HEI - Rebuild or replace with new - The 1947 - Present Chevrolet & GMC Truck Message Board Network

snowblind · 01-05-2010, 11:15 PM

My HEI gave up the ghost last night. I have 12v to the dizzy but no spark at the plugs. It's probably the coil or the module that has failed. From what I've read it's best to replace the cap, rotor, coil and module all at the same time but Napa wants close to $150 for those parts.

So... looking at Summit I can get a rebuild/upgrade kit for $72 or an entirely new Summit HEI distributor for $92 or one of the "Skip White" ones for $55.

Is there any reason to rebuild the stock unit versus buying a new one?

Thanks.

1949gmc · 01-05-2010, 11:42 PM

I'd say, unless you have a reason to replace the entire distributor, just go for the upgrade. That way you don't have to reset the timing... not that resetting the timing is hard, but if you don't have a timing light, it's difficult to do. Of course, 55 beans for a new HEI is hard to beat.

snowblind · 01-05-2010, 11:57 PM

Quote:

Originally Posted by 1949gmc

I'd say, unless you have a reason to replace the entire distributor, just go for the upgrade. That way you don't have to reset the timing... not that resetting the timing is hard, but if you don't have a timing light, it's difficult to do. Of course, 55 beans for a new HEI is hard to beat.

My thoughts also... I've read some install instructions that say you can sometimes get it perfect by marking the position of the old rotor and vac advance before removal and then matching them on install. We all know how that could go though!

I would need to buy a timing light but then I would have one so it's not like money wasted.

packers05 · 01-06-2010, 12:04 AM

just time it by ear ,just as good as a light if you are patient, my engine has no timing pointer and it runs like mother.

snowblind · 01-06-2010, 02:25 PM

I ordered a new dizzy and a rebuild kit from Skip White. Prices have come down an the dizzy was less than $50 and the kit was $25 for cap, rotor, coil and module. I figure I 'll swap the rebuild stuff into my old GM unit first and then put in the new dizzy when the weather warms up.

I will report back after the weekend.

piecesparts · 01-06-2010, 04:19 PM

There are two possibilities for your NO SPARK issue. #1, the module inside the dizzy went bad---that would be my first choice and by far the easiest to change out. Remember to put a coating of Die-Electric grease under the module. #2 The pick up coil at the base of the dizzy (inside the cap) can go bad---been there, seen that. This will require the dizzy to be pulled from the engine and the center shaft pulled out of the housing. I would try this ONLY if the module changeout does NOT work. As for the rest of the dizzy parts, I would consider the cap and rotor while you are there.

OhOneWS6 · 01-06-2010, 09:13 PM

Quote:

Originally Posted by piecesparts

There are two possibilities for your NO SPARK issue. #1, the module inside the dizzy went bad---that would be my first choice and by far the easiest to change out. Remember to put a coating of Die-Electric grease under the module. #2 The pick up coil at the base of the dizzy (inside the cap) can go bad---been there, seen that. This will require the dizzy to be pulled from the engine and the center shaft pulled out of the housing. I would try this ONLY if the module changeout does NOT work. As for the rest of the dizzy parts, I would consider the cap and rotor while you are there.

There are more that 2 reasons for no spark. Bad coil or busted carbon button just to name a couple more.

BAGNDRAGIT · 01-06-2010, 10:51 PM

Quote:

Originally Posted by packers05

just time it by ear ,just as good as a light if you are patient, my engine has no timing pointer and it runs like mother.

problem with that is not everyone can do that, i did it with mine, and yes it screams, but there are more factors than just timing. like carb adjustment.

but if your up to it, go for it, once you do it you will be invaluable in a situation as such, as i have been lol.

67slammer · 01-07-2010, 07:24 AM

at our shop we have used the hei distributors off ebay. we have been buying them for $51 shipped to the door and they work great. its not worth rebuilding one when you can buy new that cheap. mike

snowblind · 01-13-2010, 03:47 PM

OK...

The new distributor is in. I got it started and it idles OK but stumbles when you try to drive. It doesn't die but it runs very poorly.

Seems like it's running best with the dizzy rotated clockwise until the vac canister almost hits the trans dipstick... and I think it might benefit from MORE turning. If I rotate counterclockwise it quickly starts to backfire on one cylinder on the passenger side.

