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After 3 months since acquiring this 41 straight 8 sedan it is finally ready for a drive. Problem is that it will not gain much speed and when trying to accelerate, the pedal gets to the metal with no response and the engine begins to stall. Then I realease the gas pedal and at low acceleration keeps goind fairly well, say up to 30 MPH or so. Any attempt to increase speed and it stalls again.
The car was not running when I started working on it last February. After replacing fuel tank, fixing fuel lines, changing spark plugs, cleaning points, replacing condensor and distributor cap and replacing all fluids it fires up very well and runs fine. Initially the idle was way too high, over a 1000 RPM so I adusted the carb throttle to about 375 RPM (Hydramatic should be 375 per manual). When idling, initially needs some help from gas pedal or it will stop (idle sounds sooooo slow) but in about 2 minutes after firing - as it is gaining normal operating temperature - it idles OK but still has this intermittent "slowing down" for a few seconds and spontaneously recovers without stopping. I don't want to increase the throttle RPM over the recommended one so I figure the problem might be somewhere else, not on the throtthle RPM.
I thought the mixture is not correct and tried multiple times to adjust the 2 idle screws on the carburetor with no improvement. The carburetor is the original 480s. Car has been sitting for 30 years prior to my ownership. I the suspect the carburetor is the problem so I used plenty of carb cleaner in the throttle valve and the carb throat and added all sort of additives to the gas intake but nothing made a difference.
Any suggestion I can try besides removing the carburetor and rebuilding it? I have no ability to do such a job and will have to send to a shop. Not a good deal as they give a return time of 3 months and I don't want to miss the whole Summer waiting.
Hope to learn from the more experienced owners, Thank you for any advice, Manuel
What is your dwell or point gap setting? What is the timing set to? Outside of timing, my first inclination would be a bad accelerator pump and a carb that needs a rebuild. Next would be a fuel pump issue.
I once helped an uncle many years ago (actually he was showing me how) to adjust timing on a 1941(?) straight eight engine (Buick, Oldsmobile I don't recall). Your post brought back some memories & I was looking through some other forum threads earlier this morning and found this one (link below). Like Eric stated, I'm more inclined to check your dwell/timing. You first have to find the BTDC alignment marks (looks like a wire mesh pattern) window. I never knew they existed. There is some good information in this thread which may help. You really need to get the timing sorted out first.
After sitting 30 years it is practically guaranteed that the carb needs to be disassembled and cleaned internally. There may be other problems with dwell, timing etc. which are also critical.
Disassembling and cleaning an older carburetor isn't overly difficult. If you are mechanically inclined which you must be based upon what you've done already, get a manual, a kit and do the carb. If it doesn't work then send it out. Take pictures, go slowly, work clean, follow a manual and be methodical.
This isn't causing the current problem but also find out if the valves are adjustable. A member will know and chime in. If they are adjustable don't overlook doing them.
Check the fuel pump for volume flow of gas. This is something you can do it's cheap and it will eliminate or point to some of the other potential areas. I would adjust the idle up a little till you feel the car creep a little at a stop sign but won't put you out in the street if you aren't paying attention.
If you pull(unscrew) the gas line at the carburetor using a pop bottle stick the gas line in the bottle, un plug the coil wire so it won't start and crank the engine over for about 10 seconds, bottle should be at least 1/3 full. If not your pump maynot be supporting the needed fuel to run the engine at a load or higher RPM.
Do you experience any backfire through the carb when you push the engine during its bogging period? If so it is a sign that it running lean and needs more fuel or the points are burnt or closing up. You say it starts right up so it's probably not points. Wish we were there I'm sure we could get you running without much trouble...Tedd
Thank you for your comments. I tried to follow all the advise but unfortunately today, for the first time, engine cranked like crazy but it will not fire up. I feel guilty because all these issues followed my attempt to "refresh" things, including putting new spark plugs, adjusting throttle and idle and removing and cleaning the breaker points and I must have done something wrong. Today I checked the plugs and points again: Spark plugs, despite being brand new, were covered with lots of dark dry carbon deposits (running super rich) after just a few times that the engine was running. I checked the spark plugs gap and they are set correctly at 0.030. I also checked breaker point gap again and set it at 0.015. It was way too small, about 0.008, and don't know how that happened because I set them correctly last week. Now is correct but engine still won't fire.
