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pertronix vacuum advance unit snapped off

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FrankE Avatar
FrankE Silver Member Frank Papp
Pleasanton, CA, USA   USA
1979 MG MGB
I'm quite embarrassed (and upset) to post this..but....i was adjusting the timing on my 79 MG (as we've all done a million times..) and grabbed the vacuum advance unit to turn the distributor. The vacuum advance unit snapped off in my hand. Its a pertronix replacement for the 45D; been in place and working fine for ~8yrs. I can't tell if i broke the unit, or if it can be 'snapped' back in place.

Help please...can someone point me to a detailed diagram of the distributor assembly; should i call someone or just put in a whole new distributor ? Picture below.

thanks much
frank

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pinkyponk Avatar
pinkyponk Gold Member Adrian Page
Berwick, Nova Scotia, Canada   CAN
I get the impression from this site that you can't buy parts for these distributors. I'd ask Pertronix anyway for all it would cost to ask. failing a new one... it looks like you can remove the plate it was attached to by taking out the 2 screws. Maybe you can pop rivet it back on from behind? Or JB Weld it?

Adrian



Home built Eaton M62 Supercharger with 9psi boost, "stock" high ratio rocker arms, 8:1 compression, Piper 270 cam, ported head, matched manifolds, CB Performance computerized ignition.

tahoe36c Avatar
tahoe36c Paul Hruza
Panama City, FL, USA   USA
1969 MG MGC GT "Little Red Rocket..."
1972 MG MGB GT "Tiny Dancer"
2002 Harley-Davidson Dyna
X2 with Adrian... Or maybe some high temp epoxy. Some of todays adhesives are very impressive. Just be sure to prep the metal per the instructions.

Gluing it is less expensive than replacing it!

P.S. I will call you this weekend Adrian. Busy at work all this week...

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course2kid Jeffrey Johnson
Fountain Valley, CA, USA   USA
1979 MG MGB "Lucy (Lucifer)"
The mounting bracket and the control arm (not sure what it's really called) look a lot like the vacuum advance on a lucas distributor. Maybe you can ask Jeff Schlemer of Advance Distributors if they are interchangeable. You'll want to make note of the advance numbers on your existing unit. They are the 3 numbers stamped on the unit - example 3 12 5 would mean the vacuum advance starts to advance the timing at 3 psi vacuum and continues to advance up to 10 psi when it reaches a total of 5 degrees at the distributor (10 degrees of crank). I apologize if the pressures are inches of mercury rather than psi - I'm too tired to remember right now.

ohlord Avatar
ohlord Gold Member Rob C
North of Seattle, N.W., USA   USA
1957 Land Rover Series I "EYEYIYI"
1971 MG MGB
1971 MG MGB "Bedouin 2"
It's a cheap $10 clone of a distributor
Generic curve one suits all
Call pertronix if no help
Replace it



"I'm a long way gone down this wild road I'm on
It's gonna take me where I'm bound
It's a long way around"



"These are the days that must happen to you"

RD2 Radar/ Electronic Warfare Technician
Vietnam 1969-1972

tahoe36c Avatar
tahoe36c Paul Hruza
Panama City, FL, USA   USA
1969 MG MGC GT "Little Red Rocket..."
1972 MG MGB GT "Tiny Dancer"
2002 Harley-Davidson Dyna
Frank,

One other suggestion... I'd bet 10:1 that I could tack that in place with my MIG welder. One tiny dot on each side... It wouldn't have time to get hot, so no damage done. Both parts are steel so no worries there. Do you know anyone with some talent? I am self taught and found it is amazing how precise you can be with a little practice and patience! Just sayin'

Paul

pinkyponk Avatar
pinkyponk Gold Member Adrian Page
Berwick, Nova Scotia, Canada   CAN
In reply to # 3550922 by ohlord It's a cheap $10 clone of a distributor
Generic curve one suits all
Call pertronix if no help
Replace it

I don't know where you shop but most dealers are selling these distributors for just over 200 bucks. I'd try to fix it... but I'm a mechanic not a parts changer. If it doesn't work out (the fix) it was broken and nothing was lost. If I couldn't fix it I'd ask the manufacturer for a new part or canvass buy sell trade on this site for a used one... or make a bracket to adapt an old Lucas can, or...

