Spark Timing tip

Park_W

The recent threads on gasoline choices reminded me to pass this one along: While reviewing the service manual specs and discussion on timing recently, I noted the statement that the recommended basic setting of TDC is for 81 octane fuel(!), and if you're using better than that, the timing should be advance accordingly. Well ... I'd been troubled by the low mileage on our Twin-H '51 Hornet (that's why I was rechecking the timing), so I advanced the basic setting to 6 degrees before TDC. No ping yet, so pushed it up to 8 degrees. Then drove to Front Royal for Doc's Meet (1,000 miles round trip). Mileage went up 6 mpg from what I'd been getting!

Unknown

Park



Your experience mirrors what Bernie Siegfried had told us all when he was still with us and providing tech sessions. 6 degrees ahead minimum ... play with the advance till you match your altitude, engine performance and driving preferences. Good to hear this is still true.



Cheers from the Heart Of Texas

Unknown

I generally run at 12 degrees advance. But...I'm at 4500 feet in altitude as well.

rambos_ride

Has anyone put one of their Hudson's on a dyno? I have had good luck getting cars tweaked for performance and/or mileage by taking to a good shop with a dyno.



I had a 1968 Chevelle with a built 350/solid lifter cam and couldn't get it to idle - and it just didn't seem to run the way I thought.



I took it to a shop with a dyno and without cracking the engine open - just by running some basic tests on the dyno they were able to tell me that number 8 cylinder needed to be re-adjusted.



I was a bit skeptical - but when I got home I re-adjusted number 8 and whoa and behold it ran like a top idle. I was so impressed I took it back to have them run through the timing and adjust the camshaft degree and jet/adjust the carb.