it to 20 degrees at idle, and then up to 70 degrees at 4000rpm and above. Currently have a 3 ohm coil
That will be ok for a 3 ohm coil but you need to change the coil and the dwell curve to match. I think it’s about 22-23 at idle and about 45 max to work with a 0.8 ohm coil and no ballast resistor
@@ACDodd thanks! Would does the dwell directly relate to the ohm of the coil - ie the lower the ohm the quicker the dwell? My module is only rated to 1.5 ohm minimum
Quick question, after watching your videos about dizzy and coils - I have A+1275, non-balasted wiring, with 65D4 dizzy and I found out that my coil is 1.1Ohm. About to swap new plugs (NGK BP6ES) and I was thinking that 0.35mm gap would be too much and 0.32mm could be more optimal for this setup? (Measured my HT leads and they are between 4.7 and 7.5kOhm)
0.35mm is not 0.035”. Change the coil to the correct 0.8ohm unit and run the correct plug gaps. Use lead sets from Powerspark and you will be in the 1 to 3kohm range
@@ACDodd Correct, I meant 0.035", typo there :) I have plan to get correct coil, but it will take some time before it will get to my place and I want to have car available until then. Will have a look at the HT leads as well.
Great video as always. All questions answered. Concise and informative.
great that AC Dodd shares his know how ! my mini has dual points and runs hard at 7000
Yes a dual point setup would be ideal
Thanks for the informative video as always👍
Another great video, thanks for sharing the knowledge
So usefull to know!! Awesome content ac😊
Great vid buddy :)
Good stuff 👍
Hi AC Dodd, Great video! do you know if powerspark do a recurve service for their distributors?
No I don’t think they do
AC: don’t really understand vacuum advance. Does the vacuum increase or decrease under heavy throttle applications? Does the vacuum system work with or against mechanical advance? Why doesn’t the S engine have a vacuum advance? If the vacuum advance isn’t there, has the mechanical advance been modified to compensate? I would greatly appreciate your straight-talking advice on all this. I note both the dizzies you were discussing in this video had vacuum advance systems. Would you use these on a Cooper S motor? Cheers, Will
Vacuum advance is used in conjunction with mechanical advance to add additional ignition advance at low throttle openings and light load running. This increases efficiency and resposiveness and is a must for road driven vehicles where economy is required. When the throttle is opened fully, vacuum drops to near zero and the advance unit retards the ignition back to that delivered solely by the centrifugal advance mechanism. Cooper ‘a’ engines never used vacuum advance because it simply was not needed on an engine that is driven at wide open throttle everywhere
Thanks for another great vid. I'm current using an electronic module in a 45D that doesn't have variable dwell. Is there anything to gain by switching it to a variable dwell module that can run a 1.5ohm (or less) coil?
Yes that’s the point running a lower ohm coil means you can run more spark power
@@ACDodd thank you, yes I understand that. I've always been in the "if it's lit, it's lit" camp but I will experiment with a variable dwell and lower ohm coil to see if there's any improvement in the upper RPMs.
@@user-du8cs8sn2v the real benefit I see is better part throttle torque and the ability to light off leaner mixtures and still generate the same power. Higher rpm should also be noticeable.
Would be interested in your dizzy course
Keep an eye on my channel.
The dizzy you have in your hands at 4:33 is very similar to mine. How do I know if I have a high energy one, are their any marks to go off?
Take a picture of the dizzy with the cap off and send it to me
I've got a programmable ignition module which can adjust the dwell. Have you got any idea what the dwell curve is like on the 65D from idle to max dwell? For the moment I've updated it to 20 degrees at idle, and then up to 70 degrees at 4000rpm and above. Currently have a 3 ohm coil
That will be ok for a 3 ohm coil but you need to change the coil and the dwell curve to match. I think it’s about 22-23 at idle and about 45 max to work with a 0.8 ohm coil and no ballast resistor
@@ACDodd thanks! Would does the dwell directly relate to the ohm of the coil - ie the lower the ohm the quicker the dwell?
My module is only rated to 1.5 ohm minimum
@@timsminigarage kind of.
Quick question, after watching your videos about dizzy and coils - I have A+1275, non-balasted wiring, with 65D4 dizzy and I found out that my coil is 1.1Ohm. About to swap new plugs (NGK BP6ES) and I was thinking that 0.35mm gap would be too much and 0.32mm could be more optimal for this setup? (Measured my HT leads and they are between 4.7 and 7.5kOhm)
0.35mm is not 0.035”. Change the coil to the correct 0.8ohm unit and run the correct plug gaps. Use lead sets from
Powerspark and you will be in the 1 to 3kohm range
@@ACDodd Correct, I meant 0.035", typo there :) I have plan to get correct coil, but it will take some time before it will get to my place and I want to have car available until then. Will have a look at the HT leads as well.
I fitted a complete accuspark to my 2.5 V6..can't get a spark now. worked ok with points... any ideas ?
Contact accuspark
Are the 65d electronics replaceable AC? For that matter, do they ever need replacing? Thx
Yes the module is available and replaceable. Yes they do fail, but it is rare
@@ACDodd thanks (who sells them btw?)
@@clairelouiseatkinson minispares and other suppliers
@@ACDodd thanks 🙂