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Ignition Timing Page

      UPDATED: February 13, 2024         CONTACT     
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  This page offers a bunch of useful knowledge about Volvo ignition stuff that I have learned over many years. If you have any comments or questions or if you can help to improve this information, please email.
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Factory 240 Ignitions
Ignition Timing
Non-Factory Ignition Options MSD Ignition Amplifier
How to Make Custom Spark Plug Cables
Spark Plug Cable Resistance
240 Factory Ignitions
I will not be getting into old points distributor ignitions. I'll begin with early Volvo 240 electronic ignitions, since most 240s found in the US and Canada have electronic ignitions.

The most common ignitions found in 240s in the U.S. will be as follows:

 Breakerless Electronic Ignitions were found in the 1970s and early 1980s up to 1982 (for Bosch K-Jetronic injection equipped non-turbos) and up to 1985 for the 240 Turbo. This was a Bosch ignition system with a RED distributor cap. It had a smaller ignition control unit box placed under the hood.
Detailed FUNCTION DIAGRAMS can be found in my Harness Page for both versions.

Computer Controlled Ignitions (Chrysler) were believed to have begun with the 1981 240 equipped with Bosch K-Jetronic mechanical fuel injection (engine designation: B21F MPG). This Chrysler designed ignition was carried over to the 1983 and 1984 240 non-turbo, which had Bosch LH 2.0 electronic fuel injection. This ignition could be recognized by a larger ignition control unit box mounted on the right inner fender. Early year cars would have a WHITE distributor cap. In 1983-84 you will might find a WHITE distributor cap or a RED distributor cap, so the distributor type varied, but the ignition control units did not. 
Detailed FUNCTION DIAGRAMS for these systems may also be found in my Harness page.

Beginning in 1985 for the new B230F equipped 240, a newer version of the above
Computer Controlled Ignition (Chrysler) was found in 240s through 1988. These 240s were all equipped with Bosch LH 2.2 fuel injection.
This ignition could be also recognized by a large ignition control unit mounted on the right inner fender, but the distributor cap was RED again for all 240s from this point forward.
Detailed FUNCTION DIAGRAMS for these systems may also be found in my Harness page.


With the introduction of Bosch LH 2.4 fuel injection, the 1989 to 1993 240 began getting the Bosch EZK (EZ116K) ignition, which was very similar to EZK ignitions in 700 models. The ignition control unit for this 240 was found under the right side dash near the Bosch EFI control unit, so no ignition module is found under the hood in a 240 after 1988. The distributor had a RED cap.

Detailed FUNCTION DIAGRAMS for these systems may also be found in my Harness page.

Ignitions with a Ballast Resistor connected to the coil.
Questions about ballast resistors will come up occasionally, so I thought I would mention what these were for and what coils were normally used with them or without them. In 240 ignition systems, the early Bosch Breakerless Ignitions (B21F, B21FT and B23F) and the late-1982 Computer Controlled Ignition (Chrysler) (B23F) were all equipped with Ballast Resistors to reduce voltage to the coil to about 9 volts during normal running. The type of coil used in these systems were designed for and required this voltage reduction in order to promote coil longevity (Coil PN 1219230, Bosch 0221122006). Allowing these coils to run with a full 12 volts constantly will cause them to fail.

The ballast resistor in a 240 can be found on the right inner fender near the firewall, not very far from the wiper motor. This one is Volvo PN 1266014, Bosch 0 227 900 010, for B21 or B21FT.

  Volvo ignitions beginning in 1983 (for B23F) and beginning in 1985 (for B230F) no longer used Ballast Resistors and the types of coils in these cars were of a different design. With this in mind, I think it's important to make sure your 240 is using the proper type of coil. If there's a question about a Bosch coil you have, you can measure the primary resistance to see what type it is.
Coil Primary Resistance: 1.9 0.1 Ω: For use WITH ballast resistor.
Coil Primary Resistance: 1.2 0.1 Ω: For use WITHOUT a ballast resistor.


Also this article helps explain a lot on this subject: https://www.burtonpower.com/tuning-guides/tuning-guide-pages/ignition-systems.html

 
Ignition Timing
This section will begin with BASIC Volvo ignition timing stuff and then slowing introduce more advanced stuff. If you're a novice in this subject, I recommend that you read this beginning from here and absorb it one section at a time (don't skip around). I guarantee you'll learn a lot about Volvo ignition timing. If you're already advanced in this subject, I think you'll learn some things too.

IGNITION TIMING BASICS
An example: This image offers a good example of basic ignition timing advance. Volvo B21FT (1981-85).
 

Volvo Ignition System Manual TP30432 pg 16.
I altered the above map to make it more simple. It only shows RPM and degrees of ignition timing. It does not show static base timing at idle or vacuum/boost timing adjustments. It only shows the timing advance the bare distributor will provide. If you need to know, the base timing at idle for a B21FT is 12 BTDC (Before Top Dead Center).

To keep this simple for now, this map doesn't take into account variable changes in engine manifold vacuum or BOOST. The factory B21FT ignition system will compensate for engine vacuum and boost changes, creating small adjustments in the timing map, which are designed to achieve good performance with regard to power, gas mileage, emissions and safety from too much timing advance during boost (or over-boost). More info about this will be explained later. 

This B21FT timing ramp is generated by a centrifugal (mechanical) advance inside the distributor. The reason why it's max is
24-28 is because it's not precise enough to choose just one precise setting. Don't expect miracles from 1970s tech. Once it reaches the max time of around  25 to 26 it will maintain that level until redline.

If the above timing map was laid out like a more modern timing map (and nothing is added for base timing at idle), it would look like this chart below. 
RPM
9001000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
Degrees
10
(provided by distributor mechanical advance)
12
18
22
26
26
25
25
25
25
25
25
The reason why I made this chart without adding base timing at idle is to show ONLY the timing advance the distributor will provide. If you're questioning why there's 10 shown at idle below, it's because the centrifugal (mechanical) advance in the distributor adds 0 of timing with the engine off, but 10 of timing at 900 RPM. If you wanted to zero that out at idle, you would need to rotate the distributor to change it to 0 at idle. If this was done, then the other numbers on this map would be off by 1 0. So I made this map above with standard distributor advance only.

But don't worry about the above info if it's confusing. If the B21FT timing map was laid out like a more modern map AND if I included 12 base timing at idle, it would look like this below.  To achieve this, all I would need to do is rotate the distributor + 2 to get 12 at idle.
RPM
9001000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
Degrees
12 14
20
24
28
28
27
27
27
27
27
27
So what you now see above is the base timing for a B21FT.

