Those of you with '65-66 300's and related....

[TylerW]

Hey guys:

I've had my '66 on the road for a year or so and have been working out some bugs along the way. I thought it might be both fun and informative to describe the issues I've had with MY car to see whether you guys have had the same things happen.

1. The worst, and still ongoing issue I've had is getting the AFB sorted out. For whatever reason, I can't get that carburetor to run on the secondaries. It transitions smoothly with no bog, but a couple seconds after getting the secondaries opened up it starts to starve for fuel. I've rebuilt it twice, and the rest of the fuel system is completely new, so I'm going to go into it a third time and inspect it with a fine toothed comb. It also starts pretty hard after it heat soaks, so something isn't right in there.

2. Distributor issues. The original 2642248 unit was long gone when I got this car(non-running with the engine in pieces), so I cleaned up a good core('67 383) that hadn't been through a rebuilder and bought a set of NORS Mopar points. The problem is, the dwell is too low. I can get only about 18 degrees of dwell with the point gap tightened as tight as I dare. So far I haven't had a solid suggestion why that is happening.

3. Ammeter/regulator issues. When I put everything together under the hood, I removed the ORIGINAL '66 regulator and replaced it with one of those expensive "restoration" regulators that came on a parts car. That's the one that looks like the original but is in fact electronic. The result is that the ammeter needle twitches incessantly. Not wild swings, but it dances around just over and under the middle all the time unless I'm over 60 mph or so. I have an electronic regulator on my '68 Valiant and it does no such shenanigans.

4. Underwhelming brakes. I've had to mess with these brakes a lot, specifically the power brake unit and master cylinder. They are still not strong and it always feels like I have more rear brakes than front.

5. Broken spring on the heat riser.

6. Power steering leak on the pressure line at the pump. I've been into this at least twice. New line and took the seat out and dressed it. Didn't completely fix it so i think I'll have to locate a replacement brass seat.

7. Gas tank issues. This is another area that has taken multiple repairs. New tank and sender. After 300 miles the sender failed. Tank came back out, new sender free of charge, tank back in, works good. Now, I put the brakes on hard the other day for a red light and got a strong smell of gas. No visible leaks, so I figure it is that vent line that dumps into the frame rail, the same as my other two cars. Has anyone ever modified that to minimize the gas fumes?

Now, these aren't complaints. It's a fantastic car and I enjoy driving it. Just thought I would share my to-do list and see if any are just the nature of these cars. Thanks!

 

[cbarge]

1. After 2 rebuilds time to put the carb on a shelf and install a new or good working used Eddy or Holley. Summit sells a nice carb that works well on big block Mopars.
Get a carb with electric choke then pull the intake and block off the heat crossover ports to eliminate fuel perculation when hot.
2. I am a purist at heart when it cimes our cars. But I also prefer my cars to work properly and reliably.
I hate points. Ditch them for Pertronix or go all out with a Chrysler electronic ignition conversion.
3. No surprise here.
All Mopars prior to 1976 had ammeter gauge issues.
Do the bulkhead bypass and underhood ammeter bypass and she will be fine.
4. If you are still running the single pot master upgrade to the dual circuit master.
Drum brakes on our barges were marginal at best. Plan your stops if you cannot afford disc conversion
5. Common but if you do #1 heat riser is irrevalent.
6. Never seen a C with a pump that did not leak. Unless it is run dry lol.
7. Double check vent lines and possibky reroute them??
The combo of worn out carb and shitty dwell can contribute to poor running and starting.
Nothing that you are experiencing is out of the ordinary.
Hope this helps

 

[Xenon]

1. After 2 rebuilds time to put the carb on a shelf and install a new or good working used Eddy or Holley. Summit sells a nice carb that works well on big block Mopars.
Get a carb with electric choke then pull the intake and block off the heat crossover ports to eliminate fuel perculation when hot.
2. I am a purist at heart when it cimes our cars. But I also prefer my cars to work properly and reliably.

Send the carb to dana on this board..
@Dana

Probably less cost and will be the correct fit for your car.....

 

[detmatt]

Check the length of your fuel pump pushrod.