Paul,

I like your mig welder idea Paul. You could probably do it from the back by removing the bracket.

The pop rivets would be risky too as you could easily puncture the diaphragm when you drilled the holes. Perhaps a little air pressure would move the diaphragm back for welding or riveting?

Adrian



Home built Eaton M62 Supercharger with 9psi boost, "stock" high ratio rocker arms, 8:1 compression, Piper 270 cam, ported head, matched manifolds, CB Performance computerized ignition.



Edited 1 time(s). Last edit at 2017-07-13 06:41 AM by pinkyponk.

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B-racer Avatar
B-racer Jeff Schlemmer
Shakopee, Minnesota, USA   USA
1950 Willys Jeep Pickup "Ratrod"
1971 MG MGB
2014 Dodge Charger
That looks like a distributor I built. That's not a Pertronix vac unit - it has Lucas stampings on it. You can get a new vac unit for a 1975 MGB from Moss. 10-15-5 stamping for manifold vacuum use.

The distributor has Lucas retaining clips on the cap clips, so its not aftermarket. Aftermarket versions have screws holding the cap clips on. It also looks like you have phillips screws holding the vac unit on, not pozi-drive. That's something I do when I remove an Opus system and install a new vac unit. Keep it. Fix it!



jeff@advanceddistributors.com

lewk Avatar
lewk Silver Member Keith Lewis
Cambridge, Ontario, Canada   CAN
Maybe try JB Weld.

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CraigN Avatar
CraigN Craig Newton
Aurora, OH, USA   USA
Same thing happened to my 79 MGB two years ago. First solution was crazy glue, lasted a year. Second try is JB Weld which has been good for a month so far.

The Vacuum advance for my car is no longer available, searched EBAY and MFGs website. Part is listed but "out of stock" with no information on when it might be available.

If or when it fails will take it to welder and see if they can weld without ruining diaphragm. worst case is new distributor.

Good luck.

ohlord Avatar
ohlord Gold Member Rob C
North of Seattle, N.W., USA   USA
1957 Land Rover Series I "EYEYIYI"
1971 MG MGB
1971 MG MGB "Bedouin 2"
Yes, however the dealers dont tell you its a cheap $10 generic one curve suits all distributor when they sell it for the inflated price of 200 bucks.

If they don't fix the piece of crap. For free

Replace it with a real 25D4 rebuild and recurved

I.e. not a pos prrtronix or a fake45d in 25d clothing

In reply to # 3551001 by pinkyponk
In reply to # 3550922 by ohlord It's a cheap $10 clone of a distributor
Generic curve one suits all
Call pertronix if no help
Replace it

I don't know where you shop but most dealers are selling these distributors for just over 200 bucks. I'd try to fix it... but I'm a mechanic not a parts changer. If it doesn't work out (the fix) it was broken and nothing was lost. If I couldn't fix it I'd ask the manufacturer for a new part or canvass buy sell trade on this site for a used one... or make a bracket to adapt an old Lucas can, or...

Paul,

I like your mig welder idea Paul. You could probably do it from the back by removing the bracket.

The pop rivets would be risky too as you could easily puncture the diaphragm when you drilled the holes. Perhaps a little air pressure would move the diaphragm back for welding or riveting?

Adrian



"I'm a long way gone down this wild road I'm on
It's gonna take me where I'm bound
It's a long way around"



"These are the days that must happen to you"

RD2 Radar/ Electronic Warfare Technician
Vietnam 1969-1972

pinkyponk Avatar
pinkyponk Gold Member Adrian Page
Berwick, Nova Scotia, Canada   CAN
In reply to # 3553345 by ohlord Yes, however the dealers dont tell you its a cheap $10 generic one curve suits all distributor when they sell it for the inflated price of 200 bucks.

