Technical EVERYBODY is Stumped with no suggestions

Sorry, couldn't help myself.........

 

. That’s hilarious. And my laughing emojis don’t work here

 

Now you're cookin' ! ! !

 

Still no change. Same vacuum signal and flatline at WOT while driving.

 

I may have missed or forgotten it, but did you do a compression test?
if so do you recall the results?

 

I haven’t done one, but I can if it’s logical.

can anybody tell me what a compression test would tell us before I perform one.

 

It will tell ya if you have compression or not

 

A compression test might signal why smoke on left side exhaust. But I don't think it will help with the tune.
Others have mentioned engine miles and wear. My question is more along the lines of what the current owner is going to do with this car?
Cross country, long distance touring is more a dream than a reality for most owners of vintage cars. Full throttle pulls are probably not in it's future.
An ice cream run or summer parade is more common.
How it will be used should determine how finely tuned (or rebuild) is needed.
Get it starting and running dependably and send it home.

 

I feel you and I understand that and I’m not concerned about the smoke. I’m only concerned that it will not run at 380 CFM going down the throat. There H*** to be something physically wrong with the carburetor either giving too much fuel or not enough fuel. I do not believe that it would fall on its face from 1800 on the way up to 3800 if I open the secondary or go too far into the primary. Unless it’s physically related to the carburetor.
I came here to pick your guises brains to find out what other factors might cause this carburetor to behave this way. I have done my best to find a working carburetor of the same size range, but there are none that I’m aware of at the moment within a couple hundred miles of it.

 

It’ll tell ya if the air pump (engine) is healthy enough to pump air

 

I will take another video of this wonderful air pump throttling up to 2800 RPMs or so without jumping into the last half of the primaries and then you guys can tell me how bad you think the compression is, and then attempt to convince me that it needs a compression test

 

OK I end up taking 56 seconds of video. To me this is not a mechanical issue, except with the mechanical workings of the carburetor itself. That’s just my opinion I still need your guises opinion and don’t forget to tell me how much of a dumb*** I am if I get something wrong again lol.
https://youtube.com/shorts/2NL7Vz0vqdA?feature=share

 

Humor me and drop the timing back to 4 degrees, and 32-34 max advance. I believe there is too much timing in that high mileage motor. Or are you after the best fuel mileage at WOT? LOL!

I just can't imagine the valve heads and intake ports are not carboned up badly. Your problem probably isn't valve float, its more like the air flow in and out of the motor is restricted by build ups around the valves and head ports around the valves. Unless that timing chain has been replace, I guarantee you its stretched and loose at 100K miles. I've owned a lot of old high mileage Mopars.

These Hemi motors were the top of the line performance motors of their time, they were made to run hard. If its spent its life being babied, its so cruddy inside it can no longer run hard, which is what you are expecting.
Picture any modern high performance car, and drive it 100,000 miles never exceeding 3500 rpms, then take it to the drag strip expect it to deliver the same ETs it did just out of the factory. Disappoint awaits. Now do the same thing with that modern car but drive it 250,000 miles (beyond its expected service life like that 100K miles 54 Hemi), never exceeding 3500 rpms, and take it to the dragstrip. Let me know how well its going to perform.

I just watched your last video. Now I'm even more convinced its not a carb issue, but a wore out motor, too much timing, or the ignition breaking down at higher rpm, or some combo of all 3. Back in the old days I would have been pulling the dist and putting it on a dist machine to find out what it was doing. Sounds a lot like point bounce. Could be broken wires between the ignition switch and the coil, or even between the coil and the dist. Might even be a poor dist ground.

 

I absolutely understand your point.

man’s I hate to say it but it is very likely a shrouding issue, simply for the fact that I don’t want to get this deep into the car. It’s been here two weeks and I have neglected other customers.

timing….. sorry to say this but when I First noticed the throttle up situation, my base timing was 4degrees, my all in timing was around 39-41 degrees. It changed nothing. I can put it back and do it again, but the same results will occur.