Ignition timing is a very wide subject with a lot of chapters. We'll get to all of it slowly. HOWEVER, if you have a bone stock engine, then the idea of changing or setting ignition timing for YOU might only concern where to set the base timing at IDLE. Your factory ignition system will have a preset range of ignition timing advance for running above idle and you may not be able to modify that.

So what can you do with a Stock Engine?
For those of you with factory systems that can't really be "tuned," just about the only thing you COULD change if needed would be to alter the ignition timing at idle. So if, for example, your factory ignition timing at idle is 12 BTDC and your preset timing map is maxed out at 26, if you were to adjust your idle timing from
12 to 16, then your max total timing would change from 26 to 30. Adding the extra 4 degrees at the top might help or it might not help. We'll discuss this later.

From my old Chevy hot rod days: An old hot rod trick for performance was to add as much EARLY initial ignition advance as you can get the engine to handle at lower RPMs, beginning at or just above idle.  For example, suppose you have a factory distributor with a mechanical advance that advances timing 24 degrees maximum. If your factory idle timing is set at
10 BTDC, your total timing would be 34 degrees.  If you were able to modify the distributor to have only 10 degrees of total mechanical advance, then if you set your ignition timing to 24 BTDC, the total timing advance hasn't changed, but hot rodders discovered this mod increased power at a much earlier RPM. This can help the engine launch harder out of the hole and give you stronger starts from light to light. If done correctly, this can offer better throttle response, a better idle vacuum signal, and it can help the engine run cooler. 
 
CAUTIONS TO UNDERSTAND: An engine with timing advance that's too late (too retarded) will have lower idle vacuum, slower throttle response, it can feel like a turd at lower RPMs and it can run hotter than normal. An engine with the timing too soon (too advanced) could have an erratic vacuum signal or it might back-fire through the intake manifold. It might have a snappy throttle response but might not pull well under load. And the engine will be more prone to pre-ignition (detonation) or "pinging" under load, especially if the engine is boosted.

Later Volvo systems made after 1989 have removed the possibility of doing any idle timing adjustments, because these later systems use a crank position sensor to keep track of engine timing, instead of the ignition distributor.  These later systems can be modified with special "chips" and custom programming to the ECU, but otherwise it's pretty hard to make adjustments on a later car apart from leaving it stock.

If you're interested in custom tuned chips for LH 2.4 and EZK ignition for later Volvos, they're available in the U.S. here: https://www.redblockpowered.com/


COMBUSTION BASICS

Your familiar with the basic functions of a 4-stroke engine and the four cycles; INTAKE, COMPRESSION, COMBUSTION and EXHAUST. When concentrating on IGNITION TIMING, we only need to focus on COMBUSTION. 
An animated gif of a 4-stroke engine can be seen at: https://energyeducation.ca/encyclopedia/Four_stroke_engine

FOCUSING ON TIMING IN COMBUSTION

Picking the right place to create IGNITION SPARK in the combustion cycle is about matching the peak in-cylinder combustion pressure to a point in the cycle where it has the most leverage on the crankshaft during the POWER STROKE, which begins just after TDC (Top Dead Center).

What is peak in-cylinder combustion pressure?
In-cylinder pressure is the pressure in your cylinder during the combustion stroke. The pressure is caused by the ignition of fuel mixed with air.
The fuel in the combustion chamber doesn't really explode. It's not instantaneous. It BURNS. This burn can be measured in milliseconds, so it takes time. The PEAK pressure happens when the fuel combustion has made the biggest "flash" possible in the burn process. If you were to video the fuel combustion and then watch it in ultra slow-motion, you might see when that brightest "flash" occurs. That will be your peak in-cylinder combustion pressure. This PEAK offers the BEST benefit if it's timed to happen at a certain point.

  Back to the discussion of leverage.
Experience tells us the best crank leverage occurs around 12
to 15 ATDC (After Top Dead Center). If we understand that, then we need to move ignition spark timing ahead to compensate for different fuel burn rates associated with engine speed, cylinder filling, temperatures, various air/fuel mixtures, and more. Whatever timing value we come up with to get this "perfect" formula is called MBT Timing (Maximum Brake Torque Timing), because it results in the best possible torque, or leverage, when pushing the crankshaft DOWN during the power stroke.

If we decided to just time the spark at
12 to 15 ATDC it would be too late, because the fuel needs time to burn. We need to ignite the fuel ahead of time. So when you see that an engine at idle is set to spark at 12 BTDC, you can get the picture that the fuel needs time to burn before it reaches the best combustion pressure at 12 to 15 ATDC. If you're trying to determine precisely where MBT Timing is for your engine, that can be done on a dyno, even at lower RPMS if necessary. Have a look at the video below. That's a technique used to find MBT Timing.

From 12 BTDC to
12 ATDC is 24 of engine rotation; If you're a math nerd, you can figure out how much time it takes for the engine to rotate 24 at 900 RPM (15 revolutions per second). Nevermind, That's 0.004 seconds (4 milliseconds). If you search hard you'll find info suggesting that a gasoline/air mixture can take as low as 0.002 seconds (2 milliseconds) to light. The key to all this is timing the PEAK of that burn to push the piston at the right time (see MBT above). This burn might occur a bit faster or slower depending on air/fuel ratio, engine compression ratio (affected also by boost level), etc. Then as the engine speeds up, it needs a bit more spark advance to get the fuel burning in time. So an ignition system will take advantage of this and add a little more spark advance after idle.

This image below will offer some comparisons of fuel burn speed. Different fuels are shown, as well as different CRs (compression ratios). Higher CRs burn faster than lower CRs. This also means a turbo boosted fuel mixture burns faster. This is an easy thing to understand, since we already know that compressing the fuel mixture makes a more dense mixture, which releases more power when it burns. The higher compression the better. It explained why a 20:1 CR diesel engine can create huge torque numbers.

The OTHER thing we can discover from this image is the fuel burn speed compared to the mixture. 1.0 Lambda, or stoich, for gasoline has an air/fuel mixture of about 14.7 to 1. This image shows us that the fastest combustion occurs near stoich (1.0 Lambda) or maybe slighter richer than stoich for some fuels.  If you go too lean or too rich, the combustion speed slows down and these graphs support that, BUT the speed drop-off is not dramatic. It's a very small drop. So if you're wondering what the point of this part is in relation to TIMING, here it is. There are some theories out there (and some videos and articles) which suggest the speed of fuel combustion should be compensated by the amount of ignition advance: i.e; a LEANER mixture should get MORE timing advance and a RICHER mixture should get LESS timing advance. Maybe there's a small point to that reasoning, but it's my opinion the burn speed differences are way too small to allow this micro-crap to take up your valuable time and energy.  Feel free to email me a comment if you disagree.



