My 71 Duster work in progress

[69.5CUDA]

i wonder if the dizzy noise is the lack of anything hooked up to the tach drive?

 

[b-body-bob]

^ good point ^

It's junk to me.

 

[b-body-bob]

We put the timing light on it and revved her up, and the advance stopped at 20* around 2000 RPM, so it seems like I've got 10* or more advance already at idle. I knew I shouldn't have messed with that spring. OTOH it fires as soon as you touch the key so I've go that going for me.

 

[b-body-bob]

More good news. I'm filling out the title application and notice at the very bottom that they now require insurance to title a car where before you only needed it when you buy the tag.

248.37 for Hagerty for 10k.

 

[b-body-bob]

It just gets better.

1. The DMV needs more paperwork, this time from the hoarder nutcase who sold me the car. Can't wait to try to get that.

2. The NAPA part that crossed over to the vac advance number VC173 arrived today. It's for a small block.

It looks like the current part number for big block is VC-187 and VC-189 for small block.

 

[b-body-bob]

I finally got it tagged yesterday and put the original spring back in the distributor to see if that helps the limited timing. It got dark so I didn't get to check that.

It's supposed to stop raining this afternoon so I might get it out to see how everything is working now that it's almost legal (needs safety inspection).

 

[Dr.Jass]

We put the timing light on it and revved her up, and the advance stopped at 20* around 2000 RPM, so it seems like I've got 10* or more advance already at idle. I knew I shouldn't have messed with that spring. OTOH it fires as soon as you touch the key so I've go that going for me.

Which spring did you mess with? Did you try going to 3,000RPM and check the timing there? The Mr. G spring kit instructs one to install both of their springs on an automatic car, and only replace the heavier-wire spring for a 4-speed. Even with both light springs, 2,000RPM seems rather low for "all in".

It sounds like you're guessing about your base timing... why? If you're all in at 20°, you more than likely have base timing near TDC, possibly even a couple of degrees retarded from it. I've no way of knowing how much mechanical advance your particular distributor has, but I'll guarantee it's more than 10°--by a solid margin.

When I set total timing, I increase idle speed with the idle screw until the mark stops moving, then I wing the engine whilst watching the timing light. If there's any stiction in the advance, blipping the throttle a few times should both overcome it and show that you're not really "all in" yet. Only after raising the RPM absolutely does not change the RPM do I set the total timing, usually between 34-36°. I then turn the idle speed back to my desired RPM (or in the case of the Valiant, whatever the cam will let me) and check my base timing. Almost without fail, it will fall between 10-18° BTDC.

It should go without saying, but I'll say it anyhow for anyone else tuning in: Total timing cannot be set with the vacuum connected, nor should you even attempt it without a dial-back timing light. Either one of those rules is violated, you're just trying to urinate off the bow of a moving ship. You won't get the results you seek, you'll just have a mess.

2. The NAPA part that crossed over to the vac advance number VC173 arrived today. It's for a small block.

It looks like the current part number for big block is VC-187 and VC-189 for small block.

The current number for a '70 383 is VC173 per the Standard Motor Products website... so I started digging around in the OE book, based on the distributor numbers SMP lists. Most (if not all--I got bored) of 'em are Slant Six applications. Punching that number into my franchiser's Buyer's Guide, which is based on SMP's catalog information, that unit fits G, RG, LA, B, and RB depending on year--everything from the 198 to the 440. The same is true of VC187, though that picture looks right. Using our cataloguing, I came up with a VC188 based on a '74 Charger 400, which looks a lot like the VC187 though the canister is flipped in its photo.

This is an increasing issue with older cars. The vendors really don't care about 50-year-old applications, and the part-time college kids doing data entry for them have never even seen a distributor (or caliper, or ball joint, etc.). I typed in the OE 1970 number (3514330) from that year's Mopar parts catalog into the Chrysler system, and it supersedes backwards to 2875754--which is for a 1969 440--and crosses to exactly squat in the aftermarket. The '70 number brings the same result, if you don't count the Bilstein strut.

