My 71 Duster work in progress

I changed the vac gauge for a cheap mity vac gadget, so it's got a release on it. With the engine running the needle barely moves, and if it wasn't for the release, you could convince yourself it's not moving at all. I could connect the vac advance to manifold vacuum and it wouldn't make one bit of difference. The gauge is connected to manifold vac that is open to the manifold with no blockage or hose problems. I checked because I was gob smacked at how little vacuum it has.

The car idles better than it ever has though, so I guess it's got almost exactly how much vac it needs to feed itself. FWIW I've got the idle speed just under 1k with the engine warm.

Revving it up I saw it shoot up to 20. No idea about the RPM because I can't see the vac and the tach at the same time. With the idle vacuum such as it is, it doesn't really matter.

I bumped the initial advance to 30. The idle speed increased, the vacuum didn't. I didn't keep going. I didn't want to start chasing ghosts caused by manually advancing the timing that increases the idle speed causing the mechanical advance to advance the timing more, then when I decrease the idle speed it slows the mechanical advance and retards the timing. I'm unsure how to take that out of the equation.

I don't even like thinking about the hell that could be wrong (rings/valves/cracked head) but at the same time I don't know what could cause this and not have other symptoms. I'm kind of left with it being a symptom of the camshaft and a need to dial that in. I'll say it one more time - if I have to pull this motor it's not going back in. I would like to get it running good enough to get some ice cream before replacing all the parts that I haven't already replaced ...
 
i think docs method takes into acount an "unknown" carb setup and wild cam both and allows you to adjust based on what the engine wants so you can dial the carb back down to reality as you can litteraly screw a carb up so much that the timing has to be wacky as all get out to get it to run..

doc i think that method was close too but i feel like its missing something
 
At this point I'll try almost anything.

The only thing I haven't done is replace the carb baseplate gaskets (1 under carb, 1 under spacer).

I'm just doubtful there is going to be a fix for the lack of vacuum that doesn't involve tearing the front of the engine off, which involves the elephant ears, which involves a cherry picker in the way. Chances remain good that it has other problems too.

Not to get ahead of myself, but I started adding up the numbers to buy/install a small block and a 4-speed. Ouch.
Engine only
Mopar 408CI Stroker Crate Engine | Small Block Chrysler | Drop In Ready | Roller Cam
I've got a trans, shifter, bellhousing, fork, z-bar, and flywheel that came with the car. Not sure if any of it is ready to use or will work together. Assuming it will all work, add about another $2k to finish it up.

The cost only goes up from there. Fully dressed with an auto trans would be the route of least hassle
BluePrint Engines Builder Series Mopar 408CI Stroker Crate Engine and 727 Auto Transmission | Small Block Chrysler | Roller Cam | Black Front Accessory Drive
 
fwiw chrrypiccker not needed, a nice chunk of 2x6 on the oilpan and a jack will happily support the engine without crushing or even denting the pan, if your really worried about it tho you can use a 2x8 or longer 2x6 stretching all the way to the trans bell and another couple blocks allowing the jack to be further back, its not like the engine gotta come out you just need to set it loose from the ears, its the same method ive used several times to swap k members with engines in place...ive done the blocks under headers before with success for pan jobs..but you have to be certain that the exhaust isnt thin so i dont reccomend it
 
I had been thinking about trying to hang it with a support across the inner fenders. I've seen that done at the back end of the engine. A jack would be simpler. I wasn't sure it would catch the pan in the right place to hold the front of the motor up.

I think first I need to figure out if there could be something else causing it. There's no reason to spend time monkeying around with the timing if the engine's shot.

On the happy homeowner front - I heard a water leak under the house. Turned the water off at the meter and it's silent. At least I bought one of those water line repair insurance policies when the copper started to spring leaks. The problem is waiting on the plumber to get out here to work on it.
 
I found a compression gauge but it's sort of impossible to get the adapter installed because of the hose and everything around the motor. I got it to work with #1 and #5 so far, 120 and 135, and I should've looked closer at #1 before taking the adapter off. But, I'm already outside the 10% difference after just two holes. I'm going to take a trip to Harbor Freight to pick up a tester with a universal adapter (a steel tube with a big rubber end on it) and see if that makes it any easier or not.

I'm not sure what the psi tells me in about the vacuum, if anything, but maybe it will give me some confidence in the engine before moving on with repairs - or rule it out.

The home water line people emailed me at 5 to let me know they arranged for a plumber on Tuesday afternoon. Boy that made me happy. :mad:
 
I am going to pickup a different compression tester tomorrow, but until then I started thinking what will happen if it turns out the engine is worn out?

First I reached out on FABO to find out that a Blueprint small block has a 10 month waiting list. Noped right out of that. Plus wow the price. I was looking at between $13000 an $15000 to start down that road.

