• The Roadster Factory Recovery Fund - Friends, as you may have heard, The Roadster Factory, a respected British Car Parts business in PA, suffered a total loss in a fire on Christmas Day. Read about it, discuss or ask questions >> HERE. The Triumph Register of America is sponsoring a fund raiser to help TRF get back on their feet. If you can help, vist >> their GoFundMe page.
  • Hey there Guest!
    If you enjoy BCF and find our forum a useful resource, if you appreciate not having ads pop up all over the place and you want to ensure we can stay online - Please consider supporting with an "optional" low-cost annual subscription.
    **Upgrade Now**
    (PS: Subscribers don't see this UGLY banner)
Tips
Tips

Spark plug wires 7mm or 8mm

AUSMHLY

Obi Wan
Country flag
Offline
1964 3000 MkIII, BJ8

I'm using a Pertronix ignitor, Pertronix top entry brass distributor cap, (Moss) premium Ignition rotor (red), Lucas Sports coil and Champion RN12YC spark plugs.

What brand and mm spark plug wires are people using or recommended for this set up?

What timing degree would be recommended?

Thank you.
 

Bob_Spidell

Yoda
Gold
Country flag
Online
The stock, stranded copper wires are, I believe, 7mm but most modern suppression wires are 8mm IIRC. I'm guessing a modern cap will use 8mm.

I'd stick with the recommended 15deg BTDC@ 600RPM with the advance disconnected and plugged, or 35deg total at over 3K RPM (if you have an advance meter).
 
OP
AUSMHLY

AUSMHLY

Obi Wan
Country flag
Offline
The Pertronix top entry brass distributor cap I have I'm using 7mm Pertronix wires. I believe it will take 7mm or 8mm?
I was using copper wire but it affected the tach. With
Pertronix wires, tach works properly.
I question if I should use 8mm wires being I have the Lucas Sports coil and Pertronix ignitor.
 

Bob_Spidell

Yoda
Gold
Country flag
Online
Call Pertronix; in the past, at least, they have been helpful. Note Pertronix specifies an impedance min/max, so you might want to verify a Lucas Sports Coil meets their specs (I suspect you won't be the first person to ask).
 
OP
AUSMHLY

AUSMHLY

Obi Wan
Country flag
Offline
Will do. Read posts where Lucas coil and Pertronix ignitor are used. Haven't read about which spark plug wires in mm or brand.
 

steveg

Yoda
Gold
Country flag
Offline
I'm using Pertronix 7mm Stealth wires with my top-entry 22D distributor & Pertronix II ignitor. They make these plain black sets for those who want a period look without the bling. I gave up on the straight boots as I kept pulling the wires out of the terminals.

IMO the Lucas sports coil is fine with the Pertronix. Pertonix doesn't recommend copper wires anymore, although everyone says they work fine with Pertronix I but not with advance timing lights.

Some British racers had Pertronix failures due to imperfect grounds through the various joints in the distributors. I ran a separate ground wire from the Pertronix mounting plate to the chassis at the coil mount. Belt-and-suspenders.

screenshot.1881.jpg
 

dougie

Luke Skywalker
Country flag
Offline
Dougie - what is the black pipe going rearward from the upper radiator hose?

I thought you would pick-up on this quicker, here's my responces to Linwood's PM right after my post.

HAHA.....I wondered how long it would take and who would respond on this. So what we've found through many race hours and dyno testing, the rear cylinders don't get
enough cooling/water flow and always runs much hotter then the rest. (back to the poor head design) Solutions is to increse flow.
1f609
 

steveg

Yoda
Gold
Country flag
Offline
I thought you would pick-up on this quicker, here's my responces to Linwood's PM right after my post.

HAHA.....I wondered how long it would take and who would respond on this. So what we've found through many race hours and dyno testing, the rear cylinders don't get
enough cooling/water flow and always runs much hotter then the rest. (back to the poor head design) Solutions is to increse flow.
1f609

Thank you for the answer. Very interesting. Could do without the snark, though.
 
