CJ Factory Tach?
 

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

Re: CJ Factory Tach?
 

Yes.

"Don Wallish" <quicktruck@aol.comnospam> wrote in message
news:20030725140919.28299.00000453@mb-m24.aol.com...
> 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
>

Re: CJ Factory Tach?
 

"Don Wallish" <quicktruck@aol.comnospam> wrote in message
news:20030725140919.28299.00000453@mb-m24.aol.com...
> 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
>

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

Re: CJ Factory Tach?
 

>Since a[n AMC] V8 was swapped
>into it . . . the factory 6 cyl tach is probably
>inaccurate. Is this good thinking?

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 www.omix-ada.com for a list of distributors.


Robert Bills
KG6LMV
Orange County CA

http://www.outdoorwire.com/4x4/jeep/...p-l/billsr.htm
http://www.RobertBills.com

Re: CJ Factory Tach?
 

Robert Bills wrote:

>>Since a[n AMC] V8 was swapped
>>into it . . . the factory 6 cyl tach is probably
>>inaccurate. Is this good thinking?
>
> 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 www.omix-ada.com for a list of distributors.

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.

Re: CJ Factory Tach?
 

So what? Just know you'll be reading four at three grand.
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

Don Wallish wrote:
>
> 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

Re: CJ Factory Tach?
 

?? Does the tach have anything in common with the shape and
size of a CD stickon label? If so, just print your own number
faceplate.

L.W.(ßill) ------ III wrote:

> So what? Just know you'll be reading four at three grand.
> God Bless America, ßill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> Don Wallish wrote:
>>
>> 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

Re: CJ Factory Tach?
 

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