I followed Ted's advise also and disconnected the fuel hose entering the carburetor and cranked the engine and plenty of fuel was flowing with significant pressure. Car has also an aftermarket 6 volt fuel pump. It appears that the problem is not lack of fuel.
I still could not check to see if plugs have any spark as I had nobody available to help and I can not do it alone.
Timing is something that just about all of you mentioned. I am studying the subject, have never done it, and once engine fires up again I will give a try. Unfortunately mundane things happen, like a job, and beginning tomorrow will be very busy for 2 weeks with no spare time and may not be able to do much until then.
When you change your point gap (dwell setting) it will effect timing. Check for voltage at the coil+ terminal and advance your distributor timing a little while someone cranks the engine over.
Check to see if you have juice at the + side of the coil with key on run. It should be hot if not check back to your ignition for juice. I'm trying to think of how you can find your issue without a second person or no instruments. So far you have fuel, electricity is indoubt and so is timing, it ran before so you have compression. Are you sure it's not just severely flooded?
I would pull #1 spark plug and bring it up o TDC on the compression stroke and see if the rotor is pointing at #1 wire. That's not a timing light but should get you close enough as to get a pop or something out of the engine and a direction to look for....Tedd
Let's back up a minute. You stated the above in your first post. If that is the case i.e. "it fires up very well and runs fine", then you're getting voltage off the coil (+) terminal. If you were not, the car would not be running fine. It was some point 'after' this in which you made adjustments to further fine-tune your engine e.g. you reset idle from 1,000RPM to 375RPM, you made adjustments to carburetor A/F mixture screws, etc. You've indicated you're not familiar with establishing/setting timing & you're going to read up on this. The car sat for 30 years before you bought it 3 months ago. But, let's not get too far from facts. You stated "it fires up very well and runs fine". IMO, you made an incorrect adjustment somewhere which now is creating/exacerbating your issue.
In your reading on timing, you have to first understand what dwell is and how dwell effects timing. That is first and paramount to understanding what the effects are of adjusting timing & A/F mixture. As Eric pointed out, dwell effects timing - timing does not effect dwell. Therefore, the 'sequence' in which you tune-up your engine is critical and there's only one method/sequence to do this: (1) Dwell, (2) Timing, then (3) A/F mixture (in that order).
I am assuming your intention is to keep this car. If that is the case, you need to find out how to set your timing. To determine if your timing is adjusted correctly and to further establish what the effects are of changing your timing (e.g. advance timing) you need to determine where you are first & that would be to 'find' the timing mark on your flywheel and determine its current timing so you can move forward.
I provided you with a link for a 1941 Buick 248 inline 8. You should review that information. I am providing you with an additional link to another straight (inline) 8. You should read that information. My point here is this. As you read up on timing, you need to know where the timing marks are located and that's your first order of business in establishing timing and making further adjustments to your engine's overall health.
The basic timing/index mark looks like the below (representative) image. Find it and you'll be trending in the right direction when it comes to establishing your timing.
Check to see if you have juice at the + side of the coil with key on run. It should be hot...Tedd
Engine cranks and cranks and not starting. I followed a systematic process today based on all your recommendations trying to figure out why the engine not firing. First I checked the + side of the coil. There is current and timing light turns on. (To do this simple test I had to remove the coil because the original one has a metal cap covering the entrance of the ignition wire. I will post the process of removing the coil, which is very cumbersome).
Originally Posted by Vintage Chief
Let's back up a minute. You stated the above in your first post. If that is the case i.e. "it fires up very well and runs fine", then you're getting voltage off the coil (+) terminal. If you were not, the car would not be running fine. It was some point 'after' this in which you made adjustments to further fine-tune your engine e.g. you reset idle from 1,000RPM to 375RPM, you made adjustments to carburetor A/F mixture screws, etc...
...In your reading on timing, you have to first understand what dwell is and how dwell effects timing. That is first and paramount to understanding what the effects are of adjusting timing & A/F mixture. As Eric pointed out, dwell effects timing - timing does not effect dwell. Therefore, the 'sequence' in which you tune-up your engine is critical and there's only one method/sequence to do this: (1) Dwell, (2) Timing, then (3) A/F mixture (in that order).
