| HEI Teardown [message #307798] |
Sun, 25 September 2016 17:23  |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Senior Member |
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What started as cap and rotor ended up full take apart. The advance mechanism was not frozen but damped by old grease. The heat sink compound had turned to something else and mostly vanished. I flushed the wick and used Synpower to saturate it. Is that correct or is engine oil better? The protective yellow wrapping on the pickup coil is now dust. I will pick up a new pickup tomorrow hopefully. I found written inside the body in red marker OP or perhaps DP? How does Dick Patterson mark his work? Last thing I noticed the vac pot seems to be at a slight upward angle as it gets away from the body. Is this how they are or is it bent? Keep in mind coach ran fine but want to prevent preventable breakdowns. I figure if the module lasted almost dry it should be fine with fresh heat sink compound.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: HEI Teardown [message #307829 is a reply to message #307798] |
Mon, 26 September 2016 00:01  |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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Senior Member |
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I always use a dab hi temp grease on the advance mechanism. Keep in mind when you replace the pickup coil it needs to be matched to the coil. There are two choices of pickup coil and 2 choices of coil they can be identified bY the color of the leads . I think one color is yellow and the other is red .if I remember right the yellow is non California and the other is California . The vacuum pot should be stamped for the total vacuum advance. I use a pot stamped 10 degrees and use weights and lighter springs to give a quicker advance and total mechanical advance of around 33-36 total mechanical advance including initial at around 2500 rpm.the stock pot I believe is around 18-20 degrees which is too much if you modify the mechanical advance more aggressively.
Roy Keen
Minden,NV
76 X Glenbrook
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| Re: HEI Teardown [message #307836 is a reply to message #307798] |
Mon, 26 September 2016 04:14 |
Chris Tyler
Messages: 458
Registered: September 2013
Location: Odessa FL
Karma: 7
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Senior Member |
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Yes if you add initial and speed up the curve you will have too much vac advance. You can also install an adjustable vac advance avail from several sources. The adjustment limits the travel and is via a hex screw inside the vac port.
Or, the low buck way to limit advance is to braze a limit on the travel slot. Trust me, the adjustable unit is easier.
A caveat: If you arent willing or able to do the tuning to optimise your combination, leave it stock
76 Glenbrook
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| Re: [GMCnet] HEI Teardown [message #307839 is a reply to message #307836] |
Mon, 26 September 2016 07:35 |
Bruce Hart
Messages: 1501
Registered: October 2011
Location: La Grange, Wyoming
Karma: 5
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Senior Member |
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It is my understanding on the colors of the pick up coil (and ignition
coil) was red and yellow for passenger side starters vs white and red for
driver side starters. This was for proper polarity.
On Mon, Sep 26, 2016 at 3:14 AM, Chris Tyler
wrote:
> Yes if you add initial and speed up the curve you will have too much vac
> advance. You can also install an adjustable vac advance avail from several
> sources. The adjustment limits the travel and is via a hex screw inside
> the vac port.
>
> Or, the low buck way to limit advance is to braze a limit on the travel
> slot. Trust me, the adjustable unit is easier.
>
> A caveat: If you arent willing or able to do the tuning to optimise your
> combination, leave it stock
>
>
> --
> 76 Glenbrook
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Bruce Hart
1976 Palm Beach
Milliken, Co
GMC=Got More Class
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Bruce Hart
1976 Palm Beach
1977 28' Kingsley
La Grange, Wyoming
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| Re: HEI Teardown [message #307889 is a reply to message #307798] |
Mon, 26 September 2016 19:12 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Senior Member |
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The pu coil leads are faded and look blue and pink. So no Idea what I have but it ran fine. The GMCMI parts interchange is very confusing as it blurs pu coils and hi tension coils in one heading. The Delco pu D1908 is disco. I have Standard DR-32 pu on order. I plan to coat the bare windings on my pu coil with GOOP to replace the factory coating that has died. I will reinstall and keep the Standard for emergency. As far as Murphy he can go screw himself. I tempted him by installing new bearings and brushes in my 80 Amp Delcotron and he did not raise his ugly head on 2 x 10 hour drives so far. My weights are numbers down which seems wrong as it puts a rough surface to the rub buttons. But I put them back that way. There is a light film of Synpower on all moving parts now.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: [GMCnet] HEI Teardown [message #308003 is a reply to message #307964] |
Thu, 29 September 2016 08:30 |
Kosier
Messages: 834
Registered: February 2008
Karma: 1
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Senior Member |
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Sorry, Emery, but I have to disagree here. My GM training manual says the
reason for the polarity difference is the side of the engine
that the starter is mounted on. Hence the Toro and pass cars being opposite
in polarity. Oddly enough, if you move the secondary
ignition coil out of the cap, it makes no difference which polarity the
components have. Since I could never understand magnetism,
I just accept these things as facts and move on.
Gary Kosier
77PB w/500Cad
Newark, Ohio
--------------------------------------------------
From: "Emery Stora"
Sent: Wednesday, September 28, 2016 4:56 PM
To:
Subject: Re: [GMCnet] HEI Teardown
> It has nothing to do with California and non-California.
>
> GM found out that they had a problem with the GMC (Oldsmobile) and the
> other GM units Cadillac, Buick, etc. It was due to the rotation direction
> of the distributors.
> So they used a different polarity for the two different sets of coils and
> pickup coils. On one the ignition coil has Black-Red-White leads (white
> to tach). and the pickup coil had a black plastic connector body (or a
> blue tie wrap).
