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RVC tach into Bugeye
- Thread starter Rut
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Jim_Gruber
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Ask and you shall receive. From my things I've saved for the last 12 years file.
Frank Clarici
Electric Tachometer Face Swap for Bugeye
BUGEYE TACHOMETER CONVERSION
Many Bugeye owners are confronted with the problem of sorting out a tach drive once they have converted either to an alternator or discover that they cannot find a mechanical tach drive at a reasonable price. Frank Clarici offers a great piece of advice on how to convert an electronic tack over to negative ground. I have taken his advice one step further. Many Bugeye owners do not want to give up the stock look of the original gauges, so I have outlined here how to solve the tach drive as well as the stock looking gauges problem.
You will need:
• original Bugeye tach
• tach from a Mk3 Sprite or Mk2 Midget (this is an electric tach, the same diameter as the Bugeye)
• Frank Clarici instructions on how to convert to negative ground (if your car is negative ground)
• Small standard screwdriver
• touch up paint (optional)
1 Hour labor Procedure:
• Remove the front chrome ring, glass and seals from both tachometers by twisting the ring. The rubber seal on them may need to be replaced.
• Very carefully remove the RPM indicator needle from each of the tachs by pulling straight off the post.
• Using a small screwdriver remove the 2 small screws that hold the face plate of each tach.
• The screw spacing is different for the faceplates, lay the Mk3 faceplate over the Bugeye face plate and using a small drill bit, drill the 2 holes in the proper location. Be very careful how much pressure you put on the faceplates as they are very soft and can be deformed.
• (OPTIONAL) Use super glue to affix a thin patch to the backside of the faceplate or fill the hole with epoxy, to cosmetically close and paint the old screw holes in the Bugeye faceplate.
• Install the Bugeye faceplate and RPM needle onto the electronic tachometer.
• Reinstall the tach chrome ring and glass with new rubber seal if needed.
• Install reconfigured tach into car dash and do electrical hook up. You will connect a 12 volt line to the spade connector on the rear, the case is grounded and a length of wire will go from the coil, loop around the sensor pickup on the rear of the tach, and back to the points terminal on the distributor.
It is that easy, drop me a line if you need more information,
Bob Magnotti
bob@itgonline.com
Frank Clarici
Electric Tachometer Face Swap for Bugeye
BUGEYE TACHOMETER CONVERSION
Many Bugeye owners are confronted with the problem of sorting out a tach drive once they have converted either to an alternator or discover that they cannot find a mechanical tach drive at a reasonable price. Frank Clarici offers a great piece of advice on how to convert an electronic tack over to negative ground. I have taken his advice one step further. Many Bugeye owners do not want to give up the stock look of the original gauges, so I have outlined here how to solve the tach drive as well as the stock looking gauges problem.
You will need:
• original Bugeye tach
• tach from a Mk3 Sprite or Mk2 Midget (this is an electric tach, the same diameter as the Bugeye)
• Frank Clarici instructions on how to convert to negative ground (if your car is negative ground)
• Small standard screwdriver
• touch up paint (optional)
1 Hour labor Procedure:
• Remove the front chrome ring, glass and seals from both tachometers by twisting the ring. The rubber seal on them may need to be replaced.
• Very carefully remove the RPM indicator needle from each of the tachs by pulling straight off the post.
• Using a small screwdriver remove the 2 small screws that hold the face plate of each tach.
• The screw spacing is different for the faceplates, lay the Mk3 faceplate over the Bugeye face plate and using a small drill bit, drill the 2 holes in the proper location. Be very careful how much pressure you put on the faceplates as they are very soft and can be deformed.
• (OPTIONAL) Use super glue to affix a thin patch to the backside of the faceplate or fill the hole with epoxy, to cosmetically close and paint the old screw holes in the Bugeye faceplate.
• Install the Bugeye faceplate and RPM needle onto the electronic tachometer.
• Reinstall the tach chrome ring and glass with new rubber seal if needed.
• Install reconfigured tach into car dash and do electrical hook up. You will connect a 12 volt line to the spade connector on the rear, the case is grounded and a length of wire will go from the coil, loop around the sensor pickup on the rear of the tach, and back to the points terminal on the distributor.
It is that easy, drop me a line if you need more information,
Bob Magnotti
bob@itgonline.com
Jim_Gruber
Yoda
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If you need to convert tach to Positive Ground I have that info as well.
