Sarum

Hi from New Zealand, I am hoping to get some good advice in regard to checking/adjusting the ignition timing on my ‘65 Cutlass with original 330 4 barrel engine (315hp version).
The car has been retrofitted with an ACDelco HEI distributor setup and this morning I took delivery of a new Innova Digital smidgital Timing Light! Despite rapidly advancing years this is the first time I have ever used a timing light, most likely because for my most of my working life I have had a company provided vehicle.
As you will see I have attached a copy of a table that some kind soul loaded onto another website which provides info on Oldsmobile engine tuning for my and other engines for the 1965-1969 model engines.
Anyway, to start off I disconnected the vacuum advance from the distributor and started the engine warming to idle at 750RPM (11”Vacuum).The vacuum advance hose is connected to a full manifold vacuum port on the Edelbrock Performer RPM manifold and from the manifold the vacuum line runs to a small firewall mounted vacuum tank and then to the distributor.
After connecting up the timing light to take a base reading I found that adding 3 degrees brought the pulley timing mark to line up with the middle reference pointer.
Next I connected the vacuum back up and increased the engine RPM to 850 as per note 5 at the bottom of the table. I took the 850RPM as suitable to use for the Advance Timing Control Check (from light instructions) as 500D is listed as the Hot Idle for auto trans types.(for base testing like I figured?) Any idea what the D in the 500D means? Not Drive surely as this would imply that I should be testing with the trans in Drive? Bit dangerous, ha ha!
Testing again it took also took 3 degrees advance to line up the markers.Vacuum was a little higher with the extra 100RPM, it went to 15”
11”of vacuum at idle is the best I could get when I previously spent quite a bit of time on it.and put this down to the fact that it is an Oldsmobile and it also has a lumpy cam in it. I realize the degrees I am getting while testing are really low so maybe I am doing something wrong.
Moving on the thing is “ What do I do now? As a starter I thought I would be able to add some more advance and adjust the distributor (anticlockwise) to until I get 7.5 degrees from the pulley mark to the center of the marker at 750RPM idle? Then drive the car and see how the engine performs - looking for pinking upon acceleration from cruise?
RTW the car is starting and running well but does use a lot of fuel, 22.7 litres per 100km (95 octane) which equals 5.9 US mpg. That mileage check was mostly highway running, say 80% which is the reason I am looking at a number of things including timing.

UPDATE
Sorry for the delay in getting back to the forum but I had some issues along the way, as below.
As I had the parts sitting there and there were something like 9 threaded joins involved I thought it would be a good idea to connect up the braided 8AN SS hose and Summit SS hose dual feed carb line parts as I figured that while I was checking the timing I could keep an eye out for any fuel leaks
Long story short, couldn’t stop the the dual feed part from leaking in 2 places, paint on intake gone, put old stuff back on and am waiting for replacement from Summit Racing to arrive.
I also have a severe chronic health issue that sometimes means I am unable to do much until the pain backs off which can take quite some time. Anyway my apologies again. Moving on when I got back into the shed below is what I found.

Ignition Timing Testing
I have since found out what the timing markers on the block mean ie.the left hand marker is 10 degrees before TDC, (having realized dash and hole stands for 10!) The middle marker is 5 degrees before TDC and the lower right marker is TDC.
There is an anomaly in that on the timing light’s LCD the distance from the 10 degree mark to the 5 degree mark is an increment of 3 degrees not 5 as you would hope I made the decision to count the degrees by what is on the timing light LCD up until the 10degree BTDC mark and then add the “10” to the display number.
For example, say going from the marker on left of the pulley with the timing light adding increments to a total 20 to get to the 10 Degree Mark BTDC on the pointer the total would be 30 degrees BTDC for that test.If I had relied totally on the timing light’s increments the total number in the example would be 26 degrees BTDC.

Initial Tests At a 500rpm idle in Drive the timing light showed the pulley marker to be on the 10 degrees from TDC marker.Test was done with the distributor vacuum connected.
After disconnecting and plugging the intake manifold vacuum at the distributor I again ran the engine (in Drive) and the idle was 500rpm. Again the timing light showed the pulley marker to still be on the 10 degrees from TDC marker.
Conclusion from this is that the vacuum advance did not have any effect at this stage.

Mechanical Advance Testing : (Distributor Vacuum disconnected and plugged)
Test 1 20 degrees at 1430rpm As the 1430rpm was lower than expected I did this test again.From what I understand the rpm should have been up around the 2500-3000rpm mark.Correct?
I did not look at the lights LCD while testing so that I couldn’t “cheat” and only looked at the display when I had stopped adding degrees.
Test 2 21 degrees at 1500rpm
Test 3 22 degrees at 1590rpm
I connected the vacuum back up again and retested.
Test 4 25 degrees at 1670rpm
Notes
1) The digital tach display on the timing light is sensitive to rpm change so sometimes you have to decide what is a good median number from what is displayed on the LCD and record it.
2)Noticed better engine vacuum today - 19 inches which is a big improvement from the usual 11. The cause could be a slightly higher idle speed but could also be that I tightened up a few bolts on the intake manifold that I found a bit loose recently. Must check the rest of the bolts now I have found my big Allen Keys!Replacing all of the vacuum fittings and hoses may have helped also.
3) Funny that the degrees and rpm increased almost sequentially on the Mech. Advance Tests. Engine was warm so not sure why. Engine hunting?

