The Ford Barn

Phil Gillespie · 12-14-2018, 03:33 PM

Not long had my rebuilt 81A engine back in car and running.
Most items replaced or repaired. Even a new 97 carb fitted, even fitted the heat spacer under carb.
First hicup was a defctive adjusting screw on lifter, cam loose. Changed that out. Recently at a cold start hard to start? need to crank over a fair while.
But once running restarts ok. Earth strap engine too firewall is good.
Yesterday it cut out for no reason going into a car park and would not start up. Waited a while and eventually started up..
Have 6v divers helmet distributor, rebuilt for 3rd Gereration, new round type coil, and a newish Vertex Magneto Condenser.
So to keep it simple have changed out the Vertex Condenser with a Mallory 400 condenser..28 MF 600V. Will observe now how it goes.
At fitting the engine checked fuel pump output pressure and this was ok around 2 psi.

Ggmac · 12-14-2018, 06:21 PM

A new similar situation , but a 48 super deluxe was just posted .
Ps good luck and keep us informed

Phil Gillespie · 12-15-2018, 04:14 PM

The condenser as fitted, Vertex condenser, will this "fail" giving the above described conditions? Also I understand the condenser is not voltage specific? Can be 6 v or 12 v.
Like the one I have fitted now the Mallory 400 rated at .28mf and 600v.
Appreciate comments.
Phil NZ

rotorwrench · 12-15-2018, 07:23 PM

If the condenser is good, there is nothing there that will make it fail. It's either good or not. It would have to be properly tested to be certain but those Scintilla Vertex types are generally very good capacitors. I am not a fan of the reproduction coils. I'd trust an original that has been properly rebuild more than a new one.

koates · 12-15-2018, 09:10 PM

Hi Phil, I have been using some Mallory 400 .28mfd condensers for a while and all were good ( about 15 of them) except one which developed an open circuit connection on the wire inside the can. If I pushed in on the wire it came good. These Mallory 400 condensers are the only ones I have found with anywhere near the .33 to .36 mfd required for the early Ford V8 coils. I have two automotive condenser testers which test for capacity in MFD, leakage and series resistance. THE Mallory 400 is spot on at .28 MFD on the tester. I have one on my 34 Ford and is good so far. Most modern condensers test in the .22 MFD area which is correct for most can type ignition coils. Voltage on automotive type can condensers is usually rated at 400 to 600 volts so a 6 or 12 volt system NEG or POS ground does not matter. If using one of the Mallory 400 condensers I would suggest being very carefull not to pull on the wire or place any tension on the wire when fitting it to your car. I intend cutting the end of the can on the faulty one to see whats happened inside there. Regards, Kevin.

Graeme / New Zealand · 12-15-2018, 11:45 PM

Sponsored Links (Register now to hide all advertisements)

I've been using a Bosch GH208-C condensor on my v8. Same as used on 78-82 Nissan Skyline, 180B ,120Y,77-78 200B 280C 82-85 Pulsar. also used on 74-78 honda Accord and civic.
Just had to bend up the muonting tab and grind a bit off the edge so it mounts on my crab dizzy.

GB

Phil Gillespie · 12-15-2018, 11:50 PM

Quote:

Originally Posted by koates

Hi Phil, I have been using some Mallory 400 .28mfd condensers for a while and all were good ( about 15 of them) except one which developed an open circuit connection on the wire inside the can. If I pushed in on the wire it came good. These Mallory 400 condensers are the only ones I have found with anywhere near the .33 to .36 mfd required for the early Ford V8 coils. I have two automotive condenser testers which test for capacity in MFD, leakage and series resistance. THE Mallory 400 is spot on at .28 MFD on the tester. I have one on my 34 Ford and is good so far. Most modern condensers test in the .22 MFD area which is correct for most can type ignition coils. Voltage on automotive type can condensers is usually rated at 400 to 600 volts so a 6 or 12 volt system NEG or POS ground does not matter. If using one of the Mallory 400 condensers I would suggest being very carefull not to pull on the wire or place any tension on the wire when fitting it to your car. I intend cutting the end of the can on the faulty one to see whats happened inside there. Regards, Kevin.

