Ok, The tuner at the dyno shop told me to pull out the power valve and put a block off in it and then go up 10 jet sizes front and back.

This is completely wrong information. When you delete the power valve you only go up jet sizes on the secondary side of the carb. If you increase the primary side your going to run WAY rich under part throttle conditions. Remember under part throttle conditions the power valve will remain closed. Also it isn't 10 jets sizes all the way around, it's 10 jet sizes on the rear jets, with the front jets remaining the same. And this is just a "rule of thumb", your probably going to only have to go up about 7-8 jet sizes in reality. Now this only stands for carbs with one power valve that is on the Primary side of the carb. If the carb as a power valve on the secondaries, then you may have to go up more than 10 jet sizes. Your best bet is to get a LM-1 or some other type of A/F meter and log your fuel ratios. Other than that your just going to be stabbing in the dark.

 

Reading this short article in CHP makes me think that we are on the right trail.. finding the right combo should be lots of fun.. hopefully the tuning book will provide some general guidance on both IFR and Air bleed sizing

maybe I will try the wire strand trick for testing purposes then replace with proper size IFR if the results are good...

http://www.chevyhiperformance.com/howto/71498/index.html

I tried the wire strand (staple) trick and didnt have any success at all, it ran really rough after I did that, actually to rough to get an accurate result.. The problem with the wire is that it blocks about 50% of the hole because its roughly .017 going into a .034 hole.. I think we only need to drop one or two sizes .002-.004 to have success.. From what I understand, changing the Air Bleeds can also effect the transition off idle so I wont go that direction unless I dont have any success with the IFR's.. My carb actually runs great and I can stomp on it from a dead 1000rpm idle and it will launch hard.. I just dont want any changes I make to effect anything else but the rich idle condition.

I assume the wire strand worked for them in that article becasue someone had already pre-drilled the IFR's out to .055 so when they stuck a .017 wire strand in it, it only reduced it to .038, which is almost where is was stock..

 

Ok I pulled the carb and put it back to the origional jeds and put the power valve back in along with setting the butterflys where they needed to be up the transition slot along with setting the Idle-Eze at 1 1/2. Same problem, it will not idle at all and turning the Idle-Eze does nothing. When I say it will not idle I mean it is so low that it dies (below 200 rpm). So in order to get it to idle I will either have to turn the primary idle screw in about 2 turns which will move the butterflys way up the transition slot or start drilling holes in the butterflys so I will not have to open them so far. What next???

 

How about opening the rear throttle blades a little??

There should be an adjustment screw that you can turn to open them.

If that doesn't do it, then yes you may have to drill holes in the throttle plates.

 

Ok, I will open them a little and see what happens.

 

Just for fun, rotate the distributor to 36* at idle then see what kind of vacuum you can achieve in drive, you may be able to lower the primary and secondary throttle plate to a more friendly level and work with the 4 corner idle screws. If it gets better at this point we'll get the dist. To 26* degrees initial with bushings from 4 seconds flat then crane adjustable vacuum advance for the 10* advance at idle to make 36 at idle without locking it out.

 

My initial timing is as high as I can run it, any higher and it will not turn over when it is hot.

 

Use the idle-eze instead of drilling holes in the butterflies. Drilling the butterflies is almost never needed in a case where the carb is sized correctly to the application. So do not do that at this stage. The setting was 2 turns out to start, add to that if need be.

You are on the right track by looking at the other ways to provide additional air to the idle circuit, like opening the secondaries a bit- but ultimately it is very likely going to require tuning the idle feed restrictors and/or air bleeds to get it to come around.

But for you sake, hold off on drilling the blades!

BTW, did you talk to the tech that Tech @ BG mentioned in post #17? I hope you all got together- it sounds to me like they're sincere in wanting to follow through and help you get dialed in- so give them a chance if you haven't been in contact yet, and ask more questions if you have been in touch. You have their attention on this, so take full advantage of their knowledge and willingness to help.

 

I did talk to the tech guy and he said to start over with the factory settings which is what I have done. I did get it to idle by cracking open the back and then turning the front idle screw in quite a bit so now the butterflys are not set correctly and are way up the transition slot. The Idle-Eze still does nothing, No matter which direction I turn it or how much it does nothing. My vacuum reading is up to 9 inches and it seems like it is not smoking as bad out the exhaust. I just wish I could put the butterflys where they belong and still get it to idle or at least stay running but unless they are turned way up the transition slot it will not idle at all.

