Good luck getting a B/RB points vac advance now from a parts store today. They will give you one with the curved arm not a straight arm like you need.
low vacuum 383
- Thread starter 67 ragtop
- Start date
Cardone make a good product that may be great or a dog in your application. They usually have a ten year spread of "it will work" distributors kind of set in the middle. Yes it will run.
| OEM / Interchange Numbers: 1889562, 2095054, 2095836, 2098836, 2444261, 2444676, 2642244, 2642248, 2642289, 2642363, 2642367, 2642373, 2642406, 2642410, 2642465, 2642466, 2642482, 2642531, 2642727, 2642728, 2642745, 2642810, 2642811, 2642949, 2642972, 2875162, 2875166, 2875170, 2875310, 2875352, 2875354, 2875356, 2875358, 2875574, 2875715, 2875731, 2875742, 2875747, 2875748, 2875750, 303817, 3438231, 3438233, 3438534, 3438544, 3438690, 3438823, 3656329, 3656332, 3656593 |
Distributor specs are om the "Ignition" section. Idle speeds are usually in the "Fuel-Carburetor" section. CAP cars probably were idled at 700rpm, but Federal cars were in the 550-600rpm range.
As other in here do not care for ProForm or Cardone items, but they might be the only way to get a new distributor housing with a new vac advance unit. Would be a more expensive way to do it, though. Seems like somebody has some point distributor vac units, probably in the restoration part of the hobby? Might not be specific to the engine you have, but ai also suspect they are adjustable as to when the vac advance starts, just that they don't admit it. No needd for the expensive electronic retard vac units of the early 1070s!
Chrysler had a TSB to add a thermo vacuum switch to the distributor vac advance in 1972. When engine coolant temp got to qa particular level, it would switch the disc vac advance source from ported to manifold. The additional advance would speed the engine up a bit for more cooling fan speed, then slow things down when the coolant cooled to below the TVS temp cut-in level.
CBODY67
As other in here do not care for ProForm or Cardone items, but they might be the only way to get a new distributor housing with a new vac advance unit. Would be a more expensive way to do it, though. Seems like somebody has some point distributor vac units, probably in the restoration part of the hobby? Might not be specific to the engine you have, but ai also suspect they are adjustable as to when the vac advance starts, just that they don't admit it. No needd for the expensive electronic retard vac units of the early 1070s!
Chrysler had a TSB to add a thermo vacuum switch to the distributor vac advance in 1972. When engine coolant temp got to qa particular level, it would switch the disc vac advance source from ported to manifold. The additional advance would speed the engine up a bit for more cooling fan speed, then slow things down when the coolant cooled to below the TVS temp cut-in level.
CBODY67
Looking at 1967 Polara / Monaco service manual.
BBD 2-BBL, 383 engine.
Curb idle (with A/C on) is 550 regardless of transmission. For CAP, it's 650 for manual trans, 600 for auto.
Fast idle is 700 (I think AC off). For CAP, manual trans is 1700 (!) and for auto is 1400 (!).
Stromberg is 550 regardless of AC or trans type, 700 fast idle, no mention of CAP.
Carter AFB 4-bbl is 500 regardless of AC or trans type, 700 fast idle, no mention of CAP.
Carter AFB (non-CAP) for 440 is 650 for idle (auto or manual), 800 fast idle (manual) or 700 (auto)
Carter AFB (CAP) for 440 is 650 (manual) 600 (auto) but fast idle is 1400 (!)
The big difference for CAP is the fast idle setting more than the curb idle setting.
> I am running 87 octane.
If you're running 87 octane with 10 or 12 advance at idle and you're not getting spark-knock at part-throttle under load then either you have a really mild curve or there's something extra in that gasoline and I want some.
BBD 2-BBL, 383 engine.
Curb idle (with A/C on) is 550 regardless of transmission. For CAP, it's 650 for manual trans, 600 for auto.
Fast idle is 700 (I think AC off). For CAP, manual trans is 1700 (!) and for auto is 1400 (!).
Stromberg is 550 regardless of AC or trans type, 700 fast idle, no mention of CAP.
Carter AFB 4-bbl is 500 regardless of AC or trans type, 700 fast idle, no mention of CAP.
Carter AFB (non-CAP) for 440 is 650 for idle (auto or manual), 800 fast idle (manual) or 700 (auto)
Carter AFB (CAP) for 440 is 650 (manual) 600 (auto) but fast idle is 1400 (!)
The big difference for CAP is the fast idle setting more than the curb idle setting.
> I am running 87 octane.
If you're running 87 octane with 10 or 12 advance at idle and you're not getting spark-knock at part-throttle under load then either you have a really mild curve or there's something extra in that gasoline and I want some.
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Thanks for all of that information. I suspect that you need to also look at which step on the fast idle cam the speed references to. If the fast idle cam is on its highest step, the idle speed will usually be in the 1400rpm level. When the choke pull-off pulls the choke plate open a bit, a lower step on the cam will be in play, with an appropriately lower fast idle rpm. For ANY carburetor with an automatic choke.
Consider, too, that the quoted fast idle speeds are set on a fully-warmed engine. On a fully-cold engine on first start of the day, the ending idle speed will be a bit lower due to everything being cold rather than hot. As things become hotter, the choke will open more and the fast idle speed will drop appropriately as lower steps on the fast idle cam are used.
