the coil?

[tahoe healey]

We went on a ride to Yosemite yesterday. (TRAFFIC!)(The Nocks were there. Dave Nock lead. Norm at the rear. Lunch at the Ahwanee Hotel. Great time even if there were several over-heatings in the traffic (I reached over 230 but lost no coolant. Some lost it all).
Anyway to the point (if you will excuse the pun). I mentioned my problem with the points closing in a previous post. Norm Nock suggested the coil be replaced by either a proper one if I had the wrong one and that the old one may be causing to much heat and melting the edge off the contact to the cam.
I may have the original coil and the PO switched to to neg ground (which may never have been properly polarized).
How do I check the out-put? What do I check or do I just get a new one since they aren't that expensive? I'm tired of re-gapping every 200 miles or so. The car runs great until the gap closes.

 

[Keoke]

Hello TH, If you have the original coil and the ground polarity as been changed from Positive to Negative.Then the coil terminals should be marked "CB" and "SW" .Properly connecting these coils in the negative ground configuration requires that the terminal marked "SW" be connected to the low tension lucar connector on the distributor.The "CB" terminal will then carry the white wire from the Ignition switch.However, I do not believe the coil is the culprit at all.---Fwiw---Keoke

 

[Dave Russell]

Hi TH,
Coil polarity will have little affect on point life. The wrong polarity will cause a slight reduction of available spark voltage.

The resistance of the coil primary winding can have a large affect on the point heat & life if it is too low. It IS possible that the points are getting so hot that the rubbing block is softening/melting. Especially with some of the newer "plastic" type rubbing blocks. It may be possible to find a point set with a "real" phenolic rubbing block instead of the plastic type.

It's kind of a long shot, but I have experienced this situation before.

Check the following first:

The coil primary resistance should be about 2.7 to 3.2 ohms. Any less will shorten point life.

It's pretty hard to find a good enough ohmmeter to accurately measure three ohms. If you can find one, well enough. If you can't find a good ohmmeter, an accurate ammeter in series with the coil primary (points) should read somewhere between 4 and 4.5 amps when the points are closed. If the current is much higher, point life will be short. The wrong coil installed or the coil being defective could be reasons for the coil resistance being too low & the current too high.

If the coil current is within range, look for a "better" set of points.

Good luck,
D

 

[Rick60]

...or just replace your points with a Pertronix. Did it more than a year ago, never regret it.

 

[zblu]

Had the same problem with a Ford F100 pick up, the points kept closing up about every 100-150 miles, worked out it was either a lack of lube on the dizzy cam lobes that the plastic piece rides on or the plastic piece itself was a dud (seemed to be excessive wear on the plastic piece)

 

[dklawson]

Sidebar: The trick to using a cheap volt/ohm meter for checking low resistance is start with a baseline. Before measuring the item (coil) in question, hold the two test probe tips together and record the resulting resistance value shown on your meter. When you measure the item in question, subtract this baseline reading from it. You'll still have some drift away from "perfect" but you'll have more confidence in your readings.

Originality is great... until it starts to affect reliability. If you are having to re-gap every 200 miles perhaps it is time to consider Pertronix. If you are careful routing your wires you can virtually conceal the substitution... right down to wire colors. The only give-away would be the second wire exiting the dizzy for the Pertronix +12v connection.

 

[tahoe healey]

Apparently I do not have an original coil. It is marked + and - at the terminals and looks like it says "Standardplus"and "made in the USA"

 

[Keoke]

OK TH, Put that thing in the bin and get a new replacement coil.However, that coil should be hooked up as follows: Negative terminal to the Lucar connector on the Distributor and the Positive terminal to the White wire coming from the Ignition SW. Do not use the new Lucas sport coil unless you also go to Pertronics!---Keoke

 

[vette]

Hello TH, you might want to check to make sure that the cam in the distributor doesn't just have a rough surface from age, or from carbon build up, or rust.
Dave. /ubbthreads/images/graemlins/cheers.gif

 

[tahoe healey]

Cam is fine and well lubed. Those were my first thoughts years ago. I've been looking for the old fiber type point set. I've been told the Lucas stuff is not the quality it once was but o;thers have not had the problem I've had At one point I thought it was the lack of a lock washer on the adjusting screw. I think the distributer is fine. I've looked at everything in it. Pertronixs is sounding better all the time....but not quite yet.

