screw in air bleed upgrade anyone?
#1
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Anyone ever modified a carb to install screw in air bleeds? The idle circuits on my DP are too rich for the stock LS2 cam. From what I have read I want to further restrict the idle feed "jet" and maybe open up the air bleeds. I have a piece of wire in the idle feed, but that is not doing it.
I am a little wary about drilling out bleeds. Would prefer something more flexible.
I thought about picking up a Holley HP main body for $140, but then I lose the choke. And I would still have to get new metering blocks to get adjustable idle feeds. That's about $250 for the pair.
I found this install kit for the air bleeds. Looks like not much more than a 10-32 tap. Anyone ever do this? How idiot proof does it look.
http://www.aedperformance.com/Tools.htm
As for the idle feeds, I read a post from a Barry Grant tech that most carbs don't have enough material to install screw in idle feed restrictors. Anyone have experience otherwise? Or should I just be happy with epoxy and a drill bit?
I am a little wary about drilling out bleeds. Would prefer something more flexible.
I thought about picking up a Holley HP main body for $140, but then I lose the choke. And I would still have to get new metering blocks to get adjustable idle feeds. That's about $250 for the pair.
I found this install kit for the air bleeds. Looks like not much more than a 10-32 tap. Anyone ever do this? How idiot proof does it look.
http://www.aedperformance.com/Tools.htm
As for the idle feeds, I read a post from a Barry Grant tech that most carbs don't have enough material to install screw in idle feed restrictors. Anyone have experience otherwise? Or should I just be happy with epoxy and a drill bit?
#2
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I have done what you are contemplating on a couple of different carbs...specifcally a 4779 DP and a 3310 vacuum secondary. It's really not that big of a deal. You can find a lot of info and quite a few pictures on the Inovate web site. You can get the taps and numbered drill sets and also the brass hex headed set screws from this company www. McMaster-Carr.com. They will sell to individuals in small quantities. I use 10-32's in the air bleeds, 6-32's in the idle feed restrictions and 8-32's in the power valve channel restrictions. You'll also need a small cheap variable speed drill and a little pin vice to hold the set screws and small drill bits. And yes, you can keep the choke tower and choke plate. It's kind of fun to be able to make changes and see how they affect the carb. I use an Innovate LM-1 wideband with their RPM convertor. I can log up to 45 minutes of real time driving with it. IT logs AFR's, RPM's and I have my MAP sensor from my MSD6010 wired in also and it logs it in either PSIA or inhg vacuum. Go on Innovate's web site... register (just like on here) then download their Logworks 2 software, and then you can go on the General tuning forum and you can then see the logs that different guy's post and see the results of the changes. That will give you an idea whether you want to try it. Have fun, Ron
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Good info. Very good. That is exactly the carb I have.
I have been using an LM2. Haven't spent a lot of time on the Innovate site, just enough to know that this would help.
so there is nothing special about the taps? Just standard I assume bottoming taps? Sounds like you recommend drilling your own bleeds from blanks? I figured on buying a set from jegs and/or quickfuel, but drilling my own would be a good bit cheaper I suppose. i already ordered a full set of bits from northern tool. They had a complete set on sale, mede it cheaper than mcmaster carr.
Guess I will spend soem time on the innovate site this weekend.
I have been using an LM2. Haven't spent a lot of time on the Innovate site, just enough to know that this would help.
so there is nothing special about the taps? Just standard I assume bottoming taps? Sounds like you recommend drilling your own bleeds from blanks? I figured on buying a set from jegs and/or quickfuel, but drilling my own would be a good bit cheaper I suppose. i already ordered a full set of bits from northern tool. They had a complete set on sale, mede it cheaper than mcmaster carr.
Guess I will spend soem time on the innovate site this weekend.
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Sorry, I didn't get back sooner, I got busy in the shop. Yes, the taps are just standard. you need both tapered and bottom taps in most cases. I would use the 3/16" long hex head brass set screws and drill them to the sizes I needed. I thought it would be hard to drill them but one of the guys on the Innovate site explained how and it's easy and works great! Get a small cheap battery powered variable speed drill and chuck the set screw in it. Yes, you heard right! Then put your small numbered drill bit in a small pin vice.
If you don't have one, you can get them on Ebay. Then set down and hold your drill in your lap and turn it on slowly. Dip your drill bit in WD40 and hold it to the center of the set screw (the hex side) Keep it as straight as possible, but it will pretty much center itself due to the rotation and the way the set screw is made. Once you have drilled one, you will see how easy it really is.
