Let me say this first and it keeps swirling in my head that after the first year of just basically drag racing only I took the heads off and put 202 valves instead of the 188''s. At that time there was a little bit of detonation on the tops of the Pistons but just very very start of something. I showed the Machine Shop my plugs with the porcelain sticking out about a quarter of an inch LOL and he said well this is way too hot. And recommended the ones that I'm using now. Back when I had an average cranking pressure of 190.
I sure appreciate you taking the time because I'm getting a little bit lost with all these things for some reason. It's always ran at about 35 36 degrees of advance with my old cam. It was used a lot for drag racing but a lot of putting as well. I always seemed to be burning rich and have black plugs.
Now I've changed the cam and my compression is higher so I backed the timing off to 34 right out of the gate. I've been putting smaller and smaller Jets and larger metering rods to lean the carbs to stop having such a rich condition. but here I am reading the plugs and seeing some speckling on the porcelain thinking I'm back to getting detonation. But still seeming to run very rich as you can see from the plug that I just pulled out the other day. All these plug reading things I'm trying as well LOL.. I'm constantly watching my AF gauge. It runs down my driver side header. It was burning about 14.2 on the freeway which I thought was a little high for cruise at 28 to 3000 RPMs. About 68 miles an hour. I have no vacuum advance canister. I would think what timing curve was probably about 3/4 open at the time. On post #1028 I'm showing my timing curve.
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This is a side-by-side comparison of the number 2 spark plug. I believe they're the same heat range that's why I bought the NGK. The one on the right is the one that I've been running for a while and it's in Autolite ar3934. The one on the left has a hundred miles on it mostly freeway and it's the NGK 4554.
That was what really the first time I've ever took it on the freeway and had it like that for 45 minutes at a time. It's mostly driving around town and short verse of yeehaw... I thought it was the timing because I dropped it down 2 about 32 degrees total. a good Lord I was reading somewhere just recently were too low of timing was the cause of too much heat in the combustion chamber. It was running 170 cool-as-a-cucumber the whole time outside the combustion chamber...
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