Jim_Gruber
Yoda
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Tachometer Conversion, Positive to Negative Ground
Items needed: soldering iron & solder, electic tape or heat shrink tube
• Remove the tachometer from the dash, take it to a clean work site, on the seat of the car is not the place to work on the inside of your tach.
• Remove the chrome bezel, glass lens,and inner black rim.
• Remove the 2 screws from the back of the tach, these hold the mechanism to the housing.
• Holding the tach by its face with the ignition light at 3 o'clock ( red line straight up ) locate the resistor which is soldered to the spade terminal that comes out the back. Locate the post imediatly to the resistors left, these must be reversed. Unsolder the resistor from the spade terminal, unsolder the green wire from the left post, solder the green wire to the spade terminal, solder the resistor to the left post.
• Reassemble the tach into its housing replace rim, clean the lens, re-fit lens and chrome bezel.
• Back in the car, you will have a white wire that makes a loop out of the harness and around a plastic terminal on the back of the tach, this loop must be reversed. Mark the wire 2 inches from each side of the loop, cut each side and switch the wire (reverse the loop) solder the connections and tape or shrink tube the bare wire.
• Mark the tach on the outside of the housing NEGATIVE GROUND.
• Install the tach in the dash, hook up the loop and green wire and be sure the housing is properly grounded.
If you do NOT agree with these ideas, if you are "mechanically challenged" or are just down right "stupid" I suggest you perchase New parts from a supplier of your choice and have a local shop do this work for you.
Frank Clarici
Items needed: soldering iron & solder, electic tape or heat shrink tube
• Remove the tachometer from the dash, take it to a clean work site, on the seat of the car is not the place to work on the inside of your tach.
• Remove the chrome bezel, glass lens,and inner black rim.
• Remove the 2 screws from the back of the tach, these hold the mechanism to the housing.
• Holding the tach by its face with the ignition light at 3 o'clock ( red line straight up ) locate the resistor which is soldered to the spade terminal that comes out the back. Locate the post imediatly to the resistors left, these must be reversed. Unsolder the resistor from the spade terminal, unsolder the green wire from the left post, solder the green wire to the spade terminal, solder the resistor to the left post.
• Reassemble the tach into its housing replace rim, clean the lens, re-fit lens and chrome bezel.
• Back in the car, you will have a white wire that makes a loop out of the harness and around a plastic terminal on the back of the tach, this loop must be reversed. Mark the wire 2 inches from each side of the loop, cut each side and switch the wire (reverse the loop) solder the connections and tape or shrink tube the bare wire.
• Mark the tach on the outside of the housing NEGATIVE GROUND.
• Install the tach in the dash, hook up the loop and green wire and be sure the housing is properly grounded.
If you do NOT agree with these ideas, if you are "mechanically challenged" or are just down right "stupid" I suggest you perchase New parts from a supplier of your choice and have a local shop do this work for you.
Frank Clarici
OP
Rut
Obi Wan
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Jim,
What a wealth of information! Will the procdure be the same for an RVC tach as an RVI tach? My car is negative ground and I bought a later RVC tach so it would work with my Crane ignition system. I'm assuming that I would use the RVC tach case and just swap the face, needle, and trim ring. I've not ordered a new wiring harness yet since I was waiting until decided on all the changes I wanted to make.
Thanks, Rut
What a wealth of information! Will the procdure be the same for an RVC tach as an RVI tach? My car is negative ground and I bought a later RVC tach so it would work with my Crane ignition system. I'm assuming that I would use the RVC tach case and just swap the face, needle, and trim ring. I've not ordered a new wiring harness yet since I was waiting until decided on all the changes I wanted to make.
Thanks, Rut
I think you are right on, Rut. The RVC followed the RVI and believe it is already neg ground but it should say on the face. You will have to do a bit different mods. Different holes in case and different spacers at the back since it is smaller. I think once you get to looking at it using the BE case will look like the best alternative since the RVC case is much smaller the warning lights and guage illuminating lights won't be right.
Kurt.
Kurt.
Jim_Gruber
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Rut,
I can't vouch for procedure. This is a YMMV thing. I've saved useful Spridget stuff and tips for the past 12 years in a simple Word document. Not indexed and it is now 150 pages or so long. Things like Rear Brake shoe pics, Alternator conversions, How to answers. We always get questions on fitting rear shoes and where the springs go. I've got a doc to refer to. Lot's of how to tips. A simple Control-F(find) allows me to search and retrieve.