For this next timing section, I want to go beyond the basics. We can call it Basics Plus.
I want to discuss ignition timing in your engine for the broad range of engine RPM, which you might choose to set if you COULD change settings for more power, better economy, etc.
The below video offers a good look at the basics of how tuning the ignition timing can be done for the benefit of more power.
Dyno testing ignition timing for maximum power through the engine RPM range. Naturally aspirated (non-boosted).
https://www.youtube.com/watch?v=AX2bn_4GEDI

When you're deciding what to do with spark timing as the RPM increases, videos like this can help.
There are a few fundamentals you should know.

1.  The timing map should generally be created from idle to redline (redline being your max usable RPM).

2. Testing like in the above video should first be done at FULL-THROTTLE with no vacuum spark advance devices and (if a turbo) no boost spark retard device. Also if it's a turbo, no boost should be allowed in this testing.
In the above video, this engine is tested through the RPM range a number of times. In the first tests, the spark is set at a low static setting. This can begin at i.e. 15
BTDC (Before Top Dead Center). This 15 setting is used through the full rev-test. No advance is allowed. This way the engine performance can be measured at all RPMs at that static spark setting.  Then another test is done at a higher spark setting (i.e. 20 BTDC). Then another at i.e. 25 BTDC, etc. Watch how that's done in the video. This will eventually give you a good idea how the engine runs at full power at various RPMs with each spark setting.  Then you can use that info to begin creating a basic spark advance map.   

3. The total timing upper limit in most cases for a naturally aspirated engine should be approximately between 25 and 35 degrees, including the base ignition timing at idle. This is the max spark timing that you will allow at any RPM. This means that if we assume your base idle timing is 12 degrees BTDC, then you have another 13 to 23 degrees to figure out after idle. Since I'm sticking to BASIC info for now, I won't go into any detail about a boosted engine yet, except to say that most boosted engines will always have a way to reduce total timing when under boost.  More info later on boosted engines.

There is some accepted theory in the small aviation engine world about base ignition timing numbers that I want to share. The reason I have such obscure info in my head is because I use SDS EFI ( www.sdsefi.com) in my 242. Besides being used in racing engines, SDS EFI is also used in aircraft engines. In the aviation world the accepted maximum total timing advance for a PARALLEL VALVE engine (Lycoming for example) is 25 degrees.  The max for an ANGLE VALVE engine is 20-22 degree s. I can't vouch for the relevance of this for a Volvo engine. It's just more random info to help keep your mind cluttered with "stuff."  A Volvo B21, B23, or B230 is a parallel valve engine. A Volvo B234 (16 valve DOHC) is an angle valve engine.   


4. Most of the timing increase in your ignition map will happen between IDLE and CRUISING RPM.
Anywhere from 2500 to 3000 RPM would be appropriate, however I'll use 2500 RPM for cruising, which represents a good general mid-range cruising speed. So if we look at the B21FT example, the timing between idle and 2500 RPM is from 12 to about 27. Then if there's any timing left in your maximum, that can be added between 2500 RPM and redline.

Here's a simple example base map below of how this might look using the numbers in steps #3 and #4 above. This gives you a base, or a beginning point to start, before you introduce other things that will add to the confusion and make more changes to timing. If you don't know what numbers to use when you're starting an ignition project, the best numbers will mimic what the stock factory ignition system used until you know what changes to make.

900 1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
12 14
20
24
28
28
27
27
27
27
27
27
If you have no idea how to actually test your engine to get this information or if you just want a basic timing map to begin with and can't do real testing, then try to find the factory timing map, or you can try the above base map to get you started.

PRE-MADE BASE MAPS
If you're using an aftermarket engine management system, you should know that some systems will have pre-made base maps for lots of different engines, which you can use as a beginning point if needed. Haltech and MaxxECU are some that offer base maps in their programs for almost any engine ever made.


WARNING TO NOT PURSUE MORE TIMING UNLESS YOU KNOW.
You WILL be tempted to add more total timing, because you'll read or hear somewhere that more timing is more power. This is only true until more timing reduces power.
You will probably see spark maps made by other people who tell you 30 or 35 degrees or more of total timing works for their engine. Before you copy those maps, let's have another discussion about this image so you can have a better understanding of why more timing might not be a good idea.
 

The above image shows spark occurring at TDC (Top Dead Center). If you've been reading, you know that the spark actually needs to begin the fuel burn before TDC for the fuel to burn in time. Now look at the image above with "
12- 15 ATDC". It shows burning fuel is pushing the piston down. The best location for the best leverage for that burn energy to PEAK is at 12-15 ATDC. That's a pretty specific place, isn't it?
This should give you a clue that precision is king here.


So if you add more timing and the fuel burn begins too soon, then some of that energy gets used up before the piston can get into the best position to be pushed down. In simple terms, that results in less power available to push it down. It's easy for this to happen without you noticing if you choose more timing than the engine needs. The ultimate test of course is dyno testing. So this is why I recommend staying with FACTORY NUMBERS for this map until you test it or until you find a real reason to change.

Take a few minutes to watch this video. This guy is dyno testing a 400 plus HP V8 that's mostly stock with a few mods. The factory ignition has maxxed out timing at
only 18 BTDC. He decides to test the power at 18, 20, 22, 24 and 26 BTDC. He finds the most power with a max of 26. If he had used someone else's map with total timing different than 26, he would have risked getting less power.
https://www.youtube.com/watch?v=kRdHfMgkCwk



Beyond the Basics. Using Vacuum to further alter Timing (part-throttle cruising).
The next step for your ignition is to find out if slightly different spark timing could improve things at certain RPMs under PART-THROTTLE (when your engine sees the most manifold vacuum).
Remember, the above spark advance map and discussion was all about finding the best FULL-THROTTLE settings. Now we can look at part-throttle. The best example of part-throttle is cruising on the highway is at around 2500 rpm. This is not the same as the 2500 RPM timing we discussed in the previous section (that was for POWER). Now we're discussing cruising only.

Some engines will become more efficient if the timing is advanced a bit during part-throttle cruise. This was the reason why many cars (including old Volvos) had vacuum diaphragms on distributors. These improvements in the engine might be harder to measure. It's still possible using a dynamometer, but most people just do these tests on a highway. If you goof in this area then you probably won't hurt the engine. You might only get less gas mileage. 