My next step is to install the PerTronix Flame-Thrower HEI III 4-pin ignition module as is here below
https://www.summitracing.com/int/par...2000/overview/ and also a MSD HEI Low-Resistance Carbon Button Bushing as at https://www.summitracing.com/int/par...8412/overview/
I didn’t buy the module as a go faster item but more because of the feedback from Summit customers who had fitted the unit to their cars.
Cheers

don71

Since you have a newer ignition, you'll need to use higher initial timing, and adjust your idle down.

That means it will read off the scale on your timing tab. The light will shine above the marker/tab at about 1.25 centimeters...or so, or more or less. Don't be afraid to give it more initial timing as long as it doesn't ping or rattle.

You're looking for about 14 to 20 degrees BTDC. Not what your attachment says, because thats for older point ignitions systems and is no good for now.

Adjust your idle down to about 750-800 in park, less or more.

In drive, it should be 650-750, less or more.

You should be able to find a happy median within these factors.

Ozzie

The 500 RPM for the hot idle is correct and it is in Drive on automatic transmissions, but it is just to set the idle, not for anything else. The 1965 Olds Service manual agrees. (550 RPM if it has A/C;with A/C off). (See footnote #2 on your chart.) Be sure to set the parking brake or block the wheels so the vehicle doesn't move.
Depending on other modifications, such as camshaft, the engine may not tolerate such a slow idle.

Use of the HEI distributor by itself doesn't require you to change the ignition timing from that originally recommended. On mine I utilize approximately the same timing as before the change. Timing will depend on other changes made as camshaft, compression, fuel being used, chamber deposits, operating temperatures, etc. There are a lot of variables which could affect initial, curve, and ultimate.

Even with a change of camshaft, 5.9 MPG sounds a bit low for a 330 traveling at a steady highway speed.

oldcutlass

The chart you posted is not applicable with your new distributor. You need to figure out how much mechanical advance is built into your HEI and when it stops advancing. In addition your vacuum advance will not work right connected to a vacuum reservoir, it needs to be connected directly to manifold vacuum at the carb or a manifold port. It varies the advance based on engine load, the way you have it connected it will not do that.

Read this:
http://www.corvette-restoration.com/.../Timing101.pdf

and this:
http://www.corvette-restoration.com/.../Timing101.pdf

joe_padavano

Also be aware that the timing specs from 1965 assume the engine is in near-new condition, with the stock distributor advance curves, and running on then-available gasoline. The cat-urine that passes for fuel today, coupled with carbon buildup in the engine, can require different initial and total timing. Use what works best and don't worry about half-century old specs.

MDchanic

I'll just run through this point by point, which will entail repeating or referencing a few things that others have said.

Which means that factory timing settings are entirely out the window.

See below and see Eric's link by John Hinckley.


One of these, for a hundred clams, from Amazon?



It looks like it should do the job.


This is a transcription of the list of stock specifications from an old Chilton's manual.
They are useful in a pinch, when you don't have time to get a proper Chassis Service Manual.
In your case, though, this is useless, as you do not have a stock engine.

Here are the original specifications, from the CSM:




11" of vacuum is extremely low unless you have quite a radical cam.

Do you have power brakes? Do they work?

Did you plug the vacuum hose with a pencil?


This does not make sense. We need a photo of what you are talking about.

The vacuum advance should be connected either directly to the intake manifold, or to the "ported" vacuum barb on the carburetor, which takes off just above the throttle valve (in your case, direct manifold vacuum would probably be best).


You mean to the 5°BTDC mark?





That's exactly what it means. Automatic transmission cars have their idle set in Drive.
As noted, you apply the parking brake, and, if you're insecure, chock the wheels.
While adjusting in Drive, though, it is vital that you resist the temptation to "blip" the throttle if the engine starts to bog down, unless you've always wanted an additional garage door.


So it's for an HEI distributor, a Performer RPM, and a "lumpy" cam.

What other modifications have been made?
Pistons (Compression)?
Heads?
Headers?
Carburetor?

If we knew all of this, we could give you slightly better advice regarding your timing (though only slightly, as once you start changing things, all bets are off, and it's trial and error).



The degrees? Which degrees? Not sure what you mean here.



You turn clockwise to advance.



Yes, once you get the basics ironed out.



6mg on the highway?!?! Holy crap. Something's wrong there.
What's your rear end ratio?

Which octane rating system do you use down there, RON or AKI?
I'm suspecting RON, which would mean that your 95 octane is the same as out 90-91 octane, which is to say, too low for a compression ratio over about 9 or 9.5:1.


Eric (OldCutlass) tends to be the guy to go over the intricacies of tuning with people (he's very patient), and he also can probably lay his fingers on a link to a previous post of his where he's already answered your questions, but I will lay out briefly what you need to do:

You have changed your distributor (ie: your centrifugal advance weights and springs, and your vacuum advance unit) and your camshaft, so factory settings are entirely out the window. Wave bye-bye to them.

