I have posted before about my 57 bird, with the 312, and various issues I have run across. I managed to get it running pretty well and took to my mechanic a couple of weeks ago.



Asked him to go through it and I told him (and you) about the points closing and car quitting or not starting. Pull the cap, adjust points (screws were tight) and back on the road. Anyway, mechanic says I have about a 10 degree movement with the dist shaft and should only be 2 degrees. They get the car all tuned up, set timing etc. Head down road, it acts up and when they get it back the timing is off and points closed.



He thinks it is the distributor gear or the timing chain. The long block was put in it and only has 3500 miles on it. What do you guys think it is? Timing chain or dist. gear? Before I spend the money tearing the front up to get to the timing chain, anyone run across this before? If it is the gear, what are the chances that the other end, on the cam is ruined? Distributor is original with 53K miles on it.



Also I just put on a new vacuum advance, points, condenser, and belts.



As always, I appreciate you time and comments...



~Rod




1957 Thunderbird

312

I'm no expert mechanic, but I fail to see why a bad timing chain can close up the points in the distributor.



Have you tried another distributor? You can get a rebuilt one for your 57 (but no tach drive) for less than $80 to see if a new distributor solves your problem. You can always sell it later

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

I agree with Paul, the chain can't affect the points gap.  What points are you using.  I have always used the ones with a fiber rubbing block, I have seen the cheap plastic rubbing blocks wear quickly, closing the point gap.  Also, are you using a lube on the cam/rubbing block?  It's vital.  If nothing is loose on the points mounting plate, rubbing block wear is the only possibility.  Is the cam rough?

John - "The Hoosier Hurricane"

I was going to try a different dist but the tach one is the only one that will fit on a 312. They are $140 for a rebuilt.

I do not know the name of the points, I should.  It does have the fiber plate and not plastic and the lobes are greased.  It has been doing this points thing for some time.  I pulled the dist apart and cleaned up the breaker plate, re-greased it. (it is a heavy duty plate) with bearings.  It ran fine for a while and I parked for a week.  Went out to start it and the points were completely closed.  Both set screws were tight.  Most bizzare thing I have ever seen.  I readjust them and the car fires right up.  The shaft itself is in good shape and did not have any bends in it.  The amount of play in the shaft concerns me but perhaps they are to do this.  The mechanic drove it for a week and half before he could get it to act up.  The harmonic balancer was loose and they tightened it all back up.  Readjusted the timing and started up.  One other thing he told me is when the points go closed it throws the timing of the car off.  This is all just out of reach of my shade tree mechanic ability to figure out.

I would not think it would be the timing chain either.

When I have the car running it is a smooth as glass!

1957 Thunderbird

312

From what you are saying the points are closed and you just reset them and they are fine again.

This would suggest that the shaft is not moving around on the gear or that the timing chain is the problem, though if the chain was really worn it would alter the timing of the car if it is flopping about. This would be evident with a timing light as the reading would not be steady.

If the shaft of the distributor was causing the problem with too much side play in the top bush it may seem like the points are closing up but you say you have 020" play which would have to affect the dwell reading and you would expect it to run like a dog if that was the problem.

Have you checked the distributor with a dwell meter when it is running as this will certainly tell you what the points are doing when it is running. The dwell reading should be rock steady but a couple of degrees is neither here nor there.

You need to make sure that the mechanical advance is free also and not causing any problem, this can be done by the timing light whilst it is running. Disconnect the vacuum advance whilst doing this and you should see the timing advance as you rev it to about 2000rpm.

Have you got the screws holding the plate which the points sit on secure and in place. I notice you have a ball bearing plate and these have three screws around the perimeter which locate it.

If none of this fixes it, Paul's idea of a new distributor seems the way to go.

Regards

Rick - West Australia
Do Y Blocks Downunder run upside down? Gravity Sucks!!

I will third the opinion that the timing chain has nothing to do with it. I don't think it is the distributor gear, either. With the exception of some earlier distributors, any Y-block distributor should fit. You don't need the tachometer to diagnose this problem so swapping a known good distributor, with or without a tach drive, could help point you in the right direction. Do any shops near you have a distributor machine? That may help to see what is going on.