 

[dklawson]

When you do make the decision to go electronic, search on the net for a company called Retro Rockets. This is not an endorsement per se, but I found they offered the lowest prices on Pertronix.

 

[John Loftus]

[ QUOTE ]
When you do make the decision to go electronic ..

[/ QUOTE ]

Just to present the other side of the coin, I reprint a correspondance with Peter Hunt who with his wife Ann, drove their Healey in the Around the World race with standard points. And then to really cover the bases, I reprinted below that a lengthy post by Chris Dimmock on distributors. At the very least it is interesting reading and what a Petronix unit will and will not do. Cheers, John


------------------
Hello John,

Good to hear from you -

Re - Healey distributor, points and rotors.

Our ATW2000 Healey is a 1962 BT7 Mk II 2 + 2 Tri-carb w/centre change
gearbox (converted to twin 1.75" SU s' for ease of fitting a foam air
filter)

I sent the distributor, Type DM6, away to our local Lucas agent for a
complete over haul, they in turn, sent it to Holden Vintage & Classic
www.holden.co.uk It came back as new with Lucas points and rotor.
During a very limited running-in period, I had a rotor arm fail.

The points gap were set at .015" when warm with the Champion NY12C plugs set at .025" gap. The engine compression ratio was reduced to 7.5 : 1 to allow for low Octane fuel en-route. Since then I have gone back to the standard 9 : 1 CR still with the same settings. Factory settings were used throughout.

During the whole 20,000 mile home to home trip the engine always started and did not miss a beat at all. None of the ignition items - plugs, points,condenser, coil or rotor needed replacing and were not adjusted. I applied the Golden Rule to British Sports Cars - "If it works, don't fiddle with it"

However - Not too long after we returned, I did have the condenser fail -simptoms - intermittant mis-fire. In addition, another rotor arm failed. As a matter of course, I replaced the points and plugs at 25,000 miles.

The only problem on the Open Roads 2002 tour was a breakage in the low
tension lead actually in the distributor, (In Death Valley with the temp. at 120 F + ) this took 20 minutes to fix. 9000 miles round trip in 5 weeks.

To date, XRU100 has covered 35,000 miles with the absolute minimum of
electrical problems.

My other Healey, a '63 Mk II BJ7, owned since 1969, gave no problems up
until she was laid up for an 8 year period 1989/97 with no attention. Basic ignition items and rubber seals had to be replaced and since then I have had three rotor arms fail. Two within 2,000 miles.

I cannot see the reason to change to electronic ignition on a 1950's design of car - maybe go to a Mallory distributor if you want to go racing. The Lucas distributor is very easy to service and set up correctly.

Rotor Arms are giving a lot of problems as they can fail with no warning at all and with no physical sign of damage. Is this happening to owners of other British Sports Cars that use the Healey Lucas range of distributors? I have heard that a more robust model of rotor arm that fits the Healey distributors is not giving the same problems but I do not know the model number - any ideas?

Motto - carry several spares.

By all means pass on all, or part, of above - Hope it helps.

Regards,

Peter

-------------

Hi all,

I apologise up front - this is a long and reasonably detailed post. Tried to
post it last night - but it didn't go through.

If you believe that a Pertronix ignitor fixes "everything" relating to wear in
a 35- 50 year old distributor - and want to keep believing that - then delete
this post now - and may you forever remain in Lucas darkness.

This post is about why it is important "WHEN" the spark gets fired (rather
than just 'what' fires the spark) - and is an attempt to explain what problems
an electronic ignition (Pertronix, Lumenition etc) or a dual points
distributor will cure - and the problems they CAN'T cure - and how to cure
those problems. With all the recent posts - I thought documenting this would
help.

Firstly - I'm not anti -Pertronix or anti-electronic ignition - I just want
to explain what I have discovered myself over the past year or so - and
demystify some of this stuff.

Pertronix part number for a positive earth Pertronix for a BJ8 Lucas 25D
distributor is LU 162AP12 - I bought a Pertronix from Aaron Couper at
coupers-cars.com (in the USA) about this time last year:

https://www.coupers-cars.com/Catalog%20Templates/Pertronix%20Units_products.ht
m

It was $US70 plus freight & taxes No commercial interest yaddah yaddah - best
price I could find - and Aaron is a Kiwi (like Mike Salter!) - so he's a good
bloke!.

But before you rush out and buy one - think about this - what problem are you
trying to solve?