In order to set your distributor up properly, you probably need an aftermarket HEI distributor recurve kit and adjustable vacuum advance, such as from Moroso or Crane. If your HEI unit is a new one, set up for "performance" engines, you may not need this, bue we don't know that, because you haven't told us.

First, you need to set your


Drat! Hit the "Submit" button by mistake... More to come.

MDchanic

Eric (OldCutlass) tends to be the guy to go over the intricacies of tuning with people (he's very patient), and he also can probably lay his fingers on a link to a previous post of his where he's already answered your questions, but I will lay out briefly what you need to do:

You have changed your distributor (ie: your centrifugal advance weights and springs, and your vacuum advance unit) and your camshaft, so factory settings are entirely out the window.
Wave bye-bye to them.

In order to set your distributor up properly, you probably need an aftermarket HEI distributor recurve kit and adjustable vacuum advance, such as from Moroso or Crane. If your HEI unit is a new one, set up for "performance" engines, you may not need this, bue we don't know that, because you haven't told us.

First, you need to set your maximum centrifugal advance -
Your centrifugal advance should max out at about 35°-36° at somewhere between 2,500 and 3,000 RPM.
Check it now (vacuum disconnected). If it does, then you don't need a spring kit.
If not, then you do.

Once your centrifugal advance has been set, you need to test it.
With the engine fully warmed up, and preferably on a hot day, take the car out and floor it a few times from low-ish RPMs, and listen very carefully. If you hear any pinging at all, pull over and retard the timing a couple of degrees and then try again.
Continue until you hear no pinging.

Now you can connect your vacuum advance.
You should use a vacuum gauge to see how much vacuum it takes to begin to pull it in, and how many degrees the vacuum advance will advance the timing, and how much vacuum is needed to pull it in completely.
If you have an adjustable vacuum advance, the vacuum level at which it starts to pull in and maxes out is (roughly) adjustable.

The amount of vacuum advance that you need at idle and low load conditions can vary, so you may need to "lock out" some of the advance unit's travel, to reduce the maximum advance obtainable, which you usually do with a little stepped piece that comes with the tuning kit. Or you may not need to.

You want to connect the vacuum and set the car's idle (in Drive) so that it's smooth and doesn't "hunt" or waver. If your engine has low vacuum, as the RPMs vary slightly at idle, they could cause the vacuum to vary, which could cause the vacuum advance to vary, which could cause the idle to surge or otherwise act weird - you want the vacuum advance to be at a stable point in its operation at the vacuum level that you have at idle (ie: if you have 16" of vacuum at idle, you'd like your vacuum advance to be "all in" at 14 or 15", so that it won't affect your idle).

Once you've got your idle fairly stable, you need to take the car out for numerous cruise and low-RPM acceleration runs, including at highway speeds, and keep listening for pinging. Every time you hear any, you have to either adjust the vacuum advance unit back a bit (either by the adjustment screw, or through the lock-out piece, depending on what works best for your situation), to reduce the amount of vacuum advance offered in the mid-range of vacuum levels, or retard the entire thing a couple of degrees (and will probably have to use trial and error to get it right).
If you can find a good run of highway with a concrete barrier just next to you as you drive (in your case, just to your left, but in the slow lane, unless your car's been converted), it is the best way to hear pinging at highway speeds, as the sound will bounce off of the concrete and into your window.

That's all there is to it. This is why I, personally, advise people not to change their stock equipment unless they're really making significant performance changes.

Good luck!

- Eric

Sarum

Thanks for your quick reply, it all makes perfect sense. Duh, stupid me course the attachment specs are wrong for the car as it with the HEI. Forest, trees? The info is just what I need so thanks very much.
Out of interest without a digital timing light (with LCD display - shows degrees advance retard & tach) how would I put say 17 degrees in? Split the crank pulley into parts of 360* & mark it up?

oldcutlass

IF your timing light is adjustable just set the amount of degrees of advance in the display or using the ****. Adjust the distributor and line up the mark from the harmonic balance to the 0 mark on the block indicator. Connect your vacuum advance hose to the carb.

Sarum

Thanks for the info, I have been sorting the idle in Drive (wheels chocked) now OK at 500RPM

Sarum

Have managed to get the car idling in Drive OK at 500RPM or should I say 470-510RPM reading the tach on the timing light, it's a bit over accurate.

oldcutlass

Depending on your cam, your engine may not like 500rpm. Again, since your engine has been modified, the stock tune up specs are not applicable. Also note, the original specs are a guide and a good starting point not etched in stone.

Sarum

One of these, for a hundred clams, from Amazon?

SARUM REPLY Yes except the one in the photo has an extra button.Got one for US$60 including delivery from Australia.Summit Racing have the same one as mine for US$99 excluding delivery.I buy a fair bit from Summit and they are good to deal with but delivery charges to NZ make you want to cry sometimes, often more than the product!
Darn, just tried to colour my text and then underline it but no good even with my new laptop.I have never been able to get any of the text custom widgets not even bold all I get is letters at the start or finish.Wonder if it's because of the Kingsoft version of Word I am using. SARUM END


11" of vacuum is extremely low unless you have quite a radical cam.

Do you have power brakes? Do they work?

