Integral Brazilian Tachometer - First Mockup Phase Successful

Tonight I finally had success on figuring out how to get a Tachometer, to fit inside the Factory Maverick/Comet Instrument Cluster, while keeping the Factory Fuel Gauge in the same spot.

Below are some pictures of me running the Tachometer up to 8000 RPM, with a Function Generator, and DC Power Supply.

This is with the Instrument Cluster completely mounted inside the Dash, clipped in properly, and the mounting screws put in.







I tried a few different tachs, and discovered that the Sunpro Super Tach II Model CP7904 is a perfect fit. It even has an ideal mounting bracket, that surrounds the guts of the Tachometer, that allows you to secure it to the back of the Maverick/Comet Instrument Cluster, with 2 screws. The Guts of the Sunpro Tachometer had to be completely removed from it's original case, for this to work. The Response of the Tach's pointer is the same as before I mounted it in the dash. The pointer and extended needle are so lightweight, that it responds quick. Also, I tested it with all my other gauges, and the Tach does NOT interfere with the operation of the Fuel Gauge. I noticed NO counter EMF causing the Fuel Gauge Needle to fluctuate, which is great.

I also had to lengthen the pointer's needle, so that it would extend from the back of the Instrument Cluster, all the way through the dial face, while just missing the bottom of the fuel gauge. I had to raise the Fuel Gauge 1/8th of an inch upwards (towards sky) so the Tach Needle would clear. ** The "Fuel" Gauge words are completely visible after moving, and then some, when viewing from ALL angles. I took a regular sewing needle from Wal-Mart (it was the same diameter as the Sunpro needle), and cut both ends with a side cutter, and epoxy/super glued the needle, to the Sunpro Needle, with a small plastic coupler that I made from the original Sunpro pointer. The plastic coupler fit perfectly, and also kept the extended needle, perfectly straight.

For the Ford Maverick Factory looking Tachometer pointer, I used a Maverick Speedometer pointer, that I got from a junkyard, and it fits right onto the Wal-Mart sewing needle, that was used to lengthen the original Sunpro's pointer needle. I will shorten the length of the Tach pointer after the Dial face and gauge graphics are finished.

The Sunpro Tach clears all the metal brackets, that are located behind the Instrument Cluster. NONE of the circuitry on the back of the Instrument Cluster had to be rewired so far. I was prepared to do that if I had to, but so far I haven't needed to. The 6 holes that I drilled in the back of the Instrument Cluster housing did NOT interfere with the Instrument Cluster backplane wiring.

I plan on having a custom Black Dial Face made by a local graphics company, and it will basically look like the Concept Drawing I posted in this thread:

http://mmb.maverick.to/showthread.php?t=81260



The new Black Dial will be the Brazilian Tachometer Face, that you could get for the Brazilian Mavericks, and it will be in the same Ford Font, that is on the Speedometer. It will be ranged for 8000 RPM, instead of 6K, and it will have the Red Lines on the high RPM's, to match my 1970 Speedometer that also has the Red Lines. I will also shorten, and repaint the pointer, after I am sure how the graphics of the Dial, and other gauges will end up.

Next, I will work on figuring out the 90 degree sweep, electric gauges for Oil, Water Temp, and Battery Voltage.

 

Very impressive! Good job!

 

That's awesome... Can't wait to see the finished product...

 

Nice job! Looks really good.

 

great work,

 

Nice. I'll take one.

 

Very nice job - looks factory for sure

 

Love it!!!

 

Oh, my... Well done sir!

I have that tach! I have an extra cluster! I think I might have to follow in your footsteps if you don't mind me tagging along... How much for one of those gauge faces you're having made?

 

So cool

Wow, that is really cool!!

Nice work.

 

Hi Drew, and thanks for ALL the compliments guys. I haven't submitted graphics yet, so I'm not sure on what my dial face graphics will cost, but I will know soon, and I will save the graphics, so that more can be made. I will post pictures when I have my final graphics finished.

It certainly makes it easier, if you have a spare Instrument Cluster to work with. If all you are doing is putting a Tachometer into the dash instrument cluster, then you could certainly do this proceedure.

There are alot more details that I could have gone into, but basically you have to be extremely careful when working with the Instrument Cluster, especially removing/installing screws, and drilling holes, because it is VERY brittle.

I had to glue/seal a couple of screw standoffs, that cracked/broke when I was doing mine, but it was easy to repair. There are only 6 holes that you need to drill, a 2 inch needle, some super glue, and a spare Maverick speedometer pointer (if you want a Factory look). There is room for a smaller, custom plastic dust cover, and I'll be adding that to mine on final sealup.