Most people buy a Pertronix - and spend their $US70 plus freight (or more) -
basically to compensate for the fact that their 35 - 50 year old distributor
is worn out. Your distributor shaft bearings, shaft, distributor cam etc are
worn - and so the shaft wobbles. The distributor runs at half engine rpm -
you'd expect its bearings to be worn out after 35- 50 years of driving!.

So why not fix the distributor?

By fitting a Pertronix - you eliminate the mechanical actuation of the
mechanical points (and the condensor) - and replace them with a very accurate
electronic 'switch'. The wobbly mechanical shaft now doesn't mechanically open
and close the points - and you don't have to maintain the points. That's one
problem solved - 'how' the spark is fired.

But - what determines WHEN that spark gets fired?. Its your advance curve -
determined by two weights, pivoting on posts, retained by 2 springs - which
spin in and out at different RPMs - and a cam and post which limit the
movement to a 'maximum' advance. How does the wobbly old worn shaft/ bearings/
Cam/ springs and worn spring posts in the distributor decide WHEN to fire the
spark? The same way that it did before you fitted the Pertronix - by just
wobbling around!. You haven't fixed that problem!

So what are the advantage of fitting a Pertronics inside your Lucas
distributor - or fitting a modern twin point distributor instead of your
Lucas?:

1. a pertronix removes shaft/cam wear as a SPARK IGNITION consistency factor
- by changing HOW the spark is fired - by changing from mechanical actuation
of mechanical points, to optical . But it doesn't remove the shaft/cam wear -
or post/pivot wear, lack of spring tension etc - which affects WHEN the spark
is fired - i.e. the advance curve itself. The Mallory twin point - being brand
new - isn't worn - so it also solves the 'wear' problem.

2. you can't get points bounce with a Pertronix - as it is a hall effect
rather than mechanical points. A dual point eg Mallory distributor also cures
points bounce by halving the amount of work each set of points does. Both are
great to extend revs past say 6,400 rpm on a 6 cylinder engine, and past
7,500rpm on a 4 cylinder engine.

3. a pertronix is cheaper (at around $US70) than a full distributor rebuild
with a complete advance curve regraph (at around $US150 - or so) The Mallory
is dearer still - at around $US200 plus you still need to set the advance
curve of the Mallory to match your engine.

4. a much more consistent 15 KV is maintained at eg 6,000 rpm at the spark
plug - whereas points systems reduce KVA at higher rpm. Both Perrtronix and
dual point Mallory will provide this consistency.

A Pertronix DOESN'T address the effect that the wear in the distributor has
on the actual advance curve itself - i.e. the amount of advance an engine
requires at any particular revs. Your worn out old distributor decides that -
and we just ascertained that your motivation to put in a Pertronix was to
compensate for the worn out bearings/ cam/ shaft!!! But you've ignored the
springs, action plate posts, weights and the wear means you no longer have the
advance curve provided 35 - 50 years ago. And lets face it - if you don't have
a standard camshaft grind, and a standard compression ratio - and aren't
running 100 octane RON (NOT AKI - and not MON) leaded fuel (check in your
owners handbook!) - then that curve isn't correct anyway!.

The correct solution to 1. above - to solve BOTH issues - is the old fashioned
'rebuilding your distributor' method! Replace the worn out bearing/ worn
shaft/ action plate posts/pivots. Then regraph to suit your Healey engine.

Regarding 2 and 4. Is points points bbbounce actually a problem? I don't
believe it is with a road going 6 cyl big Healey with a standard crankshaft.
Points
bounce is only a problem on high revving cars - eg 4 cylinder racing sprites,
or Healey 3000's with Denis Welch's steel bottom end - which go regularly
past 7,000 rpm on the track, and get points bounce - which a Pertronics
solves. On a 6 cylinder engine you don't get points bounce with standard
points until around 6,200 - 6,400 rpm - at which time a standard crankshaft
cures the points bounce - by breaking......... Suffice to say - if you intend
to rev your 100/4 over 7,000 rpm - or your 6 cylinder healey over 6,500 rpm
regularly - then get a pertronix or a Mallory dual point.

Personally - on a BJ8 which sees 5,800 rpm regularly - a correctly set up
Lucas distributor is fine - remember - that was the same distributor which
Formula Juniors and Cooper S and Healeys used in International motorsport
during the 1960s!. Its just that todays ones are 35 - 40 years older and need
to be rebuilt!

