I read an article about holley tuning and it said you should never resize the
air jets. The air jets on the carb I am using are same size on the idle air jets
and slightly smaller on the main air jets. I put a 50 jet on passenger side and
52 on the driver side (I did not have 54 jet) and the flat spot is starting to leave. it still boughs down when you hold down the thottle to the floor.
I spayed starting fuilfluidit when it was boughed down and it helped, so i guess I will buy some bigger jets. It now pops and crakcraklesough the exaust
almost all the time.

don't wanna be the smartypants here... (that's reserved for others ) but did you check your valvle lash?

Other things: don't pay any attention to holley servicing manuals. They're written by people whom hates them. Ream your accel pump shooter a few thousands bigger, especially the one that would match the bigger main fuel jet.

_________________
Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

Luckily I have a couple minutes in front of s computer today:

Several things to look at here:

1) your engine is a Hydro Slant isn't it?
2) If this is a truck is the timing locked out due to the 1981+ ESC or do you really have a *normal* distributor
3) Do you have a vaccuum gauge hooked up to check to see what readings you are getting when making carb changes along with checking the plugs?
4) You might take the time and $$$ to intall an O2 bung and install a 1 wire O2 sensor and gauge so you can check your flat spot out with the meter and the vaccuum reading to see if you have a vaccuum leak (metered orifices are 'plugged' on the carb right?)
5) You can use a drill set and pin vise from a model shop to open up the bleeds (this changes how soon certain circuits react depending on the mods...), remember if you 'botch' the job you'll need to have a shop install new bleeds or get another throttle body to start over (some cities may not have a nice reputable shop to help with this)
6)You can up the acc. pump cam a bit, or change it from the #1 screw hole to the #2 screw hole for a little bit more gas, you also can change the shooter size (what is on there now a '25' or a '28'? Maybe a orange 466 cam in the #1 position with a '25' might be right assuming that when you're done it doesn't puff gobs of black crap out the tail pipe on hard acceleration)...

I only get to 'visit' here occasionally due to my assignment and computer availability, best of luck to you.


-D.Idiot

Yep. I author holley repair manuals in my spare time under an assumed name.

D/W

_________________

If it ain't broke, fix it!

I installed a 52 jet on the pass. side and a 54 on the drivers side, a 55 power valve, and adjusted the timing. It is now drivable with only a flat spot for a second when you floor it. I did not ream out one side of the accelerator pump
(didn't have anything that small) and I'm trying a 29 accelerator. It does not back fire anymore. And runs pretty good. A big mopar guy in town told me it was impossible to run a 350cfm holley on a stock internal slant 6. I'm going
to start driving it and will try larger jets soon.

OK go for the 29 accel instead of getting a spring broach (pentagon tapered reamer...) glad to hear you tuned it! Some Holleys can be tuned! the other 99% gave birth to the saying "holley crap! " ....
Advance the timing just a bit more... just a bit. Holleys sometimes are richer than others so that would make the mill less prone to pinging. Did nyou drive tested it cruising?
As far as for "not being able to use a 350 CFM holley on a bone stock /6"... well, if you have the later cam borrowed from marine division, a nice not-too-small runners on your intake, and good comp #'s, I'd say it's BS.

_________________
Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

just to ask what readings do you get at:
idle
idle in gear
cruise on street
cruise on highway (@55-65 mph)
hard acceleration in gear (tromp the pedal hard like a drag launch)

I see the 5.5" power valve and go huh? Most applications for the slant like an 8.5 to 10 power valve to help take out that leanout that occurs on launch....


Another question to ask is which 'R' number holley do you have, and does it use reverse idle screws by any chance? (Late model 2 barrel, emissions versions)

-D.idiot

I use a 6.5 poer valvle in mine. no bog whatsoever.... no flat spot. Just richer jets and you're good to go with low HG rated power valvles... your fuel consumption may hurt some, though.

_________________
Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

So why bother even using the power valve...if his slant never gets close to 6" on acceleration, he'd be using about the same gas as if he did the drag mod of plugging the power valve hole and richening the jets up...

That's why I asked for the vacc. numbers...tuning a carb and timing without a gauge and numbers sets you up for making lots of guesses on your mods.

don't forget this article from ways back, but that was on a solid cam 180K motor with bad rings, etc:


http://www.slantsix.org/forum/viewtopic ... olley+2300


-D.idiot

I don't have a vaccum guage. It does not have any vaccuum leaks. It does not have reverse idle screws. On the power valves I found the smaller ones work better, the highest I have is a 7.5 and ran the worst with that one. I'm going to order 56 jets next and try them. The truck does cruise nice. When you floor it esitates for second but then revs up. which you could drive with
but I don't like it.

I remember that thread...

I suppose I was just talking outta my vac #'s... I'm idling at 17, mild accel near 12, med accel just below 10 and full throttleing it like 2 or 4.

I used to have a 1922 w/o power valvle, since it was on a heavily modified motor (not a street mill tough) and not in a daily driven car. I'm about to reinstall my 2300... just haven't find the time to finish some "touches" I'd like to get done, but when I install it I'll find about my vac #'s. (I installed the vacuumeter after I reswaped the 1 bbl on my car)

But most likely if it's a truck a 6.5" reading on accel would be possible due to the increased load huh? we may need to know what rear end ratio he's using....

_________________
Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

It's been a busy summer. And I'm still waiting on the DOT to get my Title and
plates. With the 56 jets in there it runs okay. I got a vacuum gauge now so I can test it some more. I think its running rich but I'll have to wait and check the gas milelage when I get my plates.