# How to time my Lemans HP 400



## Red Skeleton (Jul 2, 2019)

Hi all,

I have a 68 Lemans/GTO clone with a 68 400 ys code motor. Compression is in the 125-145 range. It has a cam but I have no info on it. It also has an edelbrock intake and 1406 carb and MSD 6AL ignition box and MSD distributor. She has headers too and a 3.55 10 bolt posi rear end with a muncie 4 speed. (close ratio I think)

When I bought her she had been stored 10 years and run occasionally. the advance springs had rusted off and the "commutator"? was rusty which I cleaned. I replaced the advance springs with the closest size I could with an over the counter advance curve kit.

It has no vacuum advance. She idles fine at 750 and is a rocket. I had set the initial timing to stock 9 degrees BTDC but got a low speed surging or mild bucking that interferes with the pleasure of driving it. I read on the forum and at the MSD site that mentions initial to be about 12 degrees before TDC at 750rpm for a Chevy small block. THEN, they say to run your engine full advance and set your timing there at 35 degrees. Then check initial to see what the spread is?

Being a back yard mechanic and not really dealing with the advance curve and never having a hopped up car before, Can you give me step by step on how to time this beast? What would timing be with this setup? BTW, NO pinging at ALL even when trying to and I run premium gas.

I also tried (mentioned on this forum) setting intitial timing at about 22 degrees BTDC and fully advance about 44 degrees. It seemed a little better but is still annoying at lower speeds.:|


----------



## Red Skeleton (Jul 2, 2019)

Update: put heavier advance springs with initial timing at 14 BTDC, no change for the better. I then turned the distributer to about 30 degrees btdc and seemed worse but still drivable. No hard cranking either.


----------



## PontiacJim (Dec 29, 2012)

Red Skeleton said:


> Update: put heavier advance springs with initial timing at 14 BTDC, no change for the better. I then turned the distributer to about 30 degrees btdc and seemed worse but still drivable. No hard cranking either.



There is a Google Custom Search box in the upper right hand corner of the page. Timing has been covered in many previous posts and how to check and set it up. Here are just a couple you can click on and read over. 44 degrees advance on a Pontiac engine will melt pistons.

https://www.gtoforum.com/f170/timing-adjustment-455-pontiac-125953/
https://www.gtoforum.com/f170/total-timing-115153/
https://www.gtoforum.com/f170/1968-gto-set-base-timing-total-timing-130433/
https://www.gtoforum.com/f170/set-timing-before-engine-start-131713/
https://www.gtoforum.com/f170/1968-gto-timing-issue-132423/


----------



## Red Skeleton (Jul 2, 2019)

This may be a stupid question? If I set my initial timing first to 12 btdc at 750rpm and then my my total to 34 by setting the adjustable timing light to 34, rev up the engine to 3k while setting the balancer mark to zero, won't that change my initial timing reading?

Update: did as instructed.
Engine warm at 750 rpm idle, set timing to 12btdc.
Increase rpm till advance max’s
Have timing light set at 34 degrees and move distributor again till marker goes to zero
Reset idle back down to 750rpm (it increased a little)
Check base timing reads 22 btdc with timing light reset to zero
CORRECT? Thanks for all you help!


----------



## PontiacJim (Dec 29, 2012)

Red Skeleton said:


> This may be a stupid question? If I set my initial timing first to 12 btdc at 750rpm and then my my total to 34 by setting the adjustable timing light to 34, rev up the engine to 3k while setting the balancer mark to zero, won't that change my initial timing reading?
> 
> Update: did as instructed.
> Engine warm at 750 rpm idle, set timing to 12btdc.
> ...



Sounds like you got it and a learning lesson along the way. As long as you do not have any detonation when you lug or put a load on the engine, and it starts up easy, you should be OK. Detonation will kill an engine, so you would want to drop your timing back a couple degrees and see how that works.

