Circle track 4412 help needed

[bmodracer]

HOLLEY 4412 2BBL 500CFM
5.5 power valve
84 jets
re-worked metering block for E85
50cc accelerator
37 quirter
not sure on what the air bleeds are
AR133 spark plugs
stock cast iron head #487 sbc heads

2-weeks ago the motor ran great on the dyno. On the track it was a whole different story

Here is what it is doing.
There is a very bad dead spot upon acceleration. Going down the straightaway it missfires something terrible and acts like the motor is cutting out. It starts all over when I let off the gas in the corner and stomp back on it. I have re-set the bowl levels, went up and down on jetting, checked the fuel to make sure it was a true E85 and changes spark plugs. In the garage it misses badly when raising the RPM’s. On the track I’ve notice the fuel preasure will drop down to 4-5lb at WOT. I have a Holley pump rated at 110gpm and 7-1/2 to 8psi and have switched that out to a 120gpm pump with the same results. The fuel line are #8 to the pump and to the carb. I have a stainless steel alcohol fuel filter that I have checked to make sure it wasn’t in backwards. The water temp will not get past 160deg but it has been rater cool in the 60’s here. I blocked the radiator off in the garage to bring the temp up to 180 but still no change. The last time I fired it up I could not get the idle screws to adjust. I could turn them all the way in and it would still run. I have changed my carb adapter gaskets and the carb gasket itself thinking there was a vacuum leak.
Since my last race I have converted my carb back over to run on gas and can tell a major difference just in the garage how much better it runs. Track points start this weekend and I really don’t want to risk it not running well unless I can definitely pin point the problem.

Any help you could give me would be very appreciated.

Thanks!!!!!!!

[Heath Daniel]

bmodracer, could be a number of things. Things that can't be overcome I assure you. Need to know what size your air bleeds are and how you "re-worked" your metering block for E85.

[cook2270]

hey. i had sort of the same problem when i first changed. my squirters were too small. we took them off and drilled them out to a 1/16th and put the hollow screws in. it did fine then. the water temp not coming up sounds like the jetting may be too fat. also look at your high speed air bleeds. we went down to 26's on my carb. hope this helps.

[Heath Daniel]

Thanks for checking in Cook. Your car really looked good this past weekend at pinks. What do you think the chances are that we can talk Tony into letting us run quarter mile when we go back to ZMax with the PTRA?

[ron]

Heath, What size booster comes in a 4412 holley. I assume their stock , bmodracer did not say if they were changed and if not are they large enough for E85. Just wondering.

[bmodracer]

Went home last night and did alot of trial and error stuff. Best I can tell, there might have been a piece of garbage in one of the passages. I took everything apart and blew out all the passages re-assembled and the miss and blubber were gone. I ran it up to 7000rpm without a hicup.
Is there a better metering block and bowl gasket a guy can use other than the blue non-stick ones? It seems with E85, the blue coating wants to bubble and maybe flake off.
After I got done running it I ran gas through the carb to remove all the E85 hopefully to save the gasket and not have this problem anymore. I'm going to give it another shot on Saturday to see what happens.

Thanks!!!!

[Heath Daniel]

bmodracer glad to hear you had success getting it to rev. I've ran into the same thing with a passage being blocked. You really should check the size of those air bleeds. I use a really small drill bit set and a pair of digital calipers and just trail fit bits until one feels like it's about the same size as the hole then measure it. E85 likes smaller air bleeds than gasoline. I just don't want you to be running out front and have a problem. Ron the 4412s I've seen have .160 boosters. bmodracer you have to be careful with the blue gaskets. What I do is loosen the bowl bolts and spray WD-40 around the block before I try and pull it off. Then just let them set for a minute. They will practically fall off after that and the WD doesn't hurt the gaskets so you can reuse them. Personally we prefer the red BG gaskets. We have used the same pair for the past 3 years and have change jets about 20 times without having to use WD. They just seem to stick less and hang together better.

[bmodracer]

Are you talking high speed air bleeds of idle air bleeds?

I did not do the work but the metering block was re-worked, the boosters, pump cam, idle air bleeds, alcohol needle and seat. The work was done by a well know carb shop.

Thanks!!!!

[Heath Daniel]

In that case it's more than likely right and you found the problem so it should be good to go.

[john]

Are the hole sizes right on the red gaskets or do you have to open them up if so what part number are they for red gaskets for e85 blocks?

[Heath Daniel]

May 1, 2009 9:26:56 GMT -5 john said:

Are the hole sizes right on the red gaskets or do you have to open them up if so what part number are they for red gaskets for e85 blocks?

Barry Grant part # 195004 (4150 Gas Mechanical Secondary)
works fine as is for us.
On the two barrel you may want to check out BG part # 195006 for 2300 gas two barrel carbs.

[bmodracer]

I have half of my problem fixed. On the starts and restarts hit the gas and its like a rocket taking off. When I get to the corner, let off to get the car to take a set hit the gas and theres is what I would call a dead hesitation. Not a blubber but a true dead spot. After a 1/2 second of nothing it takes flight again until the next corner. Reading tells me it would be pump timing but its ok on the starts and re-starts. I have adjusted the float levels up and down with no luck. Any other suggestions? Thanks!!!!

[Heath Daniel]

bmodracer what you do is switch to drag racing, problem solved. Just kidding, funny thing is we recently convert what I think was a circle track two barrel and it had a bowl extension with jet extensions. Of course this is not what you want in the front for drag racing so we removed them but I see the value in a setup like that for what you describe. How bad would you say it falls forward when you let off of it in the corner?

[bmodracer]

Bad enough that you dont know when its gonna take off. And when it does, is it going to break the tires loose? By that time the car is pushing up the track with the lack of power to the rear wheels. Its kinda scary out front of a 20 car field. Since I've been having problems with fuel presure dropping down to 4psi, I'm wondering if the bowls are about empty by the time I reach the corner. I'm looking into a 172gpm 6-8psi Carter pump that should take care of that.
Part #MS60969

PS I have a 67 Camero with a 468 big block in the garage for when that day comes

[Heath Daniel]

I've been looking at those 170 gph mechanicals myself. Carter and Holley both make one that look just the same and if I'm not mistaken they say they can be run without a regulator. they are dirt cheap for that kind of performance. Keep us posted on how it goes.