For example, if your using the 2500 RPM setting of
28 from the below table, you might find that during part-throttle cruise the engine would do better with a little extra spark advance. An ignition system that can read changing manifold vacuum levels and use info that to make timing adjustments during part-throttle cruise for better economy is a good thing.

900 1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
0 inHG 12 15
20
28
28
27
27
27
27
27
27
10 inHG



35







In the above table I have added a parameter for vacuum.  It's measures in inHG in this example. This means Inches of Mercury, which is a very common way to measure vacuum. It's the most common method used by auto vacuum gauges. Zero inHG is basically ambient atmospheric pressure at sea level. This is the same reading you'll get with your engine off. On the other hand your engine might reach up to around 25 inHG vacuum under closed-throttle deceleration (engine braking). The maximum vacuum possible is about 30 inHg, but that will be higher than your engine will ever actually get.

The above vacuum-boost gauges are pretty common. The first one here uses inHG to measure engine vacuum.  The other uses inHG to measure vacuum and PSI to measure boost.

kPa (Kilopascal) for Vacuum/Boost Measurement
You'll find that there are lots of spark advance tuning maps out there that use OTHER parameters for vacuum or boost.
kPa (Kilopascal) is a very common one for ignition maps (but not normally used for a vacuum gauge). kPa is commonly used to measure both vacuum AND boost. If you need to convert from one parameter to another, there are easy to find conversion calculators on-line.

With most engine tuning tables that use kPa, 100 kPa will basically represent ambient atmospheric pressure at sea level. Anything under 100 kPa is vacuum. Anything over 100 kPa would be pressure, or boost. 

 
An automotive gauge measuring vacuum in kPa is not as common, but if you had one like ABOVE, it would read near ZERO with your engine off. Y
our engine might reach up to around 850 kPa vacuum (8.5 x100) on this gauge under closed-throttle deceleration (engine braking). The maximum vacuum possible will be about 1000 kPa (10 x100) on this gauge, although your engine will never actually get that high.

Most engine tuning tables using kPa will measure it differently than the above kPa gauge does. On such a table, 100 kPa will usually represent normal pressure at sea level. This would be the reading you see with your engine off.
Once you begin working with tuning tables like this, you get used to it really fast. Here's another example:

900 1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
100 kPa 12 15
20
28
28
27
27
27
27
27
27
65 kPa



35







In the above table I have changed the vacuum parameters from inHG to kPa.  In this table, 100 kPa will be what you see with your engine OFF. Less than 100 kPa is vacuum. The maximum vacuum possible is ZERO kPa, although that will be more vacuum than your engine will ever actually have.  So, if your using the 2500 RPM setting of 25 BTDC, like in the above table, you might find that during PART-THROTTLE cruise the engine might read around 65 kPa vacuum, and at that vacuum level the engine might run better with some extra spark advance. The above 65 kPa row with 35 instead of 28 is an example of an adjustment that could be added for better part-throttle performance.

It's not uncommon for cars to add 15 degrees or more to the standard timing map just for this kind of freeway economy arrangement.  Many OEM ignitions using a vacuum diaphragm or programming have added such an increase of 15 degrees or more.



Using Vacuum AND Boost to Alter Timing.
An example: A Volvo B21FT (1981-85) will typically have an ignition timing advance map like this one below.
 

Volvo Ignition System Manual TP30432 pg 16.
This is the same distributor timing map I showed you before for the B21FT, except I have now added information for the dual vacuum/boost diaphragm on the distributor. This dual diaphragm was considered to be pretty advanced in 1981 and it worked well for a B21FT at the time. It looks similar to diaphragms on non-turbo engines of the era, but those control timing advance only during part throttle cruise. 
A detailed explanation of this diaphragm is below.

  This Diaphragm when under VACUUM.
This diaphragm advances ignition timing when vacuum is present, except at idle (more details on this in the Ported Vacuum section). This advance function is primarily for economy. The diaphragm can advance timing up to about 12 to 16 degrees over the normal timing map during part-throttle cruise. An increase like this offers more part-throttle engine torque at a point when it's safe, because the engine is not under a great load during part-throttle cruise. This helps to increase fuel economy.

This Diaphragm when under BOOST.
This part of the diaphragm retards ignition timing when BOOST is present. This is primarily for engine safety reasons. An engine under boost and load develops a lot more torque and more cylinder pressure. More torque is awesome, but it comes with a lot more stress and heat, which can damage the engine. So this is designed to protect the engine by retarding the timing curve as boost increases. The amount of boost retard with this diaphragm was set to max out at about 6 to 10 degrees at about 6 PSI for early 240s. Volvo info suggests this changed to about 3 to 7 degrees at full boost for later versions with the intercooler boost system (late 1984). Full boost for an early B21FT was set at 6 PSI (42 kPa), or 7.1 to 8.2 PSI (49 to 56 kPa)
for later versions with the intercooler boost system (late 1984). Maximum power for the early B21FT was about 131 HP and 155 ft lbs torque, or about 162 HP and 181 ft lbs. torque for later versions with the intercooler boost system (late 1984). 

As a bit of 240 Turbo trivia, the European version B21ET offered more turbo boost than a U.S.A. car. The B21ET  developed about 9.2 to 10.1 PSI (64 to 70 kPa), which gave the B21ET more power: 145 HP and 167 ft lbs.torque. Later B21ET cars were never officially fitted with intercoolers from the factory, but later B19ET cars were (for the Italian market). The B19ET was the same as a B21ET, except with a smaller bore. The later intercooled B19ET cars had 11 to 12.1 PSI (76 to 82 kPa) and developed 170 HP and 184 ft lbs. torque.

If the above B21FT distributor timing map was laid out like a more modern map, it would look like this below. Note that the above map uses 0 kPa (zero kPa) for ambient atmospheric pressure. So this sample scale will do the same.
In this example, nothing is added for base timing at idle. Idle will be 0. You would not use this to set your timing. I'm showing this to demonstrate ONLY what the timing advance that the distributor providing using it's advance or retard mechanism. If you're questioning why some numbers on the vacuum side seem to be off by 10, this is because the centrifugal (mechanical) advance in a B21FT distributor adds up to 10 of timing at 900 RPM, so the distributor would need to be rotated BACKWARD to achieve 0.
Boost

900 1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
+40 kPa -8
-8 -6 0 4 8 8 7 7 7 7 7 7
+30 kPa -6
-6 -4 2 6 10 10 9 9 9 9 9 9
+20 kPa -2
-2 0 6 10 14 14 13 13 13 13 13 13
+10 kPa
-0
0 2 8 12 16 16 15 15 15 15 15 15
0 kPa

0 2 8 12 16 16 15 15 15 15 15 15
-10 kPa +0
0 2 8 12 16 16 15 15 15 15 15 15
-20 kPa +5
5 7 13 17 21 21 20 20 20 20 20 20
-30 kPa +14
14 16 22 26 30 30 29 29 29 29 29 29
-40 kPa +15
15 17 23 27 31 31 30 30 30 30 30 30
Vacuum













If the large number of boxes in this image above seems like too much to grasp, you can just concentrate first on the base map in the middle inside the GREEN boxes. That base map will be the spark timing advance for this engine before it sees any changes caused by vacuum or boost.