Keep in mind that the vacuum advance serves 2 purposes - it'll help with gas mileage (who buys a GTO for gas mileage?) and keep your engine running cooler. So if you notice your engine running a higher temp than what you would like to see, most likely adding the vacuum advance will take care of that problem. Otherwise, leave it off and run it as it is. :thumbsup:


----------



## Lemans guy (Oct 14, 2014)

Red, well maybe. The only fly in the ointment is you seem to stop revving at 3000. That is where you might be confusing what you want your springs to do with what your total centrifigal advance really is.

If you stop revving at 3000 then all you have determined is that is all the advance you get until 3000. your may or may not have more advance.

Here is how to tell, forget 3000. remove one spring from your vac advance and just have one medium weight spring on it. set the base at 10 or 12 and start it up 

now rev it up until the timing no longer will advance no matter the number once it stops and you use your light or timing tape to tell. Stop, replace the missing spring. use a medium one for now.

what is the reading? say it is 38......subtract whatever base timing you had say 12.....38 -12 = 24.......24 is your centrifigal timing. Now you want 36 or 34, say 36.

then use the centrifigal number in this example 24 and add to get 36.....add 12.....24 + 12 = 36....set your base at 12.

I think it is unlikely that you have 12 degrees of centrifigal timing, likely you have more.... and if you have say 24 centrifigal and set base at 22....that is 46 and you will destroy your engine.

so you have to make sure what your centrifigal is, once that is known subtraction gets you the base. Now don't despair that it idles nice with 22 degrees and not as good with it at 12 degrees. a properly st up vac advance can will give you 10 more degrees above idle and can go above the 36 number because vac advance drope at at WOT and does not count against total.

Make sure, I think you may have too much because you are confusing the springs and at what RPM they bring in the total centrigigal to what the total is.

The total centrifigal is limited by the weights and bushings where they reach their mechanical limits, springs have no effect on the limit,...only how fast that limit is achieved,....once you get all the things I said right then mess with the springs and change weights and bushings if required.

you will get it let us know how you do


----------



## Lemans guy (Oct 14, 2014)

typo sorry.....remove one spring from Centrifigal advance weights...not vac!...Vac has no weights

you remove a spring just to achieve the total fast and at a lower rpm for the test only


----------



## Red Skeleton (Jul 2, 2019)

PontiacJim said:


> Sounds like you got it and a learning lesson along the way. As long as you do not have any detonation when you lug or put a load on the engine, and it starts up easy, you should be OK. Detonation will kill an engine, so you would want to drop your timing back a couple degrees and see how that works.
> 
> Keep in mind that the vacuum advance serves 2 purposes - it'll help with gas mileage (who buys a GTO for gas mileage?) and keep your engine running cooler. So if you notice your engine running a higher temp than what you would like to see, most likely adding the vacuum advance will take care of that problem. Otherwise, leave it off and run it as it is. :thumbsup:


So you think that 22 degrees base timing is ok instead of 12?


----------



## Lemans guy (Oct 14, 2014)

Red nobody can tell what is OK at base unless you know what Centrifigal is. If Centrifigal is 12 or 14 then 22 at base will work. 

So you have to verify Centrifigal for sure. The usual springs are stiff and at 3000 rpm will not bring all the advance in. So when you stop at 3000 you may not have measure all the advance...

Use the one spring method make sure the other spring is not too heavy and retest, the advance will come in fast that way at lower rpm and you will know that it reached it limit.

Then you can determine base timing and add vac as needed and mess with springs etc


----------



## Red Skeleton (Jul 2, 2019)

Lemans guy said:


> Red, well maybe. The only fly in the ointment is you seem to stop revving at 3000. That is where you might be confusing what you want your springs to do with what your total centrifigal advance really is.
> 
> If you stop revving at 3000 then all you have determined is that is all the advance you get until 3000. your may or may not have more advance.
> 
> ...


