Contact point adjustment - '49 Cadillac

[Raymond919]

Hi Everyone,
I have always been under the impression that the most accurate way to set your contact points is electronically by using a dwell meter. I set my points to within 2 degrees of optimum as stated in the shop manual which it says is acceptable.
Upon further reading the manual, it says, "Dwell angle should not be used as the absolute setting for contact point gap. A feeler gauge or a dial indicator is the only accurate method of measuring point gap".
I have no idea of how to use a dial indicator nor do I own one. Can anyone give me some advice on this issue?
Ray Schuman

[Jay Friedman]

A dial indicator is an instrument used to measure "small linear distances" or movement of machine parts.  A "dial test indicator" is a variation which is used to measure this sort of distance at an angle.  (If you google these you'll get photos of them.)  I suppose one of the latter could be set up with a distributor on a workbench to measure point gap but it would be more time and trouble than it's worth when you can do the same thing quickly with a feeler gauge. 

I always measure point gap with a feeler gauge on my '49.  To do this I remove the distributor, since its location at the back of the motor makes it difficult to reach and almost requires acrobatics if you want to do it with the distributor installed.  Since taking  the distributor off to do this takes time and effort, I sometimes check point gap with a dwell meter if the motor starts running roughly and I suspect the points might need adjustment or replacement.  The specifications for point gap provide an acceptable range of several thousandths of an inch, so the measurement doesn't have to be super accurate.  I remember as a young guy measuring point gap with a match book cover if a feeler gauge wasn't handy. 

[kkarrer]

I'll say two things on this issue and this is derived from many years of tune ups on older cars including Cadillacs.  Start out by setting the points with a feeler gauge according to specs (just be sure to wipe the feeler gauge with a cloth that has a little carb cleaner or lacquer thinner on it first.  You don't want to get body oils or other grease on new points.)  Once you get the car started adjust the dwell using your dwell meter and you're done.  The second thing I'd say is that I'd just replace all of that with a Pertronics kit.  If you do that you'll not only get rid of the points, you'll also get rid of the condenser which is often what fails...and with very little warning.  The elect. ignition will also give you better performance.  You'll want to get the recommended coil as well (get the black ceramic one).  It'll take you about 30 minutes to switch it out.  Their most recent versions are very reliable and you'll immediately notice the improvement on starting and running.   They have the kits for 6 or 12 volt.  I would also recommend a 12v conversion using a "genernator" type generator (actually a standard GM generator body that has been converted to an alternator inside...very slick and not detectable by show judges as the externals are OEM GM).  By the way, I did this on my 50 Cadillac and my 56 Sunliner Convertible (just the elect. ign. switch here as the 56 was a 12v car.)  I was very pleased with the results.
Ken Karrer

[Raymond919]

Thank you Jay and Ken. Based on Jay's description, I have seen dial indicators but have never used one. Also, based on the information both of you have given, I will use my feeler gauge to set the points since I have a sensitive touch. I will use the dwell meter just for over-all checks. I don't think that I'll remove the distributor, though. I've previously adjusted the points by draping myself across the fender and over the engine with my feet in the air in one of those acrobatic positions you mention. I intend to devote more time to getting a perfect setting, this time. My car has excellent cold starts jumping to life after about one second of cranking. My problem is after the car is warmed up. When re-starting, it cranks a bit longer before 'kicking' over. The carb is set well. The car runs very smoothly and quiet. It's just the warm start that bothers me. I'm thinking that the points are a bit off. The dwell meter shows it to be off about 2 degrees from the best targetted setting. I realize that there's a 2 degree leeway but wanted to get it 'on the money'. (Note that the distributor caps for '49 Caddies do not have the GM window allowing 'fine tuning' of the point gap by dwell with the engine running. You have to get it right with the cap off).

I bought the car last year. The seller told me about the 6/12 volt system which he had his mechanic install a few years prior. I was uncomfortable with it wanting to keep the car as original as possible. I didn't like the sound of the solenoid kicking in and its questionable starting of the car. Since he was having new points installed as well as a new battery before selling it, he asked me if I wanted to continue using that system since it required a special battery. I chose a conventional 6 volt battery and asked that his mechanic disable the 6/12 system.

