140 3 liter mercruiser yet again

[rolmops]

Ok. So I found a good block -a 1987 chevy 3 liter-replaced its guts and everything looks dandy. The points ignition was replaced with an AC Delco electronic ignition and the timing was set with a timing shunt according to the specs at 1 past top of cylinder, which is base time for these engines. After removing the shunt,the engine runs great. Now comes my question.
I checked the timing without the shunt and it is somewhere around 12 before top of cylinder, while the timing specs for the regular distributor would be 6 before top of cylinder. should I leave things be or should I reset to 6 before top of cylinder?
This engine finally made me understand the concept of 4 stroke, now I just have to learn to work with it instead of on it.
Cornelis.

 

[achris]

Re: 140 3 liter mercruiser yet again

Sounds about normal to me...

Welcome to the dark side...

Chris.....

 

[Bondo]

Re: 140 3 liter mercruiser yet again

Ok. So I found a good block -a 1987 chevy 3 liter-replaced its guts and everything looks dandy. The points ignition was replaced with an AC Delco electronic ignition and the timing was set with a timing shunt according to the specs at 1 past top of cylinder, which is base time for these engines. After removing the shunt,the engine runs great. Now comes my question.
I checked the timing without the shunt and it is somewhere around 12 before top of cylinder, while the timing specs for the regular distributor would be 6 before top of cylinder. should I leave things be or should I reset to 6 before top of cylinder?
This engine finally made me understand the concept of 4 stroke, now I just have to learn to work with it instead of on it.
Cornelis.

Ayuh,.... That's the ignition system, doin' it's job,.... aka; the reason for the shunt,....

Good luck with yer build,....

 

[fishrdan]

Re: 140 3 liter mercruiser yet again

I checked the timing without the shunt and it is somewhere around 12 before top of cylinder, while the timing specs for the regular distributor would be 6 before top of cylinder.

12* BTDC at idle is normal for an EST ignition in a 3.0, sounds spot-on. For whatever reason, the EST ignition runs more initial timing and less advance, opposed to the old points distributor that runs less initial timing and more advance. They work out to be about the same total advance in the upper RPM range.

(EST runs a tad less total timing, compared to points dizzy's...... for whatever reason.)