hi all

put a voodoo 60103 cam in my 78 and wanted to know what to set the timing at? should I set it to 8 BTDC?

thanks

pete

You can start there.  It will still be a few weeks until I install mine.  You will need to play with the timing a bit to find the right setting.  A vacuum gauge may help.  There are a few past threads describing how to do this.  Ben listed a good procedure.

Yeah, find Ben;s thread.  I set the initial advance on my '81 a little higher using Ben's vacuum methind and the result was a VERY noticeable increase in throttle response and (perceived) power.

Use a dial back timing light,set it at 36 deg, take the motor to 3000 rpm with the vac adv. disconnected, when the mark on the dampner reads O on timing tab lock the dist. there, might have to reset idle,check intl.
timing by turning dial on light back to O, check timing at idle ,hook up vac.adv.take the car and wring it out,see what happens, should be real close.anips38482.8457523148

[QUOTE=anips]Use a dial back timing light,set it at 36 deg, take the motor to 3000 rpm with the vac adv. disconnected, when the mark on the dampner reads O on timing tab lock the dist. there, hook up vac. adv, might have to reset idle,check inst. timing by turning dial on light back to O, check timing at idle ,take the car and wring it out,see what happens, should be real close[/QUOTE]

anips..  no disrespect but I dont like this method..  you get your timing good for 3000 but not for idle..

most of us drive street cars and therefore we want the best off idle response ..  so the best way is to tune your idle timing to the best..  then use springs of different strengths to tune your timing at later rpms.

if you had a distributor where the springs had not been replaced recently (which most people do) getting the timing to 36 at 3K could leave your initial timing at an incredibly low level..  and kill your off idle response.

 

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http://www.vetteprojects.com/bmv

Ben, no disrespect taken,what your telling me is that you don't agree with my method of timing a chev V-8, let me explain a little more , Chevy V-8's like to run somewhere around 36-38 degrees total mech. advance all in at about 3000 RPM, most distributors have depending what year have somewhere between 20-28 degree's built in, when you add in your initial setting that gives you your total, when I had my dist. built Performance Distributors built in 24 degs. so that makes my initial setting 12 degrees advanced. simple, as far as the weights and springs are concerned all they do is regulate how fast your advance comes in, heavy weights and light springs come in faster than heavy springs and lighter weights, you don't want it to fast to cause it to ping or too slow so that its a dog, the advance curve should be somewhere in the middle, but the total advance should remain the same, getting to the original post there was a cam change and question about initial timing, set the engine at total timing turn the dial on the light back to O and see where initial is at and go from there, do the math, subtract initial timing and that will give you built in adv.its a place to start, you folks with emission controls, EGR, smog pumps, etc. have to take that into consideration when timing the motor, the only emissions equipment my motors have is a PCV valve, with a new cam and emissions you might have do some distributor work.      anips38482.8653240741

my problem isnt with the total timing concept..  my problem is that the method you described involves using an arbitrary figure.. of 36-38 in about 3000 RPM...

while this is a good starting point.. it isnt exact for every engine...

fuel quality, aluminum heads, individual variations in an engine block all affect your detonation threshold

if your timing springs are worn you will get your timing advanced too quick..  too strong it comes in too late.

so for example  i have a worn 20 yr old dist that ive never changed springs in..  i get my timing to 36 @ 3000..    then check it at idle and its at 4 BTDC..  this is too low at idle..  even though it is correct at 3K

say i put some brand new strong springs in..  i get the timing to 36 @ 3000 and then drop it down to idle and its at 20 BTDC..  too high at idle..

so the problem i have is using an abitrary figure that is the "safe bet" for most engines and then trying to work backwards from there to get the idle timing right is a pain.

I prefer to work the other way around..  get the timing set at idle correctly..  using vacuum..  not just some arbitrary figure with a light.. then tuning the timing curve from there.. 

