These are pictures of before and after changing the plugs yesterday. A little history... Edlebrock 1406 I haven't cracked open yet but seems to work fine. Unknown miles on the old plugs. Old plug wires were crapola. No rich smell at all while running or driving. May be too lean I'm guessing. Starts easy and has good throttle response and great drivability. The timing is a mystery right now. HEI dist. I checked the timing and I'm not sure how accurate it is. At idle the timing mark is so far advanced it's towards the passenger side. So either the dampener spun or something else is wrong. Dialing the timing light shows 22 degrees at the zero mark. Too far advanced? The vacuum advance doesn't move the timing at all. I have a new small cap HEI distributor coming to replace the current bloated one. The two pics of the plugs showing 2 plugs each are the 4 from the passenger side. Then a shot of all 4. Then the 4 from the drivers side. The porcelain of all 4 on the drivers side are totally clean. No color changes at all. The 4 on the passenger side are all very dark brown. I'm gonna clean and rebuild the carb. I usually can tell what the timing is by looking at the straps. All 8 look almost completely white. Again, too far advanced? The last two pics are of the new AC R45TS plugs and new wires after only 5 miles of hard driving. One plug from each bank. I guess I need more miles on them because they still look brand new. What should I aim at for timing a stock 350? Start at 12-15? Or tune it by ear and throttle response? Thanks all.
Get rid of the Edelbrock carb if you have stock intake. Get Q-Jet or spread bore carb for stock intake this is the only carbs that will work. If you have a TA intake then carb is ok. The adapter on those carbs and stock intakes do not run right. Plugs are looking hot with too much timing since new need more time. Those old plugs were crap could be a lot of crap in there that needs to clean out I use NGK plugs UR5 is good I use YR5 for nitrous. it looks like you have a lot of timing in the engine you have to get the points straight first then do the timing and ten use Larry's timing instructions in this site. The HEI could be over timing the engine if from junkyard motor, the ones made for the engine should be better on the timimg. maybe he will post it real quick I got to go can't look right now. lol
Heat range wise those plugs with only 5 hard miles on them look good, the color change over point is nice! I would just richen up the secondary's a bit to be on the safe side at full throttle and then go fly!
Thanks guys. This is the first I've heard that an Edelbrock is not a good carb for these. I understand what you're saying though about the mismatched base. If need be in the future I'll try a Rochester, but I can tune the 1406 a lot easier. Or maybe a spreadbore throttle body type and TA intake when I win the lottery. I figured it was lean, and too far advanced. I do like what I see on the new plugs though. That was a surprise. Once I swap the distributor this weekend and drive the piss out of it, I'll do another plug check. I'm just going to tune it by ear and throttle response... I can't trust the timing marks.
That's a good way to get into trouble. Why can't you trust the timing marks? It's a very simple thing to measure the actual maximum timing.
I don't know what the timing should even be on this thing with a different ignition than factory. The sticker on the radiator says 4BTDC but that's with an old points distributor. 4? Really? I've always shot for something like 12-14 initial and 32-35 vacuum advance, then tuned for drivability and response. With todays fuels and the age of this engine, setting a specific number doesn't really seem practical to me.
No, this is exactly why I wrote this thread many moons ago. https://www.v8buick.com/index.php?threads/power-timing-your-buick-v8.63475/ You can’t arbitrarily pick your initial, and total timing. You are constrained by the amount of mechanical timing in the distributor you are using. Set the total timing, and the initial is what it must be for the total you want.
Duly noted. Thanks Larry. I haven't played with distributors\timing in quite a while since LS swapping and computer bug hit me. The new dist that's coming has a selection of bushings and springs so I can dial it in.
You should mechanically determine if the balancer is actually off. It's not that hard. I can't remember if Larry's thread describes this? Basically , you turn the engine until #1 piston is coming up on the compression stroke, and then when it's at the top, That's TDC. now go look at the balancer and the scale. If it's wrong, make your own mark that you can see ( I have a paint marker I like.). This is necessary as a starting point. Sounds like you are on the right track! Have fun.
You use a piston stop. You can make one out of an old sparkplug and 3/8-16 4 inch bolt. Put the piston stop in #1 cylinder. Turn the crank until the piston hits the stop. Make a mark on the balancer even with the 0 on the timing scale. Turn the crank the opposite way until the piston hits the stop. Make another mark. True TDC is halfway between your two marks.
Yes, the piston stop method gives you an exact reading. Kind of similar to what you do during the cam degree procedure.
I used the piston stop does a nice job you can creep on exact TDC by going one way then the other and screwing in/out little at a time. Balancer should be pointing close to "0" on the timing chain cover. Taking all the plugs out makes this easier too.
So I swapped to the new distributor. I made sure to clock it so I have plenty of Retard and Advance play for timing. The fat HEI won't be missed. It runs great, but haven't road-tested yet because the steering column is apart. If I knew what initial timing should be I'd maybe know what I was shooting for. It looked like it ran best at somewhere around 12 but it's tough to say because the tab is almost hidden. And I think my Amazon dial-back light is funky. Vacuum advance works now at least. And no, I have not marked the dampener yet. I'll get to it at some point.
Find TDC and follow Larry’s thread. As stated above there is a lot more to timing than just the initial setting. You need to be sure that you are getting the correct advance at various load/speeds for optimal performance and avoiding engine damage.
There is no such thing as what the initial timing is supposed to be except on a stock engine with the stock distributor. There is only what the engine likes. A stock engine will like 12* initial. Then you will want an additional 18-22* in mechanical advance for a total of 30-34* WITHOUT vacuum advance. Depending on how fast you bring in the mechanical advance, you may need to limit the vacuum advance.
Gotcha. I'm headed in the right direction then. Gotta borrow a different light and mess around again. When I was able to get it to flash properly, it looks like I'm at ~12 initial and close to 34 mechanical.