If there's a major difference between the VC187 and VC188, it's the amount of vacuum they'll ultimately pull. The VC187 appears to be stamped "9L", which means it'll pull 9° of timing and is for a left-hand rotation. The VC188 photo doesn't clearly show a stamping, but zoomed as far as I can get it I think I can make out "11" (I even manipulated it in Photoshop but I'm not 100% sure). If that's the case it would provide an extra couple of degrees of advance in high-vacuum circumstances like highway cruising. Either unit should be adjustable for rate/threshold via an allen wrench through the vacuum nipple.

1. The DMV needs more paperwork, this time from the hoarder nutcase who sold me the car. Can't wait to try to get that.

I'm not sure what they need, but if it's just a bill of sale one could fabricate that pretty easily. "Hey, babe... how do you feel about role-playing? No, not that kind. Well, not at the moment anyhow... perhaps later. I need you to pretend you're the psycho that had the Duster and fill out some stuff." It worked on at least one car of which I'm aware and may or may not own.

 

[b-body-bob]

The DMV needed an official document making her the administrator of what was left.

I swapped out the one spring back to factory and even though I marked the location at idle it was 10* lower or ~5*. Then we revved it up, and it stopped at 20*, which I guess makes sense since the limit is mechanical so it should be repeatable. I will probably swap the distributor for the one in my A12 to prove to myself I'm not losing my mind.

It is absolutely gutless and barks the tires on every 1-2 shift. I'm working up to feeling comfortable enough to take it to a trans shop.

IMO the carb's way too big and a double pumper on top of that so I'm considering purchase of a used 3310 to set up but am hesitant to spend money before I'm sure the thing's not going to show it's puke the crank out in a week or two.

 

[b-body-bob]

I think I'm going to put a different box on it to see if there could be something wrong with it. If no change, I'm planning to pull the known good distributor out of the road runner , install it it in the Duster, have Gina rev it up to 3500, and set it at 35*. That will eliminate the ignition as my problem.

 

[Dr.Jass]

I'm not surprised it's a dog without vacuum advance and with only 20° of total timing.

Yes, your results should be repeatable... but cars are funny things. The very first time I actually bothered to set total timing on the Valiant, it showed 24°BTDC base timing with the total @ 36°. That's how it was set for several months. When I started futzing with it this spring, apparently in search of world-record initial timing, things changed even though no parts did. I don't remember exactly where it landed but after a lot of monkeying around with and without vacuum, if memory serves I was quite a bit closer to 14-16° base. I know it was under 20; I have so many numbers flying around in my head from that time I can't nail it down.

In your case, if you've got a vacuum advance pickup plate but no canister installed, you can't set timing. You don't know where the pickup plate is sitting relative to the reluctor, and its position can change from the vibration of running the engine. You're trying to hit a moving target. Though they're separate mechanisms, if the pickup plate is positioned 10° advanced, the timing will stay at that position until the flyweights catch up to and exceed that number. Even though I went through my distribuor completely, it's possible my vacuum-advance plate was sticky from sitting and simply worked itself loose after many, many trips up and down the RPM scale.

Don't go crazy swapping parts until you've both installed the vacuum advance and put some actual timing in it. Don't worry about the actual initial number so long as the car will start normally while at operating temperature. If you've got 18° and the car starts OK, so be it. It's not going to knock at idle. I've told the tale often, but it bears mention again: Other than hard starting while warm (and even then, only in hot weather) my Trans Am ran perfectly with 24° base timing. It ran even better with 26° but hot starts were out of the question. Yes, it was a Pontiac but it was also a 400, ~9.5:1, with a Crane Fireball II cam (292° adv, .454" lift)--far from wild, but it sure loved a bunch of timing. The subsequent owner backed the initial off to something like 10° and the car was a total pig by comparison.

While it's on my mind (due to a completely-unrelated car) did you ever take the intake manifold off and re-seal it? I think we've already covered the known problem of intake-manifold vacuum leaks, particularly if the paper gasket facings that come with the single-use turkey pan gasket are installed. You'll never get the combination nailed down in terms of timing, idle mixture, and jetting with a vacuum leak. I speak from experience here: although it's a small-block, this was one of the problems I was having in the spring. I didn't know about it until disassembly, and it shouldn't be an issue on reassembly because I've got brand-new heads this time (intake was new both times). It's also something I dealt with on my 440 Six Pack engine until I learned to do it the right way. Trying to tune around it will drive you insane.