Then I worked on the timing issue. Thank you Vintage Chief for your long didactic response. I studied the subject and tried to apply the information to this car. First I found the timing hole on the flywheel. It is visible only from the driver's side way back behind the starter motor. These are the photos I could obtain after many attempts. It is in a very crowded area and very "user unfriendly" site.
Timing mark on flywheel
After I found this timing mark, I turned the engine by hand and kept looking at this tiny timing hole until I found the round steel ball mark as shown in next photo
Timing mark pointing at steel ball
OK, this means the rotor is supposed to be pointing to the # 1 cylinder in the distributor, which I confirmed and next photo shows it. I understand this also means the # 1 piston is at the TDC. However, so far I have not done anything to change current status and don't really know what I have to do next.
Rotor pointing to # 1 cylinder spark plug wire
At this stage, I decided to replace both the condensor and the breaker points (the condensor was a new one I installed a couple of weeks ago). The following photos show these 2 new parts after I mounted them. I think all the connections are correct. The points are sitting (I guess dwelling is the term?) in the middle of the flat surface of the cam and at this time the points are closed. I believe they should be closed at dwell. Is this the time to check the gap? I did not do it because will have to rotate the engine again and the rotor will not be at # 1 any longer.
At this time I also checked that all 8 spark plug wire are connected correctly in the right firing order on the distributor cap.
Timing, points are closed
Next I loosened up the clamp holding the distributor. This gives a minimal rotational movement to the distributor. I am not sure but I believe this is used to retard or advance the ignition but for that engine has to start first !!
This was time to try firing the engine again. I did try many times, changing the position of the distributor head from all the way to the left to all the way to the right (is only a few degrees rotation of the distributor), Engine will not even POP. Nothing.
Since 2 of us were trying to sort this out, decided to check for sparks. I removed the # 1 spark wire and attached a spare spark plug to it, placed it over the engine block, grounded well and then hit starter button many times. To my surprise, NO SPARK! I have a video of this step but don't know how to post a video in this forum.
I am stuck now. All suggestions are welcome. My idea is to get a set of spark plug wires and replace them but this is a bit illogical in my view because as Vintage Chief stated, all the problems came after I made the original changes in an attempt to correct idle and RPM. I still believe I changed something inadvertently which led to this engine failure. WIll see.,
Hope to receive new suggestions, Thank you, Manuel
Manuel - Good for you on finding the timing mark/index window. I can't speak directly to your engine's timing mark/index, but generally the timing mark was indexed (in line) with the flywheel at a predetermined point by the factory. IOW, when the flywheel timing mark is aligned with the timing index, it demonstrated a preset (pre-configured) timing position e.g. 4° BTDC, 5° BTDC, etc. That information is contained in the engine's manual. Don't assume when the timing mark is aligned with the timing index that represents TDC because in these old jalopies it most likely is not TDC.
Regarding dwell (point gap). No. You set the point gap when the points rubbing block is directly over one of the cam lobes on the distributor - not on the flat spot. This is critical. Also, it looks like in your one picture even when the points are sitting on a flat spot of the distributor the points are slightly open - they should be closed. So, gap your points directly on top of a distributor cam lobe. That is the position to establish the point gap not on a flat spot.
I re-read a couple of things. To be clear, you do not need to be @ TDC on #1 cylinder to adjust contact points gap. You need to be on any of the distributor's highest contact lobes. Therefore, just turn the engine to find one of the distributor high lobes, then adjust the contact points gap at that position. In general, we used to use a matchbook cover to first establish contact points gap at this position, this would be enough to fire off the engine before fine-tuning further.
My advice at this point would be don't make any more new adjustment or add new parts till you find out where you are loosing juice. If you have juice at the coil move on to the condenser then to the points. Somewhere between the coil and the spark plugs(probably not the plugs them selves) lies your problem. My guess is the condenser is bad or the points are too close. But don't just throw parts at it till you isolate the part or system that is causing the issue other wise you are just adding another possibility to the puzzle.