Lawrenceville, GA

That style point plate uses L shaped clips to hold it down.  The shorter part of the L rests against the outer race of the plate, and the longer part has the hole for the screw.  If those are not present, when the distributor warms up and expands, the plate can cock in the housing, and when the housing cools again, the plate may remain cocked.  Maybe that is why you have to re-adjust the points to get it started.

John - "The Hoosier Hurricane"

The screws are tight and hold the plate in place but the plate does not roll smooth.



Almost like there are golf ball dimples that the bearings will catch on. I found the smoothest area and since the advance is so small and I have 1/4" of movement either direction before it hits one of those dimples, I thought I would be OK.



A normal distributor did not fit as it was about 2" too short. When I went to install, the base of the distributor cup hit the head. Everything else was fine. Perhaps they make a long necked dist. I am not aware of. Concours will rebuild mine for $140. If I could find the kit, I might be able to do it myself. Hate to get rid of an original chrome Ford dist for a core charge though. I have not found anyone in St. Louis to rebuild it.



My distributor gear came in today so I will take it up to mechanic on Monday and see if that is the problem. I guess the pin could be sheered causing the dist to miss every once in a while.



Regarding the closing of the points, I would rotate motor til I Hit lobe and then set at high point. When the car would quite, I would rotate the points til I hit lobe and the points would be closed. I even marked the lobe and went back to same one to verify everything. Sure enough, they would be closed. Now every 4-5 times it would do this, I would find the points gaped too far. Again the screws on the breaker plate and points are both tight.



I have not checked the counter weights other than visually inspected. I would not know what I was looking at. Should those springs be tight all the time or loose?



Thanks again for time. Let me know if I can answer any other questions to narrow this down.



I would think if the timing chain was whacked, then I would be misfiring and having more problems. my only problem is this closing of the points.



Rod


1957 Thunderbird

312

Reading you latest post, I think you may have answered the problem yourself in the first line. This contact plate runs on bearings and should rotate freely once the vacuum advance arm is disconnected.

I would change the plate and see where you are after that.

I note that you are against sending your distributor off to be repaired as it chromed.

The distributor gear cannot be spinning on the shaft because the car would not run if this was the case and you would not be able to simply reset the points and drive off. This would suggest that the distributor is lined up correctly and the gear has not moved. Remember you say that the points are closed and you just reset and they are fine.

You do need to check that the mechanical and vacuum advance is working correctly as the problem could be caused or worsened if one of these was sticking, though no advance working on the distributor would not allow it to run sweetly as you said in the first posting.

It is possible the gear could be worn or have a loose pin fixing it to the shaft. If this was the case it would be possible to move the rotor an excessive amount taking into consideration that the rotor also moves due to the mechanical advance. The easy way to check this would be to turn the rotor button clockwise as far as it will go and then release. When it returns to its stopped position see how much more you can turn it counterclockwise. If you get too much travel it is obviously loose on the shaft and you should be able to feel it slipping. I have never seen a distributor do this though I have seen one shear the pin in a Cleveland 400M engine with a high volume oil pump. The symptoms you are experiencing would suggest that this is not happening. If the gear moves at all your timing will go out quickly (like the moment you start the engine) and it will not drive sweet.

Also check that the vacuum advance is working correctly. I usually do this by placing a tube on the nipple of the canister and sucking it. If it moves it is working and it should flick back to the rest position immediately when you release the vacuum. You have to suck pretty hard. On this type of distributor, the arm from the vacuum canister actually locates and maintains the positioning of the points in relation to the lobes. As I said the plate should spin around willy nilly without this connected within the confines imposed by the wiring to the plate.

I would certainly pull the distributor and check it out but from what you are saying I would think the problem lies either with the plate or the vacuum advance canister.

Hope this gives you somewhere to look.

Regards

Rick - West Australia
Do Y Blocks Downunder run upside down? Gravity Sucks!!

Quite obviously the problem arises in the distributor as the point close up. The other answers have given you something to look at.



With the exception of the 54 distributor, all YBlock distributors will interchange, regardless whether its off a 272, 292 or 312. The 55 and 56 ones will not work correctly with a later carb.



A new timing chain or a new gear will not fix the points problem.



Beg, borrow or buy a 57 or later distributor that you know is good. Put in it and run the car. If the problem goes away you then know that your distributor is bad and must be repaired. It seems to me you are flogging a dead horse with your current distributor.

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