Then I realized I've got a 440 and a real nice transmission sitting right next to it in my A12. It ain't number matching anyway, and I could use it if not for the hassle of the big motor in the small car. Then I read some more and found out it'll cost about a grand to get rid of the elephant ears and alleviates any nightmare header scenarios.

mounts for a LA k-frame to B/RB
https://www.hedman.com/product-detail/4698
and some fancy headers
Big Block Tri-Y Under Chassis Headers

According to Schumacher's website, they only have the more expensive coated ones in stock $850!!! That's the same price as uncoated/painted TTIs but they work with PS and don't capture the starter. There's a limitation on how far you can go with them performance wise, but that motor doesn't have 500 HP anyway. Plus the ease sounds worth it to me.

The 440 has a 509 cam, cleaned up heads, .030 over w/forged pistons and crank. I bet it was lighter than my Duster and ran 11.70s / 7.20s.

The trans currently has a RMVB Cheetah with no LBA, but I've got a Coan RMVB with LBA on the shelf for it. It's also got a super sprag in it, so I'm trying to be *almost* as safe as I can WRT a drum explosion.. There's a blanket on it too but that ain't going to fit in the narrower A-body tunnel. Plus could be too much heat in street duty.

It's been seen before - it's the one I was working on in the photo where I used a wheelbarrow as a trans repair stand.

I hope it doesn't come to that - it's a lot of heavy work. But I was thinking even if the motor that's in it works out I might buy the mounts and headers to get rid of some headaches in the off season.
 
I checked the vacuum at the PVC and got a better reading. It's also a different gauge - on a mity vac that I also used to test the other gauge and found it's off by about 3 inches.

It wants to idle in two places - 500 and 900. When its idling at 500 the timing is 15 and the vacuum is 6-7, then I rev the engine and when it settles down it's at 900 where the timing is 23 and the vac is 11-12.

It did that and I let it run until it eventually started idling rough like it was running out of gas and the timing went back to 15* all on its own.

Apparently the mechanical advance is sticking.

Also no matter how many times I tested the fuel gauge , the sender, and the wiring, and it should have worked it does not. I put 8 gallons in it yesterday and the gauge says empty. I'm just going to get an aftermarket gauge that will at least tell give me an idea of the fuel level..
 
First and foremost, on the timing/tuning situation:

S.F.G. on another site said... said:
A test to see what the engine wants for idle timing for highest vacuum, is keep advancing the timing, while having a vacuum gauge attached to manifold vacuum. As you advance the timing, the vacuum will increase as well as the idle rpm. Lower the idle rpm to keep it the same during the test. Advance timing, lower idle, look at gauge. Keep doing this until you don't see a gain in vacuum. Then see what the timing is at idle. That value is then your goal. The more vacuum the engine makes, the more efficient it is running.

Only once that is done should you proceed with tuning the carb.
Click to expand...

More than one guy on that site was adamant about the "timing first, idle and cruise tuning later" aspect, particularly after I'd mentioned my own "hang" at 1,100+ which would eventually work its way back down to 800-900RPM. It was suggested to live with the resultant idle timing and make adjustments on the big end,limiting mechanical advance if necessary. It may or may not be depending on vacuum signal at WFO. Yes, it drops to zero instantaneously but on many engines it starts climbing again after that.

Also worth asking: Are you letting the engine get fully up to operating temperature before you try anything? If it's not at the typical temperature at which it'll be running, you're just pissing windward. Things are dramatically different on a cold/lukewarm engine--including a compression test--as compared to everything hot and thermally expanded (especially the pistons).

Which brings me to my next question, which may have been asked: Does the factory temperature gauge read correctly, if at all? The reason I mention it is because if not, it's very possible the voltage limiter has gone open circuit. They're notorious for failing, which is why I spring for the RTE unit for every car I can (the Imperial doesn't have one). The only two things in your dash that operate off the voltage limiter are the temperature and fuel gauges; the oil-pressure gauge on cars so equipped does as well.

110 is relatively low, yes, but that number is directly related to the camshaft, too... and the only way we'll have an idea of what's in there is by checking lift and duration with a dial indicator on a lifter and a degree wheel. However, the 11" at 900 is encouraging.

While the 440 is a proven performer, I'm not 100% convinced it wouldn't compound your headaches since the 440 is wider than your low-deck. I'm assuming the current headers won't work for some reason, which of course brings in the big-dollar units for an engine you still may not keep in the car. I will say that personal experience tells me the Trans-Dapt adapter mounts work well; in my case a 1/8" shim was needed for header clearance on the driver's side--the header was just touching the (manual) steering gear. On the other hand, they'll apparently give you cancer. So there's that.