I can't vouch for procedure. This is a YMMV thing. I've saved useful Spridget stuff and tips for the past 12 years in a simple Word document. Not indexed and it is now 150 pages or so long. Things like Rear Brake shoe pics, Alternator conversions, How to answers. We always get questions on fitting rear shoes and where the springs go. I've got a doc to refer to. Lot's of how to tips. A simple Control-F(find) allows me to search and retrieve.
OP
Rut
Obi Wan
Offline
Thanks again Jim! I've cleaned both tachs and the bezel/glass from the Bugeye tach fits the RVC tach case, so this may be easier than I thought. When swaping the needles I assume you just replace it in the same position and use the adjustment screw in the back to 'fine tune'. I also remember a post a good while back that showed white paint instead of lt blue on the inside of the case along with a strip of LED lights to increase nightime visibility. My intention is to keep all of my original restored parts and update used parts for use in my car for functionality/reliability. The car won't be original, but I want it to look close to original when finished (1275, 5 speed, etc.). Not that these are valuable cars, but I feel some sense of preservation and hope to be a good steward for the next owner.
Thanks, Rut
Thanks, Rut
Jim_Gruber
Yoda
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Kurt,
This is a simple MS-Word Document. Nothing more. A simple Cut and Paste from useful stuff I've read and saved over the past 12 years since I bought Bugsy. If you can use MS-Word you can do something like this. Happy to even offer it up to anyone who wants a copy. A note to jamesgruber@sbcglobal.net will get you a copy of the file. Nothing I've originally authored and again YMMV with any advice contained within.
This is a simple MS-Word Document. Nothing more. A simple Cut and Paste from useful stuff I've read and saved over the past 12 years since I bought Bugsy. If you can use MS-Word you can do something like this. Happy to even offer it up to anyone who wants a copy. A note to jamesgruber@sbcglobal.net will get you a copy of the file. Nothing I've originally authored and again YMMV with any advice contained within.
OP
Rut
Obi Wan
Offline
The Bugeye tach faceplate is mounted on the RVC tach and all looks good, but the post the needle mounts on is too short and the diameter is smaller than the original needle post. I can cut down the 2 mounts about 1/8" to make the post longer, but what do I do to make it fit tightly? I have the old RVC needle and can use the aluminum mount in place of the original brass Bugeye one, but the counter weights will be very different. Thoughts?
Thanks, Rut
Thanks, Rut
dklawson
Yoda
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What I have done in the past is to use a short piece of nylon rod about 1/8" in diameter. Drill through to fit the diameter of the spindle on the gauge movement. Drill 1/2 way through to make a hole that will press onto the stem on the back of the needle. This "bushing' will adapt the diameters and compensate for the shorter length of the spindle.
You may not have a piece of nylon rod sitting around. In that case I suggest you find a local hobby shop and visit their train model building area. Look for rack from K&S full of brass and plastic extrusions. Select a piece of grey PVC rod and use that instead of nylon. Do not use styrene (the white plastic they are likely to have). The hobby shop may also have a small set of number drills and pin vices to hold them. You will want those to make the through-hole for the needle spindle. The hole for the stem on the back of the needle will be larger (something like 2mm or 5/64). Measure twice, cut once.
You may not have a piece of nylon rod sitting around. In that case I suggest you find a local hobby shop and visit their train model building area. Look for rack from K&S full of brass and plastic extrusions. Select a piece of grey PVC rod and use that instead of nylon. Do not use styrene (the white plastic they are likely to have). The hobby shop may also have a small set of number drills and pin vices to hold them. You will want those to make the through-hole for the needle spindle. The hole for the stem on the back of the needle will be larger (something like 2mm or 5/64). Measure twice, cut once.
OP
Rut
Obi Wan
Offline
Doug,
Thanks for your solution. Last night I removed the brass counter weight from the original needle and prepped the needle for the RVC aluminum adaper which is much lighter in weight. Do you think the lighter weight will affect the operation and if so, should I reinstall the brass one?
Thanks, Rut
Thanks for your solution. Last night I removed the brass counter weight from the original needle and prepped the needle for the RVC aluminum adaper which is much lighter in weight. Do you think the lighter weight will affect the operation and if so, should I reinstall the brass one?
