GM V8 Conv - Tacho ?

[beatle_bayly]

What's everyone do to have an operable tacho on a 6.2/6.5 conversion ? Mine has never worked since the conversion but it's one of those things I'd love to finish. Besides, the A/C gets a feed signal from the tach and without it, I've had to hotwire the A/C and it doesn't cycle. This results in a block of ice in humid weather.

Oh yeah, my 60 was a petrol B4 the conversion.

[80UTE]

Ive fitted a few 6.5 and used the sensor on the front of the crank ( 4 pulse /rev ) and had the tacho modded by a electronic's dude to read correct a 4 pulses /rev std they are 3 pulses/rev. Im not sure if the 6.2 has the sensor as it was used for the efi system on the 6.5 turbo's but the motors i fitted has been converted to mechanical pumps so the sensor was not used.

Wally

[beatle_bayly]

Thanks 80UTE. The 6.2 has 12 holes around the H/balancer and I've tried using a mag pickup and 3 bolts thru the balancer to give a 3-pulse-per-rev as you describe. However, I can't seem to get enough signal to activate the tach. Being a petrol tacho I thought it would be fairly easy but the electronic amplifier I have is obviously missing something.

Can I ask how much it costs (roughly) to get the tach modified, and whether you use diesel or petrol tachos ??