I don't think you can use the ready made air bleeds in a drilled an tapped Holley, because they have a head on them which makes them to big to fit.
But on the other hand you CAN use the brass set screws in the ProForm bodies that fit Holleys and probably in the Holleys that are drilled from the factory for air bleeds. I have a friend with a ProForm body on a Holley DP and I use the brass set screws in the bleeds on it. I put a small amount of blue thread locker on them and then screw them down flush because they don't have that big ole head to stop them from threading down too far in the hole. Been using them in it for over a year with no problems. Hope this helps, Ron
If you don't have one, you can get them on Ebay. Then set down and hold your drill in your lap and turn it on slowly. Dip your drill bit in WD40 and hold it to the center of the set screw (the hex side) Keep it as straight as possible, but it will pretty much center itself due to the rotation and the way the set screw is made. Once you have drilled one, you will see how easy it really is.
I don't think you can use the ready made air bleeds in a drilled an tapped Holley, because they have a head on them which makes them to big to fit.
But on the other hand you CAN use the brass set screws in the ProForm bodies that fit Holleys and probably in the Holleys that are drilled from the factory for air bleeds. I have a friend with a ProForm body on a Holley DP and I use the brass set screws in the bleeds on it. I put a small amount of blue thread locker on them and then screw them down flush because they don't have that big ole head to stop them from threading down too far in the hole. Been using them in it for over a year with no problems. Hope this helps, Ron
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Thanks again. You just saved me a bunch of money. McMaster Carr has packs of 50 screws for the price of a single air bleed from Jegs.
I got on the innovate site last night. There are some long winded people on there. But lots of good info too. Should be fun. Now just need spring so the car can come out.
I got on the innovate site last night. There are some long winded people on there. But lots of good info too. Should be fun. Now just need spring so the car can come out.
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Thanks again. You just saved me a bunch of money. McMaster Carr has packs of 50 screws for the price of a single air bleed from Jegs.
I got on the innovate site last night. There are some long winded people on there. But lots of good info too. Should be fun. Now just need spring so the car can come out.
I got on the innovate site last night. There are some long winded people on there. But lots of good info too. Should be fun. Now just need spring so the car can come out.
You probably have an old junk main body you can practice on. Most everyone uses the 3/16" long set screws in whatever size. I usually put a small piece of tape around the bit at the depth I want to drill (usually just over 3/16". I've got the chuck out of an old junk 1/4" drill that I use with the larger drills. For the Holley air bleeds, I usually pick a drill that will take out the original brass bleed, and then I hand drill up in steps of about .005 until I get to the size I need for the tap. I always use WD40 to lube drills and taps. If you don't have one already, you can get a tap & drill chart several different places on the internet. The thread on the General Tuning Forum on Innovates site titled * Avenger 870 tuning * has pictures of the metering block and main body modifications. You may have to register to be able to view them and also to search or open tuning logs. If I can help, let me know. Ron
Last edited by rojs234; 01-26-2010 at 11:20 AM. Reason: added name of thread
#7
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I joined the innovate forum Friday. Ordered some set screws from McMaster, should be here this week. Already had a tap and die set, but went ahead and got bottom taps. I will definitely contact you once I get going on all this.
I just finished upgrading the rear suspension with coil overs, disk brakes, new struts, and LSD and stronger stub axles. Still need to do the same to the front before I can do any serious tuning. That will have to wait until the weather warms up. In the mean time I can map the carb restrictions and add the bleeds. I have the idle screws at less than a quarter turn right now.
I just finished upgrading the rear suspension with coil overs, disk brakes, new struts, and LSD and stronger stub axles. Still need to do the same to the front before I can do any serious tuning. That will have to wait until the weather warms up. In the mean time I can map the carb restrictions and add the bleeds. I have the idle screws at less than a quarter turn right now.
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I'm having a problem with the weather also. Worst I've seen in southwest Missouri in years. I've got the 3310 on my 6.0 at present but I've been helping a young friend put a 5.3 in his old Ford (in a HEATED shop
), so I haven't done anything to it lately. I have trouble chewing gum and walking at the same time.LOL. Anyway the last time I logged it, I had it reasonably close except it had small lean spikes where it was accelerating hardest and at shift points. I don't have jet extensions in the back bowl, so I guess that is the next thing to try. Have fun on your new project, Ron
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