Did you plug the vacuum hose with a pencil?

SARUM REPLY No idea what the grind is on the camshaft but it does sound pretty lumpy.In the past I spent quite a bit of time adjusting the idle mixture and 11" at idle is the best I can get. I do have power brakes that came attached to a large booster set up but I found not too flash under some conditions so I installed a vacuum tank which helped somewhat. (See photos)SARUM END

The vacuum advance should be connected either directly to the intake manifold, or to the "ported" vacuum barb on the carburetor, which takes off just above the throttle valve (in your case, direct manifold vacuum would probably be best).
SARUM REPLY I have recently replaced all vacuum lines with braided SS and alloy fittings as well as installing a 6 port alloy manifold with a liquid filled vac gauge as well as another gauge inside the car. The distributor vacuum line is separate from the others and runs from a direct inlet manifold port to a small tank and then to the distributor.The "tank" was there when I bought the car,looked new and it's ports were blocked off. My guess was that it had something to do with A/C (partially reinstalled) but it's only a guess. Just before Xmas I took the car to a guy locally to get it "tuned" and when I came back to get the car he told me that he had reconfigured the vacuum hosing as he thought having the vacuum tank in the (distributor) circuit would " hold the vacuum advance up a little longer" which was a good thing apparently. SARUM END



You mean to the 5°BTDC mark?

SARUM REPLY At 500RPM in Drive the 2 lines on the crank pulley lined up with the pointer marking on the left which has a dot hole and a minus sign punched above it.If I added an increment of 3 degrees on the timing light's LCD the pulley marker lines up with the middle marker on the pointer.No difference if the Vacuum Advance hose was connected at the distributor or not
Obviously I need a bit of education as at this stage I don't know about BTDC marks etc (See photos) SARUM END

That's exactly what it means. Automatic transmission cars have their idle set in Drive.
As noted, you apply the parking brake, and, if you're insecure, chock the wheels.
While adjusting in Drive, though, it is vital that you resist the temptation to "blip" the throttle if the engine starts to bog down, unless you've always wanted an additional garage door.

SARUM REPLY Yep taken on board, car moved a bit further back from wall, wheels chocked and idle adjusted to get 500rpm in Drive.

So it's for an HEI distributor, a Performer RPM, and a "lumpy" cam.
What other modifications have been made?
Pistons (Compression)?
Heads?
Headers?
Carburetor?
SARUM REPLY Other mods unknown but I don't think much, still has factory heads, no headers -(don't seem to be available for 330 in a '65 A body, whole saga by itself).It does have a nice stainless exhaust and as of 4 months ago a SS Pypes Xchange kit which has an X pipe and dump pipes was beautifully mig welded in. SARUM END

If we knew all of this, we could give you slightly better advice regarding your timing (though only slightly, as once you start changing things, all bets are off, and it's trial and error).
SARUM REPLY I appreciate any advice given and I understand that every engine setup ends up being unique especially cars over 50 years old!SARUM END

You turn clockwise to advance.
SARUM REPLY Got that wrong! As I know the distributor on Old's V8 engines runs anticlockwise I figured as we are advancing the movement would be in the same direction SARUM END

6mg on the highway?!?! Holy crap. Something's wrong there.
What's your rear end ratio?
SARUM REPLY Removed a lot of paint from the rear end looking for stamped info but no good.As I want to fit an LSD I am going to remove the diff cover and check there in the near future.
At an indicated 60mph the tachometer shows 2500rpm.I really don't know how accurate the speedo is as for one,tyre diameters may be out (SS11s with 235/60/14 BFG TAs, still 14" but profile will be different.
Two minutes ago I just completed a second mileage check and when I thought it would be worse because the driving was all short bursts with a fair bit of idling thrown in, it was better, much better.It was 14.95 litres per 100km which equals 15.74mpg(US).That's a big improvement which I can only put down to the car being tuned before the mileage was recorded again.SARUM END
Which octane rating system do you use down there, RON or AKI?
I'm suspecting RON, which would mean that your 95 octane is the same as out 90-91 octane, which is to say, too low for a compression ratio over about 9 or 9.5:1.
SARUM REPLY Yep like almost all of the world we use RON so 4-6 points difference.I use 95 sometimes with a booster but there is also 98 Octane readily available but as it is high in Ethanol I am reluctant to use it.

Eric (OldCutlass) tends to be the guy to go over the intricacies of tuning with people (he's very patient), and he also can probably lay his fingers on a link to a previous post of his where he's already answered your questions, but I will lay out briefly what you need to do:

You have changed your distributor (ie: your centrifugal advance weights and springs, and your vacuum advance unit) and your camshaft, so factory settings are entirely out the window. Wave bye-bye to them.

In order to set your distributor up properly, you probably need an aftermarket HEI distributor recurve kit and adjustable vacuum advance, such as from Moroso or Crane. If your HEI unit is a new one, set up for "performance" engines, you may not need this, bue we don't know that, because you haven't told us.
SARUM REPLY All I can say about the HEI is that it is an original ACDelco model with a black cap not red :-}SARUM END

SARUM Will have to continue this tomorrow as it's 1.45am here now.Thanks to all


Drat! Hit the "Submit" button by mistake... More to come.[/QUOTE]

MDchanic

Good. That should be fine.