Thanks Lemans guy, any comment on this thread? difference is mine has a cam. https://www.gtoforum.com/f170/1968-gto-timing-issue-132423/


----------



## Lemans guy (Oct 14, 2014)

Right Red that is a good discussion on timing, I recall it.

but a hot cam does not change the need to have the correct "total" timing so your engine does not detonate. A hot cam cam usually take more idle timing. That can be achieved thru base timing only, like you did with your hand at 22. Or thru a combination of base timing and vacumn advance set on full manifold vacumn.

i usually set em at 20 to 28 degrees of idle timing with 10 degrees from vac advance....so ten to 18 of base timing and then the vac advance on top of that.

but that base is dependent on what the centrifigal is to achieve 36. so I set the base at 14 if I have 22 degrees centrifigal...that gives 36.

a hot cam can allow more idle timing but not more total timing. as a rule a most cams, 12 to 14 degrees base,with 10 degrees vac on top for 22 o 24 idle timing. a radical cam can take a bit more, 16, 18 + 10 degrees vac. as long as you don"t get hard starts, starter kickback or detonation on acceleration. Smart to be a little conservative, I know Pontiac Jim likes his at 34.

as far as the total, it is truly a range say 32 degrees to 40 degrees. with 36 the dead on center. 34 is a tad safer, 38 is a tad hotter.....so it can be adjusted, but I always start at 36. if detonating turn down to 34 or 32 if needed.' If you want to experiment you can push 38, just make sure it does not detonate.

with timing we all want to start everywhere but at the begining.., springs, RPM levels base timing etc.

it is like a house you can start with the second floor bedroom or the roof, without the foundation everything will be wrong and the foundation of timing is .......

What is your "total centrifigal advance", ...it is one number unless you change it with different weights or bushings.......regardless of RPM's it will not exceed that number

now you can st the proper base and add vac advance and adjust as needed. you cannot just add base timing to an unknown centrifigal number without risking damage.

so Just verify your centrifigal number, then once known you can begin. With that test I described it will come on fast since the springs are not holding it back....

and you will know the total.

I do strongly recommend a proper vac advance setup,....if you are street driving the car at all.

you are doing great, and your car sounds cool too........the right timing will smooth it out and make it run even better!:nerd::nerd::nerd:


----------



## John Schutt (Aug 27, 2018)

Lemans Guy, Excellent info and explanation!!


----------



## Red Skeleton (Jul 2, 2019)

*Please tell me again this is correct? Sorry!*



Red Skeleton said:


> This may be a stupid question? If I set my initial timing first to 12 btdc at 750rpm and then my my total to 34 by setting the adjustable timing light to 34, rev up the engine to 3k while setting the balancer mark to zero, won't that change my initial timing reading?
> 
> Update: did as instructed.
> Engine warm at 750 rpm idle, set timing to 12btdc.
> ...


Please read the above and tell me I did it correctly, just making sure it was read carefully as I'm still confused if it doesn't ping and doesn't have a tough time starting like the starter is straining I'm ok (It doesn't). Then if it still is lurching a bit at slower speeds I should ad a vacuum advance to advance timing MORE to eliminate that? 

I've gotten a wealth of information from you guys and I appreciate but some posts use terminology that confuses me. Base and initial timing mean the same thing right? Stuff like that.

One other thing is since I've had this taken compression which is good but I haven't pulled a valve cover to see if this has adjustable valves. Do most other than stock cams have adjustable valves?


----------



## PontiacJim (Dec 29, 2012)

Still lurching at lower speeds could be anything. Lean carb, rich carb, bad carb, bad PCV valve, vacuum leak, more/less timing, camshaft selection, fuel pressure, valves, etc.. This is where you come into play and start playing around to figure out what it is.

*initial/base timing* : this is your timing at idle with the vacuum advance disconnected.

*total timing* : this is your high RPM timing with full mechanical advance but with the vacuum advance disconnected.

*maximum timing *: this is your high RPM timing with the vacuum advance connected, also about what your timing is during cruise conditions.

*idle timing* : this is your initial plus any vacuum advance at idle.


