Digital rev counter

[AllAlloyCup]

Can anyone recommend a digital read out rev counter
Or method of displaying engine revs on an iphone?

I don’t envisage permanent display just something to
help check what the engine is doing.

Either 6v. Or internal own battery with an inductive takeoff from one spark plug lead or a small transmitter( Hall effect?) on the camshaft pulley?

Regards 

Bill G

[wild_willy]

I use my electronic timing light which will indicate RPM and also has a dial back feature for setting max. advance. It is 12Volt and can be used with a separate 12V battery or a 6V to 12V inverter as I have done.

[Chris KC]

These work OK, just twist the wire around an HT lead. I used it to plot ignition advance curve.

https://www.ebay.co.uk/itm/Digital-Engin...2f131078b5

[MartinH]

In my experience these inductive devices can be erratic. Mostly due to all the ht "noise" on our older cars. Won't work at all with a magneto, mixed results with coil.

[Bob Culver]

The main revs of interest are whatever the driver deems prudent. For those not with sporty, trial or racing cars; there is time to ponder. If decide say the equivalent of 50 mph in top, it just requires remembering 2 or 3 equivalent speeds in the gears, hardly worth the effort of fitting a counter.

[nrzam]

This works for me on my 1933 Tourer. There have been no issues and a bonus has been that it works just as well on my coil lead which is tidier. I have a magnet stuck on the back so that it can be moved as required or hidden.

Being fairly new to Sevens, I have found it useful in learning the speeds and sounds for gear changes.

Engine Hour Meter Inductive Tachometer Gauge Backlit Digital Resettable for Motorcycle Marine Glider ATV Snow Blower Lawn Mower jet ski pit bike https://www.amazon.co.uk/dp/B076D4CSZK/r...rDb11AB61C

As usual it seems to be sold with various names on it at a variety of prices.

Ian