[charlie66]

Does anyone know how to make one of these tachs work for a 4 cylinder?

I was thinking if the signal was changed with less power or changing around wires ?

I would appreciate it if someone could shed some light on this for me.

Thanks....

[charlie66]

I thought being i had my a digital 6 box set on 4 cylinder that it would take care of the tech being synchronized..

[Tom Vaught]

My assumption Charlie is that most Tachs work off of coil firing pulses.
Where do you have the 64 Tach reading the signal?

Tom V.

[shaker455]

Factory Tach ?

[Tom Vaught]

Charlie has a 1964 A-Body and his 1st post says 64 Tach
so I AM ASSUMING a factory 90 degree sweep dash tach.

Know really nothing about the Pontiac Tachs except mine works and always has with a Points distributor.

Tom V.

[charlie66]

Originally Posted by Tom Vaught

My assumption Charlie is that most Tachs work off of coil firing pulses.
Where do you have the 64 Tach reading the signal?

Tom V.

It pluged into the MSD box.

[charlie66]

Originally Posted by shaker455

Factory Tach ?

Yes

[64speed]

What 4 cylinder do you have in a 64 Abody?

[charlie66]

Originally Posted by 64speed

What 4 cylinder do you have in a 64 Abody?

1961 194.5 ci Pontiac from a tempest..

[64speed]

I have to ask why

[shaker455]

Originally Posted by charlie66

Yes

Did it ever work for you before?
all the old factory tachs I've seen are pretty slow.

I did think this tach in pic was a neat idea for my GP, it was installed in place of the clock.

[flat-bill]

I think, but could be wrong about this, that the tach reads pulses from the ignition. Your four will put out 1/2 the pulses for a given rpm and give an incorrect rpm on the tach. Billk

[charlie66]

Originally Posted by 64speed

I have to ask why

Why not?

[charlie66]

Originally Posted by shaker455

Did it ever work for you before?
all the old factory tachs I've seen are pretty slow.

I did think this tach in pic was a neat idea for my GP, it was installed in place of the clock.

It worked great. It still works but at half the rpm as it actually is..

Heres what i got...

[charlie66]

Originally Posted by flat-bill

I think, but could be wrong about this, that the tach reads pulses from the ignition. Your four will put out 1/2 the pulses for a given rpm and give an incorrect rpm on the tach. Billk

Thats whats happening.

Do they make an inline converter ?

[charlie66]

Originally Posted by 64speed

I have to ask why

Here it is

[shaker455]

Charlie,
Your tach wire brown? does it have any resistor built into the wire?
If I remember correctly that 4-cyl is what that car came with so why can you not simply take the wire directly to the coil?

[Tom Vaught]

Charlie, you are not giving 64 speed the whole story.

Charlie's 4 cylinder turbocharged engine make about 800 hp at 30+ pounds of boost pressure. So the "why" is, his 4 cylinder engine and the mods he made would destroy your V8 64 tempest on the street if the two of you had a street race. We are not talking a couple of cars we are talking bus lengths difference in "The Gap".

Plus Charlie like to be different. His engine has a race turbo and fuel injection on it.
The picture he posted is a carbed 4 cylinder Pontiac engine.
Tom V.

[flat-bill]

Originally Posted by charlie66

Thats whats happening.

Do they make an inline converter ?

I don't think so. Sorry. I think your car is great. Billk

[Sirrotica]

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