Hey, I have a question on timing. Ive had this 73 350/350 m22 for about a year now. Been trying to time it right. I got a new distributer, and it works great. It came with 3 sets of springs for the weights. The manual says timing is 8 degree on these at under 800rpm vaccum plugged off. So I set it there. Ran ok, but alot of pinging on acceleration, and some hunting on hard throttle. So changed out the tightest springs and put the middle ones on. No more hunting but still alot of pinging. Read up on it and everyone says I need to retard the timing. Checked, its still at 8, so this baffles me a bit. I should be good. So I drop it 2 degrees to 6, and boy does it run good now, but still a slight pinging, but much better. So Im thinking of taking a couple more degree off? but thats pretty close to 0, being 4 then. First , how do you tell what it should be? And how far can I retard this before its bad news? I don't want to break anything or bend a valve or something. Its so close, I can taste victory. What can I do?

 

Needs an adjustable vacuum advance. Do you have a light that will ck total timing?

 

Click on the last sticky (What happened to my sticky) and go to information on timing.

 

My timing light has a feature to dial up or down the timing. I just leave it on 0 and look at timing mark on the degree marker. but that said the marker is right under the water pump and almost impossible to see. So i end up putting 8 degrees for example on the timing gun, then line the timing mark up on 0 since its the only visible mark. So I think my light has that option if its what I just described. Vaccum is not adjustable on this distributor. And I have it attached to the manifold vaccum because the metered one up to gets no vaccum at idle, and it was hard to get it to idle and stay there. It would change idle speeds at random. Moving to the manifold vaccum fixed that. Seems the more I retard it the better it runs, mostly at top end. seems advanced gives you low end power, retarded top end. But my car sure likes the retarded better. Advanced pings alot.

 

I am a semi senile old amateur but I closely followed the procedures in the sticky on several cars with great results. The procedure does take some time, especially with test runs, but I believe it's worth the effort. I dont adjust the initial timing but let it "fall out" after setting total timing and it usually winds up pretty high like 18 degrees. On each car I had to modify the distributor advance slot and the vacuum canister.

 

I am confused about a few things you wrote.
there are 3 timing actions on the car.
base timing,, no vacuum, at idle, springs not allowing any advance.
centrifugal timing,, rpm when springs allow weights to move and add timing
vacuum timing,, the amount timing increased at full vacuum

base timing + centrifugal + vacuum = total timing

sounds like you are miss reading the 8 deg at 800rpm note.
I think it is more about adding 8 deg starting 800rpm, centrifugal
which may be double and be 16 deg at the crank.
so at 800rpm the centrifugal starts and adds 8deg dist movement which is 16 at the crank
basically you have a good timing light and can dial it in.

these are guides
12 base, 16 to 20 total centrifugal at 2800 to 3200rpm = 28 to 32 total no vacuum.

hope you understand

pinging could be vacuum advance can issues.
unplug it and seal carb/mani nipple

 

I’m surprised you’re getting pinging with only 8 degrees.
that must be hella big mechanical advance.
I think you should figure out what total advance you have.
set the timing gun dial to 30 or so, rev it up to 3000-3500 rpm and see if the mark is near zero.
adjust the dial and repeat.
if you have an extra person, have them hold the revs at 3500 and then adjust the dial to see what total advance you have. Small blocks usually run best 32-36 total.
i use very light springs, I run 18 initial, 36 total, all in by 2500rpm

 

yup
he has a good light to see what is happening

the dist instructions should tell him which springs

 

Before you get too far down the timing rabbit hole, be sure your hash mark on your balancer is correct on TDC. You don't say if it's the original balancer, but if so it may have spun.

 

Yes, verify the mark on the balancer is true TDC....or else you are just chasing stuff......
By no means should you be pinging at 8 degrees initial........and your initial should be somewhere around 15 degrees actually and not the weak setting specd' by GM to curb emissions......in fact, nobody should be setting timing at initial....you set it at max advance while revving the engine to around 3000rpm......the initial is just a guide and reference.

