No spark from coil chevy 350

[JP6438]

Good evening, and thanks in advance for any assistance. I have a 5.7 carbureted Chevy 350 I just built from a long block, and am trying to get running on the floor before reinstalling in the boat. I have 2 issues that i would appreciate any assistance with.
(1) I put a new Arco starter on, but the engine turns very slowly for only a couple of seconds, then peters out. I am wondering if my temporary cables are too small? Or because the engine is "tight" from being new?
(2) I have an aftermarket coil that has worked fine for years, and Pertronix in the Mallory Dsitributor. I can not see any spark from the coil (pulled the wire from the distributor and held to metal), although the coil gets very warm. Am i missing a secondary wire connection somewhere, somehow?

I have the coil connected directly to the battery with the hot side wire, is the coil supposed to be grounded to the block as well? I have the black and red (+/-) wires from the distributor connected to the coil. Should it be connected to the starter in some fashion?

I suppose the diffuculty is that I am doing this without the harness, which is still on board the boat, along with my diagrams and notes- 2 hours away. However, I would like to run the engien prior to putting it in the boat for obvious reasons.

Thanks very much for your input and direction!

 

[V-Tech]

Re: No spark from coil chevy 350

Your cranking engine issue could very well be the temporary cables you are using. In fact, since it cranks initially and then peters out suggests high resistance in the connections or small diameter conductors. As for no spark, when you say you grounded the coil, do you mean to the negative terminal of the coil or the housing of the coil? The + positive terminal should get battery power when the ignition is on. The - negative connector goes to the ingnition system, not directly to ground. If you have it grounded directly that would explain why it is getting hot. You probably need the harness.

 

[lonemust]

Re: No spark from coil chevy 350

If you grounded the neg terminal of the coil to the battery or the block. go buy a new coil. you fried it.. the wire from the the distributer goes to the neg side of coil.. pos to the battery.. As for slow turning. use bigger cables and make sure the battery is fully charged

 

[jmorgan87]

Re: No spark from coil chevy 350

What gauge are your temporary cables? Using smaller than intended cables,or loose cables on a starter can cause a fire. When it's 'petering' out, those cables are most likely getting very hott where they connect to the starter. I've had a loose starter cable catch fire on an old camaro.

+ from coil to battery
- from coil to dist

I believe petronix hooks up similar, + to + off coil, and black wire to - off coil. But I could be wrong, it's been a while since I looked at those.

I'd get a new coil though, if you grounded the - post to the battery or engine.

 

[JP6438]

Re: No spark from coil chevy 350

Guys- Thanks very much for your input. I went down and got the harness from the boat and intalled it. Then i got a big fat 2 gauge hot cable from the battery to the starter. Ran a jumper from slave solenoid to hot side of coil, and vrrrooooommm! What was confusing was that somewhere during the prevous owners over the past 35 years, someone changed the color of some of the wires in the harness, and it didn't match the diagram in the manual. And BTW, the coil was still good! Thanks again