You can't make text style changes in Word and have them stick on here.
You have to use HTML-type code:
Bold is .
Italic is .
Red is , etc.



Okay, so you have a cam which delivers barely enough vacuum under the best of circumstances.
This means that other components that rely on manifold vacuum for their function (power brakes, carburetor idle circuit) or for their signal (vacuum advance, carburetor power valve) need to be configured for the vacuum that you have.

You either need a power brake vacuum reservoir with a check valve, that is properly connected, or a separate vacuum pump for the power brakes, or to use a HydroBoost system that runs off of the power steering pump.

I cannot see the top of your power brake reservoir clearly, but the hose with the check valve (plastic, like the one that goes into your brake booster) must go directly to the intake manifold, and the other one must go to the booster.

Your carburetor needs to be set up with idle circuit jets and air bleeds that provide the proper amount of fuel at low vacuum.

Your carburetor power valve needs to have a lighter spring, so that it is not operating all the time, but only under high-throttle conditions (your normal vacuum is the same as stock throttle-open vacuum).

You need to have a vacuum advance that begins to pull in at a low vacuum and is all-in by 9 or 10".




This will not make the car go faster.


I do not know what this is. It sounds like a possible trouble point, though.



This is good to have while tuning.


Lose the mechanic. He is an idiot.

The entire point of vacuum advance is to have an instantaneous signal related to engine load. If you damp that signal with a reservoir tank, you have screwed up the whole thing.
If he knew that the vacuum advance wasn't functioning correctly at your vacuum level, he should have replaced it with one that would. This is not that complicated.

He also should have recognized the vacuum reservoir for the A/C controls and connected it properly to run your A/C vents, and not tried to use it to cover up his utter lack of understanding of how an internal combustion engine works.







Here is your timing tab:



There are three horizontal lines, indicating index points, and two numbers, a zero ("zed" to you), consisting of a round punched out hole, and a 10, consisting of a vertical punched out line and a punched out hole, with the mark for 5 being the line between them.

I am concerned when you say "the 2 lines on the crank pulley," since there should be only one, single, straight line on the crank pulley.
Though difficult, a photo would be helpful.

There was no difference with the vacuum advance connected or disconnected because either
a. your vacuum advance is no good, or
b. your vacuum advance has too strong a spring to be activated by your low vacuum (in either case, it needs to be replaced).


BUT, as Eric (OldCutlass) said, you have a very different cam than the factory, so the factory specs go right out the window.
You may need a significantly higher idle to keep your car from stalling out.




So we do not know whether the cam was properly matched to the compression ratio, and whether the carburetor matches the combination.
Cast iron exhaust manifolds with the rest of the modifications you describe is unusual, and will also affect the way that the timing, and especially the carburetor, are set up.



If you turn the distributor in the direction that the rotor turns, you are "running away from it," thus making the spark occur later.
If you turn the distributor in the opposite direction, you are "running towards the rotor," thus making the spark occur sooner.



You should just jack up the car, mark the tires and driveshaft with chalk, turn the driveshaft 10 times, and count how many times the tires rotate.
If only one tire turns (which happens - brake drag and all that), then it will turn twice as fast, so divide by 2 to get the ratio.



Better to avoid detonation which will ruin your engine than to be concerned about reduced fuel mileage from the ethanol.

MDchanic

You could find out what car it's from by finding the GM part number stamped along the edge, but the easiest is probably to use that fancy timing light to map the advance as a function of RPM (with no vacuum), and as a function of vacuum (at a set RPM), then get back to us.


Good luck!

- Eric

MDchanic

One more thing:

The best advice (not necessarily the easiest or the cheapest) I would give you at this point (not sure whether others would agree), would be that it's time to pull a head, measure the bore, stroke, deck height, head gasket thickness, and combustion chamber volume, and calculate your static compression ratio, then pull the timing sprockets and see whether you have the good luck of having a camshaft with a number stamped in the front end (some are stamped on the rear, some not at all).

With this information, you can determine whether your engine has a mix of parts that go well together, and, if necessary, you can switch to a cam that is better suited for your needs.