Jebby

 

Ok, seems i'm terrible at writing things down. or explaining. To set the timing. I used the manual. The old distributor was the original one with points converted to electronic and it began to fail because the magnet was rubbing the pick up and it was missing. So I bought an A Team pro ready to run electronic distributor , cap everything to replace it. It went in great, nice unit. Its the original style with tach gear and separate coil like original. Ok. To get it going, I learned in school to static time. So I did. #1 to top dead center, then move the balancer mark to 8 degrees what the manual said is base timing. Start, warm up, then plug the vacuum line to distributor and drop idle to 750 (under 800) and check timing is at 8 degree. Its usually pretty close. 8 degrees on mine is exactly straight up for the mark on the balancer. So 12 o clock exactly is 8 degrees, 0 is a bit to drivers side. As said its almost impossible to see the marks running because the mark is right under the water pump. I can only see the tip of the 8 degree mark, and I can see the 0, rest is impossible to see unless the motor is off and you use a mirror. Real poor design placement. I notice newer 350s have the marks an indicator moved way over onto the drivers side to remedy this. Anyway, thats how I get it to 8 degrees were the manual says to start. It does ping there alot at take off, and about half way up the rpm scale. Its annoying as hell. So I moved it to about 6 degrees, maybe 7, as stated its hard to see. It really improved but still pings a bit. So, I have tried to move it to 10 degrees as an experiment. While running at the 750rpm , 10 degrees really makes it idle smooth. Real smooth. But if you try to drive it it starts backfiring and bucking. If you shut it off it starts, but after alot of cranking. It does not like over 8 degrees. Some history. When I got the car, it was full of new parts but the old guy hadn't a clue how to install. So I had to re install all the new parts to fix. It was hard to start then, smoked when you started it after alot of cranking. Especially when warmed up. So first thing I checked was timing. I was amazed were it was set. It was set at what I would guess to be 30 degrees retarded! Yup, it was way over on the drivers side, off the scale almost at about 2 oclock on the balancer marks position. I couldnt believe it ran like that. So at that point I moved it majorly to 8 degrees by the markers, and it ran pretty good except for the old distributor issues and the pinging. So I'm thinking something is not in the right place. Like the balancer wheel is wrong, or the mark on it is in the wrong place. I verified tdc somewhat by pulling the plug, turning motor until #1 compressed, then checked mark and it was close to 0 on the marker, but I wasn't totally sure the piston was all the way up. But it appears to be pretty much correct. Guess I could borrow a bore scope to ensure the piston was all the way up. One guy here said to not use the vacuum advance? Will it even work then? Its running real good at 6/7 degrees except for the bit of ping it still has. Seems bit gutless off the line, but rips at top end. On hard acceleration it runs up pretty good, some times has a slight hunt or miss but pretty smooth and builds power quick. At 8 degrees the bottom end power was more but pings like crazy. This total timing stuff confuses me. So many numbers all around 28 to 35, how do I know whats right. Is vacuum attached to advance when you do this 3000 rpm test? Never had so much trouble timing a motor. Usually just set my trucks to the manuals number and done deal. This thing has a mind of its own and wont tell me the number. Gonna try 4 degrees today, see if ping goes away, and I may try those lightest springs first to see if its just advancing too slow at 6/7 degrees were I have it now. Might fix that slight hunting too since the strong springs made it hunt like crazy. I'll try to figure out what this total timing procedure is. Seems doing that is going to put my base timing at around 10 or more, and I don't think it will run that high. wouldn't with the old distributor. I'll post my results, and try this total timing so I can tell you were it is now anyway. Just not sure if I do that with vacuum on or off?