Have you snapped the points to see if they spark (ignition on) , is the rotor making contact, do you have juice coming out of the coil wire into the distributor. Some where in this sequence lies the problem is my guess..... Keep us posted....Tedd
Good advice from, Tedd. There's certainly a learning curve here on figuring out how these beasts operate. Good for you on bringing a 1941 engine to life. Having spent a number of years working with family on farm tractors of the 1940s & 1950s (and several family members with these old jalopies), they're quite different with regards to the 1960s & 1970s vehicles; so, the learning curve is even more peculiar i.e. finding timing marks & timing indexes - much easier on a JD, MF, Farmall, etc. tractor and not too dissimilar on an automobile of this age; yet, still they're peculiar for sure - you begin to wonder just why they put those timing windows in the locations they did on automobiles. Hang in there. Like Tedd suggested, don't throw parts at it, you most likely nudged something out of place maybe, like the coil wire came loose from the coil to the distributor, or the points are not set right - something most likely really simple when you were making adjustments to fine-tuning.
I can't help but surmise the points are set to close (tight) or the condenser is dead. Are you setting the points on the lobe or the flat? Gotta be something simple we are over looking. Like I said before snap the points and see if they spark. That would get you one step closer to the coil for that problem or move you forward to the spark plugs. Follow the juice....Tedd
Can we see a picture of the UNDERSIDE of the distributor cap? Particularly the rotor contact on the coil wire tower.
Certainly. The first one is the one currently on the car. Is brand new and I installed it about a month ago. The 2nd photo is the one that came with the car. Both look identical to me.
New distributor cap
Old cap
I did not replace the rotor though. May be the old rotor misses its partner?
Both caps and the rotor look good so don't think those are the issue.
Have you tried spinning the engine over with the distributor cap off, to make sure distributor is actually rotating?
Also- is there a ballast resistor in the car's ignition circuit. Should be on the firewall if it does, but with the low voltage electrical systems of the 40s it may have not used one.
Last edited by rocketraider; June 6th, 2021 at 03:18 PM.
Two things after reading again. (1) You stated you cleaned the points I see no mention you changed the points. Nothing wrong with cleaning points if you know that is in fact all they need is a good cleaning but much better to replace contact points with new ones. I don’t read anywhere you changed points. (2) Generally, you change rotor whenever you install a new distributor cap; and, most importantly that rotor has to match the distributor cap - a must. I’m still thinking this is really simple. Points gap is not set correctly or tightened down correctly. You stated earlier you set point gap at some number 0.015(?) then a week later the points were set to 0.008? That is not right and something is wrong. Wrong style points, reassembled incorrectly or something. Make sure they’re the correct points and you’re installing the points correctly. Something not right about that. BTW, 0.008 is almost no gap at all double check what’s going on here and make sure that rotor is matched for your distributor cap.
Add in any scenario you like here - parts guy sells you wrong distributor cap, fits fine, must be OK I guess, original rotor was not designed for that distributor cap, whatever. You realize if that button cap on the rotor is NOT making contact with the coil wire center position of the distributor cap you will have zero, no, none, nada spark to any spark plug. Just saying.
Good news! Able to fire the engine today. This is the process I followed and you may refer to the attached videos that are in sequence.
Originally Posted by Tedd Thompson
My advice at this point would be don't make any more new adjustment or add new parts till you find out where you are loosing juice..If you have juice at the coil move on to the condenser then to the points. Somewhere between the coil and the spark plugs(probably not the plugs them selves) lies your problem. My guess is the condenser is bad or the points are too close. But don't just throw parts at it till you isolate the part or system that is causing the issue other wise you are just adding another possibility to the puzzle.
Have you snapped the points to see if they spark (ignition on) , is the rotor making contact, do you have juice coming out of the coil wire into the distributor. Some where in this sequence lies the problem is my guess..... Keep us posted....Tedd
Thank you for the advise to snap the points Ted! This simple test showed me that electricity was going all the way to the distributor but for some reason not to the spark plugs. My first test was to look for sparks at the end of the wires, on the plugs themselves. Video labeled "No spark" shows the result.
Then I did the snapping of the points test (scared me a bit initially as I read that thousands of voltage can get there from the coil) and had consistent sparks as shown in the video labeled "Snapping points". Good news, meaning my coil is fine, my cable from coil to distributor is fine.