I wish my bore scope had a shorter tip. I can’t take it around the intake runner corners to get a look inside at the back of the valves.

when changing the plugs, the piston tops were black, but not carboned up.

 

Looked under the valve covers, turned it over without the covers to see if anything odd is going on?

 

Close the spark plug gap to .032 and try it.

 

X10^^^^^^^^ No one can dismiss the 10 million man years of collective automotive experience here on the H.A.M.B. without at least some consideration.

 

The plugs I took out we’re not bad and they were all gapped to 35 which is the specs for this car and it still did it then. Two hundred thousandths of an inch will not do this if my hunch is correct.

 

did you not read my reply? When I first put everything back together I had my FaceTime in at 4° like it supposed to be am I all in timing was 39 or 40 or something like that but it was still doing the same thing, whether max out at 40° or 50° or 39.

I am here specifically because there is 10,000 years of knowledge floating around the brains of the people on this forum, and I am accessing all of it but I have already done the 4° before top dead center timing with the exact same results

 

I’m not pulling your leg, I seriously began this with factory setting on the timing and after talking to my distributor guy that rebuilt my distributor and knows the range plus I know the range of the vacuum canister I installed on it my all in at 50 must be with 13 to 14° initial

 

better move that decimal point....

 

Oh nowhere did I go wrong? Lol. Decimal points are overrated lol.

 

You own a shop and do not know the benefit of a compression test? It is obvious you do know how to properly do a vacuum test. You have to have the gauge connected to manifold vacuum, I am ***uming you are connected to something else because you vacuum readings are real odd for manifold vacuum.

Do a wet/dry compression test.
Do a proper vacuum test with the timing set at 4°.

The results more than likely will give you an indication of what the problem is.

 

You keep answering your own questions !

 

I’ll drop the timing down to 4 degrees again. I’ll leave the vacuum plumbed into brake booster manifold source.

a compression test will not lend credence to this specific problem. Wether there’s 90 psi across the board or 135, or every other hole is 100 psi and the rest are 60.

I don’t see how knowing that will provide flatline information. I’m a damn good mechanic, at least I was until ****ercup was dropped off in my driveway……. Maybe my refusal to do a compression test is just me being a stubborn old ***. But I’m 100% certain it won’t answer the issue.

 

Your 4 degree timing was tested before you discovered the vacuum leak at the base gasket and the jetting issue. You also discovered the dist didn't have any advance system in it and replaced it with one that did. Then you jacked the timing, it didn't solve your problem, but you didn't return it to where it was originally.

You now have a smoother running motor gained through some advance in the dist, and carb work, but the RPM won't increase past 3200. You are still looking at what you have probably fixed thinking its still the problem. Now look at what you changed before the carb fix, and look at the things you just know can't be the problem because you still have one. Or give the car back to the customer and hope its good enough. It sounds like predentenation to me, you just can't hear the pinging because the dual gl*** packs drowns it out. Could be bad wires or dist cap too, we don't know their history

We all beat ourselves sometimes. I put new plugs, dist cap, rotor and plug wires on my old truck and developed a misfire it didn't have before. I was sure I had all the plug wires ran correctly. I even checked them the 2nd time and was sure they were correct. It took the 3rd time before I found the two wires I had crossed.

 

Oh SNAP! You are 100% correct that was before I discovered that mismatch base to bowl gasket so I will gladly put it back to 4° tomorrow or tonight when I get home and do it all over again because I really don’t mind it car running at 43° versus 50°

 

Sounds like one of my uncles wore out log trucks.

 

I'd be on that compression test like a dog on a steak. Still here, Lippy

 

I want somebody to explain to me how having one bank with 150 psi in the other bank with C 60 or eight plugs with 90 psi in one plug with 150 how is that going to make the carburetor work or not work?
And you wouldn’t think that it would run so beautifully smoothly all the way down to 450 RPMs if I wanted it to run that low it is not a compression issue. This thing is smooth as a sewing machine