OP
AUSMHLY

AUSMHLY

Obi Wan
Country flag
Offline
When is it time to replace spark plug wires?

How do you determine if they are good? I've tested them with an ohm meter and get different reading depending on length. I'll assume if it getting a good reading, the wire is good?
Do they eventually start wearing out and it's just a good idea to replace them?

Some shops install new everything when they do a tune up. Points, cap, wires, plugs.

As a side question, what about the Pertronix Ignitor replacement. It's good until it's not working, or to be safe, replace after x yrs or miles?
 

John Turney

Yoda
Silver
Country flag
Offline
What goes bad on the wires is the insulation. If you run the car at night in a dark garage (with the door open) and see sparking, it's time to replace. If you touch the wires when the engine is running and you get "bit", it's time to replace.
 

Keoke

Great Pumpkin
Country flag
Offline
What goes bad on the wires is the insulation. If you run the car at night in a dark garage (with the door open) and see sparking, it's time to replace. If you touch the wires when the engine is running and you get "bit", it's time to replace.

YEP , However since we are alking about new wire the one that fits the hole in the diszzy cap is the one to use. Stranded copper wire works good for me
combined with resister plugs.
 

LarryK

Yoda
Gold
Country flag
Offline
Open bonnet in the dark, fire up engine, see sparks, replace wires. Easiest way.
 

Bob_Spidell

Yoda
Gold
Country flag
Online
... As a side question, what about the Pertronix Ignitor replacement. It's good until it's not working, or to be safe, replace after x yrs or miles?

Theoretically, they should last forever. A few years ago I replaced the one in my BJ8--I wanted to carry a spare, ready to go, so I installed the new one and put the old one in the boot--but it wasn't a drop-in as they've changed the baseplate and the car needed to be re-timed. I'd put probably over 75K miles on the old one, and it was running fine.

I had an old '79 Subaru, and it had a module that looked just like a Pertronix, and it was going strong at 175K miles.
 
OP
AUSMHLY

AUSMHLY

Obi Wan
Country flag
Offline
When asking a shop for a tune up, why do they replace everything. Cap, rotor, points, wires and spark plugs.
Don't they check the wires to find out if they need to be replaced?

Replacing / selling wires makes a profit?
Labor to check each wire is more then the cost of a set of replacement wires?
Don't take any chances, replace the wires?
Gives guys like us something to discus?
 

LarryK

Yoda
Gold
Country flag
Offline
I learned when I first started started working on cars, my Dad worked for a shop and would reccomend full cap, rotor wires, etc every couple years, was a given back in the 50s. Then, I worked in a shop and an older Master Mechanic (not technician, they weren't around yet) asked me what a tune up was. Explained the proceedure my Dad taught me and he said "No!" "A tune up is the fixing of a running problem!" " If you replace everything you hide the problem and it will come back!" "Fix the problem, then do the maintenance!" Back then, you would take the time to check each wire with an ohmeter and disassemble carbs starters and generators. Hourly wages and shop charges prevent that today as (technicians) can't do it.
 

Keoke

Great Pumpkin
Country flag
Offline
When is it time to replace spark plug wires?

How do you determine if they are good? I've tested them with an ohm meter and get different reading depending on length. I'll assume if it getting a good reading, the wire is good?
Do they eventually start wearing out and it's just a good idea to replace them

Some shops install new everything when they do a tune up. Points, cap, wires, plugs.

As a side question, what about the Pertronix Ignitor replacement. It's good until it's not working, or to be safe, replace after x yrs or miles?

Just carry a spare dizzy in the boot
 

steveg

Yoda
Gold
Country flag
Offline
Just carry a spare dizzy in the boot

Agree.

Because I run a Pertronix II, my spare dizzy, cap and wires are set up with a Distributor Doctor condenser and points in the hope that if something fries my Pertronix, the same issue won't fry my condenser and points.
 

