outofspec

I agree Mike, all I meant to say was that what appear to be the correct parts are there, it's clearly messed up, and I appreciate you guys helping me fix it because I'm in over my head.
Frankie, appreciate the tip, and the link, on the hot idle compensator. Never knew it was there, but I'm going to find out about it. My rebuilder has been around for 50 years. The son is at it now. He's the only guy in the area. He cleaned the carb, but didn't polish for show. Regarding the cotter pin on the accelerator linkage rod, I don't know what the IIRC is, but it must supersede this lousy 1963 AIM I have. The AIM clearly shows a cotter pin on the carb side and the spring over the bend in the rod. Looks like page C134 in my book. Not sure if all AIM's are the same, or are subject to edit??
Thanks again fellas! I hope to get some wrench time tomorrow.
Frankie, Just reviewed the PDF information you provided.. it's excellent. Thank you. Very helpful. Wondering if it's from the book you suggested. I found the book on eBay and I'm getting it.

sjhanc

If you detect a low/fluctuating manifold vacuum reading at idle/off idle always check the valve to valve guide clearance first before attempting to tune distributor/carb. Small block chevy engines/cyl heads have been delivered BRAND NEW with excessive valve to guide clearance since the 1960s. A combination of High performance camshaft and excess valve guide clearance causes stalling, hesitation, and seems to have clutch chatter. This condition is not AS noticeable if the car has an automatic transmission.

Unacceptable valve to valve guide clearance is greater than .002 in. intake and .003 in. exhaust. If the valve seals are good no smoke will be observed, however, the excess clearance will allow the valve heads to 'WALK' on their seats and combustion gases will leak back into the intake manifold, contaminating intake air, and causing poor idle characteristics that can't be 'TUNED OUT', no matter how good the mechanic is. I have seen over-advanced distributor timing and high idle speeds set by mechanics to attempt to get the engine to run faster than the recommended idle speed. Some of these 'TUNING FIXES' resulted in serious engine damage to pistons/rings and in one case, a broken crankshaft.

In other words, fix the Vacuum problem FIRST, then tune it.

Frankie the Fink

IIRC is If I Recall Correctly shorthand. I'll let Rich Yanulis or somebody speak to the return spring to carb attachment...but I think I'm right on that. My AIM doesn't show a cotter pin (at least not for the base motor anyway)... There was a rather lengthy thread on this about 18 months ago with people owning original cars chiming in...

I resisted doing it the way shown, but resistance was futile, I was assimilated...

outofspec

SJ - I see what you're saying, and I really hope that's not it. I just had the heads rebuilt, including all new; guides, valves, and seats. If these other measures don't cure, I'll have to consider it. As you stated, the vac is the first hurdle.
Frankie, IIRC, LOL. I thought it was some kind of restorers society and documentation that I didn't know about. The only reason I went back to my AIM to check was that I remember staring at the image in disbelief, as I was putting things together, when I saw the cotter pin, because it seemed like such a goofy way of doing it. Putting the spring in the hole makes more sense. After looking at the pic of your carb, I see why you thought mine looked suspect. That's beautiful! I certainly don't want to hijack my own thread, but attached is the pic from my AIM. The only reference I could find in the book. I'll nose around for that thread you mentioned. I need to get some of this testing done. Truly appreciate the help!

Frankie the Fink

Before I got all medieval on your engine internals I'd continue hunting down your vacuum leak and dig into that carb - but that's just me.

BTW, the AFB is supposed to have baffle plates in the fuel bowls (see picture) - I've seen 1/2 dozen or so AFB's that were missing those...I don't know what the symptom would be on a hard stop - prob not anything good. They are reproduced.

I'll just lurk now as I think the entire gamut of possible causes of your issues have been covered and you just need to figure out the culprit.

This is starting to look like the experts in the second picture...

