Coil pack l20b

[79210]

Has anyone ever seen someone do this before i tried searching and couldnt find anything i need to know trigger wheels, and what ever else was needed to do the conversion

[MicroMachinery]

[ggzilla]

Do you mean a distributor-less crank-trigger ignition system? A coil pack alone is not going to do you much good.

 

Sure, crank trigger has been done many times. Not by many folks on Ratsun.

You'll find the information on Megasquirt web sites and Megajolt sites. I ran it a crank-trigger ignition system on my Datsun. Very easy to do. The confusing part is there are so many options, it's hard to pick one. Just pick one and do it.

[DanielC]

I believe the most common way to do this is to run a Ford EDIS system.

 

Nissan also has a crank fire ignition system available for L engines in some of their mid to late 1970's competition catalogues.

[Spades]

I suppose you could also make one yourself from junkyard parts...modify a distributor to use as the pickup(crank trigger). plenty of cars used a crankshaft position sensor where a distributor used to be to allow the use of coil packs on an old motor from the factory. This would be plenty of work and would require plenty of knowlege to be able to pull off, which is why I haven't seen it done much in the aftermarket world.

[ggzilla]

Running via distributor takes out part of the advantage of crank-fire. Now you talking about gear lash and timing issues. The one advantage it has it classic looks.

 

crank trigger wheel is super simple. Just bolt it on. No welding needed.

[79210]

so it sounds like i have to be efi? im trying to learn a little more about coil packs because i have heard of people gaining crazy power on small blocks with them and was wanting to try it out i dont expect the kind of numbers they got (upwards of 30 whp) but figured it would be worth a shot

[DanielC]

If your engine has accurate ignition timing, you can obviously gain power.
On your typical V-8, the crankshaft drives the cam shaft with a chain, that has a fair amount of slop. The distribute is driven by the camshaft, by two gears that add more slop. If the engine has some miles on it, bushings in the distributor can be worn out.

Datsun L engines drive the distributor off the crankshaft, eliminating any slop caused by the timing chain, or camshaft

[ggzilla]

You cannot gain crazy power with a crank-trigger ignition. A well sorted (and not worn out) distributor electronic ignition does almost as well. What you can gain is a little stability as noted above. Even the L-series has a bit or gear lash even though it uses no timing chain. You can hear it in the idle which is more steady. Of course you make no net power output at idle, so it's not realy a performance change.

 

I used mine with a 100% stock Datsun engine including the stock Hitachi carburetor.

[goonfan]

Yeah, no big power gains to be had with coil packs over the Nissan match box. It can be done though, check out DIYAutotune, they will have just about everything you'll need.

 

Money and time is spent elsewhere for any performance gains, keep that in mind.

[79210]

so then it sounds like it is not worth it is there any reason to do it at all?

[ggzilla]

It's worth it. Just not for big HP gains. Reasons include reliability, steadier idle, packaging, easier tuning for small HP gains, and of course looks. Looks incredibly cool.

[CameronT]

ggzilla, you showed a pic of your rig that I've seen before but it isn't an L20. In that blog you mentioned it was a direct bolt on for you and I saw a motorcraft box by the coil pack, but what it came off of wasn't mentioned. That's the info I'm looking for as well as the wiring, which I suppose can be used from the old (key activated) wires from the old coil to run it.

[edekalil]

I use the match box distributor on my 510 L series motors. It works great and does make her idle smoother.

[CameronT]

I just installed a 1980 matchbox dizzy in hopes it would solve the issue, but number 1 still doesn't fire constant enough or at all sometimes. My issue is below the dizzy, something is loose enough that it misses it's mark between the rotor and the cap I think. I replaced the oil pump and it worked fine temporarily, then back to running like crap and backfiring. It's a good light show though !

[banzai510(hainz)]

L series are soemwhat loose and the dizzy needs to be turned or however you say it.  I say 7k rpm is about the max.

bushing wear is another proplem if a old dizzy

 

 

maybe a new worm gear and oil spindal? might help

[datzenmike]

Intake or exhaust? Usually loud explosions are several cylinders not firing from a temporary loss of ignition. Exhaust fills and explodes. A single cylinder can't fill much of the pipe and probably not even the single pipe on the manifold, and tends to just make a dull thump sound . Sounds like a Vee Dub or Subaru.

 

Did you check for interruption of spark to the other cylinders??? Maybe the ignition is cutting out from a loose coil wire.

[CameronT]

I have confirmed all wires are tight and in place. I originally had a set that I had to put the end on and clamp it, but replaced it with a pre-done set when I bought all the other parts and plugs.

there was a pretty good sized flame that shot out of the tailpipe and a huge bang.

[datzenmike]

This would indicate to me that the ignition is being shut off to all plugs briefly. Try the timing light on different wires and see if they are firing only part of the time.

[CameronT]

I have put the timing light on the other wires and they were firing fine, I haven't tried since this last round though

[datzenmike]

Sorry if I hammer away on these points but you have to admit everything should work but doesn't so something has been overlooked or assumed.

[distributorguy]

Ohm your plug wires.  High resistance in the offending wire could be the cause, as could wear in the shaft bushing in the distributor.  Check for under 5000 Ohms in each plug wire, then check for ANY side play in the distributor shaft.  Zero perceptible play is acceptable, no more.  

[DanielC]

Putting a four cylinder engine together is more critical with the distributor, and drive installation.  A lot of four cylinder distributors only fit the distributor drive in one position.  

The relation ship between the distributor rotor, and the cap changes, depending on the engine RPM, and vacuum advance.   The cap is attached to the distributor body, and that is bolted to the engine and once the timing is set, it does not move. 

As the engine speeds up, the cam, or rotor on the distributor shaft are moved forward, in relation ship to every thing else on the distributor.  This makes the rotor under the cap point slightly ahead of the contact for the spark plug wire. 

If the engine is running with a very light load, the vacuum advance pulls the plate inside the distributor backwards.  This plate holds the points, or the electronic ignition stator, or pick up, and this too makes the rotor under the cap point slightly ahead of the contact for the spark plug wire. By the way, the tip of the cap rotor does not touch the contacts inside the distributor cap, it is just close.  The high voltage jumps the gap.

 

On a four cylinder engine, if the distributor is clocked a gear tooth or two off, the distributor cap rotor can end up between two spark plug wire contacts, that are 90 degrees apart, and a wrong plug will fire, or no plugs will fire.  On a V-8 engine, there is usually enough adjustment that you can move the distributor body enough to get a spark plug wire contact by the rotor, because the towers on the distributor cap are only 45 degrees apart, and there is usually enough rotation in the distributor body mounting to make it work.  

 

On a Datsun L-engine, there is a limited amount you can turn the distributor body.  The distributor will only fit it's drive spindle one way.  All this means you have to get the drive spindle into the engine in the right position.  If it is off a tooth on the gear, you might be able to get the engine to start, and run, but the cap rotor might be close enough to the correct spark plug wire contact to work sometimes, but when advance is added, the rotor tip moves too far away to jump the bigger gap reliably.