Pontiac engines do not use an adjustable valve train - they are non-adjustable due to the fact that they use hydraulic lifers. The rocker arm nuts get torqued down. You can make a non-adjustable valve train adjustable by using poly locks. This can be done to "zero lash" the hydraulic lifters which will prevent the lifters from "pumping up" and limiting engine RPM's by design. To "zero lash" the lifters will allow the engine to rev slightly higher.

IF you decided to use a solid lifter cam, these require a specific clearance between the rocker arm and valve tip per manufacturer's specification. In this case, you would have to make the rocker arm adjustable so that you could achieve the correct clearance between the rocker arm and valve tip. You use a feeler gauge to do this and then lock down the poly lock to keep the adjustment.


----------



## Lemans guy (Oct 14, 2014)

Thanks John and that is a solid assessment from Pontiac Jim, breaking down how the timing is set, spot on.

Yet I think the thing that is confusing you is you are somehow believing that at 3000 RPM if you saw no more advance at timing.....that is all you have.......

You could be right,....but you must be sure. The reason I say this is that the springs on the distributors even new ones are very strong, and it may only advance to 34 At 3000 RPM but at 4000 or 4500 it may have more timing that you don’t know about. I find this routinely on distributors on my Sun Distributor machine, I run them up to 7 or 8 thousand RPM on the machine to make sure I know the total.

So without a dist machine the way to do this is the one spring removed procedure that I described in this thread. You can leave one medium strength spring on. Then when you do the test you will not have to run you engine to 7000, which you did not do and don’t want to, but by 3500 or so you can be sure their is no more advance and probably sooner than that.

So if you do that and you only have 34 still you can set your base at 22. But if you find more, you just saved your engine. And then can dial it in accordingly.

You can put a little c clip above the weight where the spring was removed, but they mostly stay on anyway as you only do it once and the RPM speed is not that crazy.

Don’t feel bad it all does get confusing, but you are further ahead than you think and Re read Pontiac Jim’s description of the timing set up

You will get it! Stay with it!:nerd::nerd:


----------



## Red Skeleton (Jul 2, 2019)

Lemans guy said:


> Thanks John and that is a solid assessment from Pontiac Jim, breaking down how the timing is set, spot on.
> 
> Yet I think the thing that is confusing you is you are somehow believing that at 3000 RPM if you saw no more advance at timing.....that is all you have.......
> 
> ...


First of all the original springs that were on it were super light and if I revved the motor a just a little it would go full advance. I did your check by removing a spring and got the same reading. I've since put on heavier springs to restrict the advance more. I'll drive it tomorrow.
Still no one has addressed that the full advance and the base timing are RELATIVE. So when I set the full advance at 34 that means the base timing is set too? 34 is the most important and the base just is what ever number it turns out to be, right? Because if you change the base that's going to move the 34 number too, right? Is the 22 number you gave base timing?


----------



## Lemans guy (Oct 14, 2014)

Red, Great......Answers to your questions are yes,yes,yes, and yes.

You now know that you have “12 degrees of centrifigal advance”.....the beginning number, you then would set the base, 
vac plugged (you have none).......The bass should be 24 or 22. .....24 base gives you 36 Total advance........22 Base gives you 34 total advance. Either should work 34 is just a tad more conservative.

Yes “Total advance is the most important number” , this is the 34 or 36 we are discussing. If you have no pinging, starter kickback or hard starts you will be good to go!

At 22 it will run a nice and cool idle and smooth two. A medium and light spring would probably be best, get you close to 3000 RPM or so all in.

So you are there, you can run it this way, it is a racers setup, vac advance can add ten more for light throttle cruise....so you could be cruising with 46 if you ever decide to change, much better, more efficient burn on the leaner cruise mixture, cooler and less fuel too.

But that idea may not be what you want or consider it another day, sounds like you are good!

Nice work!:nerd::nerd:


----------



## Red Skeleton (Jul 2, 2019)

Lemans guy said:


> Red, Great......Answers to your questions are yes,yes,yes, and yes.
> 
> You now know that you have “12 degrees of centrifigal advance”.....the beginning number, you then would set the base,
> vac plugged (you have none).......The bass should be 24 or 22. .....24 base gives you 36 Total advance........22 Base gives you 34 total advance. Either should work 34 is just a tad more conservative.
> ...