Originally Posted by Vintage Chief
I re-read a couple of things. To be clear, you do not need to be @ TDC on #1 cylinder to adjust contact points gap. You need to be on any of the distributor's highest contact lobes. Therefore, just turn the engine to find one of the distributor high lobes, then adjust the contact points gap at that position...
I followed the Chief and since my timing mark showed that rotor was set for firing cylinder # 1, I rotated the engine by hand to position the ruber support of the points on the highest level of the cam. I measured gap was 0.019 (should be no more than 0.016 for this engine). I tried to narrow down to specifications and realized that every time I got the perfect gap, it got changed when tightening the screw that holds the plate. I finally decided to set the gap at 0.011 and by the time I tightened the screw it moved to 0.015 or may be a bit larger. Have no real experience feeling the gauge yet but I think is close to specifications. I was hopeful then and set the video camera to record firing attempt. I was alone and unfortunately camera got out of focus but you can hear the engine - and all its troubles - very well in the video labeled "Engine fired".
The video is the 2nd attempt at firing. The very first one, engine sputtered a lot and I moved the head of the distributor counterclockwise (chose it randomly) and it started. Notice how rough it runs. I had to keep accelerating or it would stop but then got warm and ran more or less steady. It sounded tooooo slow and by my cheap optic tachometer reading, I could get a few steady numbers under 300 RPM which is way under recommended 375 RPM. Once I noticed that engine will keep running without me pushing the accelerator pedal, about a minute into the video, I got off the car and increased the throttle a bit at the carb and seemed ran better.
The last video, "Engine hesitation" reflects what my originalk problem was. The engine slows down and picks up randomly.
Finally but not recorded on video, once engine was fully warm I started accelerating in Neutral to see if RPM will increase steadily but engine reacted the way it did when I started this post: Suddenly slowed down, unresponsive to the throttle but got better immediately after releasing the pedal, of course at a lower RPM.
Still not ready to drive but I am happy with this accomplishment. Clearly the only problem to start was related to the breaker points and maybe that is still causing the rough run. This is a big task for a newbie but persistence is paying off. Thank you all for all your advise.
I’ll mention this. There is a true difference between idle and cruise on these old jitterbugs. You’ll need to find the sweet spot where it idles OK but cruises without hesitation. You
may need to increase idle RPM, you may need to advance timing, whatever. But please do remember. You tune any engine in this sequence: Dwell>Timing>A/F mixture (with a vacuum gauge). These old buggers ran on 76 octane. Today’s blends require a little more fine-tuning to get the cruise down correct. Someone you’ll most likely find increased the idle RPM to get a better cruise response. There are three main areas of a power curve: Idle, Cruise and WOT. Pick your poison.
Last edited by Vintage Chief; June 6th, 2021 at 05:05 PM.
I’ll mention this. There is a true difference between idle and cruise on these old jitterbugs. You’ll need to find the sweet spot where it idles OK but cruises without hesitation. You
may need to increase idle RPM, you may need to advance timing, whatever. But please do remember. You tune any engine in this sequence: Dwell>Timing>A/F mixture (with a vacuum gauge). These old buggers ran on 76 octane. Today’s blends require a little more fine-tuning to get the cruise down correct. Someone you’ll most likely find increased the idle RPM to get a better cruise response. There are three main areas of a power curve: Idle, Cruise and WOT. Pick your poison.
Just to clarify, I did replace the breaker point yesterday as stated in my long post. I will now begin to read about dwell adjustment. Since the engine is running I think is time to follow that path but don't know how to do it yet. If you have a good video link please post it, or any other reference may be helpful. Thank you for your tips !