If they don't fix the piece of crap. For free

Replace it with a real 25D4 rebuild and recurved

I.e. not a pos prrtronix or a fake45d in 25d clothing

In reply to # 3551001 by pinkyponk
In reply to # 3550922 by ohlord It's a cheap $10 clone of a distributor
Generic curve one suits all
Call pertronix if no help
Replace it

I don't think you can pick up a new Lucas distributor with the correct curve either... but I could be mistaken.

I don't think even the Chinese can make one of those for $10 Rob. What is the curve on the Pertronix one anyway? Maybe it's only off a small amount? Perhaps the curve on the Accuspark ones is closer? I've never seen the data for either curve posted anywhere. Do you have it? Does the point cam move too far? That's an easy fix... just need a little sleeve or drop of weld.

I'd set it up to idle at 15 to 18 with all in at 30 degrees and total timing at 32 total. Ported vac.

Adrian



Home built Eaton M62 Supercharger with 9psi boost, "stock" high ratio rocker arms, 8:1 compression, Piper 270 cam, ported head, matched manifolds, CB Performance computerized ignition.

Gerry Avatar
Gerry Gold Member Gerry Masterman
Prairieville, Louisiana, USA   USA
Try to weld on that and all you will do is ruin the diaphragm and dizzy body. Jeff can more than likely help you as long as you don't destroy something doing a half thought out repair attempt

B-racer Avatar
B-racer Jeff Schlemmer
Shakopee, Minnesota, USA   USA
1950 Willys Jeep Pickup "Ratrod"
1971 MG MGB
2014 Dodge Charger
Guys, I built that from a 45DE4 core a LONG time ago. Its Lucas. I told him which new vac unit he needs. I'm currently out of them.

As for Chinese distributors, you're right Adrian. They're up to almost $12 for a complete points distributor, $19 for electronic. Manufacturer direct. Accuspark is a name brand that SimonBBC attached to an aftermarket generic part from China. He calls a poor copy of my red rotors Accuspark as well, except his tooling added an exposed parting line, and they don't fit the same. He calls a lot of stuff Accuspark, like how someone still applies Lucas labels to ignition parts. We all know Lucas doesn't make tune-up parts anymore.



jeff@advanceddistributors.com

pinkyponk Avatar
pinkyponk Gold Member Adrian Page
Berwick, Nova Scotia, Canada   CAN
In reply to # 3553448 by B-racer Guys, I built that from a 45DE4 core a LONG time ago. Its Lucas. I told him which new vac unit he needs. I'm currently out of them.

As for Chinese distributors, you're right Adrian. They're up to almost $12 for a complete points distributor, $19 for electronic. Manufacturer direct. Accuspark is a name brand that SimonBBC attached to an aftermarket generic part from China. He calls a poor copy of my red rotors Accuspark as well, except his tooling added an exposed parting line, and they don't fit the same. He calls a lot of stuff Accuspark, like how someone still applies Lucas labels to ignition parts. We all know Lucas doesn't make tune-up parts anymore.


What was/is the cost for a genuine Lucas 25d straight from the factory? winking smiley

Powerspark (simonBBC) and Accuspark may well come out of the same factory but they appear to be separate entities. Accuspark is sold by Watford Classics.

Accuspark say they sell red rotors that were originally developed and designed by Martin Jay... the Distributor Doctor. Martin Jay says he came up with the idea himself: "Like most good ideas, we’ve suffered from low grade pirated copies being sold very cheaply, so BEWARE CHEAP COPIES OF MY RED ROTOR ARMS." So where do you fit in to all this?

Will you post the curve to a Pertronix distributor... so we can see how far off it is?

Adrian



Home built Eaton M62 Supercharger with 9psi boost, "stock" high ratio rocker arms, 8:1 compression, Piper 270 cam, ported head, matched manifolds, CB Performance computerized ignition.

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