The stator has both batt charge windings and coils for charging the ignition system
Printable View
The last of the in line 6 Mercs ran the same ignition as the V-6. It is not a drop in for the belt driven CDI systems as the block is cut a 1/16 shorter on the top end cap surface. As stated, the flywheel and stator winding's produce both battery charging and ignition charging outputs. The trigger is in the center of the stator windings and locked in the full advanced position by the link rod on the left side just under the flywheel. Timing is set with the old fashion timing light with degree marks laid out on the flywheel.
The CDI system is more than enough for the Mark engines. It is what we ran on the alcohol burning 6's back in the day. There are plenty of those parts floating around. The only difference in the green switch boxes was the tach sender signal, 4 vs 6. Not using tach signal, run either box.
Thanks. Good Keeper File info.
I run one of those belt drive CDI systems on my Mark 78, but I must disagree with you that parts are plentiful. Getting hard to find a good used distributor (trigger) for these.
Jeff
The only part that may be a problem is the trigger if you are using the first version that had a bolt in replaceable unit. The later units used a potted tower section. Three different lengths. 3, 4 & 6 cylinder, pick your length and use 6 cylinder chopper wheel. RePair did rebuild those triggers.
I'm currently using a 4 cylinder unit with the 6 cylinder chopper wheel. It works fine, but I'd love to get a spare distributor in case....you know. Getting hard to find. CDI sells one, but for nearly 400 bucks!
As a Winter Project I'm going to convert the stock, dual points Mark 78 distributor to electronic using HEI modules from GM cars. One module will work half the cylinders, the other one the rest, with two high performance coils. Should be interesting!
Jeff
With one HEI running 3 cylinders, and the other running the rest, I should easily get 6,000 rpms (think 6 cylinder 4 stroke at 6,000 rpm). Motor tops out before that in any case.
Jeff
[QUOTE=Fastjeff57;152634]With one HEI running 3 cylinders, and the other running the rest, I should easily get 6,000 rpms (think 6 cylinder 4 stroke at 6,000 rpm). Motor tops out before that in any case.
Jeff[/
It isn't how many cylinders as much as it is the processor in the module being able to keep up. At 6 grand on a four cycle is where these things fell off. That is 3 grand on a two stroke as it fires every time not every other like a four stroke. Mad makes some better modules though but not good enough for 10 grand,
Your math is off: Three cylinders (2 stoke) at 6 grand equals 6 cylinders (4 stroke) at 6 grand. I plan to use two HEI modules, each firing 3 cylinders. Got it?
Jeff