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sereneskies65 Samba Member
Joined: January 05, 2011 Posts: 6
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Posted: Sun May 08, 2016 1:11 pm Post subject: GM HEI Module |
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Hello everyone! Just had a question about the MG HEI modules and if anyone is using them in the in the VW world? Ive searched on here but havent fod anything definitive. I have used them for motorcycles in the past and want to try with the VW. I have a 1776 in a type 1. I currently have a Pertronix SVDA distributor with a bosch blue coil and am wondering if it is usable in a conjunction with a GM HEI 4 pin unit and coil.
Some of my concerns are the the amount of resistance needed through the Pertronix points replacement unit, amount of coil resistance needed, and if the stock cap will allow for HEI use as most HEI units have bigger caps due to possible arcing across terminals.
Like I said, Im new to the HEI stuff in cars. Ive only used it for motorcycles, but they dont have distributors so just checking to make sure its possible. Any advice is appreciated!! |
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ps2375 Samba Member
Joined: April 24, 2014 Posts: 2471 Location: Meridian,ID
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Posted: Sun May 08, 2016 1:46 pm Post subject: Re: GM HEI Module |
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I use one, but it inside my HEI dist. I would think it would work with the smaller VW sized cap as with all 8 terminals in the GM cap, they are prolly a similar distance apart. I used to run a higher voltage coil on my water-cooled VW and it had a small cap and it had no problems with arcing. |
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Lingwendil Samba Member
Joined: February 25, 2009 Posts: 3987 Location: Antioch, California, a block from the hood
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modok Samba Member
Joined: October 30, 2009 Posts: 26743 Location: Colorado Springs
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Posted: Sun May 08, 2016 2:33 pm Post subject: Re: GM HEI Module |
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HEI fires going low, so it's backward, and the trigger voltage is something like 1-2 volts
IMO, if you have a VR sensor, sure use HEI, but if you have a hall sensor, use TFI
TFI module fires going high at 5 volts, so it's a lot easier to adapt.
You can make the HEI work with points to a degree by letting it fire backward, but re-indexing the rotor.
I don't think it will work with pertonix or similar because the dwell will be too short backward.
Did you plan to make a circuit to invert the trigger signal?
Pertronix is kids toy quality man, they have a lot of timing variation, and average life of those is around 2 years, best thing to do is save your money.
CB sold a HEI setup with a VR sensor rigged into a bosche distributor, that used the HEI module. Those were not very popular and now rare. DUI also makes a HEI distributor to fit VW, but it's HUGE and expensive. Even before all that, some guys modified HEI distributor to fit a VW too. |
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Sun May 08, 2016 3:36 pm Post subject: Re: GM HEI Module |
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I wonder why my petronix is over 20 years old and still works fine I was thinken about adding a hei module to one of my msd style dist & seeing how it works. I wish I still had some mercury racing modules......many diferent timing curves avaliable... |
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ps2375 Samba Member
Joined: April 24, 2014 Posts: 2471 Location: Meridian,ID
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Posted: Sun May 08, 2016 3:44 pm Post subject: Re: GM HEI Module |
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mark tucker wrote: |
I wonder why my petronix is over 20 years old and still works fine |
Either luck of the draw or the last of when quality mattered.
I tried replacing my 25+yr old aftermarket 4 pin HEI module with a new MSD module w/ built-in adjustable rev limiter, and the car just ran crappy, and it was the same after they "repaired" it under warranty and with the replacement module. So I sold it and went back to the same old module that was in it, runs perfect. Quality seems to be an after thought these days for some manufacturers.. |
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Howard 111 Samba Member
Joined: July 09, 2005 Posts: 1827 Location: Virginia
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Posted: Sun May 08, 2016 4:00 pm Post subject: Re: GM HEI Module |
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My Pertronix was 10 years old when I sold the engine it was in. But compared to how most things are made these days, it was made a long time ago when quality still mattered. _________________ 1973 Karmann Ghia
Turbocharged, Fuel Injected
http://www.thesamba.com/vw/forum/viewtopic.php?t=531270 |
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modok Samba Member
Joined: October 30, 2009 Posts: 26743 Location: Colorado Springs
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Posted: Sun May 08, 2016 7:05 pm Post subject: Re: GM HEI Module |
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Ok fine they last forever if they don't die in the first year or DOA.
How long they live is debatable, apparently. When I say they have large timing variation between cylinders nobody seems to disagree with that, so, it's still a poor choice for a trigger |
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Sun May 08, 2016 9:08 pm Post subject: Re: GM HEI Module |
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I think it has the #3 retard...... I do know if I pull it off&turn it 90 degrees it wont run for shit. just one position on mine.
Ive personaly seen 4 of the empi units doa out of the boxes....scratch that, there was some morons installing 4 of the empi units that never hit a lick so.....probably 1 was bad and the morons fried the other 3. I was amazed they could opperate the door handles. |
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sereneskies65 Samba Member
Joined: January 05, 2011 Posts: 6
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Posted: Wed May 11, 2016 5:50 pm Post subject: Re: GM HEI Module |
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Thanks everyone for the replies! I checked and the pertronix is a hall effect type trigger so it sounds like the TFI would be the way to go with that. I have to agree that the pertronix timing seems to be all over the place. It hasnt run that great since I dropped it in. My old compufire was much better but I forgot to remove it before I sold my baja it was in
My question is just would I have to run shielded wires with the TFI? Also should I change out the blue coil for something else, or is it sufficient to have a benefit?
