Installing the Hot-Spark Electronic Ignition Conversion Kit in Bosch Distributors
Applies to red Hot-Spark 3-series ignition kits
Warning: Reversing the red and black ignition wires will destroy the ignition module and void the warranty. The Hot-Spark module’s red wire connects to positive ( + or 15 on Bosch coil). The black wire connects to negative ( – or 1 on Bosch coil). Remove the condenser and its wire from vehicle. Connect any other wires to the coil in their original positions. This module is designed for 12V negative ground applications only.
Make sure that the ignition wires have plenty of slack inside the distributor and are not rubbing on any moving parts. If you need to extend the length of the ignition wires, use 18- or 20-gauge (AWG) wire. Crimp tightly or solder all connections.
Remove points, condenser and condenser wire from distributor. Remove the condenser and its wire from the vehicle. Important: Clean the distributor’s breaker points plate thoroughly, so that the ignition module’s base plate makes good thermal contact with the distributor.
Make sure that engine oil level is on the full mark before revving engine (air-cooled VW, in particular)!
Coil: Stock Bosch coil or HS15HEC high-energy coil OK. Coil should have 1.5 Ohms or more primary resistance. To measure primary resistance: Label and remove all wires to coil. Using a common digital multimeter in the 200 Ω mode, measure between coil’s + and - terminals. Allow a few seconds for the reading to settle downward, until it stabilizes. Subtract about 0.3 Ohms from the reading to compensate for multimeter’s inherent resistance. Do not use a low-resistance coil, such as the MSD or Accel coil - they don’t have enough primary resistance for this application.
The coil should also have a minimum of 7,000 Ohms secondary resistance (measured from coil’s + or – terminal to center high tension terminal.
Test Maximum Charging System Voltage: If the charging system voltage, measured at the coil’s positive terminal, is more than 14.2 volts at 2,500+ RPM, the voltage regulator likely needs replacing. Too much voltage can damage the ignition module and other electronic components.
Test Battery Voltage to Coil: With ignition switch ON, engine not running, check voltage at coil’s + terminal. The voltmeter should read somewhere around +11 to +13 volts. If voltage is too low or there’s no reading, the battery’s terminals or ground connection may be corroded and need cleaning or the battery may need charging. Some vehicles have a resistor wire running from the ignition switch to the coil’s + terminal. If this resistor wire drops the voltage below 9 volts or so, you may need to run a non-resistor wire from the ignition switch to the coil’s + terminal or run a +12V wire directly from the ignition switch to the red Hot-Spark ignition wire. Make sure that the ignition switch terminal to which you connect this wire has power only when the ignition switch is in the ON position.
Air Gap between Magnet Sleeve and Ignition Sensor: If you need to increase air gap slightly, hold ignition base plate away from distributor shaft while tightening set screw and/or loosen the two Allen head screws and retighten screws while lightly prying ignition module away from magnet sleeve. Do not over-torque these Allen screws. Black magnet sleeve should not rub against red ignition module, but exact gap is not critical. In rare instances, it may be necessary to gently pry red ignition module away from black magnet sleeve to keep them from rubbing together.
Ignition Timing: Set the ignition timing, with a stroboscopic light, to the distributor’s factory specification. The difference in distributor position with points vs. electronic ignition can be as much as 30 degrees or so clockwise or counterclockwise, so you’ll definitely have to reset the timing.
3BOS4U1 for 4-cylinder Bosch Vacuum- or Centrifugal-advance Distributor
1. Turn off the ignition switch and/or remove the ground strap from the battery. Though not absolutely necessary, it is probably easiest overall to remove the distributor from the car before installing the Hot-Spark module. If the contacts in the inside of the distributor cap are worn or damaged, replace the distributor cap. Replace the rotor if it’s worn.
2. Remove distributor cap, leaving the plug wires in place, unless replacing the distributor cap as well.
3. Remove points, condenser and the condenser’s wire from the vehicle. Because the Hot-Spark kit does not modify the distributor, the points and condenser can be reinstalled at a later time.
4. Clean any grease or dirt thoroughly from the distributor’s points cam and the breaker points plate.
5. Insert the Hot-Spark module’s wires, one at a time, from the inside of the distributor out, through the hole in the side of the distributor. Gently pull and rock, up-and-down and side-to-side, the rubber grommet, halfway through the hole, until it seats.
