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MG Midget and Sprite Technical - What to do about the gauges..?

Well, as I'm soon to put the dash back in to the car I thought I'd sort out the gauges beforehand.

Since it's an early car it has the cable driven tach, but I've switched to an alternator instead of the dynamo. I contacted speedograph-richfield and they said they could convert my existing tach to electric but that they had to change the pointer to a new one as the old would be to heavy. Then the pointer wouldn't match the speedos so the speedo would had to have the pointer changed as well. Sure it'll probably do the speedo good to have and overhaul as well but man oh man is it pricey to do the set.

Sure I could switch both the tach and speedo to ones from a newer Midget, cheaper and easier but still.. I like my old Frogeye ones.

Is buying an electric tach of eBay and switching the face with my old one myself an option? Anyone done this? Then i would just need to send the speedo to be converted and refurbed.

Thanks
Alex
Alexander Sorby Wigstrom

I had this done a few years ago, to Frogeye instruments, by John Ostick http://www.jdo1.com/ and I don't remember it's being too expensive. Nice friendly chap, too.
Nick and Cherry Scoop

..... or you could ditch the alternator and buy an alternator in a dynamo casing complete with take off for rev counter drive. Might be a cheaper option in the long run.
I saw these at a recent NEC show but I dont have the details but recall it's around £140. Alan A knows about them and has some information and I'm sure will post when he reads this.
Graeme W

Graeme, I had no idea those existed that would be great! And after a quick google search i found them at Moss, but they charge 500£. Moss aren't known to be the cheapest suppler though.

Converting the tach should cost 160£ plus VAT and the speedo something similar so i suppose the totalt is about the same in the end.

But would be nice to just swap alternator and leave the dash as is, but the pro of converting the instruments is of course that they'll be renovated and more accurate.
Alexander Sorby Wigstrom

Alexander:
There is a unit called Dynalite which is probably the one Moss sell. Accuspark make a much cheaper unit but they don't mention tacho take off. At the show we saw a supplier who was about to extend his range to include the drive from May or June. Unfortunately I don't know who it was! They were3 going to put an article in Mascot, complete with a 10% discount but that hasn't happened yet.
Leave it with me and I'll see what I can find out
Graeme W

Alexander: we think it's these people http://www.bbclassics.co.uk
Graeme W

they do a lot on ebay, seem a very reasonable outfit, I queried something before buying from them and their reply was reassuring
Nigel Atkins

Now thats what I call attention to detail

Where the 2 needles really that differant looking to each other...sometimes just being fairly close is good enough for a alot girl to sleep with you

Prop
Prop and the Blackhole Midget

Alexander,

Buy a used but working Smiths RVC tacho - from later B or Midget/Sprite - or whatever. Don't use an RVI type.

Exchange the dials and pointer, this is fiddly as the dial mounting screws are in a different location - you may have to mount an intermediate plate on the mechanism(I used a piece of circuit board) and fix the dial to that, and the mounting hole in the Frog pointer is too big for the RVC spindle so has to be packed out - I used very thin brass shim.
You'll then need to adjust the electronics as the Frog dial reads to 6,000rpm and the angle of swing also differs but a reasonably accurate result can be achieved.

It's a while since I did this but seem to recall that there was also some fiddling to fit the socket for the old Frog warning light - which has a long tube mating to another tube on the back of the dial warning light - into the new casing, but in the end it can all be done.

Can't say I've ever noticed a difficulty with the needle weight - if I remember correctly the Frog one is in fact balanced with a small weight fixed inside the silver centre.

Sorry I've no photos to help.

Dennis
D Stanfield

I think only early RVC's (with s/n ending in 00) had the potentiometer or calibration pot, so easier if you use this type to recalibrate the sweep.

Fergus Pollock

You chaps do love to make it complicated!

I just sent mine away, it came back looking exactly as it should, I wired it up, it worked perfectly.

The difficult bit for me was getting rid of the voltage regulator and adapting the loom. Not my field at all, therefore scary.

Nick and Cherry Scoop

If anyones is interested I've contacted both accuspark and bbclassics and asked if they do or will supply "alternator dynamos" with tach take off.

Accuspark said they will have them on their website in about 4-6 weeks
Bbclassics will in about 4-5 weeks.

They charge about 150£ for the one without tach take off and said that the new model will only have a small addition in price, great news! That's a huge save compared to coughing up 500£.
Alexander Sorby Wigstrom

The later RVC tacho only has a red line. When I converted to Alternator I had an RVC in the garage (is it from a 1500 Spridget ?) and just painted the facia silver in the middle to match the Frogeye speedo. Not identical but Hey! What the heck!
Alan
Alan Anstead

Alexander: bbclassics were very keen to promote this line and are supposed to be putting an item in Mascot with a discount code. I don't know whether Gary L has received anything from them.
Graeme W

If when converting to an Alternator the Regulator is gutted and a couple of terminals connected underneath then used as a junction box it can be used as an underbonnet storage compartment for as an example a spare set of spark plugs.
Alan
Alan Anstead

This thread was discussed between 07/06/2014 and 10/06/2014

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