Thanks Lemans Guy, but at 61 years old I just want driveability. I'm not going to swap cams but I want the best driveability I can get. Tomorrow I having the really loud turbo mufflers replaced with the quietest ones they have that are still listed as "turbos". 

When I was about 19 I had a 68 Lemans with the Sprint package. I paid $50. for it because it had jumped a tooth. I wish I had that car now. OHC 6, 4 speed cast iron Saginaw, 4 barrel Rochester, dual exhaust manifolds into 1, stock tach, console, and it was fast for what it was. I could give a Boss Mustang a run for his money in the 1/4. I remember a California Highway patrol officer having me pop the hood to see what I had when I was pulled over for speeding. The Mustang driver insisted I open the hood after almost beating him in the 1/4, lol after telling him I had a 6.


----------



## Red Skeleton (Jul 2, 2019)

Ok, I'm losing my mind! She was running fair but is still lurching at low speeds and not idling steady, it will change on it's own. Started suspecting carburation. It used to want to squeal the tires when just barely accelerating away from a stop sign. Way back before I pulled the distributor for the first time and had the rusted off light advance springs, I made a sharpie mark so I know where it was.
After timing it properly,and replacing the springs with like ones, that mark was a 1/2" away from where it was. 

So I thought I'd play with the timing , advancing it little by little until it would ping or strained starting. When I got to the strained starting, I'd back off (retard the timing). It took quite a bit but it still doesn't idle well and changes a little. I noticed the timing strobe moving around a little. It does go like a bat of of hell and I've NEVER gotten it to ping. 3rd gear at 20mph and floor it and it just accelerates. No over heating or pinging.

I then checked my timing and it was 52 degrees btdc from the zero mark on the scale. There's no way I can check the distributor except take it out and feel the bearing which I did about 20 miles ago. This was rusty inside when I bought it, which I cleaned out, the iron star that rotates was all rusty from sitting in a moist area.

I know something is wrong, but WHAT? Probably not related, but I hear the valves tapping like solid lifters, so I need to see what been done to the rockers if anything.


----------



## Lemans guy (Oct 14, 2014)

Red, I think you need a new distributor. It is rusted and sticks, the shaft, the center piece may be too far gone. When you checked and said it advanced only 12 degrees it was likely not giving you the correct reading, it may have been sticking.

You should take it out and examine it closely, but with all the rust you described how can you have confidence in it?

I would recommend a new one, if it is MSD and you like those, get one with vacumn advance. It will make your car run much better.

Does not sound like this one is worth messing with.


----------



## PontiacJim (Dec 29, 2012)

*RED*: "Still no one has addressed that the full advance and the base timing are RELATIVE. So when I set the full advance at 34 that means the base timing is set too? 34 is the most important and the base just is what ever number it turns out to be, right? Because if you change the base that's going to move the 34 number too, right? Is the 22 number you gave base timing?"

*PJ*: Yes, full advance and base timing _can be relative_. The distributor rotates at half the speed of the crank (or the crank rotates 2 times faster then the distributor), so you want to multiply the distributor mechanical advance by 2 to get crank degrees. So if your mechanical advance at the distributor is 12 degrees, at full advance all in at 3,000 RPM's, you should see 12 x 2 = a 24 degree increase at the crank's base timing - what ever that might be.

The thing here is that you are using a dial-back timing light and a means to read/know the engine RPM's. A typical timing option you have chosen for your engine - wanting a TOTAL timing advance of 34 degrees all in at 3,000 RPM. So when your engine reaches 3,000 RPM's, and the dial-back adjustment knob set to 34 degrees, you shoot the timing mark on the balancer and it should read "0" on the timing mark scale of the timing cover. Then you tighten down your distributor into position. TOTAL mechanical advance is now set at 34 degrees at 3,000 RPM. 

