What's the reason for plugging the vacuum line on the distributor, while setting the timing? I've finally gotten the HEI in there and we're up and running, but should I plug the vacuum line while setting the timing and why?
Yes. Because you only want to set the initial timing to start. If you don't plug the vacuum advance you'll be setting the initial AND vacuum advance timing, and you'll never know for sure how much mechanical advance you have. You want 34 - 36* total mechanical timing and about 10 - 20* vacuum advance.
uzzled: so if I've now done it without plugging the vacuum line both initial and advanced timing are adjusted, and we're out in the blue on the mechanical? Ok, this is something I don't know too much about, so what should I do? Last night I changed the distributor for the HEI I've been having laying around here. The swap went without problems, the only thing I'm puzzled about is that you were supposed to have to drill the gear that came off the original dist. to fit the pin and hole of the HEI, but it fit just perfectly as it was. The pin from the old dist. fit tight for both the old gear and the HEI shaft, so I didn't need to use the pin from HEI gear. I bought new plugs with a gap of 45 , and new 8mm wires, the ones you kind of put together yourself. I also Installed a kill switch on the ignition wire from the fuse box to the batt. term. on the HEI. Now the car idles rough, and runs a bit rough too at occasions. I set the timng to 6/7 without plugging the vacuum line for the dist. The car was bogging a bit before too, but it would idle just fine, and it would be a different kind of bogging then it is now. Now it's just a rough idle and in general rough running engine. Any ideas on where I should start looking to solve this?
Do you have a full 12 volts to the power terminal at the cap? Also if you have 6/7 degrees with the vaccum hooked up you don't have near enough advance to run right. If you put a light on it and removed the vaccum line you'd see that your ignition is then retarded, youd be subtracting 10 or 12 degrees of vaccum advance from your 6/7 you have now. In other words if you timed it with the vaccum unhooked at 6/7 degrees the hooked up the vaccum you'd have both advances working, about 16/17 degrees at idle. Dave Berry
Yes there should be a full 12v. directly from the fusebox, pulled a new larger wire yesterday. I'll have to measure to be sure though, hope there's no drop in the kill switch, got a heavy duty 50 amp switch to minimize the chance of that. Regarding the timing I'll have to go out and investigate.. I should plug it with a golf peg or screw when it's disconnected right?
Kimson- put a vacuum gauge on your engine. very simple tool and it will probably tell you what the problem is. i don't know the elevation where you are, but you're looking for something along the lines of 15-20" Hg (that's inches of mercury, a measurement of vacuum, it will matter how high you are above sea level, though) with a stock type cam, with a pretty darned steady needle. if you put a vacuum gauge on your engine (there's plenty of place to do this, even off the carb, but I use a port I made on the intake for this purpose) and tell us what you're getting for results, a solution may be easier to come by Setting your carb without one is a lot like shooting fish in a barrel in the dark in my opinion. You're gonna hit something, but I couldn't tell you what
Hmm.. I noticed that the hose for the vaccum line was disconected at the carb, must have fallen off when I took out the old coil. Well the timing is showing 6 with vacuum line connected, again 6 with it disconnected, and then when it's plugged. It doesn't change at all no matter how the line is connected/disconnected. o No: It sounds a bit like a diesel, just running rough. I put the light on all spark plug wires and it lights up on all so there's juice to all plugs. There's 12v. at the batt. terminal on the HEI.
That sounds like you have another problem...a vacuum advance unit that isn't working (If you can unplug the line going to it, and the idle doesn't change). A common problem; fairly easy to change even with the distributor still on the engine. It could also be because of where you have the vac line hooked to the carb: is it into the baseplate or directly into the manifold, or is it 'up high' on the carrb, above the throttle plates? If it's the latter, move it to one of the other places and see what happens (make sure you can feel vacuum at the line when it's unhooked from the distributor). You should hear a definite change in engine RPM with the line unhooked. If the car ran right before, you probably have a minor problem you can easily fix. Advance units are available at any parts store. There's always a possibilty you have a module problem in the HEI, but it's less likely. Usually when they go bad, the car will run until you shut it off, then won't restart....but not always. Getting your total timing exactly correct with an HEI takes some time, but for everyday, non-performance driving, it will work fine as-is.
Kimson, Click this link: http://www.v8buick.com/showthread.php?t=63475 I wrote this post because ignition questions pop up all the time. It's a sticky in the FAQ forum. Read it, and it will tell you why you can't just put in an HEI, and expect the car to run to it's full potential. It should answer some of your questions.