Here's another example below. In this example, I have included base IDLE timing, which is 12 BTDC at 900 RPM. Since the centrifugal (mechanical) advance in a B21FT distributor adds 10 degree automatically at 900 RPM,setting this idle timing to 12 means the distributor gets adjusted +2.
So the purpose of this map below is to show you the actual, real world timing that a B21FT sees with all devices in working order.
 
Boost

900
1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
+40 kPa -8
4 6 12 16 20 20 19 19 19 19 19 19
+30 kPa -6
6 8 14 18 22 22 21 21 21 21 21 21
+20 kPa -2
10 12 18 22 26 26 25 25 25 25 25 25
+10 kPa
-0
12 14 20 24 28 28 27 27 27 27 27 27
0 kPa

12 14 20 24 28 28 27 27 27 27 27 27
-10 kPa +0
12 14 20 24 28 28 27 27 27 27 27 27
-20 kPa +5
17 19 25 29 33 33 32 32 32 32 32 32
-30 kPa +14
26 28 34 38 42 42 41 41 41 41 41 41
-40 kPa +15
27 29 35 39 43 43 42 42 42 42 42 42
Vacuum













If the large number of boxes in this image above seems like too much to grasp, you can just concentrate first on the base map in the middle inside the GREEN boxes. That base map will be the spark timing advance for this engine before it sees any changes caused by vacuum or boost.


PORTED VACUUM versus MANIFOLD VACUUM
In a paragraph above I mentioned that the B21FT distributor diaphragm modifies ignition timing when vacuum is detected, except at idle. In this section I want to discuss further what happens at idle and just above idle in an engine using PORTED VACUUM.
  Engines like the the B21FT have a throttle body with special ports on the side. The vacuum line to the distributor diaphragm does not come from a manifold vacuum source. It comes from a port on the throttle body. You can see BELOW this throttle body has two very small vacuum ports on the side facing the cam cover. I've labeled them PORT 1 and PORT 2 in the below images.  The opening in PORT 1 is slightly smaller than PORT 2.
Both ports are in a position near the edge of the throttle valve which opens toward the incoming air. Due to the positions of these ports, they do not see vacuum at idle. They see only ambient atmospheric air pressure at idle.  When the throttle valve begins to open, the ports will then be below the throttle valve and that's when they'll see PORTED VACUUM. So this ported vacuum will advance timing in the diaphragm under part throttle (initial part throttle push or during part throttle cruise). 
 

<<< The vacuum diagram at left is from TP30727 Volvo greenbook discussing 240 emissions. It shows PORT 1 (or line A) going to the distributor diaphragm. 
Let's continue looking at how this vacuum line affects ignition timing in a B21FT. The initial timing at idle is set to
12 BTDC by setting or rotating the distributor. The above B21FT ignition table shows us that additional timing advance will occur when the diaphragm sees vacuum, but with this configuration, this PORT 1 vacuum circuit has no vacuum at idle. So when the throttle is slightly opened, that's when the diaphragm sees vacuum and begins advancing timing. This increase in ignition timing will help produce more engine torque at part throttle. Besides an improvement in fuel economy during part throttle cruise, this cab be especially helpful for the B21FT, because the low static compression ratio (7.5 to 1) is generally not very optimal for low RPM acceleration.

If you have a 240 Turbo, there's
something you might need to know about the above under hood vacuum hose label. All year 240 Turbo labels are similar (1981-85). If you look closely, you'll notice the throttle body ports are reversed compared to the greenbook diagram above left. The above label shows Port 2 going to the distributor diaphragm. Since I believe the Volvo GREENBOOK diagram is correct (and the actual TB plumbing has been confirmed by several 240 Turbo owners), then this means all of the vacuum hose routing labels Volvo placed under the hood for 240 Turbos are INCORRECT.  

To help reinforce this PORTED VACUUM concept into our feeble brains, here are a couple good videos below from someone showing us the difference between ported and manifold vacuum. This video shows an old Ford carbureted engine, but the concept is 100% the same with our old Volvos.
https://www.youtube.com/watch?v=ohw1oRlcC4c


https://www.youtube.com/watch?v=sLwXlsHBd4k


ONE LAST THING ABOUT PORTED versus MANIFOLD VACUUM
If you search around much on this topic, you'll undoubtedly come across some videos or articles which will argue about whether or not to used ported vacuum for a vacuum advance distributor.  You'll find people who will defend using normal MANIFOLD vacuum for that purpose or they'll insist THEIR testing proves THEIR engine runs BEST using normal manifold vacuum.  When you see that, feel free to analyze it and work out precisely what the timing advance looks and when that vacuum appears compared to when it appear in a ported vacuum source. Try to see whether it seems real or not. Some people will insist that ported vacuum was only for emissions. I'll argue that maybe it was for emissions PARTLY, but I believe it's also about economy and that's never a bad thing to have. Sometimes there's a fine line between running better or worse with too much timing at the wrong RPM. Hopefully you can make your own informed decision on this and not just take the word of others without a good look at it.

Feel free to email me if you feel like discussing this at greater length.


Modern ignition system timing maps using vacuum AND boost.
These maps below use kPa for vacuum and boost reference. Unlike the factory B21FT map image that uses 0 kPa for ambient atmospheric pressure, Microsquirt and many other systems use 100 kPa to designate ambient atmospheric pressure. So then in these maps any number below 100 kPa is vacuum and any number above 100 kPa is boost.  200 kPa equals 1 bar of boost.

Here's an CAUTIONARY example below of a spark map you might find that was made in Microsquirt.  Someone made and shared this online for a Volvo 4 cylinder (with turbo). This is not a typical B21FT or B230FT map. This one was custom made for an unknown custom Volvo turbo and it uses a lot more total timing than a typical Volvo map. I have no idea if these numbers can actually work ok on a Volvo. The engine would run, but the big question is would it run well or safely?

