Morris Minor Owners Club

I'd like to fit a rev counter as I find it a very useful tool for driving (I can't tell the revs by ear sufficiently accurately).

Obviously I'd like one that suits so I've looked around and come across a Smiths electronic counter. Looks nice and all that, but I can't find out what is necessary to drive the thing.

Does anybody have one and can tell me? I'm expecting some sort of connection to the ignition system, but that's where I'm stuck.

Power in from the green side of the fusebox (you can take a spur off the heater live, wiper live, voltage stabiliser pos in, etc), earth, and wire from the dizzy side of the coil. Plus of course a spur from the dash illumination so you can see it at night.

Simple

How are you supposed to make proper use of a rev counter? I presume you use it to judge when is the best time to change gear, but what RPM values should you change at? I had a rev counter on my Volvo but I never dared let it get anywhere near the red mark (6500 IIRC) as it screamed worryingly well below that.

Packedup, thanks. That really does seem easy.

Alex, in most driving the best place to keep the engine is around its torque peak, which is where it is most efficient. There's no point in most driving in going to the redline as torque is more useful in day-to-day driving than power and most engines' torque delivery is trailing off after about 60-70% of the rev limit.
I haven't learnt it in the Minor yet - in the Fiesta the torque peak is about 4000 revs, so I change up at about 4500. Each change 3-4 and 4-5 drops the revs by about 1000.

Having driven it for so long gearchanges are most instinct, so now the main uses for me in my Fiesta are keeping the revs below 3000 until the car is thoroughly warmed up, and keeping the revs above 2000 or so whenever I might need to accelerate (the Zetec engine doesn't pull well until then, and only really flies from about 3000).

Make sure the instrument is calibrated for a 4 cylinder car.

Peetee wrote:Make sure the instrument is calibrated for a 4 cylinder car.

It says "4 CYL" on the face. Also says "negative earth" which I thought to check for...

Waste of space on a Minor - in fact just about anything except a full race car ! The only extra gauge you need is oil pressure - and if you can't tell the revs ---- !

bmcecosse wrote:Waste of space on a Minor - in fact just about anything except a full race car ! The only extra gauge you need is oil pressure - and if you can't tell the revs ---- !

If I can't tell the revs - what?

Please bear in mind I've been driving my first ever classic car for a whole three months now and I do not yet have any idea what level of ear-bleeding racket corresponds to a particular engine speed or how high I can rev the engine without something breaking.

Cut the novices some slack, OK? You may be a pleasant, mild, considerate chap in real life but your post makes you seem blunt and opinionated. If you made your comment with a twinkle in your eye it somehow didn't translate to text.
</rant>

JimK, I don't know if you have a manual but it should have the maximum speed for each gear in the original workshop manual. I don't know about the haynes manuals.

I can't remember the actual figures but I think of it as about:
1st: 20mph (very noisy never go near 20 in first)
2nd: Just over 30, perhaps 35?
3rd: 50 (i believe the maximum may be as high as 57)
4th: never done more the 78

No - you are right - I am opinionated and very blunt!! Really - it's not a racing car , and it doesn't need a tachometer. My competion Minis never had tachometers either - just revved them to the max and then changed up - no time to look at dials anyway. You are justing 'tarting up' what looks like a very nice car. But it is your car - do with it what you wish!!

Lol I guess like this -
loud = low revs
very loud = med revs
really really loud with a rattly noise = too much!
engine jumping out of bonnet = oops should have changed gear


lol well its all wishful thinking just now anyway until Minor happy again

loud = low revs
very loud = med revs
really really loud with a rattly noise = too much!

Time for some carpets as well I think

JimK wrote:

Peetee wrote:Make sure the instrument is calibrated for a 4 cylinder car.

It says "4 CYL" on the face. Also says "negative earth" which I thought to check for...

I've spotted a little switch on quite a few counters to flick them between 4 and 6 cylinder, and most around will be from 4 pot cars, but yeah, worth checking that when buying! Unless you want to start working out the real figure every time you look at i (a 6 counter will still work but under read of course). And neg earth - I keep forgetting Minors are pos earth as standard, though how many are still pos earth now?

There's actually a few different types of counter, though not so many coil driven types:

Mechanical - Usually (always?) driven off the dizzy with a cable going in the back.
Electric - Off the alternator (diesels mainly, for obvious reasons!).
Electric - In series with the LT circuit. Wire from coil into counter, then out of counter to dizzy. Not good if it fails, as it takes the LT out as well.
Electric - Runs in parallel with the dizzy wire, if it packs in the LT usually carries on OK. Easiest to wire up, and the most common I've seen (but then most of my cars have had Smiths common as muck ones).

I've got an 80s auto at the moment, and still find the counter handy even if I can only manually hold 2nd. I'm slowly rebuilding a 70s auto, and will be fitting a counter in that too (though I can choose to hold first or second in that, and the engines are fragile so a counter is very useful). In a manual I reckon they're even more useful, you can see what your driving style means at the engine end and train yourself to suit the car quicker than doing it by ear/ feel.

I don't care how quick or slow a car is, I still like to have as much information about what it's doing as possible. I once fitted a counter to a car only to find out I'd been going about 1200rpm over the red line every change!