 

[b-body-bob]

I have not pulled the intake. I haven't even pulled the carb other than the front bowl, but I'm about to. I do have a can of ether but haven't sprayed around the intake/head surface yet either. I didn't check it today but yesterday it was holding 5" vac at idle, which is sort of suspect. I just haven't gotten to it yet.

I put a chrome box on it that I had, didn't get to rev it up since it's noon on Sunday to check the advance but set it at 15* and set the idle then checked the mixture screws and they're still not working so the carb is coming off so I can put a kit in it and check everything.

The main problem I found is that I tried to work the secondary pump by hand, and instead of pumping fuel it leaked instead. I take that to mean the circuit is clogged up. That will be corrected while the carb is apart.

ETA Here's why my first inclination is to not shop local. Here we have Autozone, Advance, O'reilly, and NAPA, none have a rebuild kit on the shelf. I've got one with the front bowl gasket and the front pump used out of it so I might be OK but wanted to see what was available if I needed. The answer was as I expected - nothing is available.

 

[69.5CUDA]

hate to say it, but theres alot of parts no one stocks any more, thats just the reality no matter where your at, however, its amazing what most stores can get next day

 

[Dr.Jass]

Not that I don't believe you, but I find it hard to comprehend that nobody stocks a Holley kit. When I worked at Advance, we stocked at least two (one for vacuum secondary, one for mechanical) and I put two similar, but more-expensive and far more complete, kits in stock at my old store.

I don't know about your NAPA, but O'Reilly/Advance/Autozone are corporate-owned and largely staffed by McDonald's refugees. Asking for a Holley kit is like asking them for a chicken leg... if you don't have a year/make/model and it's not a steering-wheel cover or air freshener, they don't have it. 99% have no idea what a carb is, much less a Holley. I'd make even odds that at least one store had it but nobody knows what it is. Sad... us parts guys are a dying breed.

 

[b-body-bob]

I'd make even odds that at least one store had it but nobody knows what it is.

I looked it up. Holley website for the kit #, then searched all the sites for it. All of them offered the kit to order, but I can do that without their help. But it doesn't matter since I didn't need any parts after all, the partial kit had everything I needed in it. I blew out the secondary shooter passage and also popped something out in two other places so it's gotta work better than it was.

I've still got idle problems, and only 5* of vacuum so the 6.5 PV is open all the time. I sprayed it down with ether and it seemed to want to kill the motor where I expected it to speed it up, but it did have an effect.

At least I'm not working under the car on my back now.

 

[Dr.Jass]

I looked it up. Holley website for the kit #, then searched all the sites for it.

The kit number we stocked was a 37-1544 "Fast Kit", which covers all square-bore mechanical-secondary carburetors but is listed as the kit for exactly none of them. The "popular" double pumpers (477x-4780, etc.) list the 37-485 as their specific kit, but the 1544 works perfectly and covers more applications.

...it doesn't matter since I didn't need any parts after all, the partial kit had everything I needed in it. I blew out the secondary shooter passage and also popped something out in two other places so it's gotta work better than it was.

The check ball beneath the discharge nozzle was probably stuck from sitting.

I've still got idle problems, and only 5* of vacuum so the 6.5 PV is open all the time. I sprayed it down with ether and it seemed to want to kill the motor where I expected it to speed it up, but it did have an effect.

Your PV isn't open. That's not how they work, which I only recently discovered while consulting with those better-versed than I. Before dealing with those guys, I was sure that my sketchy vacuum meant a 6.5 was too high, so I replaced it with a 2.5. It changed exactly nothing. When I did consult them and mentioned that, I was told the PV is functionless at idle. There's not enough airspeed through various bleeds for it to do anything, unless the diaphragm is torn allowing fuel through it. I also learned that the standard described methods for choosing a power valve are all bunk (x inches less than a particular vacuum reading, be it idle or cruise). I'd have to go back and find it now, but it's totally dependent on the transition from part-throttle acceleration to the actual power circuit, the latter of which is the only time the jets do anything. At cruise, they do nada. Worry about that stuff once it's idling and driving OK.