> The other uses a Black-Red-Yellow (yellow to tach) with the pickup coil
> with a yellow plastic connector body (or a yellow tie wrap).
>
> You could use either set on the GMC motorhome but don’t mix the coil and
> the pickup coil with the opposite ones. It can cause a jittery running
> engine (misfires).
>
> If you have to replace the coil or the pickup coil check the color of the
> wires on the other part and look in the box at the auto parts store to be
> sure you have the right match.
> Otherwise the clerk at the auto parts will just pull a box off the shelf
> and you have a 50% chance of it being wrong.
>
> Emery Stora
> 77 Kingsley
> Frederick, CO
>
>> On Sep 26, 2016, at 1:01 AM, Nv '76 Glenbrook
>> wrote:
>>
>> I always use a dab hi temp grease on the advance mechanism. Keep in mind
>> when you replace the pickup coil it needs to be matched to the coil.
>> There
>> are two choices of pickup coil and 2 choices of coil they can be
>> identified bY the color of the leads . I think one color is yellow and
>> the other is
>> red .if I remember right the yellow is non California and the other is
>> California . The vacuum pot should be stamped for the total vacuum
>> advance. I
>> use a pot stamped 10 degrees and use weights and lighter springs to give
>> a quicker advance and total mechanical advance of around 33-36 total
>> mechanical advance including initial at around 2500 rpm.the stock pot I
>> believe is around 18-20 degrees which is too much if you modify the
>> mechanical
>> advance more aggressively.
>> --
>> Roy Keen
>> Minden,NV
>> 76 X Glenbrook
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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| Re: [GMCnet] HEI Teardown [message #308007 is a reply to message #308003] |
Thu, 29 September 2016 10:47 |
emerystora
Messages: 4442
Registered: January 2004
Karma: 13
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Senior Member |
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As I said you can use either set but don't mix them. This information actually came from Duane Simpson years back. He said it was a polarity problem depending on the direction the coils were wound
Emery Stora
> On Sep 29, 2016, at 9:30 AM, Gary Kosier wrote:
>
> Sorry, Emery, but I have to disagree here. My GM training manual says the reason for the polarity difference is the side of the engine
> that the starter is mounted on. Hence the Toro and pass cars being opposite in polarity. Oddly enough, if you move the secondary
> ignition coil out of the cap, it makes no difference which polarity the components have. Since I could never understand magnetism,
> I just accept these things as facts and move on.
>
> Gary Kosier
> 77PB w/500Cad
> Newark, Ohio
>
> --------------------------------------------------
> From: "Emery Stora"
> Sent: Wednesday, September 28, 2016 4:56 PM
> To:
> Subject: Re: [GMCnet] HEI Teardown
>
>> It has nothing to do with California and non-California.
>>
>> GM found out that they had a problem with the GMC (Oldsmobile) and the other GM units Cadillac, Buick, etc. It was due to the rotation direction of the distributors.
>> So they used a different polarity for the two different sets of coils and pickup coils. On one the ignition coil has Black-Red-White leads (white to tach). and the pickup coil had a black plastic connector body (or a blue tie wrap).
>> The other uses a Black-Red-Yellow (yellow to tach) with the pickup coil with a yellow plastic connector body (or a yellow tie wrap).
>>
>> You could use either set on the GMC motorhome but don’t mix the coil and the pickup coil with the opposite ones. It can cause a jittery running engine (misfires).
>>
>> If you have to replace the coil or the pickup coil check the color of the wires on the other part and look in the box at the auto parts store to be sure you have the right match.
>> Otherwise the clerk at the auto parts will just pull a box off the shelf and you have a 50% chance of it being wrong.
>>
>> Emery Stora
>> 77 Kingsley
>> Frederick, CO
>>
>>> On Sep 26, 2016, at 1:01 AM, Nv '76 Glenbrook wrote:
>>>
>>> I always use a dab hi temp grease on the advance mechanism. Keep in mind when you replace the pickup coil it needs to be matched to the coil. There
>>> are two choices of pickup coil and 2 choices of coil they can be identified bY the color of the leads . I think one color is yellow and the other is
>>> red .if I remember right the yellow is non California and the other is California . The vacuum pot should be stamped for the total vacuum advance. I
>>> use a pot stamped 10 degrees and use weights and lighter springs to give a quicker advance and total mechanical advance of around 33-36 total
>>> mechanical advance including initial at around 2500 rpm.the stock pot I believe is around 18-20 degrees which is too much if you modify the mechanical
>>> advance more aggressively.
>>> --
>>> Roy Keen
>>> Minden,NV
>>> 76 X Glenbrook
>>>
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
_______________________________________________
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| Re: HEI Teardown [message #308008 is a reply to message #307798] |
Thu, 29 September 2016 10:53 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Senior Member |
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It appears the PU coil is disco from Delco and Standard only has one type- which I think is the wrong type for TZE. Some research and cleanup of the Parts interchange is needed in this category, but need the correct info first. Disco items should be listed but marked disco, in case you break down in a small town the disco item might be sitting on a dusty shelf.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: HEI Teardown [message #308024 is a reply to message #307798] |
Thu, 29 September 2016 17:43 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Senior Member |
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Standard appears to have the LX-303 with I think is RWD but not the LX-302 for the TZE.
John Lebetski
Woodstock, IL
77 Eleganza II
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