Kevin,
Thanks very much for your concise explanaition and assistance.
These Mallory 400 are readily available here in NZ and based upon your experience will go with them as you point out htey are better at .28mf as per their rating. I'll stay with this single change to the sytem and observe.
many thanks
Phil NZ

Phil Gillespie · 12-16-2018, 04:35 AM

Quote:

Originally Posted by Graeme / New Zealand

I've been using a Bosch GH208-C condensor on my v8. Same as used on 78-82 Nissan Skyline, 180B ,120Y,77-78 200B 280C 82-85 Pulsar. also used on 74-78 honda Accord and civic.
Just had to bend up the muonting tab and grind a bit off the edge so it mounts on my crab dizzy.

GB

Thanks for the details on that condenser. Any idea of mf rating for this one.
Phil NZ

Bored&Stroked · 12-16-2018, 10:04 AM

Hey Phil - would like to hear more on this as you continue to run the car. The Vertex condensers are expensive (about $30 USA) - and if you find this to be your problem, would like to know.

I have a high quality condenser tester - might have to do some tests once I hear back from you.

BUBBAS IGNITION · 12-16-2018, 11:28 AM

Quote:

Originally Posted by Bored&Stroked

Hey Phil - would like to hear more on this as you continue to run the car. The Vertex condensers are expensive (about $30 USA) - and if you find this to be your problem, would like to know.

I have a high quality condenser tester - might have to do some tests once I hear back from you.

The Vertex mag condensors we use are manufactured for a friend that does nothing but race car magnetos. We buy them from him , they fall in approx .36mfds and are perfect for the helmet distributors needing the .36 spec.

The later (model68 and 11A) distributor use the dual contacts and use a different unit rated at .24-.28 mfds. (we use the Crab FA54 Napa condensor for this one)

We warranty the Vertec condensor for life and i have never seen a defective one , very high quality epoxy sealed unit.

And yes they are $32....

Phil Gillespie · 12-16-2018, 01:51 PM

Quote:

Originally Posted by BUBBAS IGNITION

The Vertex mag condensors we use are manufactured for a friend that does nothing but race car magnetos. We buy them from him , they fall in approx .36mfds and are perfect for the helmet distributors needing the .36 spec.

The later (model68 and 11A) distributor use the dual contacts and use a different unit rated at .24-.28 mfds. (we use the Crab FA54 Napa condensor for this one)

We warranty the Vertec condensor for life and i have never seen a defective one , very high quality epoxy sealed unit.

And yes they are $32....

I'm not saying it is the condenser. This is the first item I have changed out in an attempt to find a problem. It may well be ok.It seems to be the first initail cold start and then its normally ok.
Phil NZ

Lawrie · 12-16-2018, 04:08 PM

Would there be any difference in the Mf if you use a rewound coil ,
Lawrie

Phil Gillespie · 12-16-2018, 06:22 PM

Quote:

Originally Posted by Lawrie

Would there be any difference in the Mf if you use a rewound coil ,
Lawrie

Not sure. Presently using a new type round coil. However have 3 original type coils rewound by Skip. This could be the next stage, a coil swap.
Phil NZ

Lawrie · 12-16-2018, 06:31 PM

Skips coils are what I use, they work good.
Lawrie

wga · 12-17-2018, 12:05 AM

Just because its new, doesn't mean it is good.....

Sent my new Mallory distributor to Bubba, along with a new Mallory condenser. Bubba set up thedistributor for me, ran well for about 50 miles. The Mallory condenser quit. Got the Vertex and for the past 5 years, no issues. Runs perfect - thanks Jim. I tossed the other Mallory condenser that was new, not used. Also using the Bosch 12 volt coil. $32 for a condenser? Excellent value.