Enjoy!
CBODY67
Consider, too, that the quoted fast idle speeds are set on a fully-warmed engine. On a fully-cold engine on first start of the day, the ending idle speed will be a bit lower due to everything being cold rather than hot. As things become hotter, the choke will open more and the fast idle speed will drop appropriately as lower steps on the fast idle cam are used.
Enjoy!
CBODY67
Some may disagree with me, but the OP is still running points ignition which can be contributing to his problems.
With his difficulty finding a vacuum advance can, maybe its time to go electronic?
No more fussing with a dwell nmmeteras the ECU gives optimum dwell.
MY reason suggesting this is FBO has a tunable breaker plate where you can do your own " recurve"
Nothing wrong with points, but they are dinosaurs and have some limitations with todays corn fed pumps which need more initial timing and a hotter spark for a cleaner burn.
FBO Mopar Distributor Limiter Plate
With his difficulty finding a vacuum advance can, maybe its time to go electronic?
No more fussing with a dwell nmmeteras the ECU gives optimum dwell.
MY reason suggesting this is FBO has a tunable breaker plate where you can do your own " recurve"
Nothing wrong with points, but they are dinosaurs and have some limitations with todays corn fed pumps which need more initial timing and a hotter spark for a cleaner burn.
FBO Mopar Distributor Limiter Plate
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67 ragtop
Member
So far I have only driven it with 10 degrees initial and no pinging . It was also cold that day/ All I can get around here without alcohol is 87 octane.
Thanks for your info. If I could get 91 octane alcohol free fuel I would run it. I will probably go with 91 octane and just partially fill my tank unless going on a long run. E10 fuel is hard on carbureted cars if they sit.
No offense, but with today's gas you can toss the factree specs out the window.
Test, tune, road test. Listen to the engine, tune it to what it needs.
Thats why I recurve all my distributors or buy one already recurved.
Compared to facrtee specs, all my Mopars want more initial timing, a slower advance curve and the curb idle gets bumped up to 750- 800 to make the engine happy and make lots of vacuum.
Ethanol runs leaner so typically the carb mixture needs to be fattened up, the accelerator pump needs an extra shot of gas, and a hotter spark helps too.
67 ragtop
Member
I found 2 problems. The carb was flooding out the float was set wrong. Also I was wrong about the compression. the specks I gave were what I had 3 tears agao when I first bought the car .I have only put about 500 miles on it s o I assumed they were the same. I found the rich issue when I pulled the Pcv hose and the idle went up 1000 rpm. I checked the float level and it was 1/8 inch too high.
I adjusted the float and rechecked the vacuum it was still low but better. At least the idle mixtures screws were responding much better/ I then pulled the plugs and rechecked the compression, I am getting 120lbs cold on all cylinders + or minus 5 lbs. The plugs were all black but the gaps were all right some were almost fowled with soot. / the porceline on all the plugs were covered with soot. I have never see that in 60 years of working on cars. I am posting a picture of the plugs.
I haven't rechecked the Vacuum or timing as a storm drove me in after I got the last plug installed. That no. 7 plug was a real Biotch to remove and replace.
I was able to find a good used vacuum advance.
You can "drive the plugs" clean, get new ones, or knock the soot off of the ones you have. DO run a gap gauge through them to clean the contacts, though.
The compression might come back up when the cyl walls allow oil to remain on them, rather than being washed off/diluted by the rich mixtures.
Thanks for the update.
CBODY67
The compression might come back up when the cyl walls allow oil to remain on them, rather than being washed off/diluted by the rich mixtures.
Thanks for the update.
CBODY67
67 ragtop
Member
Thanks I replaced all the plugs. just because. I wiil clean the old ones and save for later, I still have a spark plug cleaner from the 60's'
I am going to put some sea foam in the tank as well.
Thanks for the update.
I discovered that the best way to cook=out carbon was to just drive the car. Not the 50 miles or so that some seem to like, but for 4 hours or so, or 20 gallons of gas.
When I started driving to Lubbock (which was 4 hours each way, back then), I noticed that our '66 Newport 383 would run just a bit better after each round trip. I was keeping it tuned and it was "to spec" in all respectes. It never ran rich and the spark plugs always had a tannish ceramic in them. Yet each round trip made things just a bit better as to how the engine ran and responded.
I really liked those trips as it gave me time to spend with the car. To better learn how it did things and how WELL it did things. All things not noticed on a normal freeway commute or similar. Much less driving around town all of the time. Plus listen to some far-off AM radio stations, too. Neat times!
Enjoy!
CBODY67
I discovered that the best way to cook=out carbon was to just drive the car. Not the 50 miles or so that some seem to like, but for 4 hours or so, or 20 gallons of gas.
When I started driving to Lubbock (which was 4 hours each way, back then), I noticed that our '66 Newport 383 would run just a bit better after each round trip. I was keeping it tuned and it was "to spec" in all respectes. It never ran rich and the spark plugs always had a tannish ceramic in them. Yet each round trip made things just a bit better as to how the engine ran and responded.
I really liked those trips as it gave me time to spend with the car. To better learn how it did things and how WELL it did things. All things not noticed on a normal freeway commute or similar. Much less driving around town all of the time. Plus listen to some far-off AM radio stations, too. Neat times!
Enjoy!
CBODY67
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