So let's do what you have been doing, setting the TOTAL advance of 34 degrees *@ 3,000 RPM*'s using the dial-back timing light. If you know the distributor has 12 degrees of mechanical weight advance, and that 12 x 2 = 24 degrees advance showing on the crank, you take your 34 Total from above and minus the 24 Mechanical degrees from the Distributor to give you 10 degrees Base/Initial on the crank *@ idle* (34-24=10 base). But of course using the dial-back function of the timing light, you should see "0" at the balancer timing mark. To check that your engine base/initial timing is indeed set at 10 degrees BTDC, turn the dial-back timing light to "0" and shoot the crank timing while the engine is at idle. The crank mark should line up on the timing cover scale at the 10 degree line, or pretty darn close to it.

Here is the RELATIVE aspect of the timing using your engine as the example and the dial-back timing method. As you advance the base/initial timing at the crank, the TOTAL timing @3,000 RPM's will also advance a like amount. If you advance the crank timing to 12 degrees BTDC, you would then have 12 degrees + 24 degrees mechanical = 36 degrees TOTAL mechanical advance @ 3,000 RPM's. If you have 22 degrees base/initial + 24 degrees mechanical distributor = 46 TOTAL @ 3,000 RPM's. Too much. Advancing the base/initial timing will indeed change TOTAL timing to 36 degrees, but it may no longer happen @ 3,000 RPM's and could be slightly higher. So this needs to be checked.

What is not being shown is that the 22 degrees at base/initial is at idle - which can be OK. The danger comes in at your Total advance at 3,000 RPMs'. Here is where the Vacuum Advance is a plus. If your base initial is set at 10 degrees without vacuum advance, then you hook-up your vacuum advance to a direct manifold source for vacuum, the vacuum advance can add another 10-12 degrees of advance to your base/initial timing. So 10 degrees at the crank plus the 12 degrees vacuum at idle gives you 22 degrees of total combined advance at idle - which is fine. Now above I just told you that 22 degrees base/initial plus 24 degrees of distributor mechanical will give you 46 degrees TOTAL and is too much. WTF?, right. At wide-open-throttle, there is NO vacuum to pull on the vacuum advance aspect of the distributor. So you lose the 12 degrees of advance that you get from the vacuum advance. So that 46 degrees of TOTAL combined advance minus the 12 degrees of vacuum advance, pulls your TOTAL mechanical advance down to 34 degrees, 46-12= 34 degrees. 34 degrees is what you want under wide-open-throttle. Once the gas pedal is lifted, vacuum returns, and the TOTAL combined advance goes back up to 46 degrees - which helps to cool the engine and provide better gas mileage. Vacuum advance only activates on part or no throttle positions, not under wide-open-throttle, so the higher 46 degrees of combined total advance is OK. 

If the MSD distributor does not have the option to use the vacuum advance, then you have a distributor aimed at racing. If someone has simply removed the vacuum advance, you may want to try and add it. 

So back to changing spring rates. Lighter springs or heavier weights may allow the mechanical distributor timing to advance quicker and lower the RPM at which TOTAL advance comes in. Heavier tension springs or heavier weights will do the opposite - slow the advance rate and raise the RPM at which TOTAL advance comes in. The weights inside the distributor are spinning around at high speeds and centrifugal forces of the spinning action upon the weights causes them to move outward this is what causes the mechanical advance. The rate at which these weights get slung outward to change timing is based on spring rate and the weight of the advance weights - all figured out by the engineers at the factory. Then us hot rodders come along and want to improve or fine tune upon this.

As an example, and using a stock distributor versus the MSD you have, installing lighter springs in a factory distributor may no longer hold the weights into position as the factory springs did. At a 650 RPM idle, there is little to no mechanical advance to the base/initial timing. Rev the engine up to 1,000 RPM's, the factory mechanical advance begins to kick in and timing changes from 9 degrees BTDC to 15 degrees BTDC. But, the hot rodder takes out the factory springs and installs a set of lighter springs to bring timing in faster for a more responsive engine. So now at 650 RPM's at idle, the 9 degrees might jump up to 12 degrees BTDC. At 1,000 RPM's the timing may now be 19 degrees BTDC, and so on. Just for comparison, looking at the factory Pontiac specs, the average TOTAL advance seems to be about 4,600 RPM. 