40larry · 12-17-2018, 12:37 AM

Quote:

Originally Posted by BUBBAS IGNITION

The Vertex mag condensors we use are manufactured for a friend that does nothing but race car magnetos. We buy them from him , they fall in approx .36mfds and are perfect for the helmet distributors needing the .36 spec.

The later (model68 and 11A) distributor use the dual contacts and use a different unit rated at .24-.28 mfds. (we use the Crab FA54 Napa condensor for this one)

We warranty the Vertec condensor for life and i have never seen a defective one , very high quality epoxy sealed unit.

And yes they are $32....

Which year helmet style distributors do not have dual contacts and use this .36mf condenser?

BUBBAS IGNITION · 12-17-2018, 02:50 PM

Quote:

Originally Posted by 40larry

Which year helmet style distributors do not have dual contacts and use this .36mf condenser?

The early units used a strap one piece set of contacts.

I was refering ( dual points) to the later two individual dual contacts like the model 68 and 11A .

Note also they used a different ignition coil as well. Early units used a three bolt coil and later switched to different design using two bolts....

Phil Gillespie · 12-18-2018, 01:38 AM

Today after reading some related posts went with a check for carb.
Before attempting a start, A new Stromberg 97 Carb. Checked ooperation of acclerator pump observed fuel discharge with accelerator movement with air cleaner off.
Full choke and hit the starter and it fired up right away. So feel that perhaps fuel side is ok?
Use the same first start sequence as above on the 46 Mercury I have recently got and this one also fires up right off at first "cold start" But carb has been replaced, fuel pump & push rod replaced, all earths and ignition connections cleaned and tightened.
Each one is slightly different but generally use some choke at first starts.
Phil NZ
Phil NZ

philipswanson · 12-18-2018, 03:04 PM

Quote:

Originally Posted by BUBBAS IGNITION

The later (model68 and 11A) distributor use the dual contacts and use a different unit rated at .24-.28 mfds. (we use the Crab FA54 Napa condensor for this one)

(

What years are the later 68 and 11A crabs used? Doesn't the coil dictate the mfds you need? I have a 40, what value do I need?

Bored&Stroked · 12-19-2018, 06:07 AM

An automotive distributor capacitor (formerly called condenser) and a specific coil form sort of "tuned" package. The microfarad ratings for the capacitor should match what the coil needs - based on the coils inductance (the micro farad rating relates to how much charge they hold).

Most automotive capacitors are rated somewhere around .22uf to .28 uf - and 600v. Magneto capacitors tend to be rated higher - like .32uf to .36uf (for smaller magnetos - not hopped up ones). The reason I bring this up is that folks put all sorts of different coils on the later crab type distributor (external coil) - so the microfarad rating is really dependent upon the coil. If you're running stock type coils - then just follow the specifications for that year distributor/coil . . . if you're running aftermarket stuff . . . I have no clue as to what they need (though I'd imagine most standard automotive coils need .22uf to .28 uf).

Here is an interesting post I saw on a motorcycle forum about capacitors and automotive ignitions. It was in reply to somebody who was attempting to source capacitors from a general electronics supply place - enjoy!

