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MG MGB Technical - Source For Aftermarket Gauges
|Can somebody point me towards a good source for aftermarket or replacement gauges that will fit the cutouts in a 77B dash.|
I did a quick search in the archives with limited success. Thanks.
-is my favorite source.. They do sell other stuff as well, so go through there entire website. I purchased all new Smiths gauges for one of my cars in magnolia facing (antique white) from them and have dealt with them several times on various projects.
|BMC Brian McCullough|
Can I assume that the Magnolia facing is much brighter at night?
|AutoMeter gauges 2-1/16 size will fit and are good quality and variety available from Jegs or Summit Racing.|
|I have vdo cockpit white gauges and they are INCREDIBLY bright at night. Almost blinding.|
can be purchased at: http://www.egauges.com
|for classic smith gauge available in black or magnolia|
i remember that with this new gauge you will need a v voltage stabiliser.
"i remember that with this new gauge you will need a v voltage stabiliser"
Please keep in mind that MOST aftermarket gauges DON'T need a voltage regulator.
If you add another gauge that does need one to your existing regulator, the accuracy of all the gauges fed from the regulator will be off.
If you add another gauge to the regulator that doesn't need one, the needle will swing from zero to some value off and on in sync with the regulator, about 2-3 times a second or so.
Another thing to consider when buying your new gauge is how the wiring is attached to the new gauge. Most VDO gauges use spade connectors for all connections, including the dial lamp. Many others use pigtail leads for the dial lamps, which make it all that much more difficult to wire to. Wiring VDOs is much easier.
I have used, succesfully, Classic, Autometer, and VDO, and don't really have a preference for one over the other, except for the wiring concerns above.
I don't believe there are any aftermarket gauges, with the possible exception of Smiths, that will match the cutouts for the speedo and tach exactly. Either the holes will need to be enlarged a bit, or a filler piece will need to be added to the holes.
|Thanks everyone for the response. |
Dan; thanks for clearing up some confusion I had about the need for a voltage stabilizer when using some types of aftermarket gauges. I noticed in your custom wiring diagram that there was no voltage stabilizer included and that the gauges depicted were listed as aftermarket. I will look into the brands/sources that you & the others have listed and go from there. Is it safe to assume that the vendor will know which gauges would require stabilization?
Thanks again for everyones help.
|Picked up some smith classics magnolia gauges this spring, a speedo, tach, fuel and watertemp/oil pressure compound gauge from gaugeguys. The tach is electronic and works with a MSD6AL box and pertronix II ignition, it is also adjustible. the color and full V bezel looks great on the dash. Only 153 miles are recorded on the odo as the engine is still in pieces...|
| The modern Smiths units look the same as the originals did... Or at least the units they make. They do not make every style that they used to, but instead a variety of some of the more popular units that can also be used in aftermarket applications. The faces look the same, they have two or three different bezil styles- V type and the half V that we all have stock in our cars, as well as flat back and chrome bezil choices. The faces come in black or magnolia. Although they look the same, they are not internally going to blow up within the first 60,000 miles. I am told that the internals are now more refined. Just like all the other British automobile manufacturers, Smiths was bought out and incorporated into another company who also makes instruments, so both tradition and technology have gone into these. I believe Dan on the regulator issue. When I purchased my gauges, the regulator that I purchased with them tells you how many gauges or how much stuff can be pulled off of it.|
You 1977 B should already be setup with the voltage regualtor in it.
|BMC Brian McCullough|
The instructions that come with your gauges will tell you whether or not your gauges need a regulator. As far as I know, none of the aftermarket gauges, with the possible exception of some of the Smiths gauges, will require a regulator. I don't have experience with every brand available, so I may be wrong on this. I know that VDO, Classic, and Autometer gauges don't use one.
Perhaps a brief explaination of how a regulator works is in order.
Basically, the regulator is a bi-metal strip with a bit of heater wire wrapped around it. On one end of the strip is a switch contact. As the gauges draw current through the heater wire, the bi-metal strip heats up. When it gets hot enough, it bends enough that the switch contact opens. When this happens, current flow to the gauges, and through the heater wire, ceases, and the wire cools down. When it cools enough, the bi-metal strip again closes the switch. This repeats over and over, maintaining the "average" voltage to the gauges at about 10 volts or so. If you add extra gauges, the current increases, causing the wire to heat up faster, opening the switch quicker. As the cooldown time is the same after the switch is open, the ratio of ON to OFF will decrease, lowering the average voltage.
The gauges that came with our cars also consist of a bi-metal strip, except instead of operating a switch, it is attached to a lever arm which is attached to the needle. As the sender resistance changes, the current changes, the amount of heat around the bimetal strip changes, the strip bends, and the needle follows suit. If you lower the average voltage from the regulator, you lower the current through the gauge for a given sender resistance. Thus the gauges will all read low if you add too many to the regulator. Being a bi-metal strip, responce time is way too slow to respond to the pulsating voltage from the regulator. When you turn the key on, it takes a bit before the gauges read properly.
Modern aftermarket gauges, on the other hand, consists of two coils, one monitoring voltage, and the other monitoring current through the sender resistance. The needle responds to the "difference" between the two coils. Therefore, if the system voltage goe up, current through both coils will go up, but the difference will stay the same. These gauges have a pretty rapid response to sender changes. When you turn the key on with these gauges, the reponse is virtually instanteous.
This thread was discussed between 20/06/2003 and 22/06/2003
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