I really dont use a light for tuning..  i use it for reference after ive tuned..  or if im going to put things back exactly like it was..  but when retuning I dont use them.  I set the idle timing by vacuum..  then use springs/weights/bushings to adjust the ramp rate from there..  I have tuned cars that detonatated above 34 deg @3K ..  and ive tuned ones that didnt detonate until 41 @3K..

everyone has their method for doing this..  I think mine is a reliable and easy method for tuning every bit of timing you can get out of your car..  my grandfather and father taught me this method..  every person ive taught it too loves it.. if done right and thoroughly you will get every last bit of performance you can get.

if im working on joe blows 4 door sedan.. ill set it with a light and maybe give it a few more degrees at idle..  but ill use a safe arbitrary figure.  when i tune my car...  the light doesnt get used until im ready to record the timing figures for the current config.

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http://www.vetteprojects.com/bmv

Ben, if your method works for you and you get the performance you are looking for thats great, stick with it, but for the this debate I have to disagree, a Cup or Tour car that produce 6-700 hp and that run around all day at 8-8500 rpm with the equipment they run can run at 40+ degs. total advance, but we are talking about a mild street driven 350, the arbitrary figure of 36degs. that you speak of came down the mountain with Moses,its a fact, it states it in the GMPP catalog
and in "How to Hotrod a SB Chevy" dated 1972, pertty much the same today, in your post you stated weak springs would give you 4 BTDC and strong springs would give you 20 BTDC at Idle, you have it backwards, weak springs would allow the weights to extend outwards easier than strong springs giving you more advance, fact # 2, weights and springs play no role in initial timing and off idle responce, the reason for that is on most stock distributors the weights don't start to extend out thus advancing the timing until somewhere around 1200-1600 rpm, so unless your motor idles at those numbers they have no bearing, but what does have a role in initial timing and responce is your static initial setting and the vac. adv. dashpot that hangs on the side of the dist. so with my method   you are setting the total and initial at the same time and getting a starting point if the initial is in question and adjust from there, now, this is my story and I'am sticking to it

[QUOTE=anips]in your post you stated weak springs would give you 4 BTDC and strong springs would give you 20 BTDC at Idle, you have it backwards, weak springs would allow the weights to extend outwards easier than strong springs giving you more advance, [/QUOTE]

you miss my point..  think of it this way..  i set a car with weak spring to 10 at idle..  and it gets to 36 @ 2600 rpm...  now take the same one with strong springs..  it gets to 36 @ 3400 rpm..  so if I set the timing to 36 @ 3000 the strong strings car will be too high at idle and the weak springs car too low..  you are saying adjust your timing by turning the distributor to get your timing right at 3000 rpm..  when you do this it will change your idle timing.  this is indisputable.

[QUOTE=anips]fact # 2, weights and springs play no role in initial timing and off idle responce, the reason for that is on most stock distributors the weights don't start to extend out thus advancing the timing until somewhere around 1200-1600 rpm,[/QUOTE]

my point exactly..  set you initial/idle timing to the best value for off idle response..  then use springs/weights to get to 36 @ 3000 if that is where you want to be.

[QUOTE=anips]you are setting the total and initial at the same time and getting a starting point if the initial is in question and adjust from there, now, this is my story and I'am sticking to it[/QUOTE]

I have no idea where you got the idea that i said set them both at the same time.

this is how i do it

this example is with an MSD dist.

set INITIAL timing to the minimum required to get peak MANIFOLD vacuum.  you can turn your initial up further without vacuum increasing...  dont do this. turn it back down until it drops from peak..  then back up to barely reach peak.

this gives you the BEST off idle response.  the timing light figure from this will vary based on a number of factors.  lets just use mine as an example. 15 deg at idle.

then i usually take the second weakest springs and second smallest limit bushing and install them in the distributor. I drive the car..  i let it warm up..  and then drive it up hill with it floored..  if I get detonation early but it clears up..  i use the next stronger springs..  if i get detonation and it doesnt clear up i use a larger limit bushing.

i keep doing this until i get no detonation..  on my 427 i am using the third weakest spring combo and the second smallest limit bushing..