Lighter springs or heavier weights can change the factory engineered and designed mechanical distributor advance system which in turn can alter _ALL_ timing numbers through the entire RPM range. You cannot compare the factory timing settings or timing curves with an engine that has its distributor's mechanical timing changed by either using different spring tensions or different weights. It is comparing apples to oranges.

Keep in mind that you can also install "stops" which will limit TOTAL mechanical and TOTAL vacuum advance settings. I would think the MSD has this feature? So going back to the RELATIVE relationship between base/initial timing and TOTAL mechanical timing, even this can be altered in a way. TOTAL timing can be limited or even extended through modifications to the distributor's mechanical and vacuum advance properties. 

Each engine is different, so not 1 timing set-up fits all engines. I choose to use a total timing of 34 degrees @ 3,000 RPM as it fits a wider range of engines and is typically a "safe" number. As pointed out, your engine may work best at 36, 38, or even 32 degrees of TOTAL advance. Compression, cam, & octane all come into play on timing and timing curves. This is something that is up to you and your tuner to work out. In my youth, I always had a wrench in the back seat floor and would adjust my distributor any time I heard that engine damaging "pinging." If I did not, I would bump it up until I did, then back off slightly. Then when I hit a gas station and filled up and heard that "pinging" sound that was not there before, adjust the distributor again. This was no big deal then and "cool" when I was younger. Now it is nice just to find that happy medium setting where I am not on the verge of "pinging", yet pulling all the HP out of the engine, and not to retarded that it never "pings" and I give up a bunch of HP. 


*RED*:

"She was running fair but is still lurching at low speeds and not idling steady, it will change on it's own."

"After timing it properly,and replacing the springs with like ones, that mark was a 1/2" away from where it was."

" I noticed the timing strobe moving around a little."

"I then checked my timing and it was 52 degrees btdc from the zero mark on the scale."

*PJ*: Could be a distributor problem OR........ timing chain and gears are flat worn out. I have had the old chains break and be so stretched out it was a wonder they worked. Pontiac used an aluminum cam gear with nylon teeth up to about 1971 and chains wore out. 60,000 miles on the original parts is about it. You can check for a loose chain/worn gears by noting how far you have to rotate the crank- first one way, then the other, before you get any movement at the rotor button. You should want less than 7, preferably less than 5, degrees rotation on the crank using the timing scale. You can put a mark anywhere on the balancer to check this. Rotate by hand, very simple check and eliminates a chain/gear issue.

Cam gear and/or distributor gear could be worn out. You could also have too much play in the distributor shaft allowing the gear to force the shaft up/down changing your distributor timing. You can install shims between the gear and the dist. housing. Have read you want a minimum of .010" of play, but .012"-.015" is fine.



*RED*: "I hear the valves tapping like solid lifters, so I need to see what been done to the rockers if anything."

*PJ*: 1.) Check oil pressure, pump may be going out. 2.) Pontiac rockers get torqued down if still factory rocker arm studs. I have had a couple loosen up on me. 3.) Could also be worn lifters/cam. Watch the rocker arms while running to make sure they all appear to be lifting at about the same height. Watch for pushrod spin. Often a worn lifter will no longer spin on the cam as it should and the pushrod no longer rotates with it. Never experienced a collapsed lifter as most situations I have had were with high mileage engines that were flat worn out and lifters badly cupped on the bottoms. Engines still ran OK.

And, this could be your lurching problem.


