Muscle Car Legend Meets the 21st Century It’s no secret that the legendary Sun tachometer was an absolute requirement for any muscle car owner or wannabe muscle car owner in the 50’s, 60’s, 70’s and beyond. It was impossible to avoid ads for Sun tachometers in virtually every automobile related publication. Hyped as the 1 choice of professional racers, every fan of going fast, with style, had one. Most often they were either mounted- on the dash, or in ‘stealth mode’ on the steering column. Sun tachometers were affordable and functional, not to mention great looking with a distinctive chrome housing. It’s no surprise that, over half a century later, vintage Sun tachometers are still in demand by those whose expectations demand the authenticity of an original Sun tachometer. Although Sun, now called Sunpro, sells a ‘retro’ line of tachometers, if your dream car just has to have the genuine article, you’re got your work cut out for you. You will spend lots of time scouring craigslist ads and eBay listings to find that perfect original two piece Sun tach, just like the one you had years ago. And if you are one of those that discovers that the ‘steal of a deal’ you thought you got resulted in only half of a two piece kit, what do you do then?
Cant get any hits with the search function. If so, and you have a stock ignition The tach will connect to the coil. There should be two screw connections and one will have two pink wires.
The dwell scale is etched on the glass face and if the trace can still be properly expanded to fill the x-axis scale (marked for 4, 6 and 8 cylinder cam angle), the dwell read from the point opening and closing traces will be accurate.
How do I hook up my tachometer? Standard Ignition Coil If you have a standard ignition coil you can use the negative terminal of the coil for the signal source. If you have a high output capacitive energy discharge type coil it is recommended that you install a tachometer filter to prevent damage to the tachometer. Ignition Box If you have an ignition box i. If you have a 5V Tachometer signal you can: Install a ohm “pull up” resister from the 12V gauge power source ACC to the signal wire to increase the signal strength.
Contact us to special order a tachometer that will work with the 5V ECU signal. Due to the high voltage of the signal from the HEI you should use a tachometer filter to prevent damage to the tachometer. Coil Pack or Individual Coils Distributorless Ignitions If you have a modern vehicle with “coil pack” or “individual ignition coils” distributorless igntion you will need a tach driver like the MSD to drive the tachometer.
Troubleshooting If your tachometer has no signal or an erratic signal pointer jumping all over you first need to verify that you have correct power, ground and signal connections. Verify the gauge has 12V power.
What does a tach do? This is important in performance cars or hard working motors to keep them from overreving which can cause engine damage. On an everyday car they are used very little. If you have a 98 corolla without a tach can you install an instrument panel with a tach and will it work? There should still be a tach wire grouped into the harness plugs. Just unplug your old one and plug in the new one that’s it.
Where does a dwell tach hook up to set points? This might sound confusing, but the positive lead to the dwell meter goes to the negative side of the coil — the same side the wire to the points goes to, and the negative le ad to the dwell meter goes to a good ground .
The Ignition Module responds by rapidly switching on then off the current in the primary winding of the Ignition Coil. Note that corrosion can build up on the 6 contacts under the Distributor Cap which can eventually cause rough running. Bosch HEI fitted to a V8. Under the Rotor there is 6 or 8 pointed star device 6 points for a 6 Cyl Engine 8 for an 8 Cyl Engine. Photo by Jacks showing the Reluctor removed from the Distributor.
This is called the Reluctor. The Reluctor rotates with the Distributor Shaft. When all the points of the Reluctor pass the matching points on the Outer Ring of the Magnetic Core, a pulse is generated. That Pulse is sent to the Module to signal an activation of the Ignition Coil. Sometimes there is an unused wire hanging from the Coil negative connection. This connection is provided for a tachometer feed. The Magnetic Pickup has an internal coil that contains a plate of magnetic material.
Memory is an old friend that will let you down when you need it most. I’ve got a different brand that I’ve not used since ’78 when I changed my ’68 Elcamino to electronic distributor. Ken, I am just going by memory not as good as it used to be and have not used mine since the 80s. I am surprised they are still selling them.