This seems to be the only way to run a stock looking dist, with an electronic ignition that I can think of. |
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Wed May 11, 2016 8:02 pm Post subject: Re: GM HEI Module |
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try pulling the manetic sleve off and rotating it 90 degrees and see how it runs. do it 3 or 4 times and find the best running posisition. then mark it for that position. |
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modok Samba Member
Joined: October 30, 2009 Posts: 26743 Location: Colorado Springs
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Posted: Wed May 11, 2016 8:45 pm Post subject: Re: GM HEI Module |
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Yep, or find the most retarded one and make that #3
Points trigger the TFI module just fine up to 5500 rpm, maybe a higher depending. I realize that a lot of guys think it is kind of STRANGE to use points as a trigger but it does seem to work fine.
I like to use a stock looking coil that puts out 3x the power of the stock one. It's not too hard to do. The ford coil works too, as you'd expect, and IS very strong.
You can use a CDI with points too, of course, unless you don't like CDI and that's ok too. CDI can work well when done right. Most things work well when done right.
Yeah IMO compufire is better design. |
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Wed May 11, 2016 8:55 pm Post subject: Re: GM HEI Module |
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Ive never checked the tyming varation on mine....I need to getg some good eyeballs first.... I cnat hardly see the strobe flash on my snapon light any more on the aluminum shiney pully....hell I havent checked timing in....5 or more years no detonation and runs just fine. hmm I should probably add some oil to the advance shaft wick/felt....probably forget by tomarow and it works so good why bother it. Ive never had such a maintnance free car before. but then again I was always racing every week or trying something different. I got lazy in my old vw age.now just turn key and go....stop&turn key get out, wash a few times a year. |
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maui Samba Member
Joined: May 16, 2004 Posts: 438
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Posted: Tue May 24, 2016 10:41 pm Post subject: Re: GM HEI Module |
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I run a hei dist on my bug now with a built in hp coil and a pertronix 3 module with a msd and adjustable rev limiter and it works real nice. The hei is made by a company called dui Davies ignition. |
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Lingwendil Samba Member
Joined: February 25, 2009 Posts: 3987 Location: Antioch, California, a block from the hood
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Wed May 25, 2016 10:33 am Post subject: Re: GM HEI Module |
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dist do not eat spark plugs dui(davis unified ignition) has changed names, but is still good stuff.but kinda ugly..... |
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maui Samba Member
Joined: May 16, 2004 Posts: 438
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Posted: Fri May 27, 2016 10:14 am Post subject: Re: GM HEI Module |
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I run msd plug wires and plugs last long time and yes it is big and a strong spark so I get mine at 50 street and 40 race. |
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helowrench Samba Member
Joined: August 27, 2003 Posts: 567 Location: dallas texas
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Posted: Sat Jun 04, 2016 11:08 pm Post subject: Re: GM HEI Module |
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modok wrote: |
Points trigger the TFI module just fine up to 5500 rpm, maybe a higher depending. I realize that a lot of guys think it is kind of STRANGE to use points as a trigger but it does seem to work fine.
Yeah IMO compufire is better design. |
Modok, I am using points as a low current trigger for an aftermarket DIY transistorized ignition. (like $7 shipped from AUS). I have been using them this way for 11 years now on 2 engines, in different vehicles.
The thing I have noticed is that there is zero arcing, making the points contact face last ~forever.
However, 2 things do happen.
at about 35-40K miles, I start seeing a timing scatter above 3000ish rpm, runs kinda weird.
then at 45000 miles or so, the insulator starts breaking down, and it starts shutting itself down.
change points, and problem is gone.
Also, note that you must continue to grease the rub block each oil change, or the gap disappears as the rub block wears away.
I have over 100K miles with this setup on my Ghia. no real performance increase over a freshly adjusted stock setup, but runs that way all of the time, indefinitely. _________________ Current VWs:
70 bug vert for wifey
73Thing bucket o rust
73 914 1.7
12 Passat 2.5 Highway cruiser |
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modok Samba Member
Joined: October 30, 2009 Posts: 26743 Location: Colorado Springs
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Posted: Sun Jun 05, 2016 1:19 am Post subject: Re: GM HEI Module |
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COOL!
Yes that's about the same as my experience. I ran it once long enough the gap went to zero, which did NOT take as long as some have said, but it did take over a year, which is fine with me!
10x less often than keeping points working in top condition. |
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T Hollis Samba Member
Joined: March 30, 2004 Posts: 226 Location: midwest
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Posted: Sun Jun 05, 2016 4:17 am Post subject: Re: GM HEI Module |
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I've used one for years in a 1980 Toyota truck I used to own and it worked great! I'll try and find the wiring diagram and post it. If I remember right they also made a "5" prong module that can be used as a timing retarder on start ups, especially good for higher compression engines. |
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