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Author Topic:   Holley 4412 problems
dirtracer50
Member
posted January 21, 2002 01:42 AM
We were recently forced to run the holley 4412 and have been having problems with it. In the middle of the turns it starts to spit and sputter and sometimes goes dead completely. It doesn't do it all the time and kind of comes and goes. I've tried a Barry Grant angle cut float and an off road needle and seat kit but nothing seems to help. I have also played with the float level quite a bit. This is the second carb I've tried and it's still doing the same thing. I never had this problem with a four barrel carb on the same engine. I would really appreciate any help anyone could give I can't afford to keep buying them.


snowman
Member
posted January 21, 2002 12:50 PM
I have not run this carb,so I may not have the difinitive answer you'er looking for,but I have some questions that may point you in the right direction.First,do you think you are running out of gas or are you flooding?DO you have a pressure gauge? DO you have a 1/2in ID gas line and proper fuel pump?If you have a hi-flow fuel pump,do you have a reglulator? Is you fuel cell vented? Are you sure that all parts are installed correctly?Adjusted correctly? If so,then I suspect you may have an electrical problem instead of a carb problem.You say it doesn't happen all the time which makes me think this. This is the second carb,which means you've been trying to fix it for awhile,and you think it's the carb because it's the only thing you've changed,but something electrical could have gone bad in the meanwhile. I have fixed many "carb problems" with a new coil,module,cap and rotor,points,etc....Just some thoughts,could be wrong.......I see that you are new to the fourm,there is a race engine expert on this fourm,his fourm name is sdhnc29.....In the event he doesn't happen to see your question and answer on this page,you can send him a private message ....(is that cool or what)


racer17j
Member
posted January 21, 2002 01:25 PM
i agree sounds like you may have something else besides the carb check all your connections and wires for worn spots and loose fittings check everything from the carb back in your fuel system. sounds to me that if it's in the turns that you are either running your pick up line out of gas or somethiung is touching and grounding when the weight shifts


49mtmod
Member
posted January 21, 2002 01:46 PM
I had a similar problem once. It was caused by the engine shifting just enough in the corners to pinch the fuel line. If thats not the problem I think that snowman and 17j bring up some worthy excellent suggestions.



6pack
Member
posted January 21, 2002 04:02 PM
Thanks for all the replys. I do have a half inch line with a regulator and a good fuel pump. I also thought it may be electrical but when it quits stumbling it runs great right away. My thoughts were if it were in the ignition it would take a minute to clean out the unburned fuel. I built a new car last season and used the same motor with all new ignition and wiring and still having the same problems. Does anyone have any more information on the jet extensions and if that could help my problem at all? Thanks again for the help I really appreciate all the suggestions.

[This message has been edited by dirtracer50 (edited January 21, 2002).]

mudslinger12
Member
posted January 21, 2002 08:17 PM
i don't know if you have solved your carb prob yet or not, but if not, we have a great sponsor-Bigs Performance Carbs, from altoona, wisconsin, we used a 4412 that they sponsored to us last year on our street stock, and never had one prob with it at all..was the best we have ever had..lynn bignall is the owner, he would be glad to talk to you and help, he is great...number is 715 835 3726..if you call, tell him the brown's from wyoming sent you..you won't be sorry


ss38k
Member
posted January 21, 2002 08:50 PM
hey guy try your distributor cap i raced two weekend before we found the problem.i also thought it was my carb.


bship
Member
posted January 21, 2002 09:26 PM
quote:
Originally posted by dirtracer50:
We were recently forced to run the holley 4412 and have been having problems with it. In the middle of the turns it starts to spit and sputter and sometimes goes dead completely. It doesn't do it all the time and kind of comes and goes. I've tried a Barry Grant angle cut float and an off road needle and seat kit but nothing seems to help. I have also played with the float level quite a bit. This is the second carb I've tried and it's still doing the same thing. I never had this problem with a four barrel carb on the same engine. I would really appreciate any help anyone could give I can't afford to keep buying them.

