Docmacs'77
Active member
A friend, who's "supposed" to know a lot about building engines, and I, pulled my old tired 350 out of my '77 and commenced to build a 383 stroker and dropped it in. Anyway, the car has been idling great and sounds good, and I can cruise around normally, but if I step on it, it pings. I initially had the base timing at 12* and dropped it down 2* at a time in between test runs and took it all the way down to 2* btdc and it still pings. I have the heavy springs in the distributor and when I did the "all in" timing method described by Lars, I got a total of 32* for the centrifugal and base (with the base timing of 12*), so that should be fine. I left the dist vacuum disconnected and plugged the line. I just don't get it. I was thinking that maybe my cam wasn't degreed correctly by this friend, because actually, he didn't use a degree wheel at all. He was like "nah, don't need it. I'll just get the dots lined up on the crank and the cam and it'll be there". Now I'm really wondering what's up. At TDC on the compression stroke of #1 the rotors pointing at #1 plug wire. I was told by somebody that knew how to figure it out, that I had 10.67 CR. I'm using 93 octane. Do you think I'll need to add some racing fuel to stop the pinging, or maybe it's something else? Anyway, after taking it all the way down to 2* I took it for a test ride and it still pinged when I goosed it. So I just cruised it and it ran great and sounded fine. Actually went to Bestbuy and then drove around for probably 45 minutes before pulling into Sonic. I killed it there for about 20 minutes and when I started it up it was sputtering and just generally running crappy. I drove it back home and when I killed it, it ran on for like a half a second. This afternoon I pulled the plugs and they were really fouled out black. I replaced them thinking that's why it was sputtering and started it up and it didn't sound like it was running real smooth. I backed it out and took it for a test drive and it's still running crappy and spitting and sputtering. When I pulled it back in the garage and killed it, it backfired out the carb. I remember somebody saying that if it backfires out the exhaust, it's running lean, and if out the carb, it's running rich, which would account for the black plugs. Right? When it's idling it kind of sounds like it's surging on and off. Any ideas why all of a sudden last night it would just start running so bad? I mean it was purring nicely for almost an hour before I stopped at Sonic. Sure appreciate any advice on the pinging and the new stumbling problem. Marc.