Capacitors (a.k.a. condensers) used for coil point applications can be a trap if you are not aware of the various types of capacitors that are out there. Most folks know that capacitors have a value (usually in microfarads) and a tolerance as to how far away from the marked value that the part can be. A film type capacitor commonly has a +/- 10% tolerance. Then there is the working voltage which for ignition coil operation is often 400V but many people buy a 600V part "just to be safer". The problem is that the "typical" part that they then buy at the local electronic hobby store is a fairly inexpensive common part that is a metalized dielectric type part. At the link furnished elsewhere in this thread - that would be the yellow tubular part. You will notice that it is way cheaper than the Sprague type 716 polypropylene part listed. The type 716 part is NOT a metalized type part and it also has a different dielectric being polypropylene. What does all this have to do with anything ignition related? Well my company makes Model T Ford coils and repro buzz coils for stationary engines too and if we used the yellow parts - they would go about 5 miles in a Model T and then quit while the type 716 part (which we don't use either) would likely never fail. It has nothing to do with the quality of the parts. What you need to understand is that there are other ratings besides value, tolerance, and working voltage. The most important rating of all with regards to capacitors used for ignition points, magnetos, and coils, is the dV/dT rating. Not commonly found in a catalog but published by the manufacturers data sheet, the specification definition refers to the terms dV and dT. The term dV means "change in voltage" and dT means "change in time". There is a rating as to how fast your can safely charge and discharge a capacitor. If you charge it and discharge it at too fast of a rate - it will heat up inside and quickly fail. The rating of dV/dT is a rating of the allowable change in the charge voltage of the capacitor during a give change in time. The rating on a capacitor that will work reliably in a Model T coil is more than 700Volts/microsecond. Written the common way is that the rating needs to be dV/dT=700 or greater. You will find that the type 716 capacitor at .22 and 400Volts is well over that spec while the yellow metalized part likely doesn't have any rating at all for that. Why no dV/dT rating? Because it is not designed for use in applications that have really high charge and discharge currents as happens when the points close and force the charge in the ignition capacitor to ZERO in almost zero time. That is a huge pulse of current with very high dV/dT.

Unfortunately the most common capacitors you can find at .22uF and 400 or 600V are metalized type and their dV/dT ratings if published are probably about 25-30 which is at least a factor of 20 less than necessary hence they don't last long if you try to use them. Usually the value of the capacitor is not too critical nor is even the working voltage if you get at least 400V but ignore the dV/dT rating and you will get burned. Its a lot of work do dig the tar out of an old coil and then install a new but wrong type capacitor in there that only works for a few minutes of running.

I am new to your forum and only wish to help but this is a trap that a lot of coil rebuilders have fallen into. I could post a link to my company's web site so you could read more about this but not sure if it is OK to post web site links so I didn't do it here. We have capacitors with high dV/dT that are reasonably priced but I think in Australia it would make sense to find a source local.

Hope this makes some sense.

12-14-2018, 03:33 PM	#1
Phil Gillespie Senior Member Join Date: Sep 2011 Location: Christchurch New Zealand Posts: 1,611	Condenser Replaced Not long had my rebuilt 81A engine back in car and running. Most items replaced or repaired. Even a new 97 carb fitted, even fitted the heat spacer under carb. First hicup was a defctive adjusting screw on lifter, cam loose. Changed that out. Recently at a cold start hard to start? need to crank over a fair while. But once running restarts ok. Earth strap engine too firewall is good. Yesterday it cut out for no reason going into a car park and would not start up. Waited a while and eventually started up.. Have 6v divers helmet distributor, rebuilt for 3rd Gereration, new round type coil, and a newish Vertex Magneto Condenser. So to keep it simple have changed out the Vertex Condenser with a Mallory 400 condenser..28 MF 600V. Will observe now how it goes. At fitting the engine checked fuel pump output pressure and this was ok around 2 psi.

12-14-2018, 06:21 PM	#2
Ggmac Senior Member Join Date: Jul 2016 Location: Lake worth Florida Posts: 1,100	Re: Condenser Replaced A new similar situation , but a 48 super deluxe was just posted . Ps good luck and keep us informed

12-15-2018, 04:14 PM	#3
Phil Gillespie Senior Member Join Date: Sep 2011 Location: Christchurch New Zealand Posts: 1,611	Re: Condenser Replaced The condenser as fitted, Vertex condenser, will this "fail" giving the above described conditions? Also I understand the condenser is not voltage specific? Can be 6 v or 12 v. Like the one I have fitted now the Mallory 400 rated at .28mf and 600v. Appreciate comments. Phil NZ

12-15-2018, 07:23 PM	#4
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,431	Re: Condenser Replaced If the condenser is good, there is nothing there that will make it fail. It's either good or not. It would have to be properly tested to be certain but those Scintilla Vertex types are generally very good capacitors. I am not a fan of the reproduction coils. I'd trust an original that has been properly rebuild more than a new one.