I'm not knocking Pertronix - I'm keeping the one I have for a Sprite -
Pertronix solves the points bounce issue better than anything else, in a
standard appearance distributor. But it won't 'fix' your advance curve -
which is probably now way off due to the wear in posts / bearings / lack of
spring tension / worn bearings worn distributor cam - And it won't compensate
for the higher performance camshaft you fitted last rebuild. A rebuild , and a
regraph of your distributor to suit your engines specs, however, will.

In Summary -

- If you have a worn out old 80,000 mile old distributor, and change it to a
Pertronics/Lumenition/ electronic actuation system - your car will definitely
run better, and smoother than before you fitted the Pertronix. In fact - the
more worn out your old distributor is - the happier you'll be with the
Pertronix - hence all the positive postings.

- If you put a new (rebuilt to spec) points based Lucas distributor, with a
correct advance curve to suit the cam timing, compression ratio and the fuel
you run in your engine in 2003, into your car - and then tuned your car, reset
your carbs etc - you'll pick up noticeable seat of the pants bhp and get
better fuel economy, and the car will be smoother.

- If you put a new (rebuilt to spec) points based Lucas distributor, with a
correct advance curve etc in your car - drove it and got used to the
improvements - and then removed the points & condensor from your rebuilt
regraphed Lucas distributor - and fitted a pertronix - you would notice no
difference under 6,000 rpm There would be no measurable improvement. NONE. No
additional smoothness etc - no improvements at all - not until you were
revving past 6,000 rpm.

- If you have a worn out old 80,000 mile old distributor, with a Pertronics
fitted - and you got it rebuilt with a correct advance curve to suit the cam
timing, compression ratio and the fuel you run in your engine in 2003 - and
then tuned your car, reset your carbs etc - you'll probably pick up noticeable
bhp and get better fuel economy - and you would never have a points bounce
problem, and you would be able to continue making great BHP over 6,000rpm
(provided your engine was capable of it).

Getting the advance curve set to a sensible specification - for your engine
spec - and for your use of your Healey - and for the fuel you use - makes a
big difference. Ask anyone who has had their advance curve regraphed. If you
can't find someone 'local' to do this - Barry Campbell from the Austin Healey
Owners Club here in Sydney has done this for over 40 other healey people.
Barry has a large commercial Distributor analyser machine - which he has
converted to extremely accurate digital readouts (rather than swinging
needles).

And he understands advance curves and Healey engines - and has done heaps of
dyno and road testing.

And - aside from being a good bloke - Barry is retired and spends a
ridiculous, non commercial, amount of time doing this stuff. Did I mention
that Barry is fastidious ? : ) With the Australian peso - that makes
it pretty affordable (around $US100 - $US190 plus freight of approx $US25 -
depending on whats wrong, what model it is, and what parts/ machining is
required on your one - sometimes he has exchange or outright sale ones -
mostly BJ8 type) to get you distributor as close to 'perfect' as possible.

Barry built the distributor in my BJ8 (actually - he has built me a few -
we've tried several advance curves and done a lot of testing!)

The black & white car now has a 6 cylinder version of the no vacuum advance
Lucas 23D4 - a 23D6 - a Lucas mechanical advance only distributor. Totally
legal in all historic racing. The 23D4 is what the early/mid 1960's mini
cooper S had, and all the works Sprites/ Minis etc - with a fixed plate, no
Vacuum advance...)

So I now have one of the 'mythical' works type Lucas 23D6 distributors (as
fitted to the triple webered DHMCo prepared Sebring/ Lemans 3000's) in my BJ8
- with an advance curve tailored for my engine specs........... and no vacuum
advance. You see - you can't run a standard Healey/ Lucas Vacuum advance with
triple webers on a Healey - but that's another story... And if I ever got a
Dennis Welch steel bottom end - I'd put the Pertronix LU 162AP12 inside
it....

No commercial interest in any of this - yaddah yaddah - just passing on stuff
which may help others.

Best regards

Chris


______________________________________

Chris Dimmock
Sydney Australia

https://www.myaustinhealey.com

 

[Keoke]

Yep DK, The only way we could get Pertronix units to OZ at a reasonable price was to use Retro Rockets. I forget the owners name at the moment but he was a great guy to deal with.---Keoke

 

[dklawson]

John, thanks for posting the info on points and distributor wear. I certainly agree and the need for Pertronix users to address serious wear issues prior to any upgrade/change is important.

