Ignition timing question

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Jim Yergin
Posts: 78
Joined: Thu May 21, 2015 2:56 pm

Ignition timing question

Post by Jim Yergin » Wed Sep 12, 2018 11:31 am

Please pardon my ignorance but I am just curious why the ignition timing is different for manual transmission cars versus those with a Fordomatic. I know cars with the Fordomatic have a higher compression ratio but, from what I have read on-line, higher compression would mean less advance on the timing not more as called for on our cars (3' BTDC - STD vs. 6' BTDC - Fordomatic). Just curious and happy to learn.
Thanks.
Jim Yergin

DynoDan’55
Posts: 25
Joined: Sat Feb 24, 2018 3:34 pm

Re: Ignition timing question

Post by DynoDan’55 » Wed Sep 12, 2018 1:14 pm

You can’t lug an automatic. Too much advance (even though compression is slightly lower) would still allow engine pre-ignition damage with a manual trans.

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paul2748
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Location: Northeastern New Jersey

Re: Ignition timing question

Post by paul2748 » Wed Sep 12, 2018 8:51 pm

While factory is 3 and 6, a lot of owners go to 10 or 12 and find it runs better. I run 10 on mine
1956 Fiesta Red 312
1954 Ford Victoria 312
1948 Ford Convertible Street Rod 302

Jim Yergin
Posts: 78
Joined: Thu May 21, 2015 2:56 pm

Re: Ignition timing question

Post by Jim Yergin » Thu Sep 13, 2018 2:05 pm

Thank you DynoDan 55 for the explanation. Is that also the reason the manual transmission cars had lower compression?
Thank you paul2748, I had read that before and, when I finally get my engine running, I was going to use 10' BTDC as the initial setting.
Jim Yergin

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