- Eric

Sarum

DISTRIBUTOR DEBACLE UPDATE
After installing the new HEI module etc I went for a 3/4 hour drive and it was on my return trip while rounding a corner that the engine died.A quick look showed me that 2 of the pins on the module were bent upwards and the 2 wires that run into the pickup coil had been severed from the connector at the pickup coil end.
After being towed home that night and getting the car into the shed a few days later I also found that the fitting on the pickup that should be attached to the sliding part on the vacuum wasn’t and in fact was also bent up out of the way.Maybe why I couldn’t measure any vacuum advance previously? Don’t think so really as I think this happened when the distributor retired itself.
There was also quite a lot of plastic shavings lying inside as the inside edge of the new module had been scoured.At first I thought that I must have stuffed up somehow when installing the 4 pin module which allowed the wires on one side of the module to lift up and get hooked by a rotating part but I am not convinced of that now. Why would the wires move after a 3/4 hour drive?
I proceeded to take the distributor apart by attempting to remove the drive gear roll pin from the drive gear shaft so I could remove the pickup coil and pole piece. After some time I got one side out {1/4” long} and after a lot more time got the rest out which was bent (see image).The shaft was pretty much jammed in the housing and took a fair amount of treatment (beating) with a rubber faced hammer to remove.The drive gear end of the shaft showed some damage and was pretty gritty feeling when rotated inside the housing but the upper part of the shaft was the worst.
The lower part of the pickup coil assembly was jammed into the windings and could not be loosened (see image).The image shows tabs bent down which was me trying to find out how much it would take to remove the housing from the shaft and windings. Answer? A whole lot, I gave up after a short time.I will split these parts up at some stage to see if I can see any more damage.
An engineer friend of mine had a look and pointed out what he thought was evidence of excessive heat on the bush under the pickup housing.There is an image called shaft top which shows this area but you can’t see the heat marks.
Has anybody had experience of this sort of failure? The distributor itself doesn’t look very old at all,the housing looking nice clean and shiny as does the internals. No sign of any wear at all so I would like to know what caused this part to go awry.Any ideas?
I have ordered a new (billet and blueprinted(?) apparently!)HEI distributor from Summit Racing which will be here in a week or so.I will most likely reuse the old distributor cap which looks to be a good quality Echlin (made in USA) product and is in excellent condition.Also has brass contacts whereas I think the new one has aluminum so I am picking the brass will last longer that the alloy.
I will also reuse the wiring assembly that is used to connect the tach as I doubt the new distributor is wired for this.
Once I get the new distributor installed it will be back to checking out the timing setup. It will prove interesting to see what the differences are between the old and new. One thing I am not sure on is that when I was lifting the distributor I felt that it wanted to rotate about a 1/4 turn anticlockwise to allow it to come out. Do I now try to rotate the distributor 1/4 turn clockwise to then line up with the number 1 cylinder plug wire or just drop it straight down into position?I think I will have to turn it in but this will stuff up my markings and make it a bit of a best guess thing.

NEW DIZZIE INSTALL (NOT THAT GOOD)
Well the new distributor arrived yesterday and I spent quite a bit of time last night and this morning trying to get the car to run.The instructions that came with it said that the distributor had been set up in the factory to comply with Californian laws so it should be good to go out of the box, literally.
Before I attempted to put the new distributor in the car I installed the Pertronix 4 pin module and MSD low resistance bushing into the new unit. BTW the new distributor has an adjustable vacuum advance by way of an Allen key in the front of the vacuum advance fitting. I shouldn’t have to touch this to get the car to run.
With the new distributor installed and the engine being turned over I can hear that the engine wants to run but the timing must be so far out that it can’t. I have just had flames coming out of the carb when winding the engine over so I have stopped adjusting the position of the distributor in the hole.
I must be doing something wrong but I can’t think what at the moment.My methodology is as follows
1)Attach socket and bar onto crankcase pulley and rotate engine manually until the pulley timing mark lines up with the TDC marker on the engine.
2)Turn the rotor on the new distributor until it lines up with a point where the number 1 spark plug lead connection on the cap would normally be and then put the cap back on.
3)Place new distributor into the hole lining it up so that it matches where I think the previous distributor was sitting.
4)Take the cap off and check that the rotor hasn’t moved out of position and if still OK put the cap and leads back on.
5)Connect the vacuum advance hose onto the distributor.I have tried starting with the vacuum advance hose off and plugged up also but I think it’s best left on as this would be most like a normal starting condition.
6)Lock the distributor down again and attempt to start the engine.When it didn’t start previously I adjusted the distributor anticlockwise (retarding) a few degrees and tried again.Did this a number of times.
7)When it got to the point where the distributor was obviously turned way too far I then went clockwise (advancing) a bit at a time but still no go.During the last clockwise attempt I had a flame ignite out of the carb which I had to put out so have stopped for now.However where the distributor is sitting now I think should be a few degrees either side of where it needs to be.
8)If I am not doing something wrong the the next step would be too change out the Pertronix ignition module currently installed with the module the new distributor came with. My thoughts are that maybe the Pertronix module received some electrical damage when the previous distributor seized up.Speaking of this I don’t remember seeing any oil on the shaft of the previous distributor and I can’t remember any oil dripping out of the distributor when I removed it but that may have been because the engine hadn’t been run for a few days.How does the lubrication work? I was told that the carved spirals at the top of the shaft have something to do with moving oil around but that’s it.

Sarum

Thanks for your helpful comments.I was keeping what you said in mind when doing the testing.From what you say I could have put in some more initial timing and been OK.Won't ever know for sure now but I think timing/testing will be better with the new distributor

Sarum

[QUOTE=Ozzie
Even with a change of camshaft, 5.9 MPG sounds a bit low for a 330 traveling at a steady highway speed.[/QUOTE]

Thanks for the info and yes the gas usage was a bit of a shock.However the second and last check I did came back with 15.7mpg - a vast improvement.This was after the car was "tuned" so something may have changed.I have some smaller jets which I will install soon after the car has the new distributor and is running OK.