 

I seriously suggest you E-Mail Lars at V8fastcars@msn.com and get a copy of his timing paper. You are confused and believe that not only is your timing pointer in the wrong spot, but the balancer is spun as well. This needs to be verified before you can go any further.
Not one automobile built from the 50's to the 90's had a factory timing spec that was conducive to performance or efficiency....not a single one. They all had an emissions friendly timing spec.
The only way to set timing is with the total advance method. This is not spelled out in any manual and no manufacturer has a procedure for it.....but it is the way that ALL professional engine builders and tuners do it. Vacuum advance is unplugged for timing set.
Base/Initial timing is soley a product of total timing.....you do not drive at idle so initial timing is not important except as a reference. I have set timing on hundreds of 70's small blocks and they run best around 15 degrees of initial timing.....but that is becasue the total timing is 36...which is where most small blocks want to be. At 8 degrees of initial....your total will be about 28 degrees which lose a significant amount of performance and elevated coolant temps......
Get Lars paper to understand what timing is all about.....it is not that difficult but about 99% of people get it wrong as most were never taught correctly or refuse to believe the factory spec is wrong. Even into the 90's, all cars were timing soft.....one of the worst was the 5.0l Mustang LX/GT....which had a Ford spec of 0 degrees....if you move this to 7 degrees, the car will pickup a half second in the 1/4 mile.....huge. Computer controlled cars were all set at base timing because the computer controls total timing and it is impossible to check free revving the engine in park......so this adds to the confusion.
At any rate......no low compression engine will ping at 8 degrees base......even on 87 octane or lower.....so something is wrong.
The timing pointer should be at the 2 o'clock position.....but some early covers have the timing mark at 12 o'clock....which is a pain as no one to my knowledge makes a balancer that has the correct 12 o'clock style timing scribe.....so this is another potential screw up.......

Jebby

 

The distributor is a brand new A team ready to run pro billet distributor with tach gear. So I'm doubting the vacuum pot is broken. I set the 8 degrees at 750rpm with the vacuum disconnected and plugged. So the pot should even be in play. I have the middle springs on the weights as the strongest ones advanced too slow and it stumbled big time on hard acceleration. Middle springs seem good, but still has a slight hunt or miss up high. I noticed it passing a guy last night it hesitated slightly going by. Not sure though because I had the a/c on so when the pump kicks in its definitely robs some rpm. Lol. Anyway, I'm going to put the weakest springs on today to see if maybe it spools up a bit faster and fixes the ping at the 6 or7 degree its set at now. Cause it seems to like that spot, starts good hot and idles good, runs up ok, but gutless off the line, power up high. If no fix, then I'll take another degree off to see if that helps. IF i go over 8 degrees base timing it idles very smooth and speeds up so I have to back the idle screw off to keep it under 750 setting rpm. BUT, it stumbles and farts when you try to drive, and may stall. If it stalls it likely wont start again. If it does its after almost burning out the starter cranking so long. Especially when hot. So im not sure how it could possibly run at 12 to 15 degrees like all you guys are telling me it should be at. I'll try it there but I doubt it will run. I kind of get how to see what total timing is by running it up to 3000 and turning my degree dial until the balancer mark lines up on the 0 mark, and what the gun reads is the total timing. BUT, what will this tell me? Since Ive heard so far the total timing could be 28 to 36 or so, thats great, but which number do I use. At least the manual tells me to start with 8. lets say its 30, ok its 30. So what, should it be more? Less? Seems to put me at more of a mistery than now. Guess I'll just keep monkeying around until I find a good base number, springs, and no ping. Have a feeling thats gonna be at about 4 to 5 degrees base. Since it seems close now.

 

do yourself a favor and verify top DC and time marks.
you went from 30 retarded to 8 adv?
38 deg?
uh,,,

 

Just a couple observations that may have something to do with your problem:
From reading post 11 it sound to me like you are reading your timing from the passanger side of the car. I do not own a 73 but always thought the timing tab was on the drivers side of the engine. someone who has a 73 could verify this. also you say you have a 350/350 so is the engine original to the car? pretty sure by 1973 they were not making a 350/350. i think the 350 was rated at 250hp in 73. If you have the 350/250 you should easily be able to run 12+ degrees initial with no pinging. One test you could do - and is very simple and fast - is to disconnect the vac advance and plug it then drive the car and see if it still pings. if it runs good and doesn't ping your problem or part of your problem is in the vac advance. All good info in the previous posts.