This map was shared in TB as an "example" to help others set their timing. The problem is no info was offered about it's use. Pump gas or Ethanol? Nope. Was it verified with dyno testing?  Nope.
 

Please don't assume that the factory timing numbers no longer apply to your engine, just because you changed a cam, added a turbo or increased boost. Volvo engineers probably put in lots of work to come up with those numbers. Copying a map like this above for your use should not be done, unless you know the engine and fuel used and you trust the dyno tests that helped create it.  

Here's another modern timing map BELOW that shows much more conservative max timing numbers (27 degrees max in the base map in the red bordered box). These numbers came from a known and trusted friend and they're backed up by real dyno tests for a Volvo B230 Turbo producing over 500 hp at the wheels. This map below was using pump gas, however the highest power was using ethanol. The ethanol map was very similar, but it added about 2 degrees extra timing under boost. 

If you're newer to this stuff and the large number of boxes in images like this seem like too much to grasp, try concentrating on just the base map in the middle inside the red border. That base map will be the basic spark timing advance for this engine before any changes are made by vacuum or boost. That's a good place to begin. Once you have an understanding of a base map, then you can begin to better understand how small changes below 100 kPa (VACUUM) make changes, and also how small changes above 100 kPa (BOOST) make changes. 

If you've had experience with Megasquirt, Microsquirt, Haltech, Motec, MaxxECU or other aftermarket systems, then you're familiar with using kPa for vacuum and boost values. When I first moved from Bosch K-Jet to programmable EFI in the 1990s, my first experiences began with SDS EFI (Simple Digital Systems), which I still use on my 1984 242 Turbo. More info on that HERE. SDS EFI is primarily designed as a race car engine management system. It doesn't use kPa at all. It uses old school PSI and inHG values for boost and vacuum, but the programming is otherwise pretty much like modern systems. 

If you've made your own timing maps using Megasquirt, Microsquirt, Haltech, Motec or other aftermarket systems for a Volvo, I would love to hear from you. Please email me.
CONTACT ME



Using ignition timing to help achieve a stable idle speed.
This section will discuss IDLE ONLY. Getting a decent idle may seem a bit over-simplified. You just make sure the air/fuel is decent and your idle timing is set for something like 12 BTDC and move on, right?  No, not necessarily. If you find that your ignition system offers more capabilities that might help improve a stable idle, then try using them. I'm not talking about using idle valves or controlling an electronic throttle body if you have one.  I'm just talking about using ignition timing to optimize your idle.

Let's assume you have a 4 cylinder that has an idle target of 900 RPM and base idle timing is 
12 BTDC. If your system will allow you to control ignition timing at idle independently from timing for other uses, then a good way to help maintain a stable idle is to make it so that it increases timing advance if the idle dips below your 900 RPM target. And it reduces timing advance if your idle rises above your target. Some systems will allow you to program such a timing change if the idle deviates more than 50 RPM under or over your target idle. Some systems may not have as much resolution and it may only allow changes if it deviates more than 100 or 250 RPM. A timing change for a deviation of over 50 RPM could feasibly be 5 to 8 degrees. For a 250 RPM deviation it could be 10 to 15 degrees. With this type of system in place, when idle speed dips, ignition timing is increased, which will increase the RPM. When idle speed rises too high, ignition timing is retarded, which will decrease the RPM. This can have a nice stabilizing effect. If you have a programmable system, have a closer look and see if this kind of scheme can be used.

Doing something like this will not usually take the place of your main idle speed controls, such as an air bypass or idle valve. It's only intended as an enhancement, however it's not uncommon for a race car to use something like this without an idle valve or any other device, since a perfect idle is not usually a priority for a race car.

There are some limits to observe if you're planning to set the base idle timing higher than normal. I consider normal to be around
12 to 18 BTDC. If you plan to set your idle at over 20, then you may find that advancing the timing with this scheme may not increase RPM as easily. The reason is that you may be getting close to MBT Timing (I discussed MBT earlier HERE). Pushing timing advance beyond MBT will not produce more torque or more RPM. If this happens, you could still use the retard side of this scheme to reduce RPM spikes. 
 



  Here's a good article that will give you some more useful things.
https://www.autospeed.com/cms/a_109132/article

I welcome your comments or questions.  If you can add to any info here, please email me. CONTACT ME.

 


Non-Factory or Aftermarket Ignition Options

123 IGNITION
123 Ignition in the USA offers standalone ignition and distributor systems for a number of classic European and Japanese cars, including VOLVO.

These systems offer several different levels of programming, including Bluetooth support for IOS/Android and tablets.They have distributors for Volvo B21, B23, B230, for naturally aspirated and TURBO.

https://123ignitionusa.com/b21-b23-volvo-engines-tune-bluetooth/

They have a tutorial that will help to explain how the timing maps are programmed, including centrifugal advance, vacuum advance and boost retard:
https://123ignitionusa.com/curve-tutorial/


Ignition conversion for 1985-88 240 (convert from Chrysler to EZK Ignition).

This is a conversion harness for any 240 using LH 2.2 (1985 to 88). 
The 1985-88 240 originally came with an undesirable Chrysler ignition system with the fender mounted Ignition Control Unit. This conversion harness eliminates that Chrysler ignition. It's designed to allow you to instead use the more desirable EZ 117 K ignition system. The new ignition box mounts under your dash. The EZ 117 K ignition ECU came in the Volvo 740 series during these same years. Your existing main engine harness is not disturbed for this conversion.
All new connections under the hood are PLUG AND PLAY. Some wires will need to be spliced under the dash near the ECU.  This conversion harness is designed to work with your existing LH 2.2 system and it serves to bridge the necessary connections to the more modern EZ 117 K ignition system. 
This may be found HERE.




MSD IGNITION AMPLIFIER
If you own a 240 Turbo and it has the factory ignition system, you might discover that the ignition spark is rather weak.  It's usually ok if there are no performance modifications, but if you increase turbo boost, you'll discover that the spark is not strong enough.  It's called spark blow-out and it'll appear as a strong miss or sudden engine cut-out when under boost. It happens to weak sparks when an elevated level of boost is added. High compression or more boost pressure in the combustion chamber makes it more difficult for a spark plug to ignite the fuel mixture. If this happens to you, a band-aide cure is to reduce the spark plug gap to about half of normal.

Installing a high-performance coil doesn't cure this. Installing better plugs or better plug wires doesn't cure it. BUT INSTALLING AN MSD IGNITION AMPLIFIER DOES CURE IT.
The MSD Digital 6A ignition amplifier (PN 6201) and the MSD Tach Adapter (PN 8910) are needed.  These are added to the existing Volvo ignition. No wires from your existing ignition are removed.
You can read more about what the MSD box does at their site, but in short, it seriously amplifies the spark for your factory ignition and it will fix spark blow-out.


