When to run a stall converter?

I am just saying the tires breaking loose lets you know you have it very close so use that as your guide as to how it is launching. When it stops spinning the tire you know you are going the wrong way, or when spin more you are going the right way. The low gear is actually helping you out with the tune since it spins when it is right.

If you had a big gear in it it would blow the tires off and you would not know where it is at unless you put sticky tires on
So you are on right track and just to let you know the Holley book says to not mess with those screw in bleeds, there is not much info on that in my Holley book. Just leave them alone, Read about them before trying different ballgame there.

If you shift by yourself take it to 53 mph and shift to second and it will be at 70 instantly since you will be in the powerband of the engine at that point. I can hear it is ready to spin up out of low gear but it shifts into second before it has a chance to rev up more.
That was what mine did with a 256 gear and the 268 Comp cam I went to 55 mph and it shot to 70 in second gear and then would do 100 from there. About 5300 on the tach

 

I have been reading on them. I can tune them bleeds to increase the signal to my boosters and help with bogs. Some guys actually prefer this over the bigger accelerator pump. They claim 30cc is big enough and to look elsewhere. But I'm not there yet. In some cases guys do the 50cc conversion and once they get their bleeds and ifr right they can switch back to a 30cc. The off idle bog is a big problem on carbureted LS motors. I read for a few hours on the chevy boards about tuning these carbs. Once dialed in they'll truly outperform efi.

 

took her out this morning to measure this barn for gutters. 45 mile round trip. Pump shot still needs a little work. It's not being as consistent as yesterday. When I tap the throttle to cross a 4 lane highway I need it to be instant... this tuning might be in the other circuits of the carb though. I also feel like the car loads up a little under part throttle conditions but i think the correct power valve will fix that. Over all it was an enjoyable cruise and I got quite a few head nods.

 

With the carb setup that you guys saw on the video I wasn't getting the same level of performance the very next day or the day after. Both days were 40+ mile trips in 50 to 60 degree temps. I'm starting to wonder if the rich idle has fouled my plugs some. Im Still 99% sure that every circuit is rich. I have some idle air bleeds coming Saturday that should help with the eye burning idle. I also noticed that the blue pump cam would bottom out my secondary accelerator pump diaphragm. So I adjusted that with the help of a Holley tuning video. I'll keep you posted.

 

I figured out what was going on with my carb. The yellow pump cam that comes with the 50cc kit is for a 4500 series carb. Everytime I drove it the off idle hesitation was getting worse. The yellow cam was over working my pump diaphragm. With some pump arm bending and spring adjusting it might be usable but I didn't mess with it. I disassembled the 50cc pump, blew out all the passages, reassembled, and tried the brown cam. With a little cam arm bending and spring adjusting i got my shot just right. Car likes the long shot of the 28 squirter.


This video is my best yet BUT something strange is going on. After filming this video I checked vacuum at idle it was only 11 so I adjusted the mixing screws and got back to 14 i adjusted the curb idle back down to 850 rpm. With the mixing screws set for higher vacuum the car went back to stumbling bad right off idle. and didn't idle in gear very well. I'm curious to why the car dont perform well at best idle vacuum??? The only thing I can come up with is that the richer idle requires more curb idle which cracks the throttle blades a bit more allowing it to transition to WOT a little smoother. Any input is greatly appreciated

 

Glad you are getting it figured out! I wish I could help but I don't know diddly about carb tuning, learning a lot from this thread though!

 

Sounds a lot better, I think you could shift at 5500 sounds like it can get that far but you need a better or a good shift kit in the trans it is taking about 200 rpm to shift out of low manually. Shift sounds a little sloppy.

just crack the mixture screws another 1/8 turn and see if that helps. you now may just need a touch more shot on the primaries.

 

Looks good. When you get to some gear changes and a more torque converter it should really be fun.

 

I don't have any wild cam but this article is pretty informative.

https://www.hotrod.com/articles/7-tips-taming-wild-cams-street/

 

I think its performance is good considering the 256 rear, the cam, and the single plane. But the thing with the idle mixing screws threw me off a little. I richened up the screws a little and went for a test drive and ran good again just a little less vacuum. Might play with the idle feed restrictor some eventually.

I am ordering the afr and exhaust tonight.

Talking to jim now about a 2200 stall for my current setup

 

Larry, he will be an expert soon, as he becomes familiar with every part on that carb.

 

What would that 3200 stall do to my cruise speed and driving around town? Will that stall work if I decide to stick with the 256 rear? I'm okay running an aftermarket tranny cooler.

 

I've made great progress. Now that I fully understand how the pump cams and adjustment arm work i think i could have got the car to run good with the 30cc pump. Also I noticed that my primaries come on real quick which is common with annular boosters. I think its hurting my power right after launch, I'm going to up the high speed bleeds 2 sizes to delay them a little. My pump shot is still squirting by the time my primaries start working.

 

Here's one of the options jim gave me but I want honest opinions. With my rearend will this be a waste of time and money? I do not need a drag car but I would like to be able to do a decent burnout.

 

Jim's converters are great! I bought a 3,2k lockup, acts as a stock convertor around town. Might be slippage but not detectable. I really could use a 3,6 or 3,8 with my setup & gears. Trans cooler?... yes definitely. Keep the heat down.
Never in my life have I had taller than 308 gears, so I'm no help.

 

Heat with a 2200 converter is minimal. And gm used the 2200 in a few cars thru the 70s. And 80s with lockup. You probably won’t notice a lot at cruise, but acceleration it will show a few hundred rpm higher. a ran a tci up to 2800 in my regal in high school. It would max out 2400 on my 350 . No extra cooler. Didn’t seem to be much issue.

 

400 bucks and the time to pull tranny will I be happy with my investment?