I will check back later this afternoon, and provide more details on drilling and stuff, for anyone else that may be wanting to try this.

 

Nice work Roger. I didnt think it would fit but you found a way.

On the small gauges I dont think you will find an aftermarket gauge small enough to mount back there. But maybe something off of a factory dash cluster. I dont know what year or model but I have seen some pretty small gauges like what you drew on the concept. Maybe it was a 90s chevy truck. You could get the gauges out of the dash cluster and find a sending unit that would match the signal needed. Or just use the sending units out of whatever the gauges come out of and might have to use som eadapter bushing for them to screw into the maverick engine.

 

Bravo! I can't wait to see it with the custom background.

 

Thank You Stefan, and everyone else. To add more details in case anyone else wants to try this modification:

First, I would recommend aquiring a spare Maverick/Comet Instrument Cluster to perform this modification on, so that you are not left without a good Instrument Cluster, in case you break the brittle instrument cluster housing. *** I am using the 1972 Cluster, and I'm not sure if the fitment is the same for the later years cluster.

I didn't take pictures of the fabrication process, but if I submit a tech article later, I will try to get some pictures. I think it is straight-forward enough, that I can explain how to do this without pictures for now.

The below details may look like alot at first, but is just basically the details of a 3 Step Process:

1. Move the Factory Fuel Gauge up 1/8th of an inch.
2. Mount the Sunpro Tach to the back of the Instrument Cluster.
3. Mount the extended Needle to the Tach.

Parts/Supplies: (Around $ 40 total, not including an extra instrument cluster, and custom dial face graphics)

- Sunpro Super Tach II, Model CP7904 (Any Sunpro Super Tach II model has the same guts, and I bought it from Amazon for around $ 30)

- 2" inch long sewing needle, was bought at Wal-Mart for around $1, and it came in a multi-pack: The package said "Dritz Household Needles" item # H66.

- Instant drying Krazy Glue from Wal-Mart, around $2.

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The best way to explain this is to start by Master referencing everything to the center hole that you will drill, in the center of the Maverick/Comet Gauge Instrument Dial, which is the one on the left side.

Remember to treat the Instrument Cluster like a fragile egg shell. It is extremely brittle, and requires a little bit of patience when working with it.

Use a 1/8" Drill Bit, and drill on fast speed, with light pressure. Remove the round escutcheon/beauty ring from the center of the gauge dial face, by unclipping it. Mark the center of the dial by putting a cross that intersects over the center point...that way, if your drill slides, and removes the mark, you will still be able to see where the center is. This will be the hole that your Sunpro Tach Needle protrudes through, and this hole will be the Master Reference point for everything on this modification.

Remove the guts of the Sunpro Tach by removing the case screws, and prying the cover off. Slowly, and carefully remove the Sunpro dial pointer with a trim-type remover tool, that can slip under both sides of the dial pointer. Apply pressure slowly while slightly rocking tool side to side. * Do not throw the Sunpro pointer away...set aside for later as you will need this for the extending the Sunpro tach needle. *You won't be able to use the complete Sunpro pointer anymore, so you will either need a spare Mav/Comet Speedometer pointer, or another Sunpro pointer. Now remove the 2 philips screws holding the Sunpro Dial Face on, and you can have the tach guts completly free. Use a Sharpie Marker to mark the side of the Tach guts, as to which side is the bottom of the tach dial face (closest to 0 RPM and 8000 RPM)

Before taking the Fuel Gauge out, use a Black Sharpie marker, and put a mark on the inside-bottom of the cluster housing, right at the bottom/center of where the Fuel Gauge ends. You will use this mark later for referencing where to apporximately drill the hole for the Sunpro Tach needle to protrude through.

Before you drill the 2 holes to mount the Tach to the Mav/Comet Cluster, and the one hole at the inside/bottom of the cluster, for the Sunpro needle to protrude through, you need to move the Fuel Gauge up about 1/8th of an inch. Remove the 2 nuts holding the fuel gauge onto the circuit backplane, and set aside the fuel gauge.

Next, drill a hole right above each existing Fuel Gauge terminal hole, using a 7/32" drill bit. Be very very careful, don't grip the cluster with alot of force, use all the proper safety gear (safety glasses, etc). I set mine on a folded up towel to absorb shock while drilling. Drill on high speed, with light force. Carefully ream the paired holes, so that they join, and form a slotted hole for the Fuel gauge to be adjusted up and down. The new slotted holes still allow the Fuel Gauge's attaching Nuts to make contact with the circuit traces. As a matter of fact, luckily enough, NONE of the 6 holes interfere with the circuitry/circuit board.