I have great off idle response.. and great accleration through the power band. 

so to summarize..  I set the IDLE timing and lock it down with the dist adjustment bolt..  then adjust wieghts/springs/bushings from there..

the way you are describing it is to set your timing to be correct at 3000 rpm...  and live with the consequences of what it will do to your idle timing.

I say adjust your initial timing first..  then use weights/springs for adjust your high rpm timing.

ADDED

I have no idea what the timing light would say my timing is @ 3000..  not that a cheap timing light is worth a damn for accuracy anyway..  I have access to a snap-on light that was just calibrated..  i took a reading from a car with it and compared to three other timing lights..   not a one of them was within 2 degrees..

I dont really know or care what the light would say at 3K..  what i do know is that when manifold vacuum is highest at idle.. the engine is "hungriest" for more fuel. this improves off idle response.  there is a state that can be reached where timing and idle mix cause vaccum to be at its highest at idle.

then i also know that if I change my limit bushing to the smallest one..  i reach a threshold where it will always detonate..  i know it if put in the next weaker set of springs.. that i will detonate early.. and then even out.. 

so does it matter that it probably is not set to 36-38 at 3000...  not really..  its as aggressive as my particular car will run... and thats all im concerned about.

 

cthulhu38484.3999652778

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http://www.vetteprojects.com/bmv

some math to helpout..

assuming idle timing set to 10 btdc @ 1000 by light or vacuum.

weak spring car using figures in previous post..

this car gets 36 @ 2600 so it gains 26 deg over 1600 rpm or 1.625/100

so at 3000 it would be @ 42.5

turn this down to 36 at 3000 and you have shifted the total and initial timing both back by 6.5 degrees...  leaving your idle timing at 3.5 which will run like a DEAD DOG..

now for the strong spring car.. 

it gains 26 degrees over 2400 rpm or 1.083/100

so at 3000 it would be 31.66 deg btdc..  then shifting this 4.33 ahead to get to 36 @ 3000 also advances your idle timing up 4.33 degrees..  this leaves you at 14.33 which is too high for most mild engines on pump gas.

contrast with this..   lets just assume for sake of argument that you had the car with weak springs (as most people with 20+ year old cars who havent replaced them do)

lets assume you set it to peak vacuum and it comes out to 10 deg btdc for idle timing.  here you lock the timing adjustment bolt down and leave it alone.  you rev the car to 3000 and the timing light read 42.5 degrees total...... then you get a new spring kit and change out your springs until you find a set that gets you to 36 @ 3000

when you drop it back to idle.. it is still correct..  when you rev it back up to 3000 it is still correct.  no guessing. at this point it is CORRECT..  not pretty close.. and you have the best off idle response.. and 36 deg @ 3000

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http://www.vetteprojects.com/bmv

i just looked at the msd spring and bushing chart to guestimate what my timing is..

I know initial is 15.. (measured with calibrated snap-on light)

im not using a vacuum advance...

im using the silver limit bushing..  which gives me upto 25 degrees on centrifugal timing.. for a TOTAL timing of 40

and im using the two light blue springs in the MSD kit..

i reach 36 degrees around 2700 and i reach my peak of 40 at around 3600

here are the instruction for selecting an advance curve from MSD..

they suggest setting initial as high as you can go.. then using springs to adjust as well..

http://www.msdignition.com/pdf/8350_8352_8354_frm23728.pdf

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http://www.vetteprojects.com/bmv

Good description Ben.  I'm backing you up on this one.

