Speedo gearing

[uax12]

The 62 saloon I've got has been fitted with a 1098 engine/gearbox and back axle, but still has its original gold faced speedo, so therefore the speed indication is a bit out.

Can I take the inside out of a later 1098 black faced speedo and put that into the gold faced one?

Andy G

[Fingolfin]

As far as I'm aware, there's no reason you couldn't do that, as long as the gold and black speedometers have the same number of odometer wheels and same warning light positions.

However, most black speedos will have different speed digit positions compared to gold ones (earlier = slower), so your reading might still be off. I suppose the culprit there is the needle clock spring - changing Black's clock spring for Gold's might fix that, but heaven help you if you try!

[IslipMinor]

The earlier 1098 cars had the gold speedo, with the correct tpm and 90 mph face - that would be a better solution than transposing internals.

[uax12]

Richard, do you happen to know what the part number on the face of those speedos is please?

Andy G

[amgrave]

I have a 1963 1098 engined mog with gold faced speedo and it reads fairly accurately, the numbers on mine are SN 4477/30 and 1376. Hope this helps.

[liammonty]

Richard, do you happen to know what the part number on the face of those speedos is please?

Andy G

They are pretty easy to identify even without the numbers, as they read to 90 mph unlike all the other gold faced Minor speedos, which only read up to 80 mph.

[firedrake1942]

And they only have one light at the top whereas the earlier ones had two lights.

Here is a piccie from a mid / late (pre october1964)

download/file.php?id=966

[liammonty]

And they only have one light at the top whereas the earlier ones had two lights.

The later 948 cars just had the one light at the top too (red full beam warning) as they had the indicator tell-tale on the end of the indicator stalk - granted that wasn't the case for the earlier cars with trafficators. Sorry for being pedantic!!

[firedrake1942]

but they still had max speed indicated at 80 - sorry to be even more pedantic!

[liammonty]

I didn't say they didn't... Your photo looks remarkably similar to the speedo in my '62 948 car

[amgrave]

Here's a pic of mine I posted about earlier.

[IslipMinor]

The one I am referring to is in the picture above from Amgrave - tpm of 1376 and a 90mph face (and tenths of a mile as well, what luxury!).

When we do the Euroclassic or Spring Classic runs we have 'tulip' navigation, which uses both tenths and trip distances between turning points - gets interesting with no trip and no tenths on our speedo!

[firedrake1942]

I've got a rope with a lead weight out of the passenger window . the passenger shouts out the knots and occasionally bellows 'By the Mark Twain' or some such nonsense. Dead accurate and plod cannot understand it!

[uax12]

Well that's interesting, I'm running a SN4477/30 1376 and it seems to be fairly accurate at the bottom end (30mph on the clock shows at 28mph on the village speed sign), but I have had her off the end of the clock on dual carriageways quite easily.....
I'm running a standard 1098 with a Hif38 on a ital twin branch manifold and a big bore (straight through) exhaust, and she seems to get up to 60 very quickly!

According to here: http://potteries.mmoc.org.uk/Identify.htm the one I want is a SN4477/80, infact the 4477/30 isn't listed in the list!

Another question to ask is this, I've got a 3.89:1 dolly axle that is going to go on her (when I can get the time to put it all back together again!), which will lead to yet another speedo change, but what do I use then???

Thanks

Andy G

[IslipMinor]

Andy,

You may find that the speedo becomes pretty accurate! Worth checking with a GPS before you change the axle to find out what error there is a 60mph+.

[starbiscuit]

Alternatively, there are a number of places around that will calibrate the speedo you have to the turns-per-mile you want.

From memory, it involved pushing the car along the road for ten wheel revolutions, chalking each one on the road, then measuring how far apart were the first and last mark, then some maths to get turns per mile.

I had mine done years ago when I swapped the 948 engine/box/4.55 diff/gold speedo for a 1293 engine/1098 box/3.9 diff/black speedo.

Had I known there was a gold-faced speed the went beyond 90, I might have sought one out and had that calibrated.
But as it was, my black one was a fiver from a scrappy and about £35 to overhaul and calibrate by post.

(I expect the price doubled in the last 25 years...)