Dwell angle is used to establish the optimum point gap in relation to the ignition systems electrical field. There is a 'period' when the contact breakers (points) close - e.g. that is the flat spot between each of the eight distributor cam lobes. This 'period', is measured in degrees of distributor cam rotation. A dwell meter reads that optimal setting. The 'period' where the contact points remain closed is called the dwell angle. During the dwell angle (closed contact points gap) electrical charge is built up in the coil. When the contact points open (top of each distributor cam lobe), the electrical charge (voltage) from the coil is delivered to the distributor cap via the coil wire and voltage is supplied to each spark plug. When the contact points begin to wear, two things occur; and, one wear point effects dwell angle more than the other. (1) The rubbing block of the contact points which rides against the distributor cam (lobes) begins to wear down. As it wears down, the contact points no longer open and close as they were initially set when brand new simply because the rubbing block is wearing down. To establish the best dwell (angle), you use a dwell meter to adjust the best position for your contact points gap. (2) The contact points metal contacts simply begin to wear down from abrasion much like the abrasion of the contact points rubbing block against the distributor cam (lobes). Dwell angle is going to be the best (factory recommended) contact points position as defined in your service manual. Newer distributors on the newer cars are easier to adjust the dwell since they have a metal window in the distributor you can open to make dwell angle (contact points) adjustments. On your engine you won't have this metal window to gain access to the contact points; instead, you have to remove the distributor cap every single time to adjust dwell (contact points) making this adjustment, well, plainly stated a real PITA. I hope that makes sense to you. Generally speaking, if you have the correctly established gap on a new set of contact points, you should (in theory) not need to set dwell any further. Dwell however, is the best method to establish the best contact points gap for the best electrical delivery at exactly the correct time. Just remember, the flat spot builds electrical charge (potential) in the coil, the top of each distributor cam lobe delivers that optimal electrical potential to the spark plugs when the gap opens - a dwell meter simply tells you if your dwell is established at its optimum.
Last edited by Vintage Chief; June 6th, 2021 at 06:51 PM.
Suggestion: Let's say for $HITS, GIGGLES & GRINS (so you aren't pulling your teeth out any longer than necessary) you don't own a dwell meter (if you do I'd use it but let's move on). A good dwell meter will tell you the voltage, the dwell angle and RPM when you set your dwell angle. If you're confident with the contact points gap for a new set of contact points, call it a day and move onto the timing and the A/F mixture. You'll need to perform a deep-dive into your service manual to understand what the timing should be on your engine - only the service manual is going to tell you this information. You now know where to find the timing index and timing mark. Old school folks will (might) forego the timing and instead perform the timing via a vacuum gauge. Your service manual should state exactly what the timing should be. As I stated in earlier posts, you need to determine what the factory setting is for your timing 'window'. IOW, where exactly are you when the timing mark aligns with the timing index. On these older beasts, the timing 'mark' was often established by the factory at a predetermined position (read above in my previous posts). If you can establish your timing correctly you'll be ahead of the game. In doing so, you'll be loosening the distributor hold-down bolt (which you have already done and know where it is) and setting your timing to the correct position w/ your timing light. Then move onto the A/F mixture. Use a vacuum gauge to establish the highest achievable vacuum you can establish - it doesn't matter what that reading is, as long as it is the highest vacuum you can achieve. You adjust the carburetor A/F mixture screws (I believe there are two on your carburetor) one at a time - adjust each one to the highest vacuum possible.
Last edited by Vintage Chief; June 6th, 2021 at 07:08 PM.
The hesitation video to me sounds more like a cylinder misses than a carburetor out of adjustment. If mine I would throw a compression test on it and see if one or more cylinders are very low on compression. After 30 years the rings may (probably) are a little stuck. I also would dump a couple table spoons of regular ATF or Marvel Mystery Oil down each cylinder when it's still warm and let it set over night and do another compression test after a warm up to see if there is any major difference in the readings or smoothness of how it runs. You should be able to get a compression tester at any Auto Zone Pep Boys or the like as a free rental.
And as after thought you won't have a ballast resistor if you are still working with a 6 volt system so don't worry if you cant find yours, you don't have one. I think you have this problem close to fixed, let us know if you have other problems ... Tedd
Just a thought, I have had this issue with newer vehicles and lack of power when accelerating, I have had clogged exhaust systems cause this exact problem?? Seeing this car has sat so long it may be something to check, had a 69 442 that a family of mice decided to make a nice big home in the muffler, it did finally blow out but took a bit of time. Just a thought.
