[novech]

My dad has a 75 Datsun with a 350, originally a 4 cyl. He wants to use the factory tach but needs to get it to work right for the eight cyl. We thought if he changed the resistor it would work but it didn't. Does anyone know how to convert the tach from a 4 cyl to an 8 so it shows the correct engine speed?

 

[Keith64]

Great conversion! (SBC in a Datsun) Tough question though. I'd thing you really need a schematic for the factory tach. Obviously there should be some way to make it work. You might look at how the old style tacs work where you change the resistor to match the number of cylinders. If you know how to hook up the resistor but aren't sure what resistance you need, you might install a potentiometer and try different settings until you find a match.

Keith
64ssv84spd
:chev:

 

[americangraffiti]

Call John at Redline, he can probably put in new internals which will make the tach work with an 8 cylinder.
Link is at bottom of my tag line.
AG