I bought mine new off the Mac truck over 30 years ago. Kevin – They’re sold on the big auction site.
Hook the purple/black wire to the positive lead on a dwell/tach meter and the negative to brown wire. Set it to 6cylinder and start it up. The meter will act like your tach if all is working properly.
Its simple, easy to tune, and plenty powerful to light off any naturally aspirated engine up to RPM if properly equipped. Let’s start with the coil. Its located on top of the distributor between the plug wire towers under a plastic cover. It’s the “engine” that makes the sparks. Stock its capable of about 35, volts and so-so total spark energy. Its fine for a naturally aspirated street motor that rarely sees the high side of RPM. It will provide the energy to jump a plug gap of.
Either one is a worthwhile upgrade for a hot street motor- you’ll get better response and HP especially at higher RPM where the stock one hits a kind of “wall”.
Unsportsmanshiplike Conduct – There’s a cheater in every sport, and competition tractor pulling is no different. Honest pullers who ignore the cheater s are fools. And when there’s prize money involved, a fool and their money are soon parted.
Nov 19, · For this procedure, you will need your Vacuum Gauge, your Dwell/Tachometer, your 1/2″ and/or 7/16″ short box/open end wrench (or your distributor tool), a 1/4″ tool to adjust the Steel Idle Stop Screw, and a blade screwdriver to adjust your Mixture Screw.
Maximum Dwell Duration This is in your ‘C: Edit the following line with Notepad. Note that since the optoisolator U4 inverts the trigger signal, you specify ‘Rising edge’ for the ‘Input Capture’ in the tuning software, which refers to the signal at the processor. Positive trigger offsets are used to specify the number of degrees before top dead center BTDC , negative numbers are used for triggers that occur after top dead center ATDC. At each reference pulse, the period between it and the previous reference pulse is calculated.
The difference is used with a time interpolation technique to set up the timing pulse for the next ignition event. Specifically, the reference period is added to the time of the current pulse, a calculated amount subtracted for the advance, another amount subtracted for the dwell to determine the rise time. When the signal is pulled low, current stops, the magnetic field in the coil collapses, and a spark is produced.
However, the low to high transition is not used to determine when coil charging begins, instead the MSD box controls this itself. Thus, the HEI module fires on the ‘trailing edge’ of the advance signal. The advance signal is generated by MegaSquirt-II from the tach signal by modifying the end point of the ‘high’ pulse. If you are using a VR pick-up in your distributor and a 4-pin module, be sure to get the variable reluctor pick-up wires connected properly.
Reversing the variable reluctor sensor wires and thus the polarity of the sensor causes the leading voltage to go negative first and the electronics ignores the positive going transition.
Zora Arkus-Duntov , who had been instrumental in breathing life into the Corvette, retired on January 1, after 21 years and 7 months with General Motors. He had come to work for Chevrolet later that same year after writing to Ed Cole with his insights about the Corvette Prototype. Image courtesy of GM Media. The person tasked with the challenging position — and the sizable shoes to fill — was David Ramsay McLellan , who had worked with Duntov and had been groomed for the job after joining General Motors in Despite this, McLellan would not have a significant influence on the design of the Corvette until the introduction of the C4 Corvette some eight years later.
The Corvette look was almost identical physically to the model.
You can also use a dwell/tach meter. These are useful because they typically work in a range of , so you can more accurately see the RPM you are trying to achieve. A dwell/tach is best if you have points and need to set the dwell also.
The bike still runs on one cylinder but with a lot less power and will be very hard to start if you stall it. The tach MAY go to zero when this happens. Typically this lasts about 2 – 15 seconds and then may cut back in and run normally. Sometimes it will not run at all at low rpm. Tach is also at zero or may jump around wildly. Bike backfires badly, etc Gets worse when its hot.
In outboards they’re called “Powerpacks” or “Pulse packs”.