12-15-2018, 09:10 PM	#5
koates Senior Member Join Date: May 2010 Location: Melbourne Australia. Posts: 2,079	Re: Condenser Replaced Hi Phil, I have been using some Mallory 400 .28mfd condensers for a while and all were good ( about 15 of them) except one which developed an open circuit connection on the wire inside the can. If I pushed in on the wire it came good. These Mallory 400 condensers are the only ones I have found with anywhere near the .33 to .36 mfd required for the early Ford V8 coils. I have two automotive condenser testers which test for capacity in MFD, leakage and series resistance. THE Mallory 400 is spot on at .28 MFD on the tester. I have one on my 34 Ford and is good so far. Most modern condensers test in the .22 MFD area which is correct for most can type ignition coils. Voltage on automotive type can condensers is usually rated at 400 to 600 volts so a 6 or 12 volt system NEG or POS ground does not matter. If using one of the Mallory 400 condensers I would suggest being very carefull not to pull on the wire or place any tension on the wire when fitting it to your car. I intend cutting the end of the can on the faulty one to see whats happened inside there. Regards, Kevin.

12-15-2018, 11:45 PM	#6
Graeme / New Zealand Senior Member Join Date: May 2010 Location: Lower Hutt , New Zealand Posts: 2,126	Re: Condenser Replaced Sponsored Links (Register now to hide all advertisements) I've been using a Bosch GH208-C condensor on my v8. Same as used on 78-82 Nissan Skyline, 180B ,120Y,77-78 200B 280C 82-85 Pulsar. also used on 74-78 honda Accord and civic. Just had to bend up the muonting tab and grind a bit off the edge so it mounts on my crab dizzy. GB __________________ "you can't make honey out of dog sh*t" "You're a long time looking at the lid"

12-16-2018, 10:04 AM	#9
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,067	Re: Condenser Replaced Hey Phil - would like to hear more on this as you continue to run the car. The Vertex condensers are expensive (about $30 USA) - and if you find this to be your problem, would like to know. I have a high quality condenser tester - might have to do some tests once I hear back from you.

12-16-2018, 04:08 PM	#12
Lawrie Senior Member Join Date: May 2010 Location: Qld, Australia Posts: 4,215	Re: Condenser Replaced Would there be any difference in the Mf if you use a rewound coil , Lawrie

12-16-2018, 06:31 PM	#14
Lawrie Senior Member Join Date: May 2010 Location: Qld, Australia Posts: 4,215	Re: Condenser Replaced Skips coils are what I use, they work good. Lawrie

12-17-2018, 12:05 AM	#15
wga Senior Member Join Date: Jul 2010 Location: Yorba Linda, CA Posts: 898	Re: Condenser Replaced Just because its new, doesn't mean it is good..... Sent my new Mallory distributor to Bubba, along with a new Mallory condenser. Bubba set up thedistributor for me, ran well for about 50 miles. The Mallory condenser quit. Got the Vertex and for the past 5 years, no issues. Runs perfect - thanks Jim. I tossed the other Mallory condenser that was new, not used. Also using the Bosch 12 volt coil. $32 for a condenser? Excellent value. __________________ Henry Ford designed the flathead without the aid of a computer.

12-18-2018, 01:38 AM	#18
Phil Gillespie Senior Member Join Date: Sep 2011 Location: Christchurch New Zealand Posts: 1,611	Re: Condenser Replaced Today after reading some related posts went with a check for carb. Before attempting a start, A new Stromberg 97 Carb. Checked ooperation of acclerator pump observed fuel discharge with accelerator movement with air cleaner off. Full choke and hit the starter and it fired up right away. So feel that perhaps fuel side is ok? Use the same first start sequence as above on the 46 Mercury I have recently got and this one also fires up right off at first "cold start" But carb has been replaced, fuel pump & push rod replaced, all earths and ignition connections cleaned and tightened. Each one is slightly different but generally use some choke at first starts. Phil NZ Phil NZ