I got no vacuum coming from where it is connected at the carb. I disconected it and reconnected it with cluster of vacuum lines in front of the carb. Now there's vacuum to it. So with the line connected the timing reads 6. With it disconnected it reads something like 18. So if I've understood this right, I should time it with the vacuum line disconnected and plugged to 6. Then I should be able to read 16/17 on the harmonic balancer when the vacuum line is reconected? I found this 4 gauge set at JCWhiteney is this something to look in to or is it junk? Now I've got some crappy 2 gauge water temp and oil pressure gauge that I wouldn't mind changing out. http://www.jcwhitney.com/autoparts/...Id-100000234283/Pr-p_CATENTRY_ID:100000234283
That sure is a well describing layout of how it works :TU: , I'm just confused about all of this, I used a timing light for the first time two days ago, so figuring out all numbers and vacuum, timing, intitial, mechanical etc etc heck I can barely use inches when measuring something.. is a bit to sort through when you can't ask someone who's standing next to you and is looking at what you're looking at. I'm most thankful to all the help I'm getting on this board :beer Now, this crane kit with the springs: "Crane adjustable vacuum advance kit. It comes with 3 sets of springs to allow your advance in as early as 1600 RPM, or as late as 3200 RPM, or anything in between" Is this something that's kind of a must in this situation, to get things moving down from 18.43?
:3gears: it sure liked having that vacuum line connected and working. The timing with it plugged is now at 6 and when connected at 16 or something, off the scale somewhere there. It stopped sounding lika a diesel too The idling is a bit high, makes the windows work real good tough :Brow: I don't have a tach, so when I get one, what should it be set at? It gets the "tyre" going at half throttle now whoppeeeeee... p
uzzled: hmm..seems like there's some more tuning here to do. At first I just started it drove it for a few car lengths, then backed it up into the parking spot again. Now I took it for a longer run around the block. It's more responsive at first, then it kind of backs off a bit, not the same power. The idle i a lot better than before, but still a little bit odd. I haven't taken it up past 35 mph, so we'll see how it behaves past that. I'm just sooooo glad that the HEI is in there and the car is up and running. Some more tuning shall be done, I'll just have to get a better feel for it so I can explain the situation better.
Kimson, Like I described in the post, most HEI's have alot of mechanical advance in them. The amount of mechanical advance in a distributor determines what initial advance you can run for a set total advance. For example, let's say your distributor has 30* of mechanical advance, and you want to run 34* total. That means you must run 4* intial (4+30=34*) You have no choice in this. If you run a higher initial the total will be higher. You have no idea how much mechanical advance is in that distributor you are using. The result is, you are flying blind, so to speak. The easiest way to determine how much mechanical advance is in your distributor, is to get the Crane kit, and install the lightest springs. Then make a 30* mark on your balancer, disconnect and plug the vacuum advance, and rev the motor to 2000 RPM. Read the total advance off the timing tab. If the 30 degree mark is at the 0, your total is 30, if it is at the 4, it's 34, etc. If the 30* mark is higher than the timing tab(it might be), then you total is too high. Loosen the distributor, rev the engine to 2000 RPM, and turn the distributor until the 30* mark lines up with the 0, 2, 4, or 6. Then road test the car, and see if it pings or detonates. Set the total accordingly. Buick engines run best between 30-36* of total timing. Forget the vacuum advance for now. The secret to getting the most performance is to set your total advance. You can't do any of this with the stock springs in the distributor. They don't allow the total advance in until 4000 or more RPM. That's too late, and you don't want to rev a motor that high in neutral, so that you can see the total advance. Once you determine how much mechanical advance is in YOUR distributor, and what total advance(30-36) the motor likes, you can determine the proper initial timing to run. Then we can play with the vacuum advance. First things first. Go back and read that FAQ timing post. Make sure you understand it. If you don't, ask questions, I'll try to help. Read it several times, it's easy if you understand.
I'll do that, thanks for all the help, on Monday I'll give Crane a call, I couldn't find the kit on their site. There was also something about a bushing in your article, I'll have to read it again to see if it was needed, that was a different kit. Once again, many thanks to all of you.... :TU:
Just to throw in a little more info, in your pic the original port labeled "no vacuum" is a ported vacuum port, and has no vacuum at idle, but vacuum comes up when the motor is revved. Some folks like ported vacuum for the advance, some like manifold vacuum (vacuum all the time, including idle)
uzzled: But when the vacuum line was hooked up to "the ported" vacuum port, the engine sounded like a diesel. I was out there to lower the idle a bit, I noticed how it still idles a bit rough uzzled: .. I turned it down a bit, and any more you notice how it starts to vibrate, I guess that's the no go area.