Ben and Ken, I believe we are talking apple's and orange's here from reading your latest posts, tell me if I'am wrong, I thought we were talking about a 78 with a cam change and a question about initial timing and I'am assuming he has a stock distrubitor with a vac. advance, not a MSD with no vac. advance and full mech. advance, but for the sake of the debate I will assume that all you have told me is correct, although I pertty much know how they opperate I don't fool around with weights and springs, why, because I don't have a distributor machine and if I did I wouldn't know how to opperate it, swapping springs and weights from a instruction sheet, the time it takes and not to mention what I would do if I dropped one of springs into never never land would really piss me off, so here's what I'd do, I would set my total timing at 36 degs., turn the dial back to 0 on the light, then check my initial, if I had lets say 3.5 initial, I would kill the motor, pull the distributor and take a ride to my engine builder and tell him I want 36 degs.total @ 3000 RPM with a Initial of 10-12 degs. and spin it on his machine, a couple hours later I'd go and pick it up, come home and reinstall, time my initial 10-12, DONE, and sleep good knowing it was right.

Hi All,

my 78 has the stock dist.

and I know the adv spring are shot .

I wanted to know what to set it as a starting point and then I can play around with it.

thanks for all the extra info its stuff i never knew!!!!!

pete k

Ben, may be we are both missing the point, I'am running a tack drive HEI with vac adv. built by Performance Distributors out of Memphis Tenn, they requested my cu in, weight of the car, comp ratio,cam spec, trans, gear ratio, carb, what type of driving, and sent me a hand built to my spec's distributor with 24 mech.degs total BUILT into it, that means when the weights were fully extended could not go any further I had 24 degrees, no more advance out of the distributor,thats it,the spring- weight combination was as such as to allow a middle of the road advance curve with 24 degs.total all in at 3000 RPM, so the only way I'am going to get a total of 36 is to crank 12 degs into my static initial timing, so I drop in the dist. hook up the "dial back" timing light, turn the dial on the timing light to 36, bring the engine to 3000, lock it down when the mark on the dampner reads O on the timing tab, let it return to idle, turn the dial on the light to 0 and I now have a 12 degs static initial timing, (12+24=36) after a ride and If I felt 36 was to much I crank in 10 initial gives me 34 total at 3000, if I want more I crank in 14 and that gives me 38 mech degs. at 3000 and so on, after the initial 3000 RPM run up to get my starting point of 36 all I have to do is time it in the normal way at idle with the light set on O, like I said chevy's make the most power + or - 36 total on a mild to med. street machine, that doesn't include what the vac adv. brings to the party, anips38484.8890162037

 bravo guys---have you ever looked in the factory service manuals at the spec sheets for distributers and at timing specs---so many different distributers,weights,vacuum advance and timing settings---different curves for both mechanical and vacuum advances---different initial and total timing settings depending on engine hp rating---wow---let's line them up on the 1320 and see who comes out on top----then we'll check mpg figures--marty     (totally stock LS5--including dist timing)

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Well not to add to the debate, but Cam design, cam timing, engine stroke, plug type, plug gap, dwell time and coil type can be added into the mix to what an engine likes for timing.  I'm not one for picking one way to time over another.  I prefer to stick to initial, plus what ever is designed or set into my distributor and stick to a total advance.

I have never set timing the way Ben has described it, but it makes 100% sense to me.  IF you think about it using manifold vacuum is the best way to set fuel air mixture on a carb at idle.  However since I have never set dist advance as Ben has described I'm not sure how that would affect carb tuning.  I guess what I am saying is I'm not sure how I would go about tackling which task first.

I have always set timing first and then went about tuing the carb.  If you adjust the distributor first and tune it for max vacuum you would have to do some adjustment on carburetor, because rpm will rise as vacuum rises.  so if you lower the idle rpm then I would suspect you would need to come back and adjust distributor again.  I guess you could keep going back and forth like you do with a carb until the idle speed and distributor adjustment balance out and no changes occur to engine vacuum.  Then from that point you could work on idle air fuel ratio for engine vacuum.

Ben, can you give me some insight because the ideal of tuning distributor advance is new to me and i'm not sure how carb tuning would play into that mix.  You would think after working at Holley all these years I would have hear this method, but I have not and I would like to be educated and possibly learn something new.

Thanks.

