Hey Everyone, I thought my '82 Scrambler was turning incredibly high revs on the factory tach, but a friend gave me something to think about. Since a V8 was swapped into it (401 before, i'm putting in a 360) the factory 6 cyl tach is probably inaccurate. Is this good thinking?
Thanks, Don W
Yes.
Absolutely. Your tach records ignition pulses, so every revolution on a 6 cylinder registers 6 pulses, an 8 cylinder registers 8 pulses. Your tach will read high by 33%. Aftermarket tachs have a switch on them to select the number of cylinders that matches your engine. There may be something similar, or an easy modification for your tach, otherwise you'll have to find a factory 6 cylinder tach if you want it to read correctly.
Chris
Yes.
Your choices are either an aftermarket tach mounted to the steering column (none will fit the hole in your dash), or a factory repro.
The repro has a 4-6-8 switch on the back, and will work with your AMC V-8.
Collins Bros. in Texas advertises the repros in the jeeps mags. It is actually an Omix-Ada part, #5459418. Check
Robert Bills KG6LMV Orange County CA
Odd, one would think that someone would make and sell an inline tach convertor. Would just need a resistor net to drop the voltage to the input of a counter chip, then a driver chip to run the output back up to normal voltage if needed. All you'd need would be a johnson counter that outputs 3 pulses for every 4 in.
Hey Everyone, Thanks for the advice. I found an AutoMeter tach i had in my old truck, i'm going to put on the column for now. I want to get one of the replacements, though. I love the package with the tach, but i've pumped too much $$$ into it lately to worry about it now.
Thanks, Don W
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