When adjusting a holley carb, what does "stumbling" mean?

I would like that alot!

 

I will dig into the file cabinet later on.

The difference between the two types of nozzles is extremely minimal and from the few conversations I've had about the various designs.. it has to do with tube types having a better aim at the booster under high vacuum situations(such as a restricted 390cfm or 2bbl class racing engine would see).

On the other side of the coin.. it's been said that the tube type slightly disrupts airflow and the straights are better from a maximum airflow standpoint. Those heads will cause flow loss long before that carb ever will and I wouldn't sweat it either way as you're definitely not airflow starved from the carburetor's standpoint.


Not positive.. but I believe all the HP stuff comes with the straight style for that very reason. It get's pretty crazy when you start nitpicking those little details and even the shape of the discharge nozzle screw heads that hold them in place can detract from the airflow to some small degree. The newest Ultra HP's even relocated the air bleeds to improve upon the airflow potential if that gives you an idea of how picky things can get.


If the car is leaving from a dead stop well enough for your taste?.. leave the front cam and shooter alone and only concentrate on the rear setup. That's where the hole in the fuel curve is located anyways. However.. if you do want that last little bit of power from the extra initial advance you've given it?.. the extra pump shot on the front side will give you an extra little bit you probably never thought you could have. Personally.. I figure it's free power for the time I spend(but I already have boxes of Holley parts to pull from) and I continue to tune them till I see black smoke or they start softening up.. then back off a cam and/or shooter size or two.

 

Nope, hesitates there too. I have to slowly accelerate or it will miss/stall out for a second.

Found the cams locally, going to have to order the squirters, so if you get a good idea which ones I will need, I will order those asap.

I will wait and see what your file cabinet has to say.

Will have to go to the storage unit and find my jet kit, too.

 

Like I said earlier.. the trend will be very obvious once you install the brown cams on both front and rear.

Also forgot to mention that if you have some precision drill bits?.. they can be drilled out pretty easily too. That's what everyone used to do years ago. Good luck with it.

PS.. if you don't have 2 brown cams?.. use the brown in the back and the green in the front.

 

That was going to be my next question. Kit only comes with one of each color.

I do not have precision drillbits. Besides, I would like the number to be accurate on them so the next time I have to tune it, I will know what I have and which way I need to go.

 

Makes sense. Just keep in mind that there are conversion charts for drill index numbers.. and the really small one's we're talking about here are sized by the thousandths to begin with.

 

OK, got the new cams. If I am productive at work today, I might get a chance to install and try them out tomorrow afternoon.

 

Sounds good. Keep in mind that it usually takes less than 5 minutes to open the hood.. swap the cams.. and close it back up for the test drive.

Just use a magnetized screw driver so you won't lose the screws. Otherwise it'll take longer.

 

Good idea on the magnetized screwdriver.

I am not getting anything done today. Nasty drizzly weather. Not spool-friendly.

 

Got the cams, pulled them out of the package, and No Green One. And No Yellow One.

Pulled the summitracing.com picture up and blew it up, and realized that there are numbers on these things. My "green" one is black with "290" on it. My "yellow" one is orange with "644" on it.

Going to be odd working with them when they don't match the general color scheme. I have a sticky note in the bag with them, reminding me that even though it is black, it is named "green" etc.

 

Hmmm.. maybe they're an aftermarket knockoff?

Just figure out which ones are the most aggressive.. and install the most aggressive one wherever you have the biggest hole in the fuel curve. Next most aggressive one opposite of that one. If.. maybe more like.. when.. the holes start filling in.. order another set to keep going in that same direction.

I'll be digging through files tonight to see what similar combo's have run in the past. I did go look at 2 carbs(600VS and 650DP) on my shelf and they both have nothing but brown cams on them if that tells you anything about my taste in throttle response. lol

 

Nope, genuine Holley packaging and part numbers.

What is up with the holes in the cams? They are numbered. Some cams have two, some three. Brown only has one.

 

Ok.. got it. Maybe they have a few different kits these days, I guess.

The holes have to do with the primary shafts amount of opening and relate to bigger cams. IIRC.. usually only racier cams with well over 1,000 rpm idle speeds need only use the second hole locations. Stick with hole #1 for now.

I looked at some spec' cards last night and this morning but the info is long and cumbersome to post here and I will try to compile it a bit better to relay it in a somewhat effective manner to get the basic points and tuning trends across.

I really wish I could just scan all this crap in as jpeg's just to save on time.. but my stupid Canon Laser printer needs a $200 toner cartridge before I can even use any of the other multi-functions. Can't even fax with the damned thing either and I'd gladly join in on a class action lawsuit against those arse's for making firmware and "print count" chips that completely prevent use of the equipment I already spent so much money on until they get even more of my hard earned cash.

Sorry for the rant but it p***es me off at times like this when I really need it most.

Give me about 15 minutes or so to work on it and I'll post it up.

 

If you want, mail me the pages, and at work, I can feed them into our copier and scan them to pdf email to you. and mail the originals back.

I could scan them in minutes.

I have a couple of lawsuits going on and I scan everything to myself so i have digital copies. Easier to forward them on the next time someone wants a copy faxed to them.

 

The holes have to do with the timing of when you punch the gas to when the fuel expels from the jets.

Seriously...

https://www.youtube.com/watch?v=k-Nx5HEzvlY&list=PL353239D6A7D7BFF0