MG Sports Cars

To Whom It May Concern; I know some of you won’t agree with this decision, but I’ve decided to give up trying to make my old worn out 4 cylinder Smiths gauges work. I’ve worked with a number of electronic speedometers and can’t seem to get any of them to work right either so I’m going to use a Dolphin black face set with a mechanical speedometer. My question is will a Ford speedometer cable fit the back of the speedometer and does a 1989 Ford SVO T-5 (1352-200) use a slip-in cable or does it have a drive? Mine is a new, never installed, T-5 and it just has a hole where the cable hooks up to it. Has anyone out there done this, or am I the only Turn Coat?




"P"

I dont know about your cable but have you read the forums about the Dolphin guages very mixed more bad than good I thought
about them then passed I went classic Insturments and if I had it to do over I think I would go Auto Meter or VDO
just a thought

jim

I used Auto Meter "Hot Rod" series in black. Good reviews from most folks & at the lower end of the price range. Using their pulse generator which slides into the speedo cable hole & is held in by a small clamp/screw. That's a tight fit in the tranny tunnel. My tranny is from an SN95 (94/95 5.0L) Mustang -- it's 1" longer & not sure if the speedo hole is in the same place as most or not so watch the pulse generator fit if you do go w/electric.

Paul, I used a mechanical speedometer in my Midget. My trans is a T5 from a Camaro which had a cable drive speedometer to begin with, but I think that most T5s have the drive gear on the output shaft, just need the correct adaptor and driven gear to use a mechanical speedo. I found this site [www.partshp.com] while I was looking for a pulse unit for my EFI. They should have anything you need to hook up your Ford T5 to a mechanical speedometer, even inline gear reducers to get the accuracy correct.

Paul
I'm no purest, so I always use TPI electronic speedos. They made me a nice white face six gauge set with 5" tach and speedo for a little over $500. I've changed wheels and tires three times so far on my TD build and it calibrates each tire diameter. The system is simple math, a time and distance calculation. You will never get a machanical unit to read correct speed.

Just my opinion.

Paul, I don't know if you've already bought your new gauges, but I recently did some reading on GPS speedometers. These are really neat, do take a few seconds after startup to get the satalite connecton but after that you can't beat them for accuracy and no cables to run. I've been using my gps as a speedometer for several years now in the Midget as the cable broke and I just didn't want to take the dash apart to change it. I also have used it in my Subaru with an electronic speedometer and found that the Subaru unit consistantly reads 3mph slow. They're not cheap, but then not terribly expensive either and would certainly solve your problems.

Thanks for the info guys, as always you make it possible to make an informed decission.

"P"

Hey Paul,

I can't help with the cable question but I have used dolphin guages in the past.
Been pretty happy with them. Even the non marine set on my boat.
As far as the electronic speedos. What is your pulse count per mile?
Probably fairly low. This makes them very hard to set up.
Use a higher resolution transmitter or speed it up some and your good to go.
If space or gearing is a problem try an ABS wheel sensor.
You can fit it and a pulse ring to any wheel front or rear.
Or use just the sensor alone to pick up the vents on a brake rotor or the ring gear teeth on your diffy.
Depending on your diff, lots of OEMs have all the stuff to put a speed sensor in there already.
Hope that helps some

Cheers
Fred

Thanks Fred. I've had pretty good luck with Dolphin gauges too. Not all, but a number of the 22 T-Buckets we built use them. When I start the car, but still setting in park and at idle, the speedometer reads about 20 miles an hour but when you give it just a little gas the speedometer goes up to 140, still setting still in park so there shouldn't be any pulse count; I replaced the speedometer with the same results. Dolphin said it was because we were using a common ground therefor it was following the tach, we didn’t think so, but we ran an individual ground wire to the frame and replaced the pulse generator on the 700R4 and got the same results. I’ve been driving the bucket for five years now and decided any one crazy enough to drive a bucket doesn’t really care how fast they’re going anyway. I would kind of like to know on the MG though. It being what it is, the front wheels are out in the fresh air so a speed sensor would show, the rears use Wilwood Dragster disks so I’ll have to give it some thought but you have a good idea there.

"P"



Edited 1 time(s). Last edit at 03/11/2011 03:42PM by pspeaks.

You've most likely entered the wonderful world of electro magnetic interference.
Your speedo is interpreting some electrical "noise" as a signal
On something like the T's with a fibreglass body. There won't be any metal to shield the electronics from one another.
The speedo sees the electrical interference. And responds to it.
The biggest offenders are #1 solid core plug wires. #2 non resistor plugs. #3 multi strike ignitions and # 4 one wire alternators.
These alone or in combination with others can cause all sorts of problems with guages, fuel injection and stereos.
Special tools are available (at horrific cost) to identify the offending units.
Or you can do what I do.
Go get yourself the cheapest dollar store AM portable radio that you can find.
Tune it to a blank spot at the low end of the dial.
Now start your engine.
You are going to hear any interference that your vehicle is causing.
If the radio picks it up, it's a problem.
A high pitched steady whine is probably the fuel pump. If it follows the engine speed then suspect the alternator.
A slower crackling noise will be the ignition. A rapid zip type noise that follows the engine speed will be your multi strike ign.
Start the repair process by grounding everything. Including the fuel pump and ign box cases.
Get some good magnetic core plug wires and resistor plugs.
Car audio stores have a variety of noise supressors that will work for your alternator, fuel pump and ign box.
Sometimes you have to get more creative with capacitors, grounding diodes, shielding, etc.
But the easier fixes generally get the job done.
Hope thats helpfull

Cheers
Fred

You know Fred, I never thought of that; I'll bet you hit it right on the head. We had a simular problem with our Plasma Flame Table and interference from a non-shielded Plasma Cutter. My roadster has a number of the systems you mentioned so I'll try your suggestion. Thanks, I'll keep you posted.

"P"

To your point, yes, the Ford cable fits the Dolphin gauges. From direct experience going from a T5 to Dolphin mechanical speedo in previous ride.

Thanks David, I would hate to buy the gauges and find out I had to search the planet to find a way to make it work.


"P"

i just bought a cable to do just this yesterday. i got it on ebay for $19.99 .it fit into the t5 trans and is held in place with one screw and has a 5/8/18 threaded nut on the other to screw on the gauge.i use stewart warner gauges but most mechanical aftermarket gauges use this.they come in 60,66 and 82 inch versions.i bought it from a seller named belair2door dbs454@aol.com is his email.

For use with my stock smith gauges/MGB stock rear end and T5 tranny and MGB speedo cable I had a gear adapter professionally made up. I still have the mechanical one and it's for sale.

I eventually ended up with white face Cockpit Royal VDO gauges and a Hall Effect Sender. So an electronic impulse is sent to the speedo from the T5.
If I decided to change rear ends or tire sizes an I can easily recalibrate the electronics so I am still reading a mile for mile.