I'm not sure where the impetus behind a $13K engine for a mild street driver comes about. I assume that's a turn-key forged-everything stroker motor; you can make very similar power with a stock-stroke 360 done right. It doesn't have to be a beast to drive, either. I don't see the value in a 400+ inch engine unless you're going to pop the extra for "exotic" cylinder heads (offset intake rockers, special intake) since the standard LA-pattern heads all run into the same brick wall: the intake-port pushrod protrusion. Having W2 heads coming out of my ears makes me an ideal stroker candidate, and still haven't wandered into that territory. For the little I did drive the Valiant before the valvetrain debacle, it seems eminently streetable for a fairly-large solid roller cam in a small engine with an 830 carb and single-plane. In my estimation, strokers were overhyped by magazines working to sell their advertisers' parts, much like hydraulic roller cams and hypereutectic pistons--neither of which are a worthwhile idea.
 
The engine is warm for the vacuum checks. It was not for the compression tests.

I get confused on setting the timing because at what point does the mechanical come in and start messing around. I had both light springs in the distributor from the Mr Gasket kit, I changed it to one light one from the kit and the original one with the big loop and the weird idle activity seems to have gone away.

I don't know what the deal is with that front vacuum port and why it doesn't give a good reading. I wrapped tape around a piece of vacuum hose and stuck it inside a larger hose and then wrapped that with tape for the PVC outlet. Good enough.

The 440 would depend on replacing the headers for sure. I can't find out if the Schumacher headers fit as good as claimed though. The ones on the car now are beat all to hell to get them to fit. I'd run factory manifolds before I'd go through that hell.

That 10k engine is a stroker smallblock with Eddy heads, 465 HP each one dynoed before delivery. Apparently they can't get cams so they can't finish engines and all the crate engine companies are in the same boat. I guess I could put an LS in it :devilish:

It's still got a terrible off idle stumble. The accelerator pump is adjusted right and working. A little reading makes me think the pump nozzle should be bigger. I checked the two double pumpers to see if I could rob one there and found those are both way smaller than the one on my vacuum carb. I guess that makes sense give the DPs have two of them.

It still gets hot. I've seen it above the boiling point, of course it's under pressure so that's not fatal but I also don't know if it will go higher yet or not. I would switch back to the flex fan but I know that won't make any difference. The fan is pulling plenty of air through the rad based on a "does it suck a rag" test. It really needs a shroud to have any hope of keeping it cool.

I had a weird thing happen while driving it Saturday. I went around a right hand turn from a stop, and it felt like the left rear tire was loose. Kind of like it had rolled over it sideways. I was almost home and I didn't see it laying in the road so I limped it on in. When I checked it yesterday - nothing wrong. Maybe it's the differential breaking in, maybe it's the kind of diff it is, I don't know. I would have to search to figure out what it was built with. I thought it was one of the helical ones but those are pretty expensive so I kind of doubt it. It was supposed to be all new parts other than the housing and case though.
 
Reset the timing as described above before you worry about anything as obscure as pump shot. Until the idle is tuned--and you have to get the timing right first--you're just chasing your tail. Chances are very good that on a mild engine, the pump setup is very close if not spot-on. This is also true of the jetting.

Here's the issue: Despite widely-held belief, Holleys do not use the jets at cruise. Virtually all normal driving is done on the idle and transfer circuits. Period. Jets, boosters, and power valves have no effect on idle performance or cruise mixture. You can't shoot at multiple targets at once. Time the engine, then get the idle mixture set with a vacuum gauge. Only then can you worry about the other "problems" which, by then, may well have disappeared entirely.
 
I'm trying to set the timing by vacuum and it's not making a lot of sense. I had it all the way up to 50* before the idle speed stopped climbing. I've got it back down to 34* now and it revs off idle a little better but it's still not right. I don't know how the hell I'm going to set the distributor up for that though. I guess just put one light spring in it so it pulls back until the engine fires, then set it to 34 at idle and that's it.

It didn't have any trouble starting at 34* with temps at about 180. I shut it off to come back in here and try to figure things out both with the car and with the HF tach that I bought. That thing is making no sense at all. The instructions say to multiple the reading by 10 but that ain't right. It shows 9-10 where it's idling and there's no way it's idling at 100 RPM. It makes sense if I multiply by 100, but then 3 digits is way above the high range (10k). I probably should've read the damn reviews. Just about every one complained about the tach for doing exactly what this one did.

Of course my in car tach isn't helping things. I don't think it's anywhere close to right either, but at least it's old so it's got an excuse. I've got an AutoMeter out of the A12 but that thing's so big I'm not sure where I can put it.
 
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Were you doing this with the vacuum advance connected to manifold vacuum, ported, or straight mechanical advance only? I had similar results when I didn't connect the advance canister to full manifold vacuum. I reached 60° initial, yet amazingly the car started great @ 180°+heat soak on the aftermarket gauge. I never did get mine sorted out since that's where I was when I discovered my valvetrain was on the verge of catastrophic failure. It's been apart since then.
 