Pat

 

Ill try to get that info if I can find it. Your right about the pointer. 8 degrees is exactly at 12 oclock, and the only way to see it running is to get so low the alternator rips your face off. Terrible spot for it. From above with timing light on drivers side you can see the 0 mark as its off center, but cant see any of the before top dead center marks. My ford is different, the marks are on the balancer, and just a pointer to align too. Much smarter system cause you can see the number right on the mark. this is backwards with the marks on the plate and just a line on the balancer. In fact, to see were it is, is such an awkward angle that even when you can see the line near 12 oclock you cant tell if its right on the number like you could if you looked staight down on it which is impossible. Passenger side has a/c pump so cant see anything at all. Thanks, i'll try to find that article.

 

I dont know if the motor is original. It is the 350 with 350 torque, not horsepower. I think thats the 250 hp motor, not sure. I read from the drivers side because its not visible at all on passenger. The timing mark plate is right at 12 oclock , totally under the water pump. 8 degree is exactly 12 oclock, 0 degree is slightly to drivers side, you can only see 0. Timing light gets squished down under the alternator in order for the light to hit the 12 oclock area. Its amazingly difficult to see, even seeing the balancer line at 12 oclock is hard because the angle is so sharp you cant really see if its on the arrow or slightly off. Cant look straight down. as stated above, when I got the car it was terribly timed, but would start and drive. Since theres no retarded marks past 0 I was guessing it was around 30 degrees retarded. It was about 2 inches past 0 on drivers side, so majorly retarded. But it would start with lots of cranking and drove, but burned oil or something and smoked alot at idle. When I got it home I set it to 8 degrees before and it ran much better but pings. Note at the badly set retarded original setting, it did not ping at all, but clearly wasn't right.

 

I have a stock LT-1, 350/370. My "0" timing mark is off about 1 degree, verified with a piston stop. (Forget which way)

The best timing I can run without pinging is about 33 degrees total. This translates to about 9 degrees initial. Vacuum advance is set to about 13 degrees, any more than that I get rattle at part throttle. The best pump gas I can get is 91.

 

I mentioned in my comment that total timing needs to be 36 degrees.....set it there, what is the mystery? But all of this is pointless until you verify #1 TDC on your timing mark which I can almost assure you is not right. What does 8 degrees at idle tell you? Nothing. You do not drive at idle so it doesn't matter.
Total timing is the most important setting, period. If someone told you 28 degrees for total timing that is flat out wrong....and I can assure you that nobody here said that.
You can choose to stay in this confusion you have or do things as we are explaining.......
Until you verify your timing marks....you are in the dark anyway.

Jebby

 

30 degree retarded was a guess because there are no retarded marks on the pointer plate. It has 0 to about 16 before top dead center, no retarded marks. 16 is a guess too because the plate is so high at 12oclock that you cant even see the other side of the plate. Stupid place to put this. Anyway, upon getting car home from buying it, I checked timeing and it was set roughly 2 inches on the retarded side, or drivers side of the 0 mark. Way down around 2 oclock. I was amazed it ran like that. Is now set to what I think is degrees, one line before 8 closer to 0, but again hard to see with the angle, so could be 7 or 5 as well. The 1/4 inch space between the marker and the balancer line makes it hard to get right with the angle. You cant really tell if its bang on the arrow since your view is 90degree angle off the marks. Almost putting my face into the alternator fan trying to see 12 oclock area. Very hard to see. Been giving me so much head ache I actually have been looking at replacing the whole motor with a new 4 bolt main one. I notice they have since gotten smarter and mover the indicators way over to the 2 oclock position so you can see it. Also noticed the new motors have the dipstick on the passenger side. mines on the drivers side. So not sure what motor I have other than its a 350, and its orange. lol. Anyway, my 30 number was a guess, it was at 2 oclock way far away from the timing plate. Ran horrible there, but didnt ping.