Next, drill a hole in the inside/bottom of the cluster housing, using the 1/8" drill bit, approximately 1/8 of an inch above where you marked the bottom/inside of the cluster housing, where the lower/center section boundary of the Fuel Gauge ended. You can look down through the hole you drilled in the center of the dial face, to be sure your hole is lining up in the correct spot. You can also slide the Fuel Gauge up/down in the newly drilled slotted holes, to check for proper fitment and clearance.

Next, carefully take the Sunpro Tach guts, and position it on the back of the Mav/Comet Instrument Cluster backplane, being careful to place the Needle in the center of the 1/8" hole you drilled. Make sure to have the bottom of the Tach that you marked earlier, face the bottom of the Instrument Cluster.

You will notice that the Sunpro guts still have a 2 piece plastic bracket surrounding the guts. This bracket is awesome. It allows the Tach to mount with 2 screws, while missing all the vital circuit traces, and keeping the tach square with the cluster!
*** On the underside of this white colored, U-shaped plastic bracket , that surrounds the Sunpro tach guts, there are 2 round counter-sunk dimples, about the size of the 1/8" drill bit. This is exactly where you need to drill the holes into the back of the Mav/Comet Instrument cluster. So you have to first carefully drill out these 2 dimples in the Sunpro's plastic bracket. These dimples are on the elevated portion that is not directly touching the cluster backplane when istalled....they are right after the plastic u bracket makes its 90 degree turns.

The way I accurately marked my drill holes for the Instrument cluster, so that they matched these bracket holes, was first accurately position the tach guts to the back of the Instrument cluster, like we talked about before, then I used one of those plastic pin tacks, that you can pin papers on an organizer board with. (this is the kind that you can grab with your fingers, and not the more simple "thumb" tacks that don't have a grab handle. Use the tack to mark each drill hole, make sure the holes look square to the cluster/tach, then carefully drill out each hole with a 1/8" drill bit.

You can then use either 2 self tapping screws to hold the tach on, or use 2 threaded screws with nuts, either 4/40 or 6/32 screws. The screws, either way, will push in from the inside of the Instrument cluster, just missing the gauge shroud on the left side, and out through the back of the instrument cluster backplane, and finally through the plastic bracket that surrounds the Sunpro tach guts.

Now take the pointer from the Sunpro tach, that you set aside earlier, and use a pair of side cutters, and cut the complete straight plastic collar (around 1/4" long, black color), off the base of the pointer, and this will be used as a coupler, to join the Sunpro Needle, with the extended sewing needle. Take your 2" inch sewing needle, that matches the diameter of the tach needle, and use a pair of side cutters, wear safety glasses, and aim into a trash can, and cut just enought off of both ends of the needle, so that no tapers are present. It cuts very easily, and you can wait to cut to exact length later. Now apply some instant Super Glue to both ends of this black plastic coupler. This plastic coupler seems insignificant, but it is the most important piece to make this modification successful. Slide half of the coupler over the Sunpro Tach Needle, and slide the sewing needle into the other half, and wait 15 minutes to dry.

Now position the Fuel Gauge in the cluster, and slide the Fuel Gauge up, so that the bottom just misses the Tach Needle, make sure everything is square, and tighten the 2 fuel gauge backing nuts on the backplane.

You can glue the Sunpro's Dial Face to the Mav/Comet Instrument Cluster, it is a perfect fit, but you can also decide on other custom graphics for your 8000 RPM tach.

Finally, either use a Maverick/Comet Speedometer pointer, or you will have to aquire another Sunpro, or aftermarket pointer for your Integral Tach. Carefully use the side cutters to cut, and leave about 1/4 inch sticking up through the dial face, so your pointer has enough left for fitment.

*** Do NOT glue the pointer onto the Integral Tachometer Needle, until you are ready to do the FINAL sealup with a dust cover for the back of the tach, and final testing, and final repairing of any broken pieces of your Cluster housing. I have put black tape (Scotch Super 33 plus) on the back on my Sunpro's circuit board, so that it's protected against hitting anything, until I seal a dust cover over it.

I am not wiring the Sunpro Tach's light for my setup. You can follow the provided Wiring instructions for properly wiring this up to your car's engine.