1968 Mustang info needed

I have a 1968 Mustang 302 V8 power train in a 'Ford Exotic'. Four barrel carb and 4 speed.

Can someone provide me with the following factory recommendations:

Timing in degrees BTDC at idle (625 rpm) and fully advanced?

Thanks to all respondents, Ron Patterson

Reply to
Ron Patterson
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Depends on a lot of facters. Ford starts with 12* basic, about 24* mechanical, and 6* vacuum. BUT - those specs are 40 years old. Depending on where you live, what kind of gas you use, and what mods you've done, those specs are probably invalid.

So, here's how to set the timing in your car:

Base: Connect a vacuum gauge to the manifold. Set the timing where you get the most vacuum. If you don't have a vacuum gauge; set 1/2 a glass of water on the fender. Set the timing where the ripples in the water are the smoothest.

Mechanical advance: Advance until you get pinging under acceleration. Then back off 2*.

Vacuum advance: Advance until you get pinging on light acceleration, then back off 2*.

Reply to
.boB

Hey - great info. Stuff I never heard before. Thanks much.

Please to educate me a bit. I thought manifold vacuum would only be dependent on cam timing (and of course engine condition). Please explain how the ignition timing effects manifold vacuum.

Retarding from pinging is probably the ultimate way to set timing. Unfortunately my hearing is so bad that I never hear pinging so I do need a baseline to start. I have a dual point mechanical distributor - no vacuum pot and will be running 91 Octane.

Thought I would start about 2 degrees retarded from the factory settings. Assume from below that would be

12* at idle + 24* mechanical = 36* fully advanced?

Ron Patterson

Reply to
Ron Patterson

Please take some of that with a large block of deer-lick salt.

Although the '68 302 is a decendent of the 289 HiPo, I don't think it is stock with the dual point. It should have the vacuum advance. Any other hardware on the engine been changed ?

Factory spec for the '68 302 4V in a Mustang is 6* BTDC, with the stock distributor. The Fords that came with factory dual-points used more initial lead:

12* BTDC. (the dual points lacked the vacuum diaphram)

Also bear in mind that this engine is 10:1 compression and should be running premium in any case.

I couldn't find any spec from Ford for fully advanced, but any typical V8 engine will not benefit from more than about 36-38* maximum advance.

In the absence of a vacuum advance diaphram 12* BTDC is a good starting point. I'd still check for "all-in" at about 3500-4000 rpm not to excede 38*.

good luck rd

Reply to
RD Jones

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