Do I need to pull the dizzy and put it in with the housing rotated to give more clockwise adjustment? The rotor on the new dizzy went in a little "off" in that it dropped in a few degrees more "clockwise" than the original.

Camaro_nut2001 · 01-13-2010, 03:55 PM

Hello, you could pull it out and set it back a tooth or you could just move your plug wires back one. I think it would be easier to move the wires. JMO.

snowblind · 01-13-2010, 04:06 PM

Quote:

Originally Posted by Camaro_nut2001

Hello, you could pull it out and set it back a tooth or you could just move your plug wires back one. I think it would be easier to move the wires. JMO.

So I would "rotate" the plug wires clockwise?

That's great advise. I'm just trying to smooth it out a bit so I can drive and get a timing light.

mr48chev · 01-13-2010, 04:36 PM

Quote:

Originally Posted by snowblind

So I would "rotate" the plug wires clockwise?

That's great advise. I'm just trying to smooth it out a bit so I can drive and get a timing light.

Move the rotor to the correct spot and be done with it, it isn't that hard an it avoids hassles down the road when someone is trying to figure out which wire is #1.

It isn't that hard to do it right and doing it any other way is just flat being lazy.

Usually before I pull a distributor I will mark the location of the rotor an mark the location of the advance canister.

When I put the distributor back I line the rotor up with the mark and the advance up close to it's mark and set it in. If it doesn't drop I will crank the engine over and let the shaft drop down on the oil pump drive. Then usually I'll bump it over so the Timing marks are lined up and set the distributor so that the rotor is at number one, If I miss, I pull it out and move it a tooth. And repeat. No biggie, Rome wasn't built in a day and a few more minutes won't kill me if I have it right.

I've got one of the HEIs that Skip White sells on Ebay and it was one of the best things I did to my 71. It makes all the world of a difference on starting the engine and I feel like I picked up noticeable gas mileage. That means between one and two mpg but that is noticeable on our trucks.

snowblind · 01-13-2010, 04:56 PM

Quote:

Originally Posted by mr48chev

Usually before I pull a distributor I will mark the location of the rotor an mark the location of the advance canister.

When I put the distributor back I line the rotor up with the mark and the advance up close to it's mark and set it in. If it doesn't drop I will crank the engine over and let the shaft drop down on the oil pump drive.

I did this but when I dropped in the new dizzy the rotor rotated a little past the marks I had set up, taking away some of my clockwise rotation. I was scared of cranking the engine with the gears not properly meshed.

I moved the wires and it gave me room to play and get it to run a little better. There may even be enough adjustment with the wires in the correct place.

I need to get a timing light.

piecesparts · 01-13-2010, 07:59 PM

Quote:

Originally Posted by snowblind

I did this but when I dropped in the new dizzy the rotor rotated a little past the marks I had set up, taking away some of my clockwise rotation. I was scared of cranking the engine with the gears not properly meshed.

I moved the wires and it gave me room to play and get it to run a little better. There may even be enough adjustment with the wires in the correct place.

I need to get a timing light.

Yeah, you do need one. I really hate the timing by ear. It is good for the trip home, but it is not the right way. I personally would pull the dizzy out and rotate it and the oil pump shaft slightly and drop it back in. You will be happier in the end. Also when you time the engine, go for a little more advance to get the power curve up a little.

snowblind · 01-14-2010, 12:53 PM

I ended up swinging by a local garage and had them check the timing. It looks like I had the dizzy in 2 or 3 teeth off so they pulled it out, pulled the #1 spark plug and had me bump over the engine with the starter 5 or 6 times. (I'm guessing this is a method of finding TDC?)

I was already running HEI before but it was "well used". With the new dizzy the truck runs and revs much smoother.

01-06-2010, 12:04 AM	#4
packers05 Registered User Join Date: Feb 2009 Location: minonk illinois Posts: 224	Re: HEI - Rebuild or replace with new just time it by ear ,just as good as a light if you are patient, my engine has no timing pointer and it runs like mother.

