madkaw

I'd say that your AFRS are high for WOT. You should be dipping into the mid 12's at wot- so you are running lean- IMHO. Is that your reason for popping, can't say for sure, but you are lean. The only time I see 15 + afr is during initial throttle tip in and than the AFRS steadily drop during wot and bottom out around 12 ish. You could try to back down your mixture screws- make a BIG adjustment to see if it makes changes to the AFRS . I doubt you will find anything under the valve cover of importance- but hey, it won't hurt

Glad to hear you have a manual and it sounds like you have time to study it before the parts come. Yes you have wiggle room. I would suggest that you pull all of your spark plugs to make the engine as easy to turn over as possible. When you do get things put back together or when you do move the crank-it will be easy to tell if you are having any issues of valves running into pistons.

I bet that dry eraser board looks busy

Sorry for the bad advice, I assumed that your head was off since you said the front cover was off. Do you have a manual for this engine? If not -you need to get one. If your having a hard time determining TDC on the dizzy, then doing a timing chain is going to be a challenge. Get a Chilton's manual or equivelant and look at setting up the timing chain. It's a matter of counting teeth and getting the chain set right on the sprocket. It's going to be hard for us to help you without you being able to reference a manual and you need a basic operational understanding of these engines.

Put the crank pulley bolt back in and crank away

Just checking!!!

You are aware that sometimes you have to loosen the domes up and retorque the screws if you experience binding. Sometimes you can tighten one of the screws too much on one side which will have your dome sitting on the carb crooked.

Working on 40 year old cars is a potential for problems

Take the starter off and use a prybar to hold the flywheel steady. Or if you are not worried about changing the position of the engine-as far as keeping it TDC or something like that-use the starter to break the torque on the bolt. Put a socket and ratchet on the crank bolt and wedge it in the right direction(motor turns clockwise), hit the starter and boom

It's better to use the crank bolt-24mm socket and try to turn clockwise at all times. Pull the spark plugs to make it easier turning the engine over .

That's what I suggested and I got that idea from googling!!

Your cylinder compression levels are great-don't even give that another thought.

I thought it sounded like it was running lean by your description-thus why I was pushing for an enrichment of the floats. The plugs look at little white from what I can tell-maybe leaner on the front 3. So she felt like she had more power with increased fuel?? This could also be a vacuum issue, but your vacuum showed strong signal at idle. After setting the rear float-did it pass the test of being able to see fuel sitting at the top of the jet with the piston removed??

It usually does come down to the basics-and you can't get more basic than a 40 year old car. I'm with Traveln man, the fun of this hobby for me is the learning. Even as basic as these cars can be, I still learn something all the time. Just got my Corky Bell book on Turbo charging-I'll be getting dangerous now!!!!

So did I miss something or did you test after float adjustments?

Getting your valve clearance correct is a MUST, but hard to say if that is the problem . Is this car stock?

reuse the gaskets until they fall apart--basically. If your careful you can take the covers off many times without issue.

I know it's tough, but hang in there. These are the situations that force me to study and research and relearn the basics. You will be the first to pop in when someone starts a thread on SU problems. !!! Google SU carbs and their operation and critical float adjustment. The more I learn about carbs and fuel injection, the more I realize how good and easy FI is

You need to get this off your list. A wrong setting would be most apparent at higher rpm cruise. If anything I would go rich on the setting-the worse scenerio would be a bit of fuel in the carbs. To low of a level will throw off your mixture at higher load/higher vacuum scenerios. I don't believe adjusting the mixture screws will make up for a poor setting on the floats. I know you have the factory setting in there, but tweeking the floats a couple off MM's will not hurt. What I have witnessed is a car that I rebuilt the carbs on that it would run in all parameters, but not much power top end. It was all about the floats not being set right. Believe it or not I just tweeked the floats without a real measurement-just richened it up a bit. Car made much more power and never overflowed the bowls. Here is what I have NOT done: I have Herchecked fuel pressure from my brand new fuel pump, which was good, but I have not checked volume. OR pressure while the car is being driven. But I ruled that out as if I can rev to 6500 rpm at wide open throttle I am getting fuel. I have NOT checked if the fuel level is right at the top of the jet opening in the carb body, I just assumed the float bowls being properly adjusted was okay.

WOW, a 20 degree timing advance- that would make a difference on any set up. That's like being a tooth off!!

I'm still stuck on float adjustment. The jet needles are being set flush against the piston with the jet collar flush??

I can understand the exhaust causing the popping, but not the loss of acceleration at part throttle. That would be a huge leak that he would hear. Vacuum leak is a possibility but his idle is great? Is the power there at WOT? Do you think your engine is making it's normal power when revving out or is it just running up the rpms with less power?

FSM states #20 weight Mobil oil. It says not to uses #30 weight or higher. I will add that the float dimensions worked for my carbs, but I did wind up richening the float setting for max power. What I am saying is that the engine would rev up, but there wasn't much power at the upper end. You still may need to adjust them in the end. Good to see your making chances that actually effect the engine.

Trans fluid works also.

Hybridz is a better site for this type ? and searching!