Sarum

Will keep the tuning info in mind when I start again with a new distributor! Good idea about how to figure out what rear end ratio I have and you are right about the timing tabs of course (see image of mine)

Sarum

By the way I have removed the vacuum reservoir and vacuum lines so the connection is straight from the manifold port to the vacuum advance fitting on the distributor or will be once I have the new dizzie. Thanks

Sarum

I've saved your post as a reference document on my pc as the plan was to use it once I got the new distributor installed. It's not gone well as you will see from my updated post. Thanks again,

Sarum

Thanks for that.At the moment I am trying to get the new distributor working.I am not confident that I have using the site correctly but you will see that I have added on 2 new sections to my original post the most recent one about trying to get the engine to run with the new distributor.Not good so far.

Sarum

Thanks for that.At the moment I am trying to get the new distributor working.I am not confident that I have using the site correctly but you will see that I have added on 2 new sections to my original post the most recent one about trying to get the engine to run with the new distributor. In the body of the post is a title called Distributor Debacle Update and the newest post is called New Dizzie Install (Not that good)
Hopefully you will be able to read them

oldcutlass

If you are getting back firing out of the carb and flames, you may have 2 things that could possibly be wrong. You either have the firing order wrong or the distributor needs to be installed with the rotor pointing 180* from its current position. Since it is back firing, you have spark.

Sarum

Thanks Eric.I am sure that I am working with the number 1 cylinder and that I am trying to get the rotor pointing at the number 1 plug lead terminal.The position of the number 1 terminal at the back against the firewall is a bit of a pain for marking up etc.Why didn't they make number 1 closest to the carb side to make things a little easier?
I was thinking that maybe the module may have been damaged and although still working isn't working properly.
Anyway after removing as much of the dry powder as I could from the engine bay I started again. Got the engine to TDC and checked that distributor was in the right place.Then lifted cap and saw rotor is a bit further around (clockwise) from the number spark lead point from where it should be.Just going back to have another go. It's a shame that you have to lift the distributor up from the correct position to turn the rotor around to its correct position.Hopefully my next post will be what I found testing the new distributor with the timing light.

Sarum

No such luck unfortunately.I tried changing out the ignition module with the one that came with the new distributor but no change.Have also tried shutting the adjustable vacuum on the new distributor down (all the way clockwise) as well as no manifold vacuum at all.I have spark and gas and am pretty sure that the distributor and the rotor are in the correct positions and the engine tries to fire when I try to start it but must be missing something.

oldcutlass

OK, if your sure it is installed right and the firing order is correct, then hook up your timing light and see where the timing is while a helper is cranking the engine.

FStanley

Whoa.............................................. ........ Nellie................................


A bit surprised at some of the advice you got. All items in your engine need to work together.. You're jumping right in, without knowing a lot..


I think you need to do the basics 1st.

1. Find out your compression on each cylinder. Not a expert but there might be a way to get a ballpark compression ratio without tearing the whole engine apart.

2. Find someone to measure your cam profile, ie lift, duration , etc and how it was installed compared to crankshaft.. straight, advanced, retarded..

3. When you know you the above, then find how what is best timing specs are for your combo. Initial timing, Curve, etc..

I also keep reading that race car parts like MSD, Edelbrock, Summit, etc etc are mostly made for race at Wide Open throttle situations. And people get fooled by this. The stock AC Delco HEI might be better overall, with a vacuum advance which will help your gas mileage. Even so, you need to know the best distributor timing curve and check it on your running car by marking the harmonic balancer and using TDC"O" Degree mark on the timing tab. Curve kits readily available for HEI.

4. Carburetor, need to find out right CFM, and how to figure out a good jet/rod for your combo. I would guestimate you can use the carb you have, but keep in mind again , too rich or too lean won't run to best performance. Run of thumb for street is to be just on the edge of lean, use "tip in"procedure.


5. Check your vacuum specs at intake and also distributor vacuum line, check for working vacuum advance, other vacuum leaks like AC, Power brakes, etc...

6. After you know what specs you have, poke around a bit on this and other internet forums to understand what you have. Figure out how you plan to drive this vehicle, then change out engine items as needed.



Overall I think you're being fooled into thinking you just have one problem "timing" but by looking at just this item,and it is not solving your problems... Not giving you the nice running car you want...

Sarum

I was going to say that it's installed right but obviously it isn't or it would go!Just to make sure that the timing markers are OK I wound the motor to TDC again and checked that when the markings are lined up that the rotor is pointing at plug lead terminal 1 at the rear of the distributor and the number one piston is at the top of its stroke. I was a bit surprised to see how close the top of the piston is,had been expecting a bit of chamber too be honest i.e a gap from the end of the spark plug hole to the top of the piston.But no, no bit of wire needed as a probe as the shiny top of the piston is right there to see.Funny thing, there are a number of marks I can see looking down the spark plug hole.It made me think that maybe a spark plug electrode had been hitting the piston top at some stage.That's the sort of marks that are apparent.
Moving on, I am going to do as you suggest and use the timing light out while the motor is turned over.It should tell me a lot.

Ozzie

I've lost "track" of how accurate your work is. Be sure to remember that you are dealing with a four cycle engine. Hence, there are two TDCs to consider. Be sure you are using the correct one for ignition timing purposes.