6. Clean the breaker plate thoroughly to provide a solid electrical ground and good thermal transfer. You can apply a very thin coat of thermal transfer grease to the bottom of the ignition base plate. Place the Hot-Spark module’s bottom plate onto the distributor’s breaker plate. The peg should fit snugly into the hole in the breaker plate and the screw holes should line up. The Hot-Spark module’s base plate should lie flat and snug on the distributor’s breaker plate. Insert the screw and tighten, while gently pressing the ignition module away from the distributor shaft.
3BOS4U1 (supersedes 3BOS4V1 and 3BOS4C1): Universal ignition kit for 4-cylinder Bosch distributors. Fits both vacuum-advance and centrifugal-advance-only distributors with one-piece, right-hand points. Installs same as 3BOS4C1, but has smaller footprint and shorter magnet sleeve. To increase air gap slightly, hold ignition base plate away from distributor shaft while tightening set screw and/or loosen the two Allen head screws and retighten screws while lightly prying ignition module away from magnet sleeve. Do not over-torque these Allen screws.
3BOS4U1L Universal ignition kit for 4-cylinder Bosch distributors with one-piece, left-hand points. Fits both vacuum-advance and centrifugal-advance-only distributors. Installation is similar to 3BOS4U1.
3BOS6U1 (supersedes 3BOS6V1): Universal ignition kit for 6-cylinder Bosch distributors with one-piece, right-hand points. Fits both vacuum-advance and centrifugal-advance-only distributors. Installation is similar to 3BOS4U1.
3BOS6U1L Universal ignition kit for 6-cylinder Bosch distributors with one-piece, left-hand points. Fits both vacuum-advance and centrifugal-advance-only distributors. Installation is similar to 3BOS4U1.
7. Install magnet sleeve, with the larger opening down. Turn the magnet sleeve left and right, while pushing down firmly, until you can feel the distributor shaft cam lobes line up with the flat spots inside the magnet sleeve Press down firmly until the magnet sleeve slides as far down as it will. Install the rotor on top of the magnet sleeve, making sure the rotor is aligned with the slot in the top of the distributor shaft. The rotor should slide all the way down and lock into place, so that it cannot turn independently of the distributor shaft. If you can still turn the rotor independently of the distributor shaft, the magnet sleeve and/or rotor is not seated all the way down.
Magnet sleeve positioned too high: Situation: The fit between the distributor shaft and the magnet sleeve is especially tight and you can't slide the magnet sleeve down onto the distributor shaft all the way. The rotor rides too high, causing the distributor cap to wobble when you rotate the distributor shaft. Fix: Rotate the magnet sleeve so that it lines up with the lobes of the distributor shaft cam and the magnet sleeve can slide down a bit. Install the rotor and tap, with the butt of a screwdriver or a small hammer or a soft rubber mallet, very gently, on the center of the rotor, until the magnet sleeve seats firmly onto the distributor shaft, over the distributor cam lobes. With the rotor and distributor cap installed, you should be able to rotate the distributor shaft without the distributor cap wobbling. If the distributor cap still wobbles, you may need to adjust the number or thickness of the distributor shaft shims, especially if you're installing the ignition in a Chinese knockoff 009 distributor.
Magnet sleeve fit too loose: If the fit between the distributor shaft lobes and the magnet sleeve is too loose, the distributor shaft may be worn down from years of the points block rubbing on the distributor cam lobes, with accumulated dirt and grit, and/or insufficient lubrication. If the fit is especially loose, the only solution, short of replacing the distributor, may be to clean the distributor cam lobes thoroughly with alcohol and wrap the lobes with a single wrap of high-quality electrical tape, before pressing the magnet sleeve down over the lobes. Too loose a fit between magnet sleeve and distributor cam lobes may result in erratic timing.
8. Check to see if the vacuum advance is working properly by sucking on the vacuum canister port. The breaker plate should move smoothly and freely.
9. Adjust the two Hot-Spark ignition wires so that they have plenty of slack inside the distributor and they’re not rubbing on any moving parts.
10. Install the distributor cap.
11. Reinstall the distributor. Be sure that the anti-chatter spring is in place in the distributor pinion gear in the bottom of the distributor shaft hole.