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    sometimes ignorance truly is bliss. 

Yes, if you set the carb, then the timing, you will have to reset the carb again.  And then that does mean you may need to recheck the timing.  When you get them close to each other, you won't see one changing the other any more.  But if they are way off, the differences can be huge. It is a balancing act.  Everything is.  Does this mean more work to get it just right?  Yes.  No way around it.

Part of the hang up between Ben and Joe comes with procedure.  Joe is looking at 3000 RPM as a set point.  Ben is not.  Ben is using a entirely different method.  Ben is looking for peaks.  Joe may not find peaks at 3000 rpm, depending on the distributor settings.  It MIGHT peak at 3000, it may be way past, and it may not have gotten to peak yet.

Joe is setting max mechanical advance up from inital.  Ben is setting max timing, then adjusting mechanical advance  back down to inital.

Both are say similar things, and getting similar results.  Both methods work.  But Joe is assuming the 36 is ideal at 3000 rpm.  It may be, but may not depending on compression, ignition system, cam, etc.  Ben's method take into account for all of these.  Joe's is long run easier.  Ben's takes more fiddling to get the weights and advance limits correct.  You can't forget the vacuum advance.  Without creating a specfic number, Ben takes that into account as well.

Bottom line, Joe's is easier to follow, and will create good results that will improve the way the engine runs, but leaves a few thing to assumptions.  It deals with hard numbers.  Ben's is more of a pain to make multiple test, but as a result does not make the assumptions that hard numbers can lead you into. But it does take the particular engine, car, drivetrain, weight, etc,  and therfore may or may not make even more power.

One way helps a lot.  The other way could buy not might help more. Are you after Big improvements, or absolute maximum improvements.  Does this mean you might set the peak with vacuum and find the inital is too far off to get the car started when warm? Sure.  Then you change initial weight stops and springs, and try again.  Yes, more fiddling.  And when you get all done, you may need a different carb set up.  Possibly a jetting change.  Of course that could screw up timing response.  Again, it's a balancing act.

You could set up one engine perfect, and change the final drive or tire size and it would change.  Lighter or heavier cars need different settings in identical built engines.  And when we build engines there are hundrends of variations within the engine itself.  There are no hard and fast rules. Just good guildlines.  Most of us will never go that far.  Serious racers do, and usually on a dyno.  I'm still backing up Ben.

kstyer38486.3563657407

Ken, the numbers I used are hard numbers used by GM and just about every one else in Chevy land, never the less, the question I have is with Ben's method what if maybe you have a bad hole or two, maybe some leaky or burnt valves, weak valve springs,some worn guides,or a hidden vac. leak somewhere, marginal carb,can't forget a leaky head gasket, then what do you do?   anips38486.6412037037

You know I have to say this is the kind of thread I really enjoy.  You can learn alot from "listening" to experienced and knowlegeable folks going back and forth.  It never gets boring around here.

Rgds
Neil

You do the same thing you do with any drivability problem.  You fix it.  If you are setting everything in a stock engine to spec, and doing a basic tune all of the problems you sited could still be there.  And it won't run right or work properly no matter what.  You have those problems, you fix them.  Very basic.

And the numbers you site from "everyone in Chevy land" are very much good numbers, as I said before.  I don't dispute them.  They will make almost any engine run quite well.  I do highly recommend your procedure.  You gave good advice.  But when you make engine mods, things change.  You cannot predict those changes unless you have been there before.  Are those good numbers for every engine made?  Of course not.  Why? Different designs.  You change designs, you can but may not, change those numbers.  Then what do you do?  Set it there and assume it's the best you can get?  Maybe it is.  In many cases it will be.  But not always.

