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GMC V6 and V12 Engines Engine repair and rebuilding

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  #11  
Old April 10th, 2014, 03:52 AM
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GMCDAC GMCDAC is offline
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Default Re: #6 not firing with eBay HEI, any ideas?

Quote:
Originally Posted by bigblockv6 View Post
For those that want to maintain the stock look the Pertronix kit is a good alternative, easy start up just like the HEI but not quite as potent.
I was wondering about that but didn't want to mouth off since I don't have a V-6 GMC. Didn't know if one was available. I had issues with my '55 GMC keeping dwell so I bought the Pertronix conversion--under 100 bucks, and it has been smooth as silk since. I didn't even have to pull the distributor to do the conversion but I did anyway just to feel the bushings and side play. The engine is a mid sixties 230 inliner.

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1970 GMC K5 Jimmy Mom drove 30 years
1972 GMC C2500 owned since 1979
1955 GMC 100 driver-project
2006 GMC Yukon Denali---wife's truck

Hope to have a '60 GMC Suburban again someday
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  #12  
Old April 10th, 2014, 12:43 PM
turbobill turbobill is offline
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Default Re: #6 not firing with eBay HEI, any ideas?

Over the years, I've had many interesting problems with distributor caps, rotors and wires. From rotors that short to ground (spark from the coil but not to any plug wire), open/shorted distributor terminals (no spark at that wire), no spark at a cylinder period (open or shorted wire) to the normal assortment of cracked and/or carbon tracked caps.

One interesting case happened on my '68 Buick Wildcat returning home from Florida. 500 miles from home, it developed an intermittent skip. No spark to one particular distributor terminal. Turns out the distributor bushing was worn enough that occasionally the distributor shaft would wobble and the breaker points to one particular cylinder wouldn't open, thus no spark. An HEI shouldn't suffer the same problem.

This being said, if your timing light is not being triggered by current flow in a particular wire, don't rule out a very high resistance or open spark plug as well. Eveything in that particular circuit becomes suspect.

As for the points verses HEI or other electronic ignition, I only have one old vehicle converted to HEI (a 427 Chevy). It has been reliable, but when I take the car on a long trip, I carry a spare stock distirbutor/coil/wires just in case. To be at the mercy of a tow company/garage on the road is asking for bankrupcy.

Besides, a lot of people drove a lot of miles over the years with breaker points and carburetors, me being one of them.

Last edited by turbobill; April 10th, 2014 at 12:53 PM.
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  #13  
Old April 10th, 2014, 02:13 PM
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aphaynes aphaynes is offline
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Default Re: #6 not firing with eBay HEI, any ideas?

Quote:
Originally Posted by bigblockv6 View Post
For those that want to maintain the stock look the Pertronix kit is a good alternative, easy start up just like the HEI but not quite as potent.
Where can I find more info on this kit?
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  #14  
Old April 10th, 2014, 02:21 PM
melmashman melmashman is offline
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Default Re: #6 not firing with eBay HEI, any ideas?

I actually had the Pertronix kit put in the distributor along with the recommended new coil. I really do not know the difference between doing this and going with a HEI. Perhaps the HEI replaces the distributor itself?
In the past I always had to use the choke at start-up. Now I only use it if I have started it in several weeks. It am a much happier camper thus far.
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  #15  
Old April 10th, 2014, 03:24 PM
BarryGMC BarryGMC is offline
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Default Re: #6 not firing with eBay HEI, any ideas?

The main reason I don't recommend the aftermarket hei is that it's made up of offshore junk. And is not better than the stock dizzy. Second reason is if the stock dizzy is reconditioned or in good shape it's really reliable and simple to maintain. Now the pertronix is not really an hei it's just an electronic pick up sensor with a good coil. You don't really need the coil though. They work fine with a stock coil. But the pertronix is known to fail and does have a failure rate that is less than ideal. Note I do run some of there stuff, but always carry a spare or the stock points. And most of the time the pertronix has to be ordered. Now I have to add I have spent countless hours playing and modifying with the big v 6 engines. Most mods did nothing or very little in the low to mid range where I was trying to build torque and hp. I have had some success and did manage over a hundred hp and 140 pounds of torque increase a 3500 rpm. With a 305. I still have this engine. And will posts some pics and specs one of these days. Barry
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  #16  
Old April 10th, 2014, 03:43 PM
turbobill turbobill is offline
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Default Re: #6 not firing with eBay HEI, any ideas?

I recall many years ago, in one of the car magazines (Hot Rod or something similar) a comparison test of an HEI and a stock points type distributor. There was no difference in HP or torque.

That being said, I have nothing against the HEI or any electronic conversion. I generally stay with original points (with the one exception).
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  #17  
Old April 10th, 2014, 03:49 PM
Irishbleueyes Irishbleueyes is offline
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Default Re: #6 not firing with eBay HEI, any ideas?

http://www.pertronix.com/ Xlnt product, I used those for yrs in VW's without fail. Simple conversion but not as powerful as an HEI.
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  #18  
Old April 10th, 2014, 03:51 PM
Irishbleueyes Irishbleueyes is offline
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Default Re: #6 not firing with eBay HEI, any ideas?

Low compression engines need the extra ignition help...
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  #19  
Old April 10th, 2014, 04:23 PM
BarryGMC BarryGMC is offline
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Default Re: #6 not firing with eBay HEI, any ideas?

It's actually just the opposite. Higher fuel charge densities. Or higher compression require greater spark energy to fire. This with lean fuel ratios is the reason you need hei ignition. Since the v6 really has neither you won't gain any hp over a good points system.
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  #20  
Old April 10th, 2014, 04:56 PM
klausz klausz is offline
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Default Re: #6 not firing with eBay HEI, any ideas?

There is one reason why I really like my GMC,it is very simple and it has no hard to understand mysteries.Black Box ,the end of the world as we known it.The real basic ignition system is one of the better arguments for the trucks.Point sets usually come with condensers for a reason,change it all together and you are good.On the road you can set points with a screwdriver and eyeballs.Black Box is go or no go.
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