Posted 13 November 2017 - 06:35 PM
Posted 13 November 2017 - 07:12 PM
Stick with the factory equipment. The '79 and '80 L20B came with a EI (electronic ignition) pointless AKA 'matchbox' distributor and matched coil with higher output. Never have to replace your points or gap them again.
Not a fan of aftermarket coils. They are like fishing lures... they catch more fishermen than fish. It's no mistake that they are painted bright red or yellow colors.
You're in the PNW which is full of Datsuns. Check out the wrecking yards and back yards for one. Or a want ad here... http://community.rat...sort_order=desc ... There is a handy like at the top of every page under the RATSUN.NET logo
- Doctor510 likes this
Posted 14 November 2017 - 06:42 AM
Simple if you keep your Points distributor Keep the point coil!!!!!!!otherwise things can go bad by putting the wrong resisitance coil in there
Key is befriend a Datsun guy that knows what hes doing
Posted 14 November 2017 - 07:26 AM
Correct. Hotter spark is from higher current flow from lower resistance coils. Don't get taken by wild claims by the maker. This buggers up the points faster. EI distributor has the lower impedance coil and can handle it.
In truth you will never notice the difference, maybe faster starting. Better idle. The best reason is to get rid of the maintenance when running points.
Posted 14 November 2017 - 09:45 AM
In Datsuns: points need 3 Ohm coils like stock or Bosch Blue (its what I run in the race truck at Bonneville).
Electronics need a 1.5 Ohm coil.
Aftermarket electronics need a 3 Ohm coil in almost all cases, but refer to the instructions for specific info.
Posted 14 November 2017 - 10:01 AM
3 ohms total. I think the points coils are 1.5 in series with a 1.5 ballast resistor. During start the ballast is by passed for a brief hotter spark.
EI coils are 0.8 to 1.0 ohms
You can use a points coil if you also use the ballast resister, but then you don't get the full time higher voltage spark.
Posted 14 November 2017 - 10:48 AM
Posted 15 November 2017 - 12:32 PM
Funny - my stock 1980 Datsun 720 coil was 1.5 Ohms on a truck with 1200 miles that was never registered for road use.
With points you will get a better quality spark by eliminating all the extra connections of having 12V at startup and a ballasted 10V at Run. Just run it all direct with a 3 Ohm Bosch coil. Proven effective at over 10,000 rpms!
Posted 15 November 2017 - 12:57 PM
The '80 720 used the EI system and it should be 0.8 to 1 ohm. The EI was also used on the 280zx which red lines at 7,600 rpm which would be 11,400 RPM on a 4 cylinder.
Spark 'intensity' of a coil, is a function of how much current flows through the coil to produce a magnetic field around it. In a points set up, 12 volts through a 3 ohm coil is 4.0 amps. (8 amps through a 1.5 ohm coil) In an EI set up 12 volts through a 1.0 ohm coil is 12 amps. In theory 3X more but in practice somewhat less but certainly a lot more than a points spark. The EI has a current limiting circuit to prevent damage.
Posted 15 November 2017 - 01:56 PM
Post a classified ad, yo. Or a "how-to" explaining why recurves should be done, etc.
I've got a matchbox I'd love you to once-over before I install it.
You can't hang if your nuts haven't dropped...it's physics
Posted 15 November 2017 - 02:17 PM
I think you really need a distributor machine and oscilloscope. Variable vacuum supply. I know my advance works because I can see it move.... but does it really work?
Advance is all about reducing pollution and increasing economy. If you throw away the pollution side then this leaves economy and performance, which would seem to go hand in hand. A well running engine should be both efficient and powerful. If you are getting the most out of your gas at part throttle then you should be getting good mileage also