Thanks, Rut
dklawson
Yoda
Offline
You removed the counterweight? Put it back if you can.
The actual weight of the needle is not as important as how it is balanced to work with the hairspring on the gauge spindle. This is true for both the electrical and mechanical tachs.
Unless you have bench calibration equipment it is not likely that you will have a way to check the affect of the needle swap and the performance without the counterweight. Without the calibration equipment I suggest you at least hook up a tune-up tach and compare what it displays relative to what your converted tach displays. Tune up tachs are seldom calibrated higher than about 1500 RPM. However, if yours is switch selectable, turn the knob to "8-cylinder" and double the displayed reading (i.e. A 4-cylinder engine running at 3000 RPM will display 1500 RPM when connected to a tachometer set for connection to an 8-cylinder engine). This doubling of the tune up tach reading will at least give you an idea how accurate your converted tach is up to about 3000 RPM.
Don't freak out if it is off by a hundred RPM here and there. That is pretty common even before you swap parts around.
The actual weight of the needle is not as important as how it is balanced to work with the hairspring on the gauge spindle. This is true for both the electrical and mechanical tachs.
Unless you have bench calibration equipment it is not likely that you will have a way to check the affect of the needle swap and the performance without the counterweight. Without the calibration equipment I suggest you at least hook up a tune-up tach and compare what it displays relative to what your converted tach displays. Tune up tachs are seldom calibrated higher than about 1500 RPM. However, if yours is switch selectable, turn the knob to "8-cylinder" and double the displayed reading (i.e. A 4-cylinder engine running at 3000 RPM will display 1500 RPM when connected to a tachometer set for connection to an 8-cylinder engine). This doubling of the tune up tach reading will at least give you an idea how accurate your converted tach is up to about 3000 RPM.
Don't freak out if it is off by a hundred RPM here and there. That is pretty common even before you swap parts around.
OP
Rut
Obi Wan
Offline
I finished the Bugeye to RVC tach conversion and other that the 2 new screws holding the face plate on it looks original. I'll connect it to a 4 cyl car that has a tach and see how it compares and adjust. I am concerned that the RVC was a 7000 rpm tach and the Bugeye is a 6000 rpm. When I swing the needle it will only go to the redline on the Bugeye tach and no further. Thoughts?
I started on the speedometer this morning and while using Spritenuts fork method of needle removal I promptly broke the shaft and now need a speedometer. Does anyone have a Bugeye speedometer they are willing to part with? The face and case condition are not important, just the working part.
Thanks, Rut
I started on the speedometer this morning and while using Spritenuts fork method of needle removal I promptly broke the shaft and now need a speedometer. Does anyone have a Bugeye speedometer they are willing to part with? The face and case condition are not important, just the working part.
Thanks, Rut
dklawson
Yoda
Offline
Sorry about the needle. I regret I don't have any parts to offer. However, what broke on the needle when you removed it?
Early RVC tachs had a trim pot on one of the circuit boards that could be used to adjust the calibration. Later gauges did not have any means of adjustment/calibration that I ever noticed. If you are lucky enough to have transplanted an early RVC with the pot, drill a hole through the gauge case right behind where that pot is located. While your tach is connected to the test vehicle you can tweak the calibration on the fly. I suggest you first position the needle first so it is close to accurate at idle. With the needle in position, bring the RPM up to the speed where you want the tach to be accurate THEN tweak the calibration pot. Return the car to idle and see if it is still close enough. Do not be upset if the tach is off by as much as 150 RPM at various points. Once you have achieved an acceptable calibration, cover the hole in the gauge case with tape to prevent dirt and moisture from getting in.
Early RVC tachs had a trim pot on one of the circuit boards that could be used to adjust the calibration. Later gauges did not have any means of adjustment/calibration that I ever noticed. If you are lucky enough to have transplanted an early RVC with the pot, drill a hole through the gauge case right behind where that pot is located. While your tach is connected to the test vehicle you can tweak the calibration on the fly. I suggest you first position the needle first so it is close to accurate at idle. With the needle in position, bring the RPM up to the speed where you want the tach to be accurate THEN tweak the calibration pot. Return the car to idle and see if it is still close enough. Do not be upset if the tach is off by as much as 150 RPM at various points. Once you have achieved an acceptable calibration, cover the hole in the gauge case with tape to prevent dirt and moisture from getting in.
