2x4 Holley carb problem

ssnake · #1 (**permalink**) 05-07-2003, 09:22 PM

For those of you who are running a 2x4 setup on your 427 S/O with twin 660 holleys..Has anyone had any problems with #1 Carb,carb backfire, won't start or won't idle?
I took my car in for an oil change and when I tried to start it, I apparently flooded it (blunder #1)and it wouldn't start..It backfired through #1 carb..A backfire so loud and sharp I couldn't believe..When I finally got it to start, it wouldn't idle and would die. It would run at 2k rpm and beyond.
I coaxed it home and parked it..Pulled the power valve and it seems okay..Haven't replaced it yet I'm going to pull the plugs and see if there is any fouling. Everything was working fine prior to the oil change.
I'm reluctant to try to start this unless I go through the litany of options.
Any thoughts or direction would be appreciated.
Thanks,

Don

ERA-FIA · #2 (**permalink**) 05-08-2003, 08:02 AM

Check for blown vacuum plugs from the backfire for your current idle problems. Float height for flooding at start. Good luck..

KobraKarl · #3 (**permalink**) 05-08-2003, 09:14 AM

Ssnake,

Just a guess here, sounds like your front carb fuel flow is very rich, (blown pv)but the symptoms would be similar if your front carb float needle was stuck closed, and your engine speed would need to be kept up to run on only the back carb.

do you have your carbs idleing primarily on the front?

ssnake · #4 (**permalink**) 05-08-2003, 09:20 PM

Thanks for the replies, Kobra Karl and ERA FIA.
Will give you an update as soon as I'm able to get to this..Unfortunately, with the holiday, this weekend doesn't look too promising.
Again thanks..
Don

ssnake · #5 (**permalink**) 05-12-2003, 08:53 PM

Guys..Here's the results of everything.

1. In checking with a couple of dealers they informed me that the 2X4, model 4224, 660 CFM Holley does not have a power valve. I pulled the wrong thing off the carb. Re-installed it. (Crap!)

2. Checked the floats on each carb..everythings ok.

3. Checked the MSD cap..No problem there.

Started the car up after parking it over a week ago. It did a little pop through the first carb. Nothing like the previous time. Once it got to operating temp, I backed off the carb idle and it idled fine.
Re-installed both air cleaners. Shut the car off and it started fine.

Understand that I really didn't do anything to the carb or anything for that matter..With this in mind, it warranted a 45 minute test drive..Of course, it had to be checked throughout it's rev range. Not a single problem was encountered.

The only thing I can speculate is a stuck float or something of a temporary nature that caused this
condition.
The weight of the 800lb gorilla is now off my back.
Maybe it didn't like its oil change.

I don't expect any further developments and will practice judicious use of the pedal when starting
this great machine.

Don

SCOBRAC · #6 (**permalink**) 07-09-2004, 10:33 PM

Sorry to revive this thread, I know it's been awhile. How did this all work out for you? How are the 660's in general.

I ask because I just bought a pair for my 427. I'm at 11:1 compression 263@.050 with .500 lift ( I think what ford speced as a 306 degree cam, maybe a little more)

I felt like the 450's I was running on my 428 were ok but I know there is more to be had from this 427. Any opinions??

Excaliber · #7 (**permalink**) 07-10-2004, 01:02 AM

I just posted this on the other thread inquiring directly about 660's. Just copy/paste here for those that might stumble on this thread in the future: The "other thread" is here

http://www.clubcobra.com/forums/show...273#post490273

"I'm running two of them on my 427. There EXPENSIVE drag race carbs. No power valve and the "secondaries" are VERY close in size to the primaries. The secondaries are slightly bigger, but it's hard to tell "looking" at them.

The mechanical linkage is VERY FAST. Center Squirters all right. The accel pump shoots into all four barrels at the same time. Thus the linkage is set up to open the secondaries when the primaries have just barely opened a little. Everything about these carbs is "fast". BIG accel squirt IS needed to avoid stall. Linkage travel distance is kind of far, keep pushing down eventually the pedal will hit the floor board and the carbs will be wide open.

I hate them! I've done ALL the tricks to make them more street friendly, it's just not in their nature. They flood REALLY easy on even modest cornering or modest braking. The go in straight line really really good however. They LOVE to run wide open throttle. Two 660's are 1320 cfm. Normally I would say that's "too much". But for MY motor setup it's "perfect"! I run high 11's at 120 plus in the 1/4, and thats taking it "easy" on the car. I DID re-jwt from 75 to 68's (total of 8 jets, all same size) and that actually HELPED performance.

If they didn't LOOK so cool and RUN so fast on the drag strip I'd sell 'em and go with something else. But there so bad, there good! I'll keep 'em, love/hate relationship.

OH, I forgot to mention the "idle circuit",,,,,, wait, they don't have one thats worth mentioning."

ERA Chas · #8 (**permalink**) 07-11-2004, 05:42 PM

Ssnake & Excal,
IMHO, forget the 660's and contact Phil Molski at PMR Racing, 860 828 8828.
I have a pair of 3310, 600's which Phil massaged to 654's [using his flow bench] and modified extensively. They carburate perfectly throughout the fuel curve and Excal, I run your numbers at the track. Did I mention mine are vacuum secondaries? My jets are 65's and PV's are 3.5.
Just ask ERA-FIA about Phil's carb tunes.
Good luck,