 

[FURYGT]

3. Ammeter/regulator issues. When I put everything together under the hood, I removed the ORIGINAL '66 regulator and replaced it with one of those expensive "restoration" regulators that came on a parts car. That's the one that looks like the original but is in fact electronic. The result is that the ammeter needle twitches incessantly. Not wild swings, but it dances around just over and under the middle all the time unless I'm over 60 mph or so. I have an electronic regulator on my '68 Valiant and it does no such shenanigans.

Make sure that you have a good ground where the voltage regulator screws into the firewall. If the ground is good, try the electronic solid state voltage regulator that I sell. At $21.95 shipped by priority mail it is not expensive. Alternatively you could upgrade to the 1970 and up style voltage regulator.

Mopar Voltage Regulator - Electronic Solid State with Correct Restoration Look | eBay

 

[commando1]

All Mopars prior to 1976 1974 had ammeter gauge issues.

 

[HWYCRZR]

2. Distributor issues. The original 2642248 unit was long gone when I got this car(non-running with the engine in pieces), so I cleaned up a good core('67 383) that hadn't been through a rebuilder and bought a set of NORS Mopar points. The problem is, the dwell is too low. I can get only about 18 degrees of dwell with the point gap tightened as tight as I dare. So far I haven't had a solid suggestion why that is happening.
Cam lobes on distributor should be fine as they are keeping your points open longer than it should = low dwell.
Or do you have the right ports hooked up on your dwell meter?
I was using my harbor freight special dwell meter one day and was getting frustrated because I kept getting the same number no matter how I adjusted. I finally looked at the manual and found I had one of the wires hooked in the wrong port giving me an inaccurate reading. Also if I am not mistaken if your engine is off, and the points are closed (on the flat) your meter should read 45 degrees dwell. A quick check.

 

[Ripinator]

Hey guys:

I've had my '66 on the road for a year or so and have been working out some bugs along the way. I thought it might be both fun and informative to describe the issues I've had with MY car to see whether you guys have had the same things happen.

1. The worst, and still ongoing issue I've had is getting the AFB sorted out. For whatever reason, I can't get that carburetor to run on the secondaries. It transitions smoothly with no bog, but a couple seconds after getting the secondaries opened up it starts to starve for fuel. I've rebuilt it twice, and the rest of the fuel system is completely new, so I'm going to go into it a third time and inspect it with a fine toothed comb. It also starts pretty hard after it heat soaks, so something isn't right in there.

2. Distributor issues. The original 2642248 unit was long gone when I got this car(non-running with the engine in pieces), so I cleaned up a good core('67 383) that hadn't been through a rebuilder and bought a set of NORS Mopar points. The problem is, the dwell is too low. I can get only about 18 degrees of dwell with the point gap tightened as tight as I dare. So far I haven't had a solid suggestion why that is happening.

3. Ammeter/regulator issues. When I put everything together under the hood, I removed the ORIGINAL '66 regulator and replaced it with one of those expensive "restoration" regulators that came on a parts car. That's the one that looks like the original but is in fact electronic. The result is that the ammeter needle twitches incessantly. Not wild swings, but it dances around just over and under the middle all the time unless I'm over 60 mph or so. I have an electronic regulator on my '68 Valiant and it does no such shenanigans.

4. Underwhelming brakes. I've had to mess with these brakes a lot, specifically the power brake unit and master cylinder. They are still not strong and it always feels like I have more rear brakes than front.

5. Broken spring on the heat riser.

6. Power steering leak on the pressure line at the pump. I've been into this at least twice. New line and took the seat out and dressed it. Didn't completely fix it so i think I'll have to locate a replacement brass seat.

7. Gas tank issues. This is another area that has taken multiple repairs. New tank and sender. After 300 miles the sender failed. Tank came back out, new sender free of charge, tank back in, works good. Now, I put the brakes on hard the other day for a red light and got a strong smell of gas. No visible leaks, so I figure it is that vent line that dumps into the frame rail, the same as my other two cars. Has anyone ever modified that to minimize the gas fumes?

Now, these aren't complaints. It's a fantastic car and I enjoy driving it. Just thought I would share my to-do list and see if any are just the nature of these cars. Thanks!

