06-04-2024, 07:35 PM
(This post was last modified: 06-04-2024, 07:36 PM by John Cornforth.)
Hi
If you use the 8 cylinder setting, at any given RPM reading the instrument "expects" to see twice the rate of impulses compared to 4 cylinders. The scale will therefore be 0 to 16000 RPM when used on a 4 cylinder, which isn't very helpful.
There may be a way of modifying the internals but unfortunately I have no details of the inner workings of the Durite gauge.
When I needed a tachometer I used a secondhand Durite instrument scaled 0-4000 RPM. This was the sort aimed at the marine market, and is normally driven from the alternator as there are no igniton pulses available. The only workaround I found to this was to build a small driver circuit and use this to drive the meter movement directly, the original circuit being bypassed. I can give you a copy of the circuit if you PM me.
If you use the 8 cylinder setting, at any given RPM reading the instrument "expects" to see twice the rate of impulses compared to 4 cylinders. The scale will therefore be 0 to 16000 RPM when used on a 4 cylinder, which isn't very helpful.
There may be a way of modifying the internals but unfortunately I have no details of the inner workings of the Durite gauge.
When I needed a tachometer I used a secondhand Durite instrument scaled 0-4000 RPM. This was the sort aimed at the marine market, and is normally driven from the alternator as there are no igniton pulses available. The only workaround I found to this was to build a small driver circuit and use this to drive the meter movement directly, the original circuit being bypassed. I can give you a copy of the circuit if you PM me.