 

I wonder if there is some kind of obstruction to the idle eze making it not work?

 

I have no idea but it does nothing. I even watched the vacuum gage while turning the IdleEze and it never changed at all.

 

I have a 650 Mighty demon that was totaly unresponsive to any adjustments & was extremely rich, even going down the road. While I was looking at it one day trying to think of something to try I just started checking my intake bolts, just routine checking for loose bolts. I snugged them down & then set back into adjusting the carb. I was then able to adjust the carb. I guess it was just loose enough to cause a problem.
this may not apply in your situation, I did not have a problem with the engine not wanting to idle.
I now check the fasteners on the engine more often. it wont cost anything to try it.

 

I agree, it does sound like you might have an air leak somewhere. Check all bolts and disconnect all vacuum lines from the motor and plug the ports. Then see if that makes a difference.

Also on the carb thing, you can have up to .060 of the transfer slot showing. Just try to equal out the front and rear throttle blades so they have equal amounts of transfer slot showing.

Also what does your carb gasket look like? Does it have the four holes or is it open in the middle??

 

I will double check the intake bolts and the carb gasket is open in the middle.

 

I dont think there is anything wrong with opening the secondaries a little more and dropping the primaries like you did.. Its the primaries that you dont want to open to far or you'll start drawing off the main circuit and that will further enhance your rich idle condition.. Mine is currently set-up the same way (secondaires are open a little more than the primaries) and thats where it runs best.. Its enough to get me by as long as I dont idle around to much.. I personally dont think you have a vacuum leak because your vacuum reading at idle is right on par with everyone else that runs this cam.. I have a steady 8hg of vacuum at idle so it sounds like were in the same ball park, I just wish my new IFR's were here so I could give you some results.. My stock IFR's are a .036 and I do have a set of .034 here so maybe I'll install those today just to see if there is a positive result. I was hoping to install some .032 but as mentioned, they are on backorder..

 

What size power valve are you using?

The idle-eze or secondaries opened a bit should give instant results. Either should make your rpm go up at least 500-1000rpm and cause you to close your primary side.

 

Ok I pulled the carb and put it back to the origional jeds and put the power valve back in along with setting the butterflys where they needed to be up the transition slot along with setting the Idle-Eze at 1 1/2. Same problem, it will not idle at all and turning the Idle-Eze does nothing.

Something ain't right. You need to get to the bottom of why the carb does not respond to turning the idle-eze. There should be a definite change when it is adjusted, so if there is no change, there's a problem.

 

Something ain't right. You need to get to the bottom of why the carb does not respond to turning the idle-eze. There should be a definite change when it is adjusted, so if there is no change, there's a problem.

Mine is the same way and I have verified and re-verified everything.. I even pulled and re-installed my intake, plugged every vacuum port and still no reponse with the Idle-eze just like the OP.. I also have my timing locked out at 38 and use a cut-off switch for starting it. I am assuming the rich idle conditon is effecting the reponse of the idle-eze because I can turn it from one extreme to the other with no results at all and I have read the same thing on other forums too (only when they have a overly rich idle)..

 

I misspoke when I said there has to be a change when the IE is adjusted. I should have said that if the A/F mix is within range, there will be a change. I can see the carb being so far out that the IE would not cause a change. My bad.

 

What size power valve are you using?

The idle-eze or secondaries opened a bit should give instant results. Either should make your rpm go up at least 500-1000rpm and cause you to close your primary side.

I am running a 6.5 pv that came with the carb.

 

Might be an issue, should be 1/2 your idle vacuum in gear (if it's an automatic).

4.5 if youre at 9hg idle vacuum. Maybe lower might even be better

Idle vacuum keeps it closed, low idle vacuum because of the cam might make it open and dump fuel...run rich.

6.5 is assumed for cars with 12hg or higher at idle, most stock motors are 15-20hg at idle.

 

This is where the confusion began w/the dyno op saying to plug the PV and jet up.

Instead of that, use a 45 PV and that will keep extra fuel from being drawn into the engine from the PV opening at idle w/the transfer slot overexposed. If the idle slot wasn't overexposed, the PV being open at idle would be far less of a problem. But as it now stands, the PV needs to go down to a 45. As was said, this is idle vacuum IN GEAR if it's an AT, neutral if a stick.

 

I will see if I can locate a 45 and see how it works.

 

I found a 35 new in the pkg in my shop, will this do?

 

For the time being- YES. It's better than the 65, for sure!