Dirtracer:
I have had this problem with the 4412 hly. You are on the right path. At midturn two important things happen in the fuel bowl. centrifugal force carries the fuel to the right side where it stands up against the bowl side. this raises the float and shuts off incoming fuel.the next thing that happens in the hly. is the power valve is uncovered (it is higher in the bowl than the jets). at this point you`re in the throttle to come off the corner and the main metering system is sucking air through the power valve. as cornering force lessens the fuel levels in the bowl and the engine will pick back up, as you described. a properly beveled float will help but not cure this problem. I have not used the BG float;I normally cut my own. The only other help I have found is running the fuel level as high as possible. Good Luck.


3xracing
Member
posted January 21, 2002 11:22 PM
It sounds like newbie is the only one here with Holley experience. What you needdd to do is get yourself a vacuum guage and measure your engine's vacuum at idle. Take that number divide it by 2, then subtract 1. The number you end up with is the correct power valve to install in your 4412. Example: your engine makes 8.5 inches of vacuum at idle.= 8.5 divided by 2 = 4.25 - 1 = 3.25. round up to a 3.5 power valve. A stock valve is to stiff and low vacuum race engines can't make it operate correctly to give you the extra fuel needed when picking up the throttle in the center of a corner. Also make sure your regulator is at 7.5 pounds of fuel pressure throughout the used RPM range of your engine. CHECK IT! don't rely on the numbers on the regulator. If your allowed to use the BG manual pump, use it without a regulator if your on gas. They don't make enough pressure to need to regulate anyway. Use an angled float and thats all. Jet extentions hurt you when accelerating down the straights because the fuel is sloshed back against the metering block and the extentions are clear out by the bowl inlet. This can lean out the engine and do damage.
Check this stuff out and let us know.


6pack
Member
posted January 23, 2002 10:37 AM
The BG pumps are set-up by BG to deliver the proper pressure. You don't need a regulator because those pumps don't make any EXTRA pressure you need to regulate.

You power valve theory of 1.5 - 2 inches below idle use correct for the street, not for race engines. - My formula came sraight from the horses mouth - In this case, the head tech rep at Holley, and I've used it on well over 50 engines and NEVER once had a huccup or hesitation coming off a corner.

3xracing
Member
posted January 23, 2002 05:42 PM
I few other things you can try...

You can put a 'plug' or 'dummy' power valve in. This isn't the recommended fix, but if your on a fast track with fast corners where te RPMs don't fall off to far,this can help. When you do this you need to do 2 other things. 1) go up about 5 jet sizes from where you were with a real power valve in. 2) Get a accelerator pump squirter with bigger holes and if your track allows, get the type with the extentions. If I remember right, the stock squirter is a .025" opening, and we went up to a .037" with the extentions on it. I can check those numbers but I know we went up .010" - .012" from the stock size.

I'm curious if your engine will idle OK when its warm also? Like after a race, will it idle without any help?

3xracing
Member
posted January 23, 2002 05:47 PM
I ALMOST FORGOT THE MOSTIMPORTANT THING!!!!!

You MUST put in a high flow, non-stick needle and seat. Get the biggest one you can find! BG makes ones that work great and should be easily found at your speed shop. TRY THIS FIRST!

You run 1/2" lines all the way from your cell to a needle and seat with a .09" opening?? Get a big one in there.