OP
Rut
Obi Wan
Offline
Doug,
I have an early RVC tach and the case is the same size as the Bugeye. I have a couple of needles so I'm ok in that department. Once I'm able to connect the tach to a car I'll know where I am on the calibration and like you, I'm not worried about being off by 150 or so. How do I connect the wires from the tach to the engine?
On another note, I ham fisted the needle removal on the speedo and the shaft broke so I have that extra needle. Now I'm looking for a Bugeye speedo. I have a good faceplate, glass, bezel, case, just need the guts.
Thanks for the help, Rut
I have an early RVC tach and the case is the same size as the Bugeye. I have a couple of needles so I'm ok in that department. Once I'm able to connect the tach to a car I'll know where I am on the calibration and like you, I'm not worried about being off by 150 or so. How do I connect the wires from the tach to the engine?
On another note, I ham fisted the needle removal on the speedo and the shaft broke so I have that extra needle. Now I'm looking for a Bugeye speedo. I have a good faceplate, glass, bezel, case, just need the guts.
Thanks for the help, Rut
dklawson
Yoda
Offline
Thankfully RVC tach connections are simpler than those for RVI tachs.
On the back of the RVC tach you should find a bullet connector and a male spade connector almost immediately next to each other on an insulator plate. Run a wire (18 or 16 AWG) from that bullet connector to the coil (-) terminal... the terminal with the wire going to the distributor. Connect the male spade lug on the tach's insulator plate to a switched 12V supply. This can be taken from any number of places including the ignition switch. You may (at your discretion) want to put an inline fuse in that wire. A 5 Amp fuse is way more than enough.
Since the original Bugeye tach was mechanical its case will not have a spade lug for a ground terminal. Put a ring terminal on a ground wire and place the ring terminal over one of the gauge mounting bracket studs right before you install and tighten the thumb nuts.
So the part that broke was the actual spindle of the Bugeye speedo movement? Ouch! I'll send you a PM.
On the back of the RVC tach you should find a bullet connector and a male spade connector almost immediately next to each other on an insulator plate. Run a wire (18 or 16 AWG) from that bullet connector to the coil (-) terminal... the terminal with the wire going to the distributor. Connect the male spade lug on the tach's insulator plate to a switched 12V supply. This can be taken from any number of places including the ignition switch. You may (at your discretion) want to put an inline fuse in that wire. A 5 Amp fuse is way more than enough.
Since the original Bugeye tach was mechanical its case will not have a spade lug for a ground terminal. Put a ring terminal on a ground wire and place the ring terminal over one of the gauge mounting bracket studs right before you install and tighten the thumb nuts.
So the part that broke was the actual spindle of the Bugeye speedo movement? Ouch! I'll send you a PM.
OP
Rut
Obi Wan
Offline
Doug,
Thanks again! I'm actually using the RVC case since it's all the same size and has the grounding lug as well as the correct opening. I'll connect it per your instructions and see how it works. I had hip surgery a couple of weeks ago and it's giving me time to work on all the small inside stuff. A table, a Dremel tool, and parts that need restoration...heaven!
Thanks, Rut
Thanks again! I'm actually using the RVC case since it's all the same size and has the grounding lug as well as the correct opening. I'll connect it per your instructions and see how it works. I had hip surgery a couple of weeks ago and it's giving me time to work on all the small inside stuff. A table, a Dremel tool, and parts that need restoration...heaven!
Thanks, Rut
I am neither mechanically challenged nor stupid but I am lazy and want the job done by someone knowledgable.
I'm also new to this forum so you'll be seeing many jaw dropping queries in the future.
Do you know someone on here that would be willing to make the pos/neg conversion for a small fee?
just purchased a 58 sprite and pos tach that needs to be converted
Bought a 58 sprite upon my return from Vietnam in 1972 that was sitting in my high school drama teachers garage with a blown clutch. The price that I paid then was $50.00 and a Nikon SLR camera purchased during my tour.
I've named the recent addition Gidget...cheers!
I'm also new to this forum so you'll be seeing many jaw dropping queries in the future.
Do you know someone on here that would be willing to make the pos/neg conversion for a small fee?
just purchased a 58 sprite and pos tach that needs to be converted
Bought a 58 sprite upon my return from Vietnam in 1972 that was sitting in my high school drama teachers garage with a blown clutch. The price that I paid then was $50.00 and a Nikon SLR camera purchased during my tour.
I've named the recent addition Gidget...cheers!