12-19-2018, 06:07 AM	#20
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,067	Re: Condenser Replaced An automotive distributor capacitor (formerly called condenser) and a specific coil form sort of "tuned" package. The microfarad ratings for the capacitor should match what the coil needs - based on the coils inductance (the micro farad rating relates to how much charge they hold). Most automotive capacitors are rated somewhere around .22uf to .28 uf - and 600v. Magneto capacitors tend to be rated higher - like .32uf to .36uf (for smaller magnetos - not hopped up ones). The reason I bring this up is that folks put all sorts of different coils on the later crab type distributor (external coil) - so the microfarad rating is really dependent upon the coil. If you're running stock type coils - then just follow the specifications for that year distributor/coil . . . if you're running aftermarket stuff . . . I have no clue as to what they need (though I'd imagine most standard automotive coils need .22uf to .28 uf). Here is an interesting post I saw on a motorcycle forum about capacitors and automotive ignitions. It was in reply to somebody who was attempting to source capacitors from a general electronics supply place - enjoy! Capacitors (a.k.a. condensers) used for coil point applications can be a trap if you are not aware of the various types of capacitors that are out there. Most folks know that capacitors have a value (usually in microfarads) and a tolerance as to how far away from the marked value that the part can be. A film type capacitor commonly has a +/- 10% tolerance. Then there is the working voltage which for ignition coil operation is often 400V but many people buy a 600V part "just to be safer". The problem is that the "typical" part that they then buy at the local electronic hobby store is a fairly inexpensive common part that is a metalized dielectric type part. At the link furnished elsewhere in this thread - that would be the yellow tubular part. You will notice that it is way cheaper than the Sprague type 716 polypropylene part listed. The type 716 part is NOT a metalized type part and it also has a different dielectric being polypropylene. What does all this have to do with anything ignition related? Well my company makes Model T Ford coils and repro buzz coils for stationary engines too and if we used the yellow parts - they would go about 5 miles in a Model T and then quit while the type 716 part (which we don't use either) would likely never fail. It has nothing to do with the quality of the parts. What you need to understand is that there are other ratings besides value, tolerance, and working voltage. The most important rating of all with regards to capacitors used for ignition points, magnetos, and coils, is the dV/dT rating. Not commonly found in a catalog but published by the manufacturers data sheet, the specification definition refers to the terms dV and dT. The term dV means "change in voltage" and dT means "change in time". There is a rating as to how fast your can safely charge and discharge a capacitor. If you charge it and discharge it at too fast of a rate - it will heat up inside and quickly fail. The rating of dV/dT is a rating of the allowable change in the charge voltage of the capacitor during a give change in time. The rating on a capacitor that will work reliably in a Model T coil is more than 700Volts/microsecond. Written the common way is that the rating needs to be dV/dT=700 or greater. You will find that the type 716 capacitor at .22 and 400Volts is well over that spec while the yellow metalized part likely doesn't have any rating at all for that. Why no dV/dT rating? Because it is not designed for use in applications that have really high charge and discharge currents as happens when the points close and force the charge in the ignition capacitor to ZERO in almost zero time. That is a huge pulse of current with very high dV/dT. Unfortunately the most common capacitors you can find at .22uF and 400 or 600V are metalized type and their dV/dT ratings if published are probably about 25-30 which is at least a factor of 20 less than necessary hence they don't last long if you try to use them. Usually the value of the capacitor is not too critical nor is even the working voltage if you get at least 400V but ignore the dV/dT rating and you will get burned. Its a lot of work do dig the tar out of an old coil and then install a new but wrong type capacitor in there that only works for a few minutes of running. I am new to your forum and only wish to help but this is a trap that a lot of coil rebuilders have fallen into. I could post a link to my company's web site so you could read more about this but not sure if it is OK to post web site links so I didn't do it here. We have capacitors with high dV/dT that are reasonably priced but I think in Australia it would make sense to find a source local. Hope this makes some sense.