----------



## Red Skeleton (Jul 2, 2019)

*Your guys help is unrelenting! THANK YOU!!*



PontiacJim said:


> *RED*: "Still no one has addressed that the full advance and the base timing are RELATIVE. So when I set the full advance at 34 that means the base timing is set too? 34 is the most important and the base just is what ever number it turns out to be, right? Because if you change the base that's going to move the 34 number too, right? Is the 22 number you gave base timing?"
> 
> *PJ*: Yes, full advance and base timing _can be relative_. The distributor rotates at half the speed of the crank (or the crank rotates 2 times faster then the distributor), so you want to multiply the distributor mechanical advance by 2 to get crank degrees. So if your mechanical advance at the distributor is 12 degrees, at full advance all in at 3,000 RPM's, you should see 12 x 2 = a 24 degree increase at the crank's base timing - what ever that might be.
> 
> ...


Thanks Jim, I'm going to have to read your post over and over to absorb it. You are a gentleman and a scholar! :grin2: 

I have a stock oil gauge that flutters at near 80 on the scale so although inaccurate it shows plenty there. I pulled a valve cover and everything is PERFECTLY clean. Yes there is puddles of oil on the rockers as is normal but I don't think there's many miles on this motor. When she's fully warm, I can hear the tappets still and they're the regular rockers. Should I hear them at ALL? I have a 66 Fury with solid lifters and it sounds about like them. Nothing terrible but I can hear them.

Since the MSD distributor is about $300. I think it will be easier for me to start a carb rebuild and then to the distributor. I was told this car sat for 10 years in storage and was run once in a while. I had the top off and found some jelling in the bowl which I cleaned out and chemtooled the jets, didn't help so I'm going to do a complete rebuild.

Update: while valve cover was off I decided to watch the valves and see the oil coming in. It seemed slow to start coming in to the rockers at high idle but started pooring in as it warmed up. I may have to put a gauge on it to see. What psi should it be, minimum?


----------



## Red Skeleton (Jul 2, 2019)

Here are some pictures of what i have.


----------



## Red Skeleton (Jul 2, 2019)

I did try to use my torque wrench set to 24ft pounds on a rocker I could wiggle just see looseness and it started to tighten indicating they're too loose?


----------



## PontiacJim (Dec 29, 2012)

Red Skeleton said:


> I did try to use my torque wrench set to 24ft pounds on a rocker I could wiggle just see looseness and it started to tighten indicating they're too loose?



The torque method won't work. You have the good heads - screw-in rocker arm studs. However, it looks like you may have the aftermarket Big Block 7/16" rocker arm studs. These are not the factory bottle neck studs which would have the 7/16" base that screws into the head, and the machined shoulder that tapers down to a 3/8" top stud allowing the rocker arm nuts to be torqued down on to the shoulder.

With those style of factory type rocker arm lock nuts, they don't hold adjustment very well. I tried a set thinking they would work and I'd save money. They kept loosing up.

You want to add the poly locks which will keep them from backing out - just as you would do if you were running a solid cam. They have different lengths, so you want to get one that will go down over the rocker arm stud far enough so you can tighten down the rocker arm and then lock the poly lock into position. That should take care of the rocker arm ticking problem.

Double check the studs as I am looking at the photo and not there in your garage.......and if I was, you would be taking me for a ride. :yesnod:


----------



## Red Skeleton (Jul 2, 2019)

PontiacJim said:


> The torque method won't work. You have the good heads - screw-in rocker arm studs. However, it looks like you may have the aftermarket Big Block 7/16" rocker arm studs. These are not the factory bottle neck studs which would have the 7/16" base that screws into the head, and the machined shoulder that tapers down to a 3/8" top stud allowing the rocker arm nuts to be torqued down on to the shoulder.
> 
> With those style of factory type rocker arm lock nuts, they don't hold adjustment very well. I tried a set thinking they would work and I'd save money. They kept loosing up.
> 
> ...


These are 7/16" with NO taper. Should I adjust these where its running and torque to where the ticking goes away (zero clearance)?


----------



## PontiacJim (Dec 29, 2012)

Red Skeleton said:


> These are 7/16" with NO taper. Should I adjust these where its running and torque to where the ticking goes away (zero clearance)?


Yep, right after you buy those poly locks and install them. :thumbsup:


----------