12. The Hot-Spark module’s red wire connects to positive ( + or 15 on Bosch coil). The black wire connects to negative ( - or 1 on Bosch coil). DO NOT reverse the polarity of these wires or the ignition module will be destroyed.
13. Check all wire connections, including the two Hot-Spark wires and the spark plug and coil high-tension wires. If you need to extend the length of the wires, use 18- or 20-gauge wire. We recommend soldering all splices and connections, if you can, or crimp all connections tightly. Make doubly sure that all wires are connected to the proper terminals, etc. before reconnecting the battery or turning the ignition switch to the ON position. Make sure that all connectors are snug. Reconnect the battery and set the distributor timing statically.
14. You can set the timing statically to about 0° (TDC) at first, so that the engine will start. You may need to turn the distributor, a little at a time, right or left, to enable the engine to start and remain running. Time the engine with a stroboscopic light in the normal manner.
Setting Timing
Setting Timing: This will probably be the last time you have to set the timing for a long time, so it’s worth it to spend the extra time and effort to set the timing absolutely spot-on accurately. An engine with its timing set to perfection will start with the slightest bump of the starter and purr like a kitten at idle – something to make you feel good every time you get in the car.
TDC = Top Dead Center, or 0° BTDC = Before Top Dead Center ATDC = After Top Dead Center
It’s hard to say which distributor an old air-cooled VW actually has in place. The original stock distributor could very well have been replaced with a different distributor over the years. Bosch distributors for VW have a Bosch number on a badge or stamped onto their sides similar to 0 231 xxx xxx. Distributors may also have a VW number, which is preceded by a VW (and maybe an Audi) symbol. It’s most useful to find the Bosch number and look up the timing specifications for that particular VW distributor here:
External link: Old Volks Home - Bosch Distributor Parts & Specifications (including timing specs)
Finding Top Dead Center on a VW Type I engine: http://www.vw-resource.com/find_tdc.html#pulley
Finding Timing Marks on Type I VW Engine (Beetle, Ghia, Thing, pre-1972 Bus, etc.)
Finding Timing Marks on Type I VW Engine (Beetle, Ghia, Thing, pre-1972 Bus, etc.): There are several different versions of stock crankshaft pulleys that came with Type I VW engines over the years, each having its own set of notches (timing marks) in different places relative to TDC - very confusing. Like the distributor, the pulley may have been swapped out several times over the years, so you don’t know what the notches on it mean. Locate Top Dead Center (0° or TDC). There should be a notch in the crankshaft pulley wheel at TDC, aligned with where the crankcase halves join. You can copy and cut out the pulley wheel degree template on the last page of these instructions to find 7.5°, 30°, 40° BTDC, etc.
Timing the Bosch 009 or 050 Centrifugal-Advance Distributor (VW or Porsche only): Use a stroboscopic timing light and tach/dwell meter or tachometer, regardless of whether the distributor is equipped with points or an electronic ignition module. Static timing at around 0° (TDC) is suitable only for the initial adjustment, in order to get the engine running. To set the timing accurately, you must use a stroboscopic light connected to No. 1 cylinder’s spark plug wire. Set the timing with the engine running at 3,200+ RPM, so that the timing is fully advanced. The 009’s timing should be set no further advanced than 30° BTDC at 3,200+ RPM.
You can locate the 30° BTDC spot on a stock VW Type I crankshaft pulley, which has a 175 mm (6-7/8 in.) diameter, by measuring, clockwise, from top dead center, around the circumference of the pulley, 45.8 mm, or 1-13/16 in. Make a small white paint mark there. That’s about 30° BTDC.
Timing a Stock, Air-Cooled VW Vacuum-advance Distributor: A stock, vacuum-advance distributor should be timed with a stroboscopic light and tach/dwell meter, according to the specifications in the VW service manual.
For dual vacuum-advance distributors (with vacuum canisters having two vacuum ports): You can locate the 5° ATDC spot on a stock VW Type I crankshaft pulley, which has a 175 mm (6-7/8 in.) diameter, by measuring, counterclockwise, from TDC, around the circumference of the pulley, 7.6 mm (5/16 in.). Paint a small white mark here. This is about 5o ATDC, the point at which the dual vacuum-advance distributor (its vacuum canister has two vacuum ports) is usually timed at idle. Refer to the official VW Service Manual for the proper timing specifications for the distributor used in your vehicle.