Bob_Spidell

Yoda
Gold
Country flag
Online
All this talk about frying to me to thinking about what could fry a Pertronix (and breakfast). It's well known a Pertronix 'I'--they were never called that AFAIK--can be cooked if you leave the key in the 'run' position with the engine off for more than a few minutes (but the II, I believe, has protection for this). All they do is switch 12V to the coil so, but if your voltage regulator went bonkers and put very high voltage into your system it could kill one, but this isn't likely (I did have a VR fail and overcharge my battery, but the Pertronix survived). If your coil developed a dead short on the primary circuit your engine wouldn't run, of course, but if you left the key on 'run' you'd kill your Pertronix in short order. Otherwise, I've not heard of a lot of them failing, and when they do it's all or nothing. I've got Pertronix Ignitors on 4 cars and none of them have ever failed (granted, 3 of them haven't been driven a lot of miles). However, I've been hearing about quite a few condenser failures in recent years.
 
Similar threads
Thread starter Title Forum Replies Date
K TR2/3/3A Testing spark plug wires..... Triumph 11
longbridgehealey Spark plug wires Austin Healey 8
S Correct colour BJ8 Spark Plug Wires / HT Leads Austin Healey 7
M Restoring proper order to spark plug wires Triumph 36
Musicman Spark Plug Wires Triumph 10
L Spark Plug Wires Triumph 12
AUSMHLY Spark plug wires affecting tachometer? Austin Healey 16
1 Spark plug wires gone 'haywire' Spridgets 16
tosoutherncars Q - spark plug wires Spridgets 3
Got_All_4 TR2/3/3A TR3A Spark Plug Wires Any Good Ones Out There? Triumph 11
K Best spark plug wires with Pertonix:what to use? Racing 1
K "Bumblebee" spark plug wires....... Triumph 10
AUSMHLY Spark plug wires Austin Healey 8
danielnorton Spark plug wires Spridgets 6
Woodie spark plug wires Spridgets 2
Woodie bosch spark plug wires Spridgets 5
C Spark plug wires MG 14
T Cut/Splice Spark Plug Wires?? Triumph 13
W Replacing spark plug wires Restoration & Tools 1
tahoe healey spark plug wires Austin Healey 11
CARSINC Spark plug thread size Spridgets 2
JohnGone MGB 1980 MGB Spark Plug recommendations MG 6
K TR2/3/3A Spark plug inspection Triumph 5
PAUL161 T-Series Odd spark plug encounter! MG 10
G Opinion on spark plug color Austin Healey 15
Lin Distributor to Spark Plug lead wire continuity Austin Healey 5
K TR2/3/3A Spark Plug Gap? Triumph 4
K Numbered Spark Plug Boots? Austin Healey 27
B Spark Plug Wire Caps Austin Healey 16
B TR6 Spark plug gap Triumph 5
toysrrus TR6 Spark plug question Triumph 23
K TR2/3/3A Spark Plug cuts and diagnosing? Triumph 13
G Correct spark plug ends - early BJ7 Austin Healey 1
R BJ7 spark plug threads Austin Healey 17
SherpaPilot TR6 Single Spark Plug is Burned Triumph 12
steveg Accidentally deleted Spark Plug Issue thread Austin Healey 2
steveg Spark Plug Issue Austin Healey 54
S TR2/3/3A Spark plug threads Triumph 10
R '60 3000 Spark Plug recommendations Austin Healey 6
D TR6 Spark Plug Triumph 8
dcoplan Spark plug and oil change question Spridgets 9
H BJ8 spark plug reach Austin Healey 32
Jer chasing spark plug threads on head? Spridgets 8
R Spark plug thread Triumph 2
T TR2/3/3A TR2/TR3 spark plug gap setting?? Triumph 8
D Spark Plug Gap Austin Healey 10
W Source for spark plug terminals Spridgets 9
af3683 TR2/3/3A TR3 Spark Plug Wire Question Triumph 11
JPSmit Quick Spark plug question Spridgets 10
Got_All_4 TR2/3/3A TR3 spark plug wire problems Triumph 3

Similar threads

Top