I would like to hear any comments and experiences with various spark
plug brands in older engines. I remember that in the 60's, there
were certain brands that just worked best in certain engines, and
changing brands usually resulted in poor performance. Having said
that, I recently replaced the plugs in my '63 T Bird 390 4V that I
just acquired. The ones that were in there were "Bosch Platinum" and
I replaced them with the same type and brand. The ones I removed
looked OK, the right color etc, and no obvious malfunction. The
engine runs OK but it seems rough, and is hard to start cold, but
when warm will start instantly. Well I changed the plugs and also
the wires thinking that they were just getting tired. It seemed to
help some, and the engine will run out OK at higher speeds, but it
still runs rough, and seems to be kind of missing when accelerating
from a stop. The dwell is OK, the compression is OK, the engine
only has about 20K miles on it. The carb seems to be OK. I am
wondering if changing to Champion plugs will make a difference? I am
open to any and all suggestions and experiences.
Rule of thumb! AC Delco----->GM Vehicles
Motorcraft----> Ford Motor Vehicles
Champion----> Chrysler Vehicles
NGK -----------> Japanese Vehicles
Bosch----------> German Vehicles
Been doing it this way for 20+ yrs.
in my 99' Ford Windstar I say Motorcraft all the way, but if I remember correctly there was a sticker on the air filter for my 66 Ford Falcon that said to use Autolite Parts so I wonder if the Autolites would still be best or if Motorcraft is now making the closest to OEM
I've had bad luck with Bosch Platinums...my wife accused me of doing
something to the transmission in her 99 Mitsubishi Galant, and
performance was noticeably down after installing Bosch Platinums. I put
the old plugs (ND regular) back in, and performance came back.
I would not waste the money on platinum plugs for this engine.
Motorcraft/Autolite would be the plug of choice.
Let us all know if you find a difference in performance!
Gerard's Automobile Book, Video, and DVD Store
In my Experience, from SEVERAL tries... regular Bosch (single) Plat's, used
in older Fords.. even late 80's Fords... ARE JUNK.
You can love the latest all you want, if you're REALLY open-minded to
idle/cruise performance they stink.
And so are Champions - in Fords, anyway.
Use Motorcraft or Autolite gapped appropriately; .035 for points ignition,
.044 for higher voltage coil/ electronic ignition.
On Wed, 10 Dec 2003 01:59:33 GMT, firstname.lastname@example.org wrote:
I will not condemn the Bosch brand plugs. They indeed make
good products including some that work well in Ford and GM
vehiocles. That said, my luck with any of the Bosch plugs
in my Ford and GM vehicles has been disappointing to say the
least. The old rule of thumb using AC/Delco products in GM
and either Autolite or motorcraft in Ford products has
gotten the best results. Also, you are probably wasting
your money to use anything better or more expensive than
than a regular platinum plug in that engine. While the
platinum tips offer good resistance to erosion and widening
gaps, the older engines will still require regularly
scheduled plug replacements for best performance. I do not
recall where I may have seen this but, there are some
assertians that the platinum tip plugs may provide more
electrical resistance resulting in a poor spark compared to
regular copper tipped plugs. If you have a marginal
ignition system during cranking, this may explain the
problem. You can probably improve ease of starting and
overall engine performance by installing an electronic
conversion like the Pertronix unit or the new unit from
Crane. Both are simple no nonsense installations that fit
entirely out of site within the distributor. This may also
offer enough ignition boost to properly fire the platinum
plugs if that is the problem and, most certainly result in
better overall engine performance over points.
Lastly, make sure you check the voltage to the coil while
cranking to be sure it is in specs. Slightly low cranking
voltage to the coil can really hurt starting.
You have undoubtedly seen "it" on the internet and like many things
found there it is hogwash. Any "extra"electrical resistance of
platinum over other conducting metals would be infinitesimal for the
amount of platinum being used. Similarly, the "copper tipped" plug
claims are also hogwash since there are no copper tipped plugs. There
are copper core plugs but they do not and could not perform any
different then an iron/steel core plug of proper heat range. The only
alleged advantage of copper would be it's somewhat better heat
transfer ability but that can easily be designed around if you want to
use iron instead for the core. Basically, the difference between
plugs is almost all marketing hype aside from the few true differences
such as double electrodes, double plat tips vs single tip, and just
the overall quality of the materials used and manufacturing
If you have a marginal
You will note the way my comments as-stated infer that these
"assertions" may or may not be accurate. I understand the
difference my be very small but, when you are dealing with
the relatively marginal ignition provide by a points system,
the difference may be the make or break point for a good
spark to occur. The are probably other reason that I
haven't even dreamed about. I am no electrical expert but,
after 46 years of screwing around with automobiles, trucks,
locomotives, generators, heavy construction equipment and
marine equipment, I know my own experience and I know the
remedies that have improved the condition - all anecdotal as
they say in this case. I am, generally, not a believer in
multiple tip plugs. It is a fact that an electrical charge
will follow and expend itself over the path of least
resistance thus negating the presence of any additional
points to which it may travel - this may not be true of
multiple discharge systems in which case subsequent impulses
may take a different path utilizing the additional points or
tips. IMHO, the additional tips may also shield the
fuel/air charge from the spark a bit - I do not know. In
any case, marketing hype may get my attention once but, will
only get my money if there is some evidence outside that
hype that indicates the product actually does what it is
hyped to do. The Bosch plugs simply have never performed up
to their hype or as well as some others in the Ford and GM
vehicles in which I have had the patience to install them
only to replace them shortly thereafter with recommended
plugs for a noticeable improvement in driveability and
performance. Maybe, someday, I will conduct the research
and write a thesis on just why this appears to be the case.
Then again, I have to assume that the automobile
manufacturers may have already done the research to
determine what works in their vehicles.
All that said, I usually only chime in when it looks as if
my comments may be useful. I apologize if this is not
always the case. Lastly, none of my comments should be
taken as fact unless it agrees with something you already
know or, you can verify through other means. Don't jump off
a cliff to cure a headache!!!
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