Rich Yanulis

GTOguy

I'll say this for the third and last time, and then I'm out of it. As a professional tuning cars, I have never run into a vacuum leak that only affected the car when you came to a stop UNLESS it was a bad power brake booster diaphragm. A sketchy PCV system or constant vacuum leak would have it stalling at all times, not when coming to a stop. I don't understand the OP's resistance to checking the first and obvious elephant in the room, the float level and drop. That would be the FIRST thing to check, as float level affects every circuit on the carb. Verify the float settings and either fix them, or rule them out and at least you have that aspect covered. A massive vacuum leak generally results in fluctuating idle, stalling out at random, stumble on take-off, etc. A float level out of kilter results in, guess what---stalling when coming to a stop.

outofspec

Frankie - You're right. Until I get the procedures done that are already laid out, there's no more to talk about. When I get results I'll let you know what happened.

GTO - For a professional tuner, I can see how this post would be horribly frustrating. I'm not a professional tuning cars. I'm a hobbyist, with limited time, knowledge, and resources. If I opened up the carb, I wouldn't even know what to look for, and how to evaluate it. I'd have to start another post of 4 pages, taking a circuitous route to a solution, sorting through a confusing barrage of information usually in an abbreviated format. I brought the carb to a well known professional and had it rebuilt. I paid, because of my lack of knowledge. I'm still working, and I haven't had time to execute on anything yet. In the first reply post Warren suggested I look at the floats and I explained my lack of confidence, experience, and knowledge in that area. From the second post in, I got 4 pages of potential solutions cures and tests unrelated to checking the floats. I'll get those kind tests and suggestions carried out ASAP. If I'm unsuccessful, I guess I'll have to grow a pair, and tear the top off the carburetor to check the floats. I hope it doesn't come to that. If it does I'll have to start another Saipan Death March of threads, this time on float checking. I can hear you guys puking from here.
I truly appreciate the help from all you fellas.

W Guy

You're taking the best approach. Do the simplest tests first.

Verne

Montana Mike

Just for what it's worth.....my '63 Fuelie developed a bizarre problem, probably not much different than yours. About 3 months prior to the problem I had the F.I. unit rebuilt and the car was running exceptionally well. Almost over night it would not run worth a crap, to to point of stalling after pulling away from idling. By the color of the exhaust I could tell it was running extremely rich and the plugs were oily. Long story short the choke tube which runs through the exhaust manifold had corroded a small hole (you could not visibly see it) and carbon was being sucked into the choke orifices. It was not obvious by looking in the choke, but once I disassembled the choke the orifices required a cleaning and the replacement of the in manifold tube. You can check to see if this is your problem by removing the choke nut that goes to the into the choke. While the engine is idling place your finger on the end of the choke where the tubing enters the choke and it should be producing a suction on the tip of your finger. If not, then you should probably delve deeper to see why not. Good Luck!

MikeM

That makes perfect sense to me. Blocking the PVC circuit like he says could make an overly rich condition even worse and cause stalling.

63 340HP

The stalling result from the test you describe is one of his car's symptoms.

On a encouraging note, setting the float levels is one of the easier jobs. Pulling the top off an AFB is nearly painless. You have time to order a rebuild book.

I asked earlier about the carb because of the missing air vent in the photo. Eventually you will want to check into the carb, because of the missing part and the unseen unknowns.

At this point addressing one thing at a time will help. Patience now will pay dividends for years down the road.

PS. I like the 2nd photo. Sometimes the magic 8-ball seems to be the best available advice.

MOXIE62

Fuel injector and choke tube in exhaust manifold?

Montana Mike

Moxie, I'm not sure where you got "Fuel injector and choke tube" from my comment. But heat to the choke (and I'm assuming the carburated choke is similar to the choke on my air meter) is served by a "Lower Clean Air Tube" which runs through the exhaust manifold. This tube will serve clean heated air to the choke. If you remove the nut (on the choke end) and place your finger over the orifice you should feeling a suction towards the choke. If you don't your likely seeing a blockage of the airflow through the choke mechanism. This is exactly what occurred on my fuelie.

