No top end power

[mcmurb]

Is it me, or does 20 degrees at 1000rpm seem like a lot?

[squidberg]

Hi gang,

thanks so much for the suggestions. I have confirmed that the gas pedal can make the carbs reach wide open throttle. Also the timing light shows the advance is working as programmed. 
the car has an electric pump that seems to supply enough, I’ll check when Phoebe returns from the dog park. 
the car probably has some kind of cam. It lopes. Does anyone have specs I can measure to see? If I remove the valve cover can I measure the difference between the shaft and back side of the lobes?

I noticed the cap has a burn mark on it (pic) so I ordered a new one. Be here Thursday. 

[paulyg]

Hmmm. Have you gone through your low voltage ignition system? Verify that voltage regulator is functioning. The 123 app should also tell you the voltage it is sending to the coil while it's running (or maybe receiving from the ignition hot circuit? Not exactly sure). 

 

It looks like the rotor arced through the cap to the clamp on the distributor body. I'm kind of at a loss as to how you'd even have spark at that rotor azimuth. Did you follow the instructions on setting the 123 up to find TDC? As others have pointed out (no pun intended), you do need to set the distributor damn close to TDC using their procedure and then all of the fancy timing curves are referenced to that. 

[paulyg]

PS I remember being taken aback at the color convention of the three wires for the 123 distributor. Blue is the power negative, black is the coil negative. 

[Hans]

I think you've got too much advance. I see sbout 8 to 10 at idle (800 or so) and 33 -35 all in at 3000. I'd start with that and as suggested, try more when car runs right.

I'm getting the two dcoe threads mixed up. How did you synch the carbs?

[Hans]

That cap is toastado. How's the rotor? What kind of coil are you using?

[Chris_B]

On 10/9/2022 at 4:54 PM, squidberg said:

We had these serviced at top end performance. Jetting is in the picture.

Top End should know what they are doing, but 130 main jets seem mighty small for your setup. I presume you don't have a wide band AFM, so tuning your carbs will be difficult. I suggest you bump up the main jets to 150s and see what happens.

[Son of Marty]

Don't do anything until you replace that cap as Hans said it's toast.

[Cabbage Fumes]

I don't know if it's been checked, but what you're describing also is indicative of a cam that is a tooth or two advanced and you've run out of cam by 3k.

[rstclark]

The 123 setup should work for  now  but It looks a little too aggressive for long term  Really would go over 36 total 

The 123 most likely is not the problem but the timing light will tell

[Stevenc22]

That curve is too aggressive. Try something like this after you fix the distributor cap.

 

500 - 6

1000 - 13

1500 - 18

2000 - 23

2500 - 28

3000 - 32

3500 - 34

6400 - 35

[Lorin]

Start with basics, what’s the cranking compression on all cylinders?

[TobyB]

Oh, dear, 

 

the internet, the internet.

 

130 mains with small chokes is fine.

38 advance at 2500+ won't be a problem.

As long as you're not detonating.

There may be a bit more power to be had by tweaking both a bit, but NEITHER 

are going to cause the car to flat run out of snot at 3500k.

It should pull hard to Byron's 5500, and beyond.

 

What WILL kill acceleration is if the carbs aren't getting enough fuel under heavy load.

The easy way to rule this out is to put it in 4th at 50, and floor it.

When it's against the wall, switch off and clutch in, coast to the side of the

road, and pop the top off of both carbs.  Or hell, just dipstick 'em

through the Mickey Mouse hats.

Check them resting, figure out where the float level is normally,

and see if, after the load test, they are roughly where they should be.

 

In fact, might as well make sure they're set right before you head out

 

And check both- it's not impossible that one's doing ok and the other's leaning out.

 

Plug checks can also help.

 

It's also possible to run out of spark- resistor plugs, resistor rotor, resistive wires, it all

adds up eventually.  But that usually shows up as more of a misfire than just power loss.

 

t

on the internet

[ray_]

Considering who did the carb work, I'd verify the jets.

 

[Chris_B]

2 hours ago, TobyB said:

Oh, dear, 

 

the internet, the internet.

 

130 mains with small chokes is fine.

 

Toby, my opinions about 02s generally come from personal experience.