Something wasn't done correctly by the mechanic and upon arriving home, the insulation on the battery cable was in flames under the hood and burned to a crisp. Fortunately, no damage was done to the car and I had the system totally removed. I now keep my cable connections clean and have installed the correct braided negative cable going from the battery to the frame and on to the starter mounting bolt. Other required braided cables are also in place and the starter now turns strongly and very effectively.

As for the electronic ignition, I like the idea very much and will probably go that route. I intend to look into it and will probably install one. Thanks for suggesting it, Ken. Jay, you may recall my emails with frequent questions to you last year about my weatherstripping when I first got the car. Your helpful answers helped in my selection and installation of door and trunk weatherstripping. I recommend anyone with a '49 Cadillac join the 'Forty-Niners', a group devoted just to owners of these marvelous vehicles. The quarterly newsletters always have great tips on improving the vehicles. Upon reading my first issue, I immediately ordered all back issues from the prior 10 years. Money well spent!

Once again, thank you both for responding.
Ray Schuman

[76eldo]

I have heard good things about the Pertronix unit and i am thinking about installing it in my '60.

Regarding adjusting the points, I would take the dwell reading as proof that the point gap is correct.  I think you need to check the initial gap, but with almost every GM car I have ever tuned up with the Allen key adjustment on the points and the little window that slides up in the distributor, the cars always started with the fresh points and I did the final adjustment with a meter and a points adjusting tool that i bought in the 70's.  It's just a long flexible screwdriver type tool with the proper Allen head on the end.

I realize that on the older cars, there is no access hole on the cap, so you have to gap the points, but use the dwell meter as your final check, in my opinion.  Dwell first, then timing, then check dwell again.

Brian

[Jay Friedman]

Ray,

I didn't realize from your Raymond919 "handle" that you are Ray Shuman, a member of the Forty Niners Chapter of the CLC. 

As for the starter turning over more when warm before the motor "catches" than when the engine is cold is, in my opinion, thsi characteristic of '49 Cadillacs and probably of most large higher compression OHV motors with 6 volt systems.  My own car does the same thing. 

Problem is that once the engine is warm, particularly if it gets real hot after a high speed run, when you shut it off and coolant is no longer circulating the internal parts (pistons, etc.) expand.  This creates more friction for the starter to overcome, particularly after 5-30 minutes before things cool down a bit.  You can improve things somewhat by making sure all ground points are clean and paint-free, which you seem to have done, scraping any paint off between the starter and flywheel housing and, most importantly, having a thick positive battery cable, at least 00 gauge.  (To paraphrase the Dutchess of Windsor who said "You can't be too skinny or too rich", a '49 Cadillac can't have too thick a positive battery cable.)  I had mine made from 600 volt welding cable, but you can buy them from McVey's in Kansas and from the Brillman Co. in Virginia.

This is one of the reasons Cadillac and other manufacturers went to 12 volts later in the '50s.

Jay

[Alan Harris CLC#1513]

They are easy enough to set with a feeler guage. It helps if you have a remote starter switch, which is cheap to buy and handy for other things.

Points have the advantage that they usually give some warning before they fail totally. the car will miss or sputter or be hard to start. Electronic ignitions usually fail abruptly. The car will simply stop running.

This is an important difference. Points were a reliable enough system for about 60 years.

The aftermarket electronic ignitions are mostly Chinese made. Their reliability can vary.

The condenser is the weakest part of the conventional system. If it changes value, the points will arc and burn, but the car will not immediately stop running

[Raymond919]

I want to thank everyone who responded to my question. I have learned now to rely more on my sense of 'feel' when doing the points. I had thought that dwell was the ultimate, exact measurement. I'll use both dwell and the sensitivity in my fingers when doing the points. Unfortunately, I'm a Virgo and a bit neurotic about getting it perfect.

Jay, what you write about the car's hard starting after a 'run' is exactly what I experience. I've recently attributed that to vapor lock and have turned on my electric fuel pump. Since this is a recent development for me, I'm not sure if this will resolve the situation every time. If it does, then I know the problem is vapor lock, if not, then the problem is the heat buildup in the engine due to the water pump not circulating the anti-freeze. If the later is the case, how do I address it if I need to restart the car shortly after having turned off the ignition? Electrically, I've done all I could by having solid braided grounds and heavy duty insulated positive cables and also good, clean connections.