Do your idle mixture screws have any effect on your idle vacuum? I'll bet it's not as much as it should be, which along with the excessively-low idle vacuum would tell me it's time to pull the intake for a new gasket. If it's leaking, it'll be on the bottom side, likely directly from the lifter valley... which makes it nearly impossible to check with the ol' ether/carb spray trick.

Of course, check to make sure the carb is tight to the manifold. I've run across a lot of engines with loose carb fasteners in the last year... very strange. Stranger still, none were mine.

 

[b-body-bob]

The kit number we stocked was a 37-1544 "Fast Kit", which covers all square-bore mechanical-secondary carburetors but is listed as the kit for exactly none of them. The "popular" double pumpers (477x-4780, etc.) list the 37-485 as their specific kit, but the 1544 works perfectly and covers more applications.

I searched for 37-485 yesterday but just checked 37-1544 and it's "call the store to order" at Advance and Autozone, and Oreilly's says it's out of stock even for ordering.

The check ball beneath the discharge nozzle was probably stuck from sitting.

No ball, only the needle. That was stuck. 30 PSI wasn't enough to pop it loose, 100 PSI was. I've got old balls (in more way than one) so I can put one under the needle but I'm pretty sure it isn't needed.

Your PV isn't open.

Good info on the PV, thanks.

Do your idle mixture screws have any effect on your idle vacuum? I'll bet it's not as much as it should be, which along with the excessively-low idle vacuum would tell me it's time to pull the intake for a new gasket. If it's leaking, it'll be on the bottom side, likely directly from the lifter valley... which makes it nearly impossible to check with the ol' ether/carb spray trick.

The idle mixture screws actually make the car run better when they're screwed in because the primary/secondary circuits kick in. To get the idle speed fast enough, the butterflies are open too far exposing the transfer slot. I've got to take it back off and tweak the secondary butterfly adjustment so I can close the primary butterflies to cover transfer slot AND get enough air into the carb for the engine to run. There's an adjustment on the secondaries but it's been so long since I messed with a carb that I forgot until I started searching so it's gotta come back off.

Once the idle circuit is working correctly, I expect the intake is going to need to come off for a new gasket.

Of course, check to make sure the carb is tight to the manifold. I've run across a lot of engines with loose carb fasteners in the last year... very strange. Stranger still, none were mine.

It's tight. There's some sort of spacer on top the manifold that I probably should've replaced the bottom gasket on but I didn't remove it and just slapped a new gasket between it and the carb.

Given the choice between loose fasteners and a snapped ear on the base plate, I'll take the loose fasteners every time.

 

[69.5CUDA]

Sad... us parts guys are a dying breed.

sadly your right
my last good guy up at orielys whos been there forever and was previously a diesel emergancy tech who basicly was a drop everything fly/drive to go fix it, from tractors to oil rigs, just retired, he could find stuff i figured couldnt be found

 

[Dr.Jass]

No ball, only the needle. That was stuck. 30 PSI wasn't enough to pop it loose, 100 PSI was.

I've seen Holleys configured with a ball, a needle, and both. I just put them back together the way I found 'em. As long as it keeps the accelerator-pump passage from draining back to the bowl, it's fine.

I've got old balls (in more way than one) so I can put one under the needle but I'm pretty sure it isn't needed.

Don't we all. See above.

The idle mixture screws actually make the car run better when they're screwed in because the primary/secondary circuits kick in. To get the idle speed fast enough, the butterflies are open too far exposing the transfer slot. I've got to take it back off and tweak the secondary butterfly adjustment so I can close the primary butterflies to cover transfer slot AND get enough air into the carb for the engine to run.

It should not require that much throttle opening to idle. Mine would idle without exposing the transfer slots, with stupid-huge ports and a comparatively-wicked solid cam. I also managed to get almost 10" of vacuum out of it.