There are other changes in ignition performance when you install Pertronix which are associated with the "dwell" or what used to be the dwell. I don't remember the specifics regarding the switch timing inside the Pertronix, but it's my understanding that the length of time the coil is on and off is optimized a bit over what is necessary and possible when using mechanically actuated points. Again, I don't have specifics and this is hearsay. What is not hearsay is that a properly tuned car with Pertronix is generally easier to start.

I would still consider the Pertronix to be a suitable solution to the points "heel wear" as precipitated this thread. Even if the dizzy is rebuilt it may not address whatever is causing this particular set of points to keep closing up ever 250 miles. If this is indeed the result of material changes and low quality points, no amount of distributor rebuild will fix the problem short of using the points to fire an external ignition module.

My last comment is a cautionary note to those considering recurving their distributor. Each engine is unique, even when outfitted with similar components. While there are general advance curves (as used by the factory) to give acceptable performance, truly optimizing the advance curve requires dyno testing of your particular engine... best done as a rolling road or chassis dyno. The recurving may involve both changes to the advance cams, springs, and or spring lengths to achieve the results you want. Again, there are general curves that are suitable but the best results will be achieve by custom dyno tuning the advance curve.

 

[Keoke]

/ubbthreads/images/graemlins/iagree.gif 100 % DK actually the first sentence of I tem "1" said it all---Keoke /ubbthreads/images/graemlins/driving.gif

 

[John Loftus]

[ QUOTE ]
Cam is fine and well lubed.

[/ QUOTE ]

Hi T.H.,

Have you also been lubing the Cam bearing, Distributor Drive shaft Bearing and the Automatic Timing Control (weights and pivot points)? The manual goes over the procedure and this is necessary to do with or without points if you want the dizzy to last as long as possible. If you remove the rotor and try to move/wiggle the shaft back and forth is there any movement? Perhaps your point wear block problem is being accelerated by a worn shaft/dry bearings which could cause the shaft to heat more than normal (just a stab in the dark).

Cheers,
John

 

[John Loftus]

[ QUOTE ]

While there are general advance curves (as used by the factory) to give acceptable performance, truly optimizing the advance curve requires dyno testing of your particular engine... best done as a rolling road or chassis dyno. The recurving may involve both changes to the advance cams, springs, and or spring lengths to achieve the results you want. Again, there are general curves that are suitable but the best results will be achieve by custom dyno tuning the advance curve.

[/ QUOTE ]

Hi Douglas,

Have you ever gone through this custom dyno tuning to dial in the advance curve to your engine? If so, could you tell us who you used, more about the procedure and what the before and after results were?

Cheers,
John

 

[dklawson]

I haven't done this. I refer you to Marcel Chichak and his web site:
https://www.planet.eon.net/~chichm/
Marcel is a nice person and perhaps the most knowledgeable person I know regarding Lucas distributors. However, a couple of years ago when I asked him for general advice on what I should try for an advance curve... he slammed me with the need for dyno tuning to set it right and would not offer any suggestions. Unlike most of us, he has his own distributor machine and access to a chassis dyno. The problem for most of us is that we may have access to either a chassis dyno... or know a business that does distributor repair/re-curving... but they're not likely to be in the same location.

 

[gonzo]

Hi TH:
Back to the points' issue...

Your BJ-8 uses different points than my early BJ-7, however mechanically they operate the same.

I alternate between Pertronix and points with little notable difference in performance. With points installed the Carbs tend to tune leaner and contacts begin to “burnout” and pit at around 800miles – I think this is common - but still remain servicable to 3000+miles. However, I’ve yet to notice significant wear in the rubbing block to cause the points to close (and the engine not to start).

Overheating of the points, as mentioned earlier, could melt/distort the rubbing block- but how could this be verified? Have you checked the Fiber Washers on the points? There should be 1 fiber washer installed at the base of each of the point’s pivot locations, these help insulate the points and keep them from grounding. Without these installed properly, the engine may not start, run very well and/or for very long if it did – I learned by trial and error.

Give this a look TH and take care. GONZO

 

[tahoe healey]

Thanks all. I just recieved the new coil from British Car Specialist. While I was reviewing some notes on neg ground conversion I got conflicting info on the coil connection. One source said to connect the wire to the side of the dist to the + terminal and another says to the - terminal. Both are respected sources on conversion. Help!