As for the electric fuel pump, I have an on/off switch under the dash and I've only turned it on if starting the car after it might have sat untouched for a couple weeks (doesn't happen often). Previously, it had to crank a while to get the gas up to the carburetor. Now, I turn on the pump for about ten seconds, press the pedal to set the automatic choke, and it springs to life immediately upon hitting the start button. I normally don't drive with the pump turned on. Is there any problem in leaving it turned on permanently? I've been told that in case of a serious accident, the gas might continue to be pumped after the engine has stopped, thereby causing a fire.

Ray Schuman

[Jay Friedman]

Ray,

Another electrical measure you can consider is to have your starter rebuilt with "heavy-duty" field coils.  A good auto electric shop should be able to do this.  You may want to look in Hemmings for an out of town shop which advertises they do electrical work on old cars if you can't find one locally.  If you can't find one anywhere else get back in touch with me as there is a good one in my area. 

I wouldn't leave your electric fuel pump turned on permanently for the reason you mention; ie., in case of a serious accident, the gas might continue to be pumped after the engine has stopped, thereby causing a fire.  Also, the mechanical pump should be adequate for normal driving and the electric pump may increase the pressure and flow excessively if you don't have a fuel pressure regulator. 

I don't know how long your electric pump has been installed in the car, but nowadays, an electric fuel pump installation requires (legally, I think in most jurisdictions) a special cut-off switch in the circuit that turns itself off if it feels a blow or an impact to the car such as in an accident.  I don't know what the technical name of these are but they well known to mechanics and auto electricians who do this sort of work.

I don't think your overall problem is that the water pump is not circulating the anti-freeze, but the fact that 6 volts is only just adequate to start a hot, high compression, 8 cylinder engine.  The motor gets very hot between about 5 and 30 minutes after shut off, creating friction.  When our cars were new, the electrics were clean and resistance-free, making it easier for the 6v, but over the years resistance builds up, coupled with the formulation of modern fuels, so the starter has to turn more revolutions before your hot motor starts.  Mine turns over longer when hot, but never fails to start, even on the hottest days after a high speed drive.

Jay

[R Sotardi #11719]

Every thing stated before,I agree with. Went to an electronic Petronix in a 68 Ford 289... remarkable difference with the 40000 volt coil. However, when they go, it's like light bulb and you will scratch your head wondering why? Also, there are 2 wires coming from the distributor, not one, if that matters to you. My 50 has the same dist and the dwell has never been exactly what the book calls for. I do like Jay , and pull the dist, place it in a vise and set the points with a feeler gauge. Only time Cornelia( cars' name) ever died was an original condenser that crapped out. It started missing and about a 1/4 mile later died. 49 -52s draw ALOT of current on cold starts. Put a meter on the battery.You will be shocked( just kidding). The 49s were the worst in that regard, until they worked out the voltage drop problem in the 1950 models. Ron

[kkarrer]

Right.  That voltage drop and aging systems are why I recommend going with the 12v conversion, but do it right.  Don't mess with those 6v/12v battery systems.  Go 12v with a "genernator" and install Runtz resistors to protect you electrical stuff.  You don't need to mess with the starter at all.  It will start just fine...and even better with 12v.  I did this on my 1950, 62 coupe and solved hard starts once and for all.  That and switching to Pertronics were the two best modifications I ever made on any car and I've made lots.  The genernators can be a bit pricey, but starting problems with your wife, kids, or grandkids on board can cost a whole lot more!  Also, if you have any more issues with hot starting you'll know that it's probably a vapor lock and nothing else.  If you stick with those points, remember that when you tighten them down they almost always close down slightly and increase your dwell setting by a few degrees. Oh, if you're concerned about your wiring as you go to 12v, don't sweat it 6v wiring is actually heavier and will handle 12v just fine.  Most folks don't know that the cost savings to the industry was one of the reasons for the change to 12v.
Ken Karrer

[Raymond919]

I'm getting so much great information. Thank you, everyone.

So far, I'm definitely planning on finding out more about the electronic ignition. I want to know how easy/difficult it is to install or take out quckly should I decide to try it. I want to carry the regular points, condenser, rotor, etc with me and be able to re-install them in case the electronic stuff dies on me and I'm stranded someplace. Another consideration is where it's made. I hadn't thought of that. I'll hold off on converting to a 12 volt system unless the problem becomes severe and I can't deal with it any longer. Also, it's comforting to know that it's not unusual  that the point gap can be perfect while the dwell can be off. I thought the dwell was the absolute best way to check. I know more about what I can trust now.