6pack
Member
posted January 23, 2002 08:26 PM
It would seem that my experience(and therefore my knowledge and the validitiy of my answer),has come under fire. I choose to believe that no insult was intended,and therefore take no offense. Be that as it may be,I would now like to clarify myself on this subject. First and foremost,I'm only trying to help and I made no claim to be an expert on this carb and in fact,informed Dirtracer50 where he could find an expert........ TO Dirtracer50, I would like to say that 3xracing and 6pack were right to bring up the subject of power valves.......If you have the wrong jets and power valve and you are lucky,the engine will run poorly and let you know that you need to fix it.Should your luck go the other direction and you lean your engine too much,it will grenade itself on the track.Bottom line,you must have the proper power valve and jets before you take your car on the track.(it's better to be a little rich than a little lean) The reason I didn't mention this in my first post is because I assumed that you already knew it.Perhaps I made a mistake in this assumption,if so,you have my apologies. The knowledge that you need correct power valve and jetting is kind of 101 stuff.You knew enough about carbs to work on your own, You knew enough about potential fuel problems in the bowl to install an angle cut float and adjust the float.Since you knew all this,I assumed(and at this writting still assume) that you know about power valves. In the event you did not know,then by now you have no doubt figured out the problem. In my "experience" or lack there of,I have seen otherwise well-tuned carbs starve for fuel due to: fuel pump,wrong size gas line,and clogged fuel cell vent.I have seen them flooding due to:no regulator,faultly regulator,and of course the common problem of trash in the seat. All of this with a well-tuned carb,no end to the problems with a poorly tuned carb. I want to list one example; a guys car is running poorly due to a bad module.Guys friend tells him to put in a bigger accelerater pump,pump cam,and bigger squirter nozzles etc; Of course,it doesn't fix anything.Guy changes module trying to do a tune-up.He has now fixed his orignal problem but his car runs like a dog because everything that can be adjusted on the carb has been adjusted wrong. This is a common problem,I've seen it many times. This can be confusing to a beginner,as these carb adjustments are correct and proper tuning tools.Many are not nessasary on streetstocks. Many streetstockers have soggy engine performance due to "trick" carb parts when they should have been using something more like what Holly put in the box. My whole point of my first post was simply to say don't pull your hair out fighting your carb while missing something simple in your distributor. I think most guys will admit doing this a couple of times,I know I have. If I have a difference of opinion with anyone,thats all it is. I am relatively new to this site,and I enjoy it.I like to help people when I can. I have no intrest in putting anybody down and certainly have not intentionaly done so. If a difference of opinion has offended someone,then you have my apologies...........


Flatlander
Member
posted January 24, 2002 10:10 PM
I had a problem at one time that I thought was the carb & come to find out that it was the fuel pump. My car had a flat spot sometimes when I accelerated in the middle of the corner just after I set the car up in the corner. I talked to holley performance & they said to adjust the acc. pump so it had 1\4 inch of play in it before the arm hit the lever for the pump. I tried new squirters, acc. pumps, acc. pump cams, power valves, new fuel line from the rear all the way to the front, new floats, had the card rebuilt by a pro speed shop, & nothing helped it. Sometimes it was there, sometimes not. I was ready to give up when I tried the new race fuel pump. It is a carter 8 psi race pump. I put it on & haven't had a problem yet. That was 5 years ago!!! I hope this might shed some light on your problem!!!

[This message has been edited by dkandy94 (edited January 26, 2002).]

mongo21
Member
posted January 26, 2002 11:37 PM
Snowman i would like to tell you nice post.....you covered it all man.... Dirtracer50 let us no what it ended up being it may still be something we have over looked thanks mongo


dirtracer50
Member
posted January 26, 2002 11:58 PM
Thanks for all the suggestions. I have a lot of different things to look at that I never thought about. It may be awhile before I can figure out what fixes it. It only does it on the track and our season doesn't start until april. Until then I've got a lot of stuff to play with. Thanks again everyone who replied.


mtwrght29
Member
posted January 28, 2002 09:29 PM
i know you have about a million suggestions here but i have experienced a couple of more that are very similar to what you are having. First i like to run the float level so you get just a bit of fuel drip out of the ;lug without shakin the car. Second i have seen many people do this simple but i didn't get it either until my carb builder explained it. The idle screws should be approx. 1 3/4 out which will make it run rich and load up at idle. When you enter the corners off the gas although your engine is turning well over idle the only fuel it is getting is from the idle circuits so if it isnt rich in the pits it brobably isnt getting enough fuel on corner entry until you pick back up on the gas. just a couple of suggestions hope they help.


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