01-06-2010, 02:25 PM	#5
snowblind Registered User Join Date: Oct 2009 Location: SLC, Utah Posts: 164	Re: HEI - Rebuild or replace with new I ordered a new dizzy and a rebuild kit from Skip White. Prices have come down an the dizzy was less than $50 and the kit was $25 for cap, rotor, coil and module. I figure I 'll swap the rebuild stuff into my old GM unit first and then put in the new dizzy when the weather warms up. I will report back after the weekend. __________________ Matt '72 Jimmy Build

01-06-2010, 04:19 PM	#6
piecesparts Parts and more parts Join Date: Nov 2003 Location: Lebo, Kansas (middle of nowhere Posts: 6,821	Re: HEI - Rebuild or replace with new There are two possibilities for your NO SPARK issue. #1, the module inside the dizzy went bad---that would be my first choice and by far the easiest to change out. Remember to put a coating of Die-Electric grease under the module. #2 The pick up coil at the base of the dizzy (inside the cap) can go bad---been there, seen that. This will require the dizzy to be pulled from the engine and the center shaft pulled out of the housing. I would try this ONLY if the module changeout does NOT work. As for the rest of the dizzy parts, I would consider the cap and rotor while you are there. __________________ Frank

01-07-2010, 07:24 AM	#9
67slammer Registered User Join Date: Jan 2008 Location: muncy pa Posts: 425	Re: HEI - Rebuild or replace with new at our shop we have used the hei distributors off ebay. we have been buying them for $51 shipped to the door and they work great. its not worth rebuilding one when you can buy new that cheap. mike __________________ 67 short bed stepside tach tilt buddy buckets bagged sittin on 20s and 4w disc brakes (not quite finnished)

01-13-2010, 03:47 PM	#10
snowblind Registered User Join Date: Oct 2009 Location: SLC, Utah Posts: 164	Re: HEI - Rebuild or replace with new OK... The new distributor is in. I got it started and it idles OK but stumbles when you try to drive. It doesn't die but it runs very poorly. Seems like it's running best with the dizzy rotated clockwise until the vac canister almost hits the trans dipstick... and I think it might benefit from MORE turning. If I rotate counterclockwise it quickly starts to backfire on one cylinder on the passenger side. Do I need to pull the dizzy and put it in with the housing rotated to give more clockwise adjustment? The rotor on the new dizzy went in a little "off" in that it dropped in a few degrees more "clockwise" than the original. __________________ Matt '72 Jimmy Build

01-05-2010, 11:15 PM	#1
snowblind Registered User Join Date: Oct 2009 Location: SLC, Utah Posts: 164	HEI - Rebuild or replace with new My HEI gave up the ghost last night. I have 12v to the dizzy but no spark at the plugs. It's probably the coil or the module that has failed. From what I've read it's best to replace the cap, rotor, coil and module all at the same time but Napa wants close to $150 for those parts. So... looking at Summit I can get a rebuild/upgrade kit for $72 or an entirely new Summit HEI distributor for $92 or one of the "Skip White" ones for $55. Is there any reason to rebuild the stock unit versus buying a new one? Thanks. __________________ Matt '72 Jimmy Build

01-05-2010, 11:42 PM	#2
1949gmc Registered User Join Date: Nov 2004 Location: Lindenhurst, IL Posts: 659	Re: HEI - Rebuild or replace with new I'd say, unless you have a reason to replace the entire distributor, just go for the upgrade. That way you don't have to reset the timing... not that resetting the timing is hard, but if you don't have a timing light, it's difficult to do. Of course, 55 beans for a new HEI is hard to beat.

01-13-2010, 03:55 PM	#11
Camaro_nut2001 Chevy Lover Till The End. Join Date: Dec 2009 Location: Mascot TN. Posts: 795	Re: HEI - Rebuild or replace with new Hello, you could pull it out and set it back a tooth or you could just move your plug wires back one. I think it would be easier to move the wires. JMO.

01-14-2010, 12:53 PM	#16
snowblind Registered User Join Date: Oct 2009 Location: SLC, Utah Posts: 164	Re: HEI - Rebuild or replace with new I ended up swinging by a local garage and had them check the timing. It looks like I had the dizzy in 2 or 3 teeth off so they pulled it out, pulled the #1 spark plug and had me bump over the engine with the starter 5 or 6 times. (I'm guessing this is a method of finding TDC?) I was already running HEI before but it was "well used". With the new dizzy the truck runs and revs much smoother. __________________ Matt '72 Jimmy Build



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