Just a thought, I have had this issue with newer vehicles and lack of power when accelerating, I have had clogged exhaust systems cause this exact problem?? Seeing this car has sat so long it may be something to check, had a 69 442 that a family of mice decided to make a nice big home in the muffler, it did finally blow out but took a bit of time. Just a thought.
I had almost the same problem with my 55 when it first came out of the equipment shed. Muffler was stuffed full of walnut hulls buy rats. Had a full blown fire going on till I soaked it down with a garden hose, Then I got to work under it with all that water and mess....Tedd
I want to update Olds fans on the condition of my 41 engine. Many of you have given very helpful advise and I think you will be happy to know that the 41 is now running well and driven all over the Black HIlls in South Dakota (well, until a few days ago when we had the first mini blizard of the season). The story is that after my endless attempts to get it running correctly, I visited a shop in town specialized in old cars. I have known the owner for a few years and he asked me to bring the car to be checked. He found 2 of the spark cables had very high resistance and were not working well. He replaced the 8 spark plug cables and using the same contact points, sparks, distributor cap, coil and everything else that I had previously described and installed, he timed the engine to the point that it runs very well. Good acceleration, idles fine, not misfiring, and purrs all along when cruising. The distributor needed 8 degrees advancement. The carburetor had no part on the problem. Engine idles at 480 RPM per shop manual and you can see (and hear) in the attached video (I hope, tried several times to upload and not sure if done correctly). In summary, poor electrical connection and my inability to do the timing explain everything. I learned a lot and am very happy with the outcome of course. Great experience. I will now move to other repairs during the long Dakota winter. Thank you all for the help ! Manuel
Sorry, unable to upload the short video of running engine. It is an 8 MB file with a .wmv name. It is compatible with the Forum but for some technical reason not uploaded. Will retry later.
I'm confused on how to check timing on my 48 (49 motor).
Do I need a 6V timing light?
Is it timed as in the past with marks on the harmonic balancer?
What are the marks on the flywheel for?
The modern timing lights all operate on 12 volts so you need to connect both the positive and the negative cables of the timing light to an extra 12 volt battery next to your 6 volt car and then need to attach an additional cable going from the negative pole of your extra battery to ground on the chassis. This is to ground the timing light so it can function. It is a simple connection. The 2 photos below show how I did
There are 3 cables at the battery, positive, negative and ground for timing light
Yellow cable is the ground for the timing light
.
Regarding your other questions, I am not the best to explain but senior forum members have answered those questions in this post about 2 months ago. If you follow the thread you will find the answers you look for. But it ain't easy ! Although I did understand all the concepts and principles, I did not succeed putting them in practice and ended up seeking help from a Pro. I don't feel bad because it is the first time I have tried something like this. Good luck !
Playing catchup here...tried to read everything posted.
BUT ... does the vacuum advance work on the dissy??
just a thought.
Cheers Paddy.
Yes, it does, at least for sure in my engine which is a 257 ci straight eight. The shop manual has a complete description (too much for me to handle for the time being). In addition, these engines have another simple way of advancing or retarding by moving the metal plate behind the distributor clockwise (advancing) or counterclockwise (retarding). The shop that did my tune-up found that 8 degrees advance was necessary given type of current fuel octanes. The photo shows the lever at 0 degrees and currently I have it at 8 degrees (each notch is 2 degrees).
I'm confused on how to check timing on my 48 (49 motor).
Do I need a 6V timing light?
Is it timed as in the past with marks on the harmonic balancer?
What are the marks on the flywheel for?
I’m not an authority on this board, but I’d recommend starting your own thread on that subject so others can learn from it in the future. I’d be happy to help you set the timing on your 49 motor. I did all that this summer and learned a lot.
hope to see you on a new thread.
nathan
With hold down plate zero mark as shown in photo lining up with mark under dirt on block rotate distributor with hold down plate still ( loosen nut under distributer).
Rotate distributor independant of hold down plate to locate ball facing pointer on flywheel behind starter with engine idling slowly.Fasten nut securing distributer to hold down plate. Dont move anything but the securing nut whilst doing this. Then with hold down plate movable advance timing to 8 degrees and then tighten hold down plate to block.Each mark on plate is 2 degrees.So move plate 4 marks in A direction.
June 1st, 2021, 11:49 PM