If you need any of these tabs for your coil, you can search for 6 mm Faston Tabs.  They're easily available as single or double tabs like these below.


Here's a diagram showing the same MSD 6A if you have a 1985-88 240 with LH 2.2 and standard ignition (perhaps you have added a turbo).





Spark Plug Cables.
How to Build a Custom Cable Set for your 240.

A number of years ago I decided I wanted a nice looking and long lasting spark plug cable set. I wanted something extra special, tougher and nicer looking than the ordinary sets than I could buy from the normal places. So i decided to buy a good crimp tool and the parts needed to make it happen.
So how long do these wires last?
Good question. I built these shown below in 2010 and they were still going strong at this writing in 2021.
I don't build these for sale.
I have created a guide below for YOU to build your own.

Here's the custom plug wire set I made for my car in 2010.  I'll show you how.
 
But if you prefer the OEM look, like this nice original 240 Turbo below, then stay with it.

   


TOOLS
This MSD 35051 crimp tool is pretty expensive, close to $100. I bought mine from Summit Racing:
https://www.summitracing.com//msd-35051


Years ago the selection of inexpensive crimp tools was not nearly as good as it is now. Now you can probably get away with a much cheaper version, such as this one from Amazon for $27:
https://www.amazon.com/Crimping/B08JG3K2HF/


Also MSD now has an inexpensive Mini-Crimper.that's used with a vise for about $10. I haven't used it, but one of the videos I found near the bottom of this page shows it in use.




Here's the full recipe below if you want to do this for your car.
  This can be overwhelming for a beginner, but if you're willing to expand your 240 experience, it's a fun and rewarding project that you will likely use again.

If you use all of the options shown below (which I did), expect to spend over $200.  Yes, that's lot.  But keep in mind that some items can only be bought in certain lengths or minimum packages, so you will have leftover parts. 
You COULD save some money by building TWO or more sets and then sell the others.
But if you're a beginner, I recommend starting with making one. Then decide if you want to keep going.

SOURCES: I bought parts from several sources.  Not every source had all the pieces I needed. Most parts can be found at Summit Racing or Speedway Motors. I have bought from both. There are plenty of other sources, but these were the main sources I used.

Most of the parts are made by MSD. They charge a premium.  If you want to shop around for other brands, there are other ignition cable parts suppliers out there;
Taylor: http://www.taylorvertex.com/, Kingsborne: https://www.kingsbornewires.com/.


  If you don't like RED, pick another color when you make yours.


Below image with added thermal boots on the spark plug ends.



You can begin with a 25 foot roll of MSD 8.5 mm cable. About $68.  You can order it in different lengths beginning with 10 feet. The total amount I used for this 4 cylinder project was about 13 feet.
https://www.summitracing.com/spark-plug-wire-bulk-wire
https://www.speedwaymotors.com/bulk+wire+8.5



  MSD 8854 high-temp spark plug boots with terminals. Cost was about $28 for set of 8 boots.
These are ONLY available in sets of 8.  MSD offers other boots, but I chose these.
https://www.summitracing.com/boots
https://www.speedwaymotors.com/boots



MSD 3321 90 degree DISTRIBUTOR Boot with terminal. TWO sets per package (about $8).
I call this a DISTRIBUTOR BOOT, but Summit Racing or other places may refer to it as a COIL BOOT. These boots are easily confused with the below 3331 90 degree COIL BOOT.  These are slightly smaller and designed for use on a distributor, although possibly they are interchangeable. So if you prefer a right-angle center boot on your distributor (for the coil wire as shown in the second photo), then this is one you can use. For my preference, I used a STRAIGHT center distributor boot when I made mine.
https://www.summitracing.com/boots
https://www.speedwaymotors.com/boots
 



MSD 3331 90 degree COIL boot with terminal. ONE set per package (about $7).
This boot looks very much like the above. It's different, larger hole on the big end. The terminal is the same.
https://www.summitracing.com/boots
https://www.speedwaymotors.com/boots


Here are both of them side by side.
The large end opening for the small 3321 boot is 14 mm. The large 3331 boot is 15 mm and this larger boot fits the Bosch coil well.
Both are very flexible silicone.



MSD 3322 STRAIGHT Distributor Boots. 
These only come in a set of TWO with terminals. About $10.
You need THREE sets (if you need 5 boots).
Many OEM Volvo style wires are made using FOUR straight boots and one 90 degree center boot on the distributor. In this case you would TWO sets and you would use the 90 degree DISTRIBUTOR boot above.

  These boots are made in RED or GRAY, but red can be hard to find. It was for me. Last time I ordered I could only find them in GRAY. Some places might show RED, but you might still get GRAY.
https://www.summitracing.com/boots
https://www.speedwaymotors.com/boots
 


Thermal outer sleeve. I have used both the DEI sleeve below and the TechFlex Insultherm Tru-Fit.
Insultherm is a much heavier product, because it has real insulation properties. Also it's less flexible. It's more expensive too.
The DEI sleeve is only 10 mm wide inside and will fit over 8.5 mm cable, just barely. It will be very, very snug on the 8.5 MSD wire and just about impossible to slip on without some lubrication for long pieces, however it will also expand slightly when you push on it. Be sure to use a lubricant (soapy water or maybe Simple Green cleaner). This sleeve would be a much better fit if it was 1/2 inch wide.
DEI sleeve is about $30 for 50 feet: https://www.summitracing.com/parts/dei-010621b50

  Insultherm Tru-Fit (second photo below) comes in a variety of sizes and colors. I have used 1/2 inch size, which is very easy to slip onto 8.5 mm cable. Cost was $38 for 25 feet: https://www.wirecare.com//insultherm-tru-fit
 


Buy some DUAL WALL heat shrink tubing to seal the thermal sleeve ends. I recommend 1 inch diameter, 3:1 shrink ratio. 
DUAL WALL means there is adhesive inside.  That adhesive keeps this stuff in place.  Standard heat shrink will move out of place on your wires. Buy a couple feet of this.




Thermo-Tec 14261 spark plug boot protectors. 6 inches long. Set of 4. About $38.00.
These are not required, but they will help to make your wires and boots last longer.  There are a number of competitors making similar boot protectors.
https://www.summitracing.com/spark-plug-boot-protectors
https://www.speedwaymotors.com/Protectors



The high radiant heat from the exhaust or turbo will eventually discolor these protectors, but it will take years. These pictured below have been in my car next to the turbo for 11 years.
Maybe these are too expensive to just keep buying more, so if YOU'RE CHEAP and this discoloration bothers you, you might just just try re-spraying them with some high heat red aerosol paint to renew them. It should be a BRIGHT RED if possible. Many engine enamel red colors are a darker red.