For SVDA (single vacuum, dual advance) distributors: You can locate the 7.5° BTDC spot on a stock VW Type I crankshaft pulley, which has a 175 mm (6.895 in.) diameter, by measuring, clockwise (to the right), from TDC, around the circumference of the pulley, 11.45 mm (7/16 in.). Paint a small white mark here. This is the point at which the centrifugal advance (009) and certain single-vacuum, dual-advance (SVDA) distributors (their vacuum canister has only one vacuum port) are timed at idle. Again, refer to the official VW Service Manual for the proper timing specifications for the distributor used in your vehicle.
Distributor Cap and Rotor: Stock Bosch rotors and distributor caps work fine with the Hot-Spark module. A worn, corroded or scored distributor cap and/or rotor is often the cause of the timing jumping around erratically at idle. With the Hot-Spark electronic ignition installed in place of points, several times as much voltage surges through the rotor to the distributor cap terminal contacts. While the rotor and distributor cap may have functioned alright with points, the increased strain of double the voltage may be too much for the old, worn rotor and distributor cap. We recommend installing a new distributor cap and rotor when converting from points to electronic ignition.
Spark Plug Gap: With the Hot-Spark ignition kit, the stock spark plug gap specification is fine. For racing purposes, you can increase the spark plug gap by about .005 inches, or .12 mm. Be aware that changing the spark plug gap can affect the timing - you should recheck the ignition timing if you change the spark plug gap.
Rubber Grommet: The 3BOS4U1 and 3BOS6U1 use the larger, square rubber grommet for later Bosch four-cylinder distributors. If your distributor uses the earlier, smaller, round grommet, you’ll need to replace the square grommet with a 3/16” round grommet. Cut off the ignition module’s ¼” female connectors. Pass the wires, from the inside of the distributor out, through the round hole in the side of the distributor body and then through the round rubber grommet. Seat the grommet in the hole. Crimp or solder new ¼” female connectors onto the ends of the wires. Make sure that the wires have plenty of slack inside the distributor and won’t rub on moving parts.
Cleaning, Lubricating, Checking the Distributor:
A. You likely won’t have the distributor out of the engine again for some time. So now is a good time to lubricate under the vacuum advance plate, the distributor shaft and its bushing and the swinging centrifugal advance weights in the bottom of the distributor. You can access the centrifugal advance weights easily by removing the curved plug on the outside of the distributor, near the bottom. A somewhat sharp, flat-bladed putty knife is handy for prying off this plug. A small amount of heavy oil, such as 90W hypoid, synthetic heavy transmission oil or heavy motor oil works well for lubricating the distributor. Don’t use a thin solvent, such as WD-40, for lubrication, as its lubricating qualities won’t last for long. Apply a few drops of oil to the felt wick under the rotor. Clean up any excess oil or grease.
B. If your engine uses a vacuum-advance distributor, test the vacuum canister by sucking hard on its vacuum port. The vacuum advance plate, under the points, should move counterclockwise and clockwise noticeably and freely when you do this repeatedly. If you suck and then cover the vacuum port with your tongue, the vacuum advance plate should stay in the same position until you lift your tongue. If it drifts back before you lift your tongue, the diaphragm is leaking and it won’t advance the timing properly. In that case you need to replace the vacuum canister or the entire distributor.
If the distributor is dirty and covered with grit and gunk inside and out, you may need to soak it overnight in a solvent such as naphtha or kerosene (don’t allow solvent to leak into the vacuum canister - remove the vacuum canister first). After soaking and scrubbing with a stiff nylon brush, rinse thoroughly with clean solvent, dry with compressed air or allow to air-dry and lubricate the shaft, bushing, advance weights and breaker advance plate. Wipe up excess grease and oil. If the vacuum advance plate still doesn’t move freely, you may need to replace the vacuum canister or replace the distributor.
C. Check the distributor shaft for axial (up-and-down) play and radial (side-to-side) play. If there’s too much radial play, you may need to replace the distributor or have it rebuilt with new bushings, etc. Axial play can be reduced by adding special washers (shims) to the distributor shaft. The Bosch distributor rebuild kit (Bosch 1 237 010 007) contains these washers.