 

[Ripinator]

I have two '66 300s, and I've had every problem you had, except for the heat riser (mine is disconnected).

1. The AFB: The carb on my 300 coupe does the same as yours. Runs along fine until you hit it to open the secondaries; then it bogs and seems to starve for fuel. The carb has been rebuilt twice. I'm sending it to @Dana at Woodruff to get it competently rebuilt.

2. The distributor in my 300 convertible was rebuilt when the engine for that car was rebuilt. Was totally messed up, so I sent it to @halifaxhops, and he rebuilt it and fixed it correctly within a week.

3. Voltage regulator: I have replaced the regulators in both of my cars. The best one is sold by @FURYGT .

4. Brakes: I replaced the boosters and the master cylinders (single-type) in both cars, and properly adjusted the drum brakes. Both cars stop fine now.

5. See above

6. Power steering fluid leak: Both cars leak fluid, mostly due to the large o-ring gasket between the reservoir and the pump body. I replaced the gaskets, but still have a little leak in one car (probably screwed up during the repair - by me).

7. Gas tank: I also replaced the gas tank in the convertible, and it leaked at a defective solder joint for one of the vent tube lines. After dicking with it a couple of times removing the tank, etc., I finally fixed it (for now) with a gob of JB Weld.

Don't give up on your '66. when you finally get it sorted, you will love the car.

 

[cbarge]

She may not be mine but I do maintain a buddy's 66 300 seeedan.
All the work done to it has made her trustworthy of long trips including Carlisle (2016).
Original carb and distributor thrown out. Heat crossovers blocked,carb spacer and electric choke installed.
Original tank dented in so gauge does not read correctly. many years ago his Dad drove into a bad road to a cottage and bottomed out.
P.S. pump leaks.
Installed electronic voltage regulator and did the underhood ammeter bypass among other electrical upgrades. (headlight relays,Full LED conversion)
So nothing uncommon here.

 

[CBODY67]

When you rebuilt the carb, did you ensure that the jets were in their correct pri/sec locations? Fuel pump pushrod length can be an issue too?

Distributor . . . is the point gap in the correct range? If the dwell is still off, with the points gapped correctly, then the lobes on the cam are worn. Use a dial indicator to set the point gap and you'll readily see how much they can vary, lobe to lobe AND visibly see how much wear they have on them. Hopefully, you're also using "point grease" on them?

What width brake shoes, f/r? Are they all correctly adjusted? In a panic stop, the rears will always lock-up first, by design. But in such a panic stop, all FOUR of the brakes would probably lock-up. Check some of the old road tests.

Fuel smell on hard stops? Check the rubber vent line connection and o-ring on the sending unit. Look for a "trail" of where the gas has come out, if possible.

Ammeter issues . . . make sure that ALL of the cable/wire connections in the charging system are clean, tight, and have good grounds. What you describe doesn't sound like everything is "right" in the system. Might put the old one back in, for testing?

Heat riser spring? If the valve is stuck in the mid-position, it's fine. That's where ours' normally stuck. Choke worked fine. No loss of performance, either.

Power steering leak? Only time I've had that issue was when the system (when I got the cars) had "red" atf added to them rather than the "clean" Chrysler or GM-spec power steering fluid in them. Leaks from the hose itself, not the fittings. But when the correct fluid was put in them, no leaks after that.

If the leak is from the pressure fitting, if the flare on the hose and the fitting are not well, that's one issue. IF there's a missing gasket/seal where the fitting screws into the back of the pump, before the line is attached, that's something else. Harley-Davidson didn't design those things, so 'no leaks" is normal.

I know it can get old trying to get some of the final things sorted out. Don't give up, yet!

Enjoy!
CBODY67

 

[halifaxhops]

Distributor . . . is the point gap in the correct range? If the dwell is still off, with the points gapped correctly, then the lobes on the cam are worn. Use a dial indicator to set the point gap and you'll readily see how much they can vary, lobe to lobe AND visibly see how much wear they have on them. Hopefully, you're also using "point grease" on them?

You nailed it the lobes wear believe it or not and also the bushings go bad, probably both of them.