Taylor 42729 Wire Separators, red plastic, (Size: LARGE).  About $16.00. 
These
have large 3/8 inch holes, which will be needed if you're adding the sleeve to your wires. If you accidentally get the smaller separators (like I did once), you can drill them out using a 3/8 inch drill bit.
A package comes with two of each piece. If you want more than TWO of the 4-hole pieces, buy two sets.
https://www.summitracing.com/taylor-cable





Building the Cables

Finished Wire Lengths.
For this project, the completed wire lengths I made were as follows.
(when assembling, cut your lengths about 1 inch longer than these finished lengths)

COIL
25 inches.
I used a straight boot on the distributor end, which requires a longer wire than using a 90 degree boot. Your coil wire may be longer or shorter, so measure-measure-measure. The coil wire shown above on the blue OEM style wires used a 90 degree boot on BOTH ends and its total length was 18 inches.
Cyl 1
30.5 inches

Cyl 2
29.75 inches

Cyl 3
31.5 inches

Cyl 4
33.75 inches


DISTRIBUTOR WIRES
Spark Plug End

I prefer to begin the assembly with the spark plug end. You'll need to lube the boot to push the wire through. I like using a water based cleaner, such as Simple Green or soapy water. Even WD-40 will be OK if that's all you have.
Some MSD videos suggest that you can push the wire through AFTER the terminal is installed. For these photos below, I did this before installing the terminal.


This one is known as "DUAL CRIMP" terminal because two crimps are made.
About 1/4 inch of insulation need to be stripped off first to exposed the center conductor.


If you're using the style of crimping tool shown below . . . 
Crimp 1.
The outer insulator should be crimped using #1 jaws. 
Crimp 2.
The center conductor should be crimped using the #2 jaws.
It's really not important to crimp in this order.  Just make the crimps tight. If you don't have a crimping tool like this, try to make the crimps look similar and tight.
The videos below will help explain this process.




Make certain the center conductor is tightly crimped.



Place a spark plug into the terminal. Feel how the conductor end snaps into place on the spark plug.
I suggest that you smear some dielectric grease, silicone grease or other non-conductive anti-seize paste on the porcelain part of the plug or inside the boot. Using such grease there is a very good idea. It will help to keep the plug it from sticking (seizing) to the silicone boot after a period of use in the heat.


Then carefully pull the wire from the back of the boot and/or push the spark plug to move the terminal into place. If you pull it too far (you probably will at first), just push it back in. 


Now for the thermal sleeve. These are optional of course, but I like them. If you're adding a thermal sleeve, make sure to do it before adding the boot on the other end.
Cut a piece of sleeve that will be roughly about 1/2 inch short of touching the boots on each end.  I prefer to then use about 1.5 inches of dual wall heat shrink tubing at each end to anchor the ends.
First put the thermal sleeve over the wire using your water based cleaner to lubricate. Then place the heat shrink tubing over it. Then after you complete your boot assembly on both ends you can and shrink it down.


DISTRIBUTOR WIRES
Distributor End

Again,
I like using a water based cleaner as a lubricant, such as Simple Green, when pushing the wire through the boot. Some MSD videos suggest that you can push the wire through the boot with or without the terminal installed. That's up to you. For these photos, I installed the terminal after inserting the wire through the boot.

I prefer dual wall heat shrink tubing, because dual wall has glue inside, which melts with heat.
 


The 1.5 inch piece of heat-shrink will be enough to hold the sleeve. The extra 0.75 inch piece is not required and is optional.
The second photo below shows these wires made without the extra piece.
 


This type of terminal is a "SINGLE CRIMP" style.  make sure to strip off enough insulation (about 1/2 to 3/4 inch), because you must fold the center conductor over and trap it between the terminal and insulation.
The photo of my crimping tool here shows the proper location to squeeze this terminal. Pay attention to the VIDEOS BELOW if you're a beginner.
 


After crimping, pull the wire back through the boot until it's positioned like this. Try a test fit onto your distributor cap to verify that the fit feels like a nice fit.


You should mark your cables as you finish each one to help keep them organized.


COIL WIRE
Coil End

I chose this 90 degree COIL boot (3331) for the coil because it works well on a stock-size 240 coil in a stock location on the left fender as pictured at the top of this page. If you prefer a straight boot for your coil, let me know which one works best for you on a 240 and I'll add that here.  Also if you have a coil that's mounted somewhere else in the engine bay, I'm interested in the wire length you used. Your comments are welcome.


If you'll be doing the same thing on the coil regarding the thermal sleeve and heat shrink, again, don't forget to add this before adding boots to both ends.


When you're ready to add the coil boot, again, you'll need to lube it up good. Then insert the wire into the rear of the boot and bring it out the front a couple of inches.
You might need to resort to forcefully pulling the wire through with pliers, so you should probably make this wire ONE INCH longer so you can cut off the end if it's damaged.
Strip about 1/2 to 3/4 inch of insulation.
 

This type of terminal is a "SINGLE CRIMP" style.  You must fold the conductor over and trap it between the terminal and insulation.
 

This is the proper location on this crimping tool to squeeze this terminal. Pay attention to the VIDEOS BELOW if you need guidance.
 

This terminal is made for multiple angles. Use some pliers to bend the terminal 90 degrees. Make sure to lubricate, then carefully pull the wire back through the boot until the terminal fits as shown.
Then you can finish with the heat shrink on this end.
 


For the distributor end of the coil wire, if you plan to install a straight distributor boot (3322) as I preferred, use the installation guide above for the straight distributor boots. If you plan to install a 90 degree distributor boot (3321) the installation technique is the same as the 90 degree boot installation shown.
 

The plug boot thermal sleeves are optional and can be added at any time AFTER the set is completed. They simply slip over the boot.




TESTING YOUR WIRES
This is optional. If you have an Ohm Meter you can test the resistance of your new wires to verify they're good. The second video below discusses this in detail. 
According to MSD, acceptable max resistance should be about 50 Ohms per foot of wire (https://www.holley.com/plug_wire_troubleshooting/).

Here are a couple videos on assembling these parts.
https://www.youtube.com/watch?v=5_sakmDb2fo

https://www.youtube.com/watch?v=uy5rMvkGZYM



 


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