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General Discussion => Q & A => Topic started by: elwood1950 on September 24, 2015, 10:19:30 AM

Title: timing a 65 skylark 401 nailhead
Post by: elwood1950 on September 24, 2015, 10:19:30 AM

 :rocker:What is the firing order on the 65 401 nailhead, and what is the timing supposed to be. I have some acceleration knocking and will check the timing, but also will add some lead to the gas, middle grade, that I have been using.The car has 39,000 original miles and is a daily driver to shows and around the neighborhood.. But does knock under acceleration after it warms up a bit. I must mention I live in Arizona and the warm summer temps probably don't help. Bill

Title: Re: timing a 65 skylark 401 nailhead
Post by: dsags on September 24, 2015, 12:06:09 PM

The info comes from the Electronic Garage section and the 65GS Service Manual.
Firing order is 1-2-7-8-4-5-6-3. Timing per the factory is 2 degrees BTDC, but don't be afraid to go further.
The original compression ratio is 10.25 to 1 so 91 or 93 octane would be recommended. A bit of knocking though would not be unusual.

Title: Re: timing a 65 skylark 401 nailhead
Post by: telriv on September 24, 2015, 08:24:39 PM

#1 is on the right side. If you have the steel valve covers the firing order is on the top of them. right side 1-3-5-7 left side 2-4-6-8  Timing is 2 1/2* BTDC   More than likely the rubber limiter timing bushing has deteriorated & fallen off which advances the timing TOO much causing the knocking/pinging noise.

Title: Re: timing a 65 skylark 401 nailhead
Post by: telriv on September 24, 2015, 08:26:18 PM

To add to that the original compression ratio was SUPPOSED to be 10.25-1   In reality the BEST I've ever measured is about 9.75-1 or lower from the factory.

Title: Re: timing a 65 skylark 401 nailhead
Post by: cwmcobra on September 24, 2015, 08:26:42 PM

Tom,

Please remind me the proper timing for a dual quad car with proper distributor setup?  And 4-speed manual if that matters......

Thanks,

Chuck

Title: Re: timing a 65 skylark 401 nailhead
Post by: telriv on September 24, 2015, 09:04:41 PM

If the distributor is stock Chuck it would be 12* BTDC. If the dist. has been modified it could fall anywhere between 8*-16*. I know a '65 Super Wildcat 4spd. is also 12*. These are ALL at a slow idle with the vacuum hose disconnected at the dist.

Title: Re: timing a 65 skylark 401 nailhead
Post by: cwmcobra on September 24, 2015, 09:18:48 PM

Thanks Tom.  The distributor was set up by Carmen Faso and I'm quite sure it is set for the 12* timing.  The car is torn down now, so I'll bookmark this for future reference.

 :cheers2:

Chuck