Vac advance was disconnected. So the idea is to add timing untili max vacuum with the vac advance connected to manifold vac, then connect to ported vac and that is my initial? I can give that a shot to see how it works out. That would definitely bring the initial timing back down to earth if the vac advance has it pulled out an extra 20*. OTOH if 50 is the max, that brings it back to 30 and I've tried it there with no joy.

Part of me keeps going back to the distributor that came in it, that was at full mechanical advance as soon as the engine started. I replaced that because of the funny clicking noise before I got to the point of setting the timing to 34* at idle.
 
I just noticed my distributor had the reluctor clocked for a small block. I don't remember having the roll pin out. The distributor came to me used so who knows, but it runs differently now. Time to start over.

I have noticed that the mechanical advance seems to come in too much at idle. It does not advance with the increasing engine speed, but if I rev it high enough if advances more. No idea what RPM that happens at, doesn't really matter. Right now it's got a Mr Gasket spring from the kit and the factory spring with the big loop. I think that the Mr Gasket spring is too light, and the factory spring is too heavy. Could be wrong.

Still no manifold vac on the front small port. It is built together with a large port next to it. The large port has vacuum. I can blow on the small port and hear air passing through the carb so it's open to at least the venturi which should mean it's open to manifold vacuum. I can also suck on it and it is not blocked. I don't understand it. I need to pull it off to set how much transfer slot is exposed so I will check the vacuum port again.

I took the A12 distributor out, which prompted me to notice the mis-clocked reluctor. It is set up with one light spring only with the mechanical advance limited to 20*. So basically at any speed above idle, it's going to be at or on the way to max advance. Makes sense for a drag race setup.

I made a half-hearted attempt at getting the top shaft out of the distributor to see what I can figure out about the 4 seconds flat limiter plate. I was working with that in place before when changing the springs. It's not the easiest thing to do that way. I couldn't get the clip out. I had a hold on it with a set of hemostats and the "ears" were pinched together but no go. I also wonder how you know what way it goes back together, or if it it is keyed and will only go back together one way. As part of that I noticed the reluctor, so I just put it back together for now.
 
Today I took that factory spring out - it was basically a valve spring. Way too heavy and with the big loop the lighter Mr Gasket spring was going as far as it could at idle speed and that was it.

I replaced the factory spring with the purple 2nd stage spring out of a Mallory kit paired with the Mr G spring. Getting that clip out of the distributor was great fun but it should be easier the next time. The breakthrough came when I realized I needed to spread the ears, not pinch them. I've got a serious case of CSS to go with my CHS and CRS. I marked the lower shaft and the position of the upper shaft before taking it apart, then realized it doesn't matter which way it goes back together because it's the same either way. I chalk that up to my case of TTDM.

I set the timing to 22* and limited it to 12 with the 4 seconds flat plate so 34 total. Put it back together and wonder of wonders I've got actual advance now. Pretty sure it topped out before 3k but oh well. The paper with the Mr G spring kit said with one of the kit springs and the factory light spring it should be all in at about 2400. That seems about right judging by my ear tach.

The manifold vac port is still acting goofy, today it had a wee bit of vac, just an inch or two where yesterday it had zero. The one next to it had 10. So that's still confusing but probably doesn't matter. I checked the vac advance and it doesn't start moving until 25 inches. I don't know if I'll ever see that but I'm going to hook it to the ported vacuum and forget about it.

The engine still has a little sag but it definitely runs better now. Maybe I'll work on that some over the weekend. I may slap the 850 DP back on it to see if that makes any difference. It's raining so I might not get to road test it until next week.
 
Replaced the .032 accelerator pump with an .035, doesn't seem to have helped much. The engine does run better now though.

I looked around some and it looks like a factory shroud will work now that I've put a normal size fan on it. It's $200 for a repop. If I knew it'd make a noticeable difference I'd have one ordered already.
 
I finally got to take it out for a short spin. It does run better, and it does get hot (>210). Checked things with a infrared thermometers, confirmed the gauge is right, that the top hose is hotter than the lower one and the tank is hotter than both.

Wondering if the transcooler mounted an inch or two away and in front of the rad could be influencing it (unlikely) and if a repop factory shroud would fit with the fan that's on it.

It seems to have some rocker sounding noise, not clicks and clacks but more of a rotational sound. I'm not too worried about that yet. Eventually I'll listen with a stethoscope.

I noticed the fuel pressure used to bounce between 6-8 idling in the garage but just now it was a touch below 6, which makes me wonder if the pushrod could be wearing.

Also I filled the tank and the gauge still reads empty so it's not a difference in scale. It just doesn't work.
 
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