Thread: Fitting a tacho to a Perentie

Originally Posted by rovercare

I'm still not sure why though, you can hold these things on the engine governer all day long without harm, I'd save the bucks and use it on diesel in it

Likewise I have never seen the point of fitting one.

Originally Posted by isuzurover

Likewise I have never seen the point of fitting one.

Likewise - I've thought about it, but then, thinking about the work and money involved, why bother?

For that matter, while they seem to be pretty much obligatory these days for anything with wheels, very few of them provide anything that is at all useful - spending the cost of them on an oil pressure gauge or a decent temperature gauge would seem more useful for most vehicles.

John

Originally Posted by bacicat

There would be 2 options as far as I could see.

Option 1 would be to convert the alternator so it has a 'W' terminal then run a tacho that can see that input - not sure what aftermarket tachos there are that will do this. The pulley ratios would need to be calculated.

Option 2 would be to use an aftermarket gauge (like a Murphy or Datcom unit) that picks up a signal from a mag pickup (speed sensor). Unless you have a hole drilled and tapped into the flywheel housing directly over the flywheel teeth, then this could potentially be a big job as you really need the engine out and the flywheel off to do this. You then just could the teeth on the flywheel and calibrate the unit. Our gensets use this style of sensing, usually into the control panel, but we do have some with gauges too.

Option 1 would be easier if you can find a tacho, option 2 will definitely work, but needs a hole drilled and tapped into the flywheel.





I'm sure there may be other ways - they are the 2 I know of.

EDIT - just having a think about it, a tacho like this - http://www.fwmurphy.com/uploaded/00-02-0260.pdf that is designed to work of a mag pickup may still work off the 'W' terminal, depending on its calibration range, but someone smarter than me would need to work out the pulses per RPM that comes out of the alternator with its pulley ratios.

Gav,
my vehicle is an FFR and has an hour meter fitted!
So....would it already have the required sender that could be utilised for a tacho?


Cheers, Mick.

Originally Posted by Brian Hjelm

I bought a genuine Isuzu tacho and sender from Zenith Engineering, the Isuzu industrial engine dealer in Brisbane. The sender replaces any one of the four threaded plugs underneath the injection pump.

Brian,
may I ask what the damage was?
(answer in dollars or litres will suffice )


Thankyou!
Cheers, Mick.

Does your hour meter count operating hours or crankshaft rotations?
Aaron

Originally Posted by mick88

Brian,
may I ask what the damage was?
(answer in dollars or litres will suffice )


Thankyou!
Cheers, Mick.

Did you read the link rovercare posted?

When I went for my HR license, the instructor had me changing gear based on the RPM of the motor as read from the tacho. I just think that would more suit my driving style rather than changing gears when it hits the rev limiter. It would probably make changing down easier when practicing double de-clutching.

Originally Posted by Mick_Marsh

When I went for my HR license, the instructor had me changing gear based on the RPM of the motor as read from the tacho. I just think that would more suit my driving style rather than changing gears when it hits the rev limiter. It would probably make changing down easier when practicing double de-clutching.

Its called feel, I drove a 4BD1 LT95 in a rangie with no clutch for a few weeks, I was working bulk hours and it was the only moving vehicle at the time....no tacho

Just crank it in first low to get started, up through to 4th, shift on the fly to high range 3rd and into 4th

You certainly should not need a tacho