Cutlass Fan

Remember that the mark on the balanced lines up with the zero timing mark at the top of the intake stroke as well as the top of the power stroke. I think you are lining up the rotor to #1 blinder when the piston is at tdc on the intake stroke. Pull out the dizzy, rotate the crank 360* then reinstall the dizzy. Hope that is your problem. Good luck from one 65 owner to another!

Sarum

Thanks for your comment. I had thought that maybe I had done as you suggest but I hadn't.
Couldn't believe it when the light on my new digital timing light would not operate! Borrowed an old school light to continue and found that when I rotated the distributor about 45 degrees from where it was the engine would run.I had stopped rotating the distributor this far as I didn't want to advance things too much.
I then lifted the dizzie up and rotated it around to the "next cog" clockwise which brought it around to where it was previously.
It looks like there would be about 20 degrees of advancement now and the engine sounds pretty happy - no bogging when the throttle is winged from idle.This is with the manifold vacuum advance connected at the distributor.They give you a small Allen key to adjust the vacuum but I am leaving that alone.
Interesting that disconnecting the vacuum at the distributor now makes the engine idle less well. It didn't make any difference with the old distributor and I think this was because the shaft was already jamming a bit.Probably explains why the max vacuum I could see with the digital light occurred at about 1500 rpm.Using the borrowed light the timing mark disappears counterclock as you wing the throttle so there is a lot higher rpm before the vacuum is "all in"as they see.One thing that is weird is the digital tach's (car has original console mount one as well) needle bounces all over the place.I thought it would be caused by a bad connection but I am wondering if it may be caused by the new Pertronix 4 pin module as it is a multi spark device.
Anyway,I am looking forward to driving the car again as I think the car will most likely drive better.Thanks to all.

Sarum

Hi all,
Have been checking the advance timing after the car has been for a quick run but only with the engine in Park and Vacuum advance hooked up.
Each time I get around 20-25 degrees at idle.Idle is a little faster than I would normally have it so I will probably drop it again.
The car now runs better than it ever has, the annoying bog I used to get trying for a quick takeoff has gone completely.The engine sounds pretty happy to me and I have been checking for pinking while under load etc but have heard nothing.
My guess is that my bogging issue was caused by a lack of advance (due to dodgy distributor) and could have been picked up by the "expert" who charged me $300 for a tuneup if he had used a timing light.
I am going to leave things alone now until I get a replacement digital timing light sent to me.
I contacted Pertronix in regard to my tach going crazy since installing their trick HEI module and was told that this can happen.It's even in their FAQ section.Installing some diodes in series with the distributor to tach feed or some resistors of various sizes in series also are possible fixes according to
their tech guy.
As my brother will be coming over from Australia to go to the Beach Hop with me if I can't get the digital tach sorted I will most likely disconnect it entirely and switch back to the factory console mounted tach for now.
Checkout http://www.beachhop.co.nz/ It's a big ( by NZ standards) hot rod festival that starts next week.

oldcutlass

If your idle is high your mechanical advance will be also. The distributor advance climbs with rpm.
Which distributor and coil are you using?

What was the issue that was preventing it from starting?

Sarum

After the previous distributor destroyed itself I ordered one of Summit Racing's own HEI models. The only one they say is for Oldsmobiles is not only "blueprinted" but also billet.Following is a link to it.
https://www.summitracing.com/int/par...0006/overview/
Despite what they say in the notes the terminals are brass.
Actually what Summit have done is a rarity for Olds owners. they have given us only one option for a HEI distributor but it is the best model and it is cheaper than the Chevy equivalent. Don't say anything cos they will change it!
Why the engine would not start was because I had the new dizzie one "cog" out. Moving the dizzie around so that the number 1 plug was at the 3 pm position allowed the engine to start.Then I lifted the dizzie back out and dropped it back in with the number 1 plug back by the firewall again and all seems good.The engine doesi not lag or bog if you try flooring it from a standstill which is something I am really pleased about.So it seems that my one issue has always been as a result of lack of advance available be it vacuum or mechanical.
The only concerns I have at the moment is that I may have too much advance and I am also thinking about lubrication.
When I took the broken dizzie out and took it apart there was no sign of oil anywhere.Lubrication was not mentioned in the installation instructions but I believe they are supposed to get some oil from the back of the camshaft.While running the engine today I thought I heard a whirring sound from the rear of the motor.Probably gears meshing with no lube perhaps?
I came across this article which I found interesting for not just the lubrication side of it. http://www.crankshaftcoalition.com/w...EI_distributor
As proven by people on this website and others as above people still help people for no gain to themselves.Cheers

Sarum

Well I got it sorted finally but I figure you can help me with another smaller issue.I got turned down for a WOF (Warrant Of Fitness) which also means I can't register the Cutlass because there is no dash light to tell the driver he is on high beam headlight wise.I don't normally drive the car at night so I hadn't noticed the "problem".I can remember seeing a small dash shaped light low in the instrument cluster but I thought you may be able to point me towards the right lamp position. I have attached a coupe of images of the back of the dash which I thought might help.PS Love you red Cutlass, is that an original colour? Sure looks nice with the chrome and the SS11s of course