A very good friend of mine used to build and run NHRA.  His engines are Chevy, but don't even come close to those numbers.  Very modified granted, but what do folks with very modified engines do?  They run it, test it, and adjust it until they get the best results.  That's what Ben is doing.

ken, there are a lot of high mileage cars out there that still run fairley good, I'am sure some with loose guides, compression down a little in a cylinder or two, maybe in need of plug wires, but generally run good, do you think that they are going to do a top end just to time the motor with a vac. gauage, I wouldn't, as a matter of fact I have a bone stock 68 chev 307 two barrel with 125,000 miles hiway miles I use for work,still runs good, doesn't smoke, uses or leaks about 1.5 qts in a K, carb and timing chain about two years ago, gets about 14 to the gal.,it time's at 5BTDC would you or Ben please put Ben's method up on this tread, so that I can print it, this dog's head is pertty hard, might be a while but I want to do a comparrison.

[QUOTE=YellowLT1]

You know I have to say this is the kind of thread I really enjoy.  You can learn alot from "listening" to experienced and knowlegeable folks going back and forth.  It never gets boring around here.

Rgds
Neil

[/QUOTE]

It's even kind of depressing......just when you thought you started to make some headway toward understanding the internal combustion engine, a thread like this comes along. Oh well, must press on. This has got to be one of the most informative exchanges I've ever experienced. Thank you, all.

JR

Joe, on the slightly worn engine you site, I would use your method, not Bens.  All of those wear factors are going to have an affect.  Not many folks are not going to tear down the engine that's a bit tired.  And I don't blame them.  I have driven a lot of older tired engines and had no interest in making them run like new, or better.  They just won't do it.  But they are still quite servicable, and could go a long time.  These engines don't get Ben's method.  The results could actually be worse.  You do the best with what you have.

But when we are speaking of peak power and peformance, you have to consider if that's the priority, someone would do the work and freshen up the engine and bring it back to new condition, and perform some modifications.  Then Ben's method wins.

So it comes down to what is trying to be done.  Do the best with a bit of wear?  Nothing wrong with that, I have done it many times for many people.  Myself included.  Then your method wins.  Or perhaps just bone stock specs is the better way to go for stock engines in aged condition.  There are times when I intentionally did not want the engine to produce more power.  I didn't think it would hold up, and set it with that in mind. Just wanted it to run well and survive.

Nothing is always right.  It depends on the situation at hand, and the goal to be reached.

Would it be possible to put the method up anyway, I was talking to some friends of mine about it,they have heard about it but didn't know the procedure, maybe I can put it together from some of the posts in the debate, the debate was giving me just enough of an excuse to buy a G-Meter so I could try both and see what would happen, hell, I'll buy it anyway, Thanks Ken, Ben anips38487.7212384259

Look back through the first page of this topic.  Ben has described it there.  I believe it's the 9 post down from the start of this thread.

I wish I had a g-force meter.  That would be a lot of fun.  And interesting.

Ken, buy one they are reasonable, 199.00 and 299.00, the 299 is the same as the 199 but you can down load the more expensive one, better than trial and error seat of the pants tuning, there are knock off's that are cheaper but if you are buying a tool like this I recomend G-Tech, if you think about it it's about the same price as a screw driver set from Snap On, or four pull's on a dyno jet.anips38488.568912037

[QUOTE=anips]Ken, the numbers I used are hard numbers used by GM and just about every one else in Chevy land, never the less, the question I have is with Ben's method what if maybe you have a bad hole or two, maybe some leaky or burnt valves, weak valve springs,some worn guides,or a hidden vac. leak somewhere, marginal carb,can't forget a leaky head gasket, then what do you do?   [/QUOTE]

fix them !!

kens assertion is right..  do i waste all this time to tune every last drop of perfomance out of joe blows 84 station wagon..  no way..

but when i tune an engine for me..  yes i do waste this much time..

everytime i make a change i start over..  many times no adjustment is necessary..  but often it is..

i just recently did this on my 80 chevy 4x4 truck..  when i put a new intake on..  the cheap light i was using to get it in the ball park until i could get my vac gauge back was so far out of calibration it was miserable..

but after i tuned the truck up properly im able to light up all four mudders in first and second....  