Another thing on my list is rebuilding the generator with heavy duty field coils as Jay suggests. I'll have to hold off on some things until the budget allows. I'd rather wait until I can do something properly than do a cheap job quickly.

Took the car out today and made frequent stops at stores, and Lucille (my car) re-started fine every time. It just had to crank a bit longer (3 to 4 seconds) each time. It seems that if I pump the gas pedal up and down while pushing the start button, it comes to life quicker. (could my mixture be too lean?) I'll have to keep playing with that and my tachometer.

Another area to check will be the positive battery cable. While it appears thick and sturdy, I'm not sure if it's 00 gauge as Jay suggests. I'll look into that and change it, if necessary.

I'll only use the electric fuel pump while starting the car for the first time, if needed, after sitting for a couple weeks or attempting to start after a 'hot' run. Then, I'll switch it off. During the winter I usually start the car weekly and move it a bit to prevent flat spots on the tires. When I got Lucille, the tires had so many flat spots that it felt like driving on a corduroy road. Over the period of 3000 miles, it's leveled out and feels pretty smooth now. (Someone told me that the concrete garage floor 'reacts' chemically with the rubber to create the flat spots. They said to put pieces of plywood under each wheel. Anyone hear of this?)

Once again, thank you everyone for the responses. There's some great information here. Please don't hesitate to send any additional thoughts you might have for me. You can send your thoughts here in the forum or to me privately at: Raymond919@aol.com.

Ray Schuman

[R Sotardi #11719]

Ray, call Y & Z auto wiring in Redlands Ca to have the proper length black 00 cable made. Once the insulation is on the cable you will never be sure the local  shops are selling you the right stuff. I speak from experience. Batteries Plus said NO Problem for 00 . I stopped on the way home from work put it on the car and it cranked over like the  DC3 in Back From Eternity. Never thought that they sold me welding cable too thin for the 6 volt with a 325 amp current draw. That took  a lot of frustration to finally cut the insulation to see what was under it. Tires ( bias ply) will always flatten if not moved often, mine does it also. Radials can develop a weak wall in the flat spot.

[R Sotardi #11719]

 BTY buy an Optima battery. You won't know it's a 6 volt and the starter will not "slam" into the ring gear, possibly chipping off a tooth by using a 6 volt starter and a 12 volt battery.

[Raymond919]

When I bought the car last year, the owner had to install a new battery and points to get the car to start. I informed him to have the previous 6/12 system disconnected and only put in a 6 volt battery not the special 6/12 battery like previous. His mechanic didn't do it properly and upon arriving home I found smoke coming out from under the hood and the insulation on one of the cables was on fire. I then went to an electrical expert to properly remove the 6/12 system. He restored the original wiring and improved the grounds on the car telling me about the importance of clean and secure grounds on a 6 volt system. Since then, I found the proper grounding cable which is actually a long flat, braided cable, not round, which connects the negative post of the battery to the frame and continues on to the lower starter mounting bolt. The starter now turns very quickly. I will use the information in your last email and improve the positive cable.

The previous owner parked the car each Autumn in his garage and didn't touch it until the Spring. He drove it about 200 miles per year during the warmer weather. The tires developed stubborn flat spots which have now seemed to disappear after I put about 3,000 miles on it. The tires are over 11 years old although the tread appears new. I need to replace them, but will have to wait first to have some front end work done. Fortunately, the tires show no cracks or dried out spots. Nevertheless, their age bothers me and I want to change them this winter.

Well, thank you again Ron, Jay, Brian, Alan, and Ken. I appreciate all the great advice you've given me. I'm willing to listen to any additional advice you have and welcome it since this is my first (and probably only) experience with old cars.

Ray Schuman

[Jay Friedman]

Ray,

Another thing you might try is to check your distributor's initial advance with a timing light.  Follow the procedure in the shop manual, including disconnecting the vacuum advance line from the carburetor base to the distributor.  On a '49 engine the arrow should be right on the "A" mark on the vibration damper.  If it it beyond the A in the direction away from the "C", the timing is too "advanced", which can contribute to hard starting, particularly when the engine is hot. 