Before going any further, get the total timing squared away first so you have a known quantity for idle advance. That's crucial. Any juggling of the timing later will require further adjustment of the mixture screws. Make sure the vacuum advance is disconnected and its port plugged on the carb.
Next, re-baseline the carb and start over. Set your mixture screws 1½ out from seated if it's a two-corner idle, or ¾ if it's four (that's an important distinction). Start with the idle speed screw a full turn past initial contact. Do not fiddle with the carburetor at all until the engine is fully warmed up to operating temperature, which should be whatever thermostat you have installed (mine is 180°). If you don't have a thermostat... what are you thinking?! Install one before you proceed. You will never get it right without consistent engine temperatures.
You'll almost certainly have to feather it for a couple of minutes to get it up to temp. Once there, set the idle speed screw to an RPM at which it will stay running; 750-800RPM should not be a problem with your (assumed, and probable) combination. Watching your vacuum gauge, move each mixture screw until you obtain the highest consistent reading, then move to the next one and do the same. If you start to gain a bunch of RPM, back off the idle speed screw to regain your initial setting. Continue fiddling with the mixture screws until you obtain the highest vacuum reading, juggling the speed screw as necessary to maintain your initial RPM setting as you go.

Now, re-seal the intake manifold and start all over, because if that's leaking you're simply riding a rocking horse: Lots to do but you're not getting anywhere. I got my combination as good as I could, and it wasn't good enough. Guess what? My intake was leaking. Massive oil tracks up the cylinder-head side of the gaskets, plus oil in the ports. You'll never get the idle mixture right when the engine's got a steady diet of oil vapor and unmetered air playing hell with the carb circuits.

I've got to take it back off and tweak the secondary butterfly adjustment so I can close the primary butterflies to cover transfer slot AND get enough air into the carb for the engine to run. There's an adjustment on the secondaries but it's been so long since I messed with a carb that I forgot until I started searching so it's gotta come back off.

I don't think that's necessary for your particular combination either, but that adjustment is a pain in the ass either way. Stock up on gaskets, or get yourself one of these. It replaces your secondary accelerator-pump cam bracket and moves the secondary idle adjustment topside. Even if you never need it, it's nice to know it's there. Since my intake was leaking I can't truly say whether I need it, because the success I was able to get was achieved with it backed off completely... but of course I had a bunch of unmetered air entering the engine too. Regardless, I consider it $22 well-spent. In fact, I bought one for my 4780 and my Demon as well. 'Tis only money.

Once the idle circuit is working correctly, I expect the intake is going to need to come off for a new gasket.

The idle circuit will never work correctly with an intake leak. That was actually carved in stone on the third tablet of Commandments of the Lord Jehovah, which Moses dropped and broke.

Given the choice between loose fasteners and a snapped ear on the base plate, I'll take the loose fasteners every time.

Flattery will get you nowhere. Use a thin gasket and you'll never have a problem. I never did. Trying to make that pillow of a gasket with, ahem, "torque limiters" work was the worst-yet idea I've had regarding the Valiant (which is really saying something considering my decision to use experimental heads). Sad that it was a genuine Holley gasket, but it probably helps them sell a lot of baseplates--which are much more expensive.

 

[b-body-bob]

So I was thinking since I have the carb off, it's not a huge deal to go ahead and redo the intake pan/gasket since I have the parts on hand. Then I realized what I've got is for a 440 and won't work on a 400. Then I found out that's another thing that my local parts stores don't carry.

If I've gotta wait 3 or more days on one, I'll go ahead and put the carb back on it to see if cracking the secondaries helped with the transfer slot / idle speed dilemma. If it still exposes too much of the slot, then I'll order a kit and wait.

I also need to replace the fan with an electric setup. It's a flex fan now, so that has it's inherent problems but also the engine is sitting high so the fan is nearly to the height of the radiator cap so there's no shroud on it, and it's kind of tense working around the front of the engine when it's running.

 

[b-body-bob]

I've got 12 inches of vac and working mixture screws now.