Perfect Timing for Distributor

Car is running a bit off beat think its the timing. What is a good timing mark for a inline 6 250. Just put in petronix coil and points and new cap, rotor and spark plugs. Thanks

 

all engines are different, that's why they give you a starting point (degree).
check for vac. leak first. then what I do is with a vac. gauge set the timing to the highest vac. reading by turning the dist. once to the highest reading on the gauge I back the dist. reading off two degrees of timing...JMO

 

The book says 6* BTDC for your engine but I would probably give it 10 or 12 degrees advance.

 

Have you ever checked your total timing after doing that? Just curious what it ends up being.

 

nope...

 

One way I've used on non-stock engines to find how much initial advance they like is to warm up the engine, advance 2*, shut down and let the engine heat soak for a minute and then try and start it. If it starts ok bump up the timing another 2*, shut down, heat soak, restart. Keep doing that until the engine drags the starter or coughs through the carb when starting and then back off 2*. The only time that didn't work was when I was running a 300* duration cam, I got to 21* advance and stopped.

 

If you're running Duraspark ignition, that method won't work. It has a cranking retard for easier starting.

 

I've never had a Duraspark and it doesn't look like the OP does either. IIRC, you just need to disconnect the white wire from the Duraspark and put 12v on the coil to defeat the start retard feature.

 

I have read somewhere on the Ford forums, that with the Pertronix ignitor and coil you should widen the gap on the spark plugs to take advantage of the better spark for combustion.

 

Back in the 50's and 60's we would advance the timing a couple of degrees at a time until it would ping a couple or three times when we really lugged the engine down.

 

Just an fyi. Unless you have checked the harmonic balancer your timing probably won't be exact when set with a light.

 

I've always gone by the butt dyno, never used a light. Always advanced until it feels weaker or starts to ping, then back off a little(to most power point, or just before ping), and made sure it'd restart while hot. Every engines different 1 engine might like 32° another might like 38°, just gotta try stuff see what works best. You can also read the spark plug ground strap.

 

The problem with that method is that detonation can be happening even if you can't hear it.

 

Done it that way for years, never had an issue. That's why you really should read plugs.

 

I'll stick to my timing light. I would do it by ear if away from the shop,but best to go with lightthen you can verify your advance and everything is working right