MOXIE62

Sorry about that. I read Fuelie and F.I. unit and thought that meant fuel injector

outofspec

Stalling condition has been remedied!
Both the NOS PCV valve and the B28 vac canister delivered on Friday.
Frankie – Tbarb – Mikem - 63 340HP – SWDUKE, all questioned the PCV and it was, after remedy, what I believe to be the main culprit in the stalling. Upon installation of the NOS PCV, the vacuum I was feeling at the oil tube air inlet was negligible. Mikem, suggested it would be just enough to grab a piece of paper, and that’s what it did. Even though the old one rattled, it didn’t restrict air flow. I think Duke referred to the aftermarkets as a PoS, and apparently he’s right.
Boyan – 63 340HP – SWCDUKE, pointed to the B20 vacuum canister. I changed it out with the B28.
Once the two parts were installed, I went to re-tune. My 42 year old Craftsman timing light, gave up the ghost when I tried to turn it on, so I went out and bought a new light with which I could check advance timing. I was glad the old one gave out, as I’m too cheap to retire anything that works. I didn’t check advance timing with the old B20 canister. Advance timing with the new B28 canister was 32 degrees BTDC, @725 RPM. 63 340HP, suggested it should be 34-36 at high RPM? Makes me wonder if I should advance initial timing from 12 degrees?? Initial timing vac seemed to raise only about an inch from previous reading.
Anyway, took it out Saturday in between rain storms, and an hour on Sunday and never stalled. Big fun.
WGuy, the vent idea was a good one. I ALWAYS forget to check that. Two years ago I had a whole season of a poor running lawn tractor because of it. It was a good reminder.
Montana, my choke tube was new thankfully, but I can see how that condition would be a needle in a haystack find; so it’s good to know it’s a possibility.
Rich Ynulis, Thanks for the heads up on the missing vent tube. My carb guy said he would take care of it for me gratis. Much appreciated.
Warrenm – DansYello – GTO Guy, I’m keeping my eye on the carb. If I can get through the summer driving season, actually driving, for a change, I’m going to take it apart this winter and learn something
I’m going to reread some of the tuning tips and see about total advance timing and maybe loosen up my lash to try and get some more vacuum.
I appreciate the help fellas!

SWCDuke

Set total WOT advance (VAC disconnected) at about 38. Since the OE centrifugal is not all in until 4600 with 24 degrees total, you'll have to rev it to 5000, assuming it has not been already modified, so check the current point of max centrifugal @ revs. If it's still OE get the Mr. Gasket 928G spring kit and install the weakest springs - silver or gold, I forgot which, so test both.

This should bring full centrifugal in at no more than 3000. Then you can set total WOT advance a few hundred revs above the point where centrifugal advance is all, which will be much lower.

The timing tab is not accurate, which is why the using the Total WOT method a few hundred revs above the point where centrifugal is all in is a better method. 16 on the timing tab is really only about 14.

Total idle advance should be in the 30-34 range with the VAC connected. This is the sum of initial, full vacuum, and maybe a couple of degrees centrifugal since it may start at less than idle speed. Idle behavior should be about 12" @ 8-900, and idle mixture screws the OE AFB for best idle quality should be about 1.5 turns out from the seat.

Maximum cruise advance is measured with VAC connected. Bring the engine to a few hundred revs above the point of max centrifugal. Advance should be the sum of initial, full vacuum, and full centrifugal, about 54 degrees.

I recommend cold valve lash of .010/.016" for reasons explained in the Hinckey-Williams valve adjustment procedure. Google if you don't have it. I highly advise AGAINST running the clearance "loose" on a Duntov cam because peak dynamic jerk occurs only a few thou above the top of the clearance ramps, which will beat up the valve train.

Set up as above a stock 340 HP engine runs very nicely - stable idle, decent, but not great low end torque, good top end power, and better fuel economy.

Duke

MikeM

Thanks for posting the solution to your problem.

W Guy

Yes, thanks for letting us know. I'm glad the problem is solved. Happy Motoring!

Verne

MOXIE62

I did not know the PCV valve could cause so much trouble. I thought it was there for environmental reasons.