its silly..  but its my hobby..  perhaps i should qualify some of my suggestions more..  my method is time consuming and a pain in the a$$...  but in my experience..  if you follow the procedure you will make more power and have better off the line response.

as for whether you adjust the carb then timing or timing then carb..  it doesnt matter..  i go through them a couple of times until they are both peaked simultaneously..

cthulhu38490.3974537037

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http://www.vetteprojects.com/bmv

OK,

well i tried to set my timing today, @3000rpm my timing was 56 BTDC.

so i adj the dist to 36 BTDC set the idle back at 750rpm and checked my base timing it was 8 ATDC, i would think i may need a new dist?

what do you guys think? the diat has ALOT of miles on it.

thanks

pete kennedy

It sounds like the stop for the mechanical advance are worn away, allowing too much advance.

Sounds weird to me, how did it even idle at 8 degs retarded? did you have the vac. adv. hooked up, that can add 10+ degs to the total, what was your procedure, did you use a "dial back timing light or a degreed vib. dampner. here's how you do it, set idle to factory spec's, disconnect the vac. adv. plug the vac. outlet at the hose or cap at carb,run the motor up to 3-K, with a "dial back light"set at 36 degs advanced on the light advance or retard the dist. till the mark on the dampner is steady on the 0 deg. mark on the timng tab, lock down the dist. there, now return engine to idle. turn the dial back to 0 on the light, now check to see what initial timing you have, hooking up the vac. adv. is the last thing you do,
    If you don't have a dial back light you can still do it with a regular timing light but you need a degreed vib. dampner, you can't dial any adv. into the light because its not a "dial back" but the process is the same you lock down the dist. when the 36 deg. mark on the dampner is steady with the 0 degr. mark on the timing tab.     anips38491.6156597222

hi,

yes i did it as you said wth my snap-on timing light,

it just about ran. is it poss the dampener has shifted on the rubber cushion?

pete

If the dampner shifted, it probably would not have the wide span of readings you have.  It would be low or high in both ranges, not just one.  Unless the dampner was constantly shifting, but then you would pick that up due to inconsistant readings.

Another possibility is slop in the timing chain or wear in the gear at the base of the distributor.

At 8 deg ATDC it has to be a real dog.

Yes, it is a possibility that the outer ring has spun, along with Ken's theory, take a close look at your dampner there might be two marks on it,the one on my 72 had two marks on it, don't know why, had to pull #1 plug bump the starter to bring #1 up on comp.,checked the cap to make sure the rotor was pointing to #1 to know which one to use, if your dist. is shot you might want to check with Performance Distributor in Memphis Tenn, They have a web site, they will hand build you a new one for your car's spec's probley for the same cost of rebuilding yours, elec.tack is around 275.00, tack drive is 500.00, I'am real happy with mine

hi all,

the timing chain and gears and new, but i did pull the dist and the springs and weights were just about on there, ready to fall off.

so i guess i will get a new dist.

thanks for all the help!!

pete

I hooked a vac. meter to my intake and it bounced from about 14 to 16. I did plug advance but nothing else. After moving the dist., it now bounces between 15 and 18. Shouldn't I be getting more of a steady reading? What would be making it fluctuate? It did seem to run better for a tired old original engine. Any ideas? Thanks for any help..........

______________

   I know the voices aren't real, but they have some pretty cool ideas...

The vacuum fluctuations can be caused by a few different things. 

Worn and leaking valves, low compression, vacuum leak on a intake runner, weak valve spring, worn cam lobe.

Quite a list.  Some testing is in order starting with a vacuum leak check, then a compression test, followed by a leak down test.   Of course if you find a vac leak, you may not need to go further.

kstyer38493.835

Thanks Ken. I figured there wasn't going to be an easy answer. I probably have all those ailments! I think I'll continue with plans to get another one built and mothball this original engine. Appreciate the reply..... Dwain

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   I know the voices aren't real, but they have some pretty cool ideas...