Also, the next time you take off your distributor check the vacuum advance mechanism for 2 things:

1. that it is the correct advance mechanism for the '49 distributor.  They usually have a model number stamped on them somewhere which should be 1116056 or sometimes is merely 56.  Other advance mechanisms meant for other distributors look the same and will even fit and work but can change the timing, particularly the initial advance if its actuating arm is a different length;

2 that the internal spring inside it is working correectly.  You can check this by grasping the actuating arm and push it into the mechanism.  It should resist and spring back out.

[Raymond919]

Thank you, Jay for the tips. When I last checked the timing, I disconnected the vacuum line and found the arrow directly opposite the 'A' as you mention while at the correct RPM. I re-attached the vacuum line and checked again slightly 'goosing' the accelerator and watched as the mark advanced then dropped back as the RPMs also dropped. I paid no attention to the amount it advanced since I didn't know how. I realize the shop manual tells you that at a certain RPMs it should advance a certain amount, but I had no idea how to measure that on the vibration damper.

When I first got the car, the timing was off and the car had no real pep. I corrected the timing to the 'A' mark and the car suddenly had more power and started easier when cold and ran smoother. I proceeded to re-check the point setting at that time. I took apart the carburetor, cleaned and re-set the various settings according to the book. I replaced all the vacuum lines from the carb and manifold to the distributor and wiper system. I've yet to continue those lines to the antenna and washer, however. Can you tell that I'm having a 'Ball With Lucille'??

I will check inside the distributor for those numbers as you mention. I know the previous owner had the distributor either rebuilt or replaced (he gave me the receipts). I'll have to check them closely to see exactly what they say. I don't have complete faith, however, in the ability of work or parts replaced by the mechanics he used.

One of the last times I had the distributor opened, I checked that the plate was spring loaded and would return. It seemed to be working fine.

Am I being too fussy about the hot re-start? I gave it good thought and realize that it would actually crank about 5 seconds before kicking back to life when hot. While you sit there and push that button, 5 seconds seem like a long time. Cold start is about 1 to 2 seconds at most. For most people that would be great. I'm very neurotic and am maybe looking for too much. Kick me if I fall into that category.

Ray

[Jay Friedman]

Ray,

You are a little to far away in NY for me to do any kicking, and I haven't been present to hear for myself your motor taking 5 seconds to start when hot, so I can't judge if you are being too picky or not.  All I can say is that slightly harder starting when hot is characteristic to an extent of 6 volt '49s that are 60+ years old and that it can only be completely eliminated with fuel injection, 12 volts and other measures that are too complicated and expensive to be worth doing.  Try installing heavy duty field coils in the starter and see what happens.   

[76eldo]

Going back a few posts, I also agree that if you change to an electronic module it can go bad and leave you on the side of the road, where points or weak condenser will make the car run poorly, and if you keep a cap, rotor, points and condenser in the trunk as spares, you can fix it on the fly if need be.  At least well enough to get home.


Brian

[Philippe M. Ruel]

There are two ways of dealing with a 1949 Cadillac

Way #1 : your purpose is to drive it from Point A to Point B, maybe even as a daily driver. This is a used car, its age being the only difference with a 1999 Lexus. Then you will consider switching to 12 volt, electric fuel pump, electronic ignition, power disc brakes, fuel injection, power rack & pinion steering, Chevy 350-350 combo, Northstar engine... everything that may help your car in making Point B closer.

Way #2 : your purpose is to use a 60+-year-old car as they used it 60+ years ago - including maintenance, as no Cadillac dealer does it anymore. All is yours. Your burden will be named vapor lock, vacuum wipers, 6-Volt system, point setting - and 5-second start . You'll learn how to set points and advance in a parking lot, remove and install a rear wheel bearing while stuck on the right lane of a highway, disassemble and reassemble a carburetor by night, using only a pocket knife to find out which jet(s) is/are clogged with fuel tank rust. Should you be unsatisfied, you can have your distributor equipped with a vintage Mallory dual point breaker plate, and your carb with a Mystery oiler.  Hydro-Lectric windows and foot-controlled radio tuning are great options, too. Then you'll be ready for older cars, with crank starting, manual oiling and advance setting while driving, and exotic pedal arrangement.

Most people here seem to use Way #1 1/2, though.