Using Hot-Spark Ignition with MSD Blaster: Refer to this diagram to use the Hot-Spark Ignition with the MSD (Multiple Spark Discharge) Blaster:
www.Hot-Spark.com/MSD-Hot-Spark.jpg
Hot-Spark Ignition and MSD 6 Series Wiring Diagram:
www.Hot-Spark.com/Hot-Spark-MSD-6-series.jpg
Volvo 1800 with Tachometer and Hot-Spark Wiring Diagram
Refer to this diagram to use the Hot-Spark Ignition with the Volvo 1800 Tachometer:
www.Hot-Spark.com/Volvo-1800-Wiring-Diagram.htm
Porsche 911 CDI Wiring Diagram: Refer to this diagram to use the Hot-Spark Ignition with the Porsche 911 with CDI Box:
www.Hot-Spark.com/Porsche-911-CDI-Wiring-Diagram.jpg
Volvo-Penta Marine Engines
with four-cylinder Bosch distributor, and with one-piece (not two-piece) points
3BOS4U1: Universal ignition kit for 4-cylinder Bosch distributors. Fits both vacuum-advance and centrifugal-advance-only distributors with one-piece, right-hand points. If you need to increase the air gap slightly, hold ignition base plate away from distributor shaft while tightening set screw and/or loosen the two Allen head screws and retighten screws while lightly prying ignition module away from magnet sleeve. Do not over-torque these Allen screws.
Make sure that there's enough space between the ignition sensor and the magnet sleeve. Sometimes, the screw that attaches the distributor cap clip to the distributor body protrudes too far into the distributor, crowding the ignition module too close to the magnet sleeve. You’ll probably have to add one or two extra washers to the distributor cap clip screw, to keep the screw from sticking too far into the distributor.
The Volvo-Penta distributor uses an 8mm (5/16”) O.D. round rubber grommet. You’ll have to cut the spade connectors off the two ignition wires. Pass the wires, from the inside of the distributor out, through the round hole in the side of the distributor body and then through the round rubber grommet. Seat the grommet in the hole. Crimp or solder (soldering is best) new ¼” (6.37mm) female quick-connect terminal connectors onto the ends of the wires.
Typically, a purple wire goes to the condenser on the Volvo-Penta distributor. When installing the Hot-Spark ignition, remove the points and condenser and tape off the purple wire, as it will no longer be used.
To get the ignition running initially, you should have only three wires going to
the coil:
1. +12 volts from the ignition switch to coil +
2. Red Hot-Spark wire to coil +
3. Black Hot-Spark wire to coil -
No other wires should be connected to the coil + and - terminals at this time.
Attach a stroboscopic timing light to the spark plug wire of Cylinder number 1.
With engine rotated to TDC (0 degrees) on the firing stroke of Cylinder number
1, ignition switch ON, turn the distributor until the timing light flashes. You
may need to tweak the distributor left or right a little, until the engine will
stay running, so that you can set the timing with the engine running, using a
stroboscopic timing light, according to Volvo-Penta specifications.
Limited Warranty: Hot-Spark Ignition Products warrants its electronic ignition conversion kits to be free from defects in material and workmanship under normal use and if properly installed for a period of three years from date of purchase. If found to be defective as mentioned above, it will be replaced or repaired if returned prepaid along with proof of date of purchase. Warranty shall be null and void if it is determined that said electronic ignition conversion kit has been connected improperly, if it is used with an ignition coil which has insufficient resistance in its primary circuit or if the polarity of the electrical wiring of the ignition kit has been reversed.
This shall constitute the sole remedy of the purchaser and the sole liability of Hot-Spark Ignition Products. To the extent permitted by law, the foregoing is exclusive and in lieu of all other warranties or representations whether expressed or implied, including any implied warranty of merchantability or fitness. In no event shall Hot-Spark Ignition Products be liable for special or consequential damages.
Problems with Installation? See www.Hot-Spark.com/Troubleshooting.pdf
Latest On-Line Installation Instructions:
www.Hot-Spark.com/Installing-Hot-Spark.pdf
A printable VW Type I crankshaft pulley degree wheel template for the SVDA 034:
www.Hot-Spark.com/Hot-Spark-SVDA034-VW-Type-I-Pulley-Degree-Template.pdf
A printable VW Type I crankshaft pulley degree wheel template for the 009 distributor:
www.Hot-Spark.com/Hot-Spark-009-VW-Type-I-Pulley-Degree-Template.pdf
Just a better idea. TM
© 2005 Hot-Spark Ignition Products
