Hemi with Joe Hunt Hei cutting out...

It's driving me crazy....here's the recipe 392 hemi, 4 barrel Edelbrock, with Joe hunt mag look a like Hei. It's runs fine at idle and all speeds unless I put my foot in it, then I can hear it cutting out. So that should be fuel or spark right? I used a vacuum gauge to time it cause I don't have a degree marker, so I'm pretty sure that is right or close. I have a jet/spring kit but I remember I used carb manufacterer suggestion. Can someone tell me where to start?

 

That sounds like a too wide a gap on the spark plugs, or that you have Champion spark plugs.

 

Check all your grounds and make sure that is not a problem. maybe look under the cap for something loose and make sure that your plugs are screwed in good and that you don't have a loose plug wire or any other loose wire for that matter.

That should give you a starting place.

 

I would no doubt loose the eddy carb but not an AFB I need one of those and every one that someone else uses is one that I can't have.

 

Didn't see it. I have one compe***ion series for my 2x4 and I was just going to fudge and tune. I will have to dig deep I haven't run an AFB in a long time but I don't recall it being rocket science when I ran them the first time.

I am going to have to sell a couple of carbs I wanted to keep so that I have spending money I guess.

 

Ok guys, I'll start with gap. If I remember I set them to factory gap. Are you hemi guys leaving that ring on the spark plug? I can't remember which brand plug but. I'll check that too. The carb was a leftover and I was broke after the hemi - if you know what I mean.

 

This is good advice, but it goes without saying that you do it one at a time.

 

I had this problem with a eddy carb. I thought it was in the secondaries so I locked them from opening and test drove it. The problem went away so put on a holley DP I had for the mud truck and it ran great.

Do not know why but the eddy carn based on the AFB just doesn't work as good as the old comp series. I but the old carters at every swap meet for $25 a piece, the eddys are $75 plus LOL

 

You have to leave the gasket (ring) on the plugs unless you are running aftermarket heads and they have taper seats.

 

Gotta disagree on this.

All oem info say the gasket has to go. The soft aluminum plug tube is the gasket. The exception is when the steel tube is used.

Any hei worth its salt will fire a 0.050 gap.

'Read' the plugs and see if one is misfiring. Plug reading chart here.

.

 

Find TDC on that 392, set up a pointer, and set up for correct spark advance! Too much advance will make engine "cut out" and also will destroy the engine!
Dave

 

Never heard that thanks for clearing that up.

 

If you think its the Joe Hunt call McLemore Automotive in Baytown and he wii check it for 25$ and thats a lot cheaper than Joe Hunt

 

Also I have the same setup you do except mine is a 331 and I run .50 gap

 

that distributor is **** and you need a pointer and timing tape,get the timing right first i think it has 22 or 24 degrees of mechanical timing its been a while since i had it open

 

That's the LAST two things I'd do..... Replacing a HEI type distributor with a point type is just crazy talk. There is a reason points and AFB's are replaced with reliable parts. You already have a WAY better setup.

Have the distributor checked out to make sure it is working correctly, then move on to the carburetor. If it's a basically stock 392, the Edelbrock will feed it just fine. They are user friendly and easy to tune.

 

In the past i heard of problems with those fake magnetos, dunno if they cured the problem or what?

 

I had a fake mag on my last 32 roadster, SBC 383 stroker. It also cut out. Sent it to Joe Hunt to go through it. Still cut out. Pulled it and put a real Vertex from my race car and it ran fine. I still have my fake mag hate not to use it. I'll try McLemore Automotive and see if they can find anything wrong with it.

 

we were running the same setup an a 354 with twin edelbrock 500s, and having some of the same issues. We did not have enough grounds. Once we added a couple of new grounds problem solved. It's now runnig a 671 with the same setup of carbs and distruibutor. And it's hard to slow it down.

 

Like some of the guys have said the distributor is a problem. I get them in quite a bit with problems.

Issue is its NOT a true HEI and uses a pertronixs control module sitting on a aluminum plate within 1/2 inch of a high energy ignition coil. When the coil is producing max load spark the magnetic field makes the pertronixs controller act up.

I really dont think this is a fixable issue. I have done a few and dont really know the fix as we have replaced parts with the new factory parts and still had issues. Wide plug gaps would make the problem worse.....

 

I gotta agree with Bubba. Its the fake vertex that is your problem. I have seen this problem with 1/2 a dozen of these. Replace with small body MSD and never worry about it again. The carb is not your problem. Get rid of the fake mag.

 

I had no idea the fake mags were such a problem. I REALLY wanted to suggest the MSD, but was hoping for the best outcome on the other. I use MSD products in anything possible. No problems, EVER.

 

i've had a hei/mag in the box for about 4 yrs. and i'm getting ready to install it, so i started reading the install sheet, looking on the web. to see others who have installed them. i read that they don't like to be rev'd above 4500 rpm. so then i thought i would call vertex to ask about this. it's not on their web site anymore. they said they took it off while they re-design it? and to call back in a month. we'll see.

 

Well I have say it pissed me off! I have real mag but I am afraid it will mess with my pacemaker so I went this route. I'm going to try mclemore in Baytown and ill report back. Maybe they have figured something out. Thanks for all the help guys.

 

A friend has one. No joy and no support. It has been on the bench sitting there and looking pretty. Spendy shop art at this point.

 

Is there a way you can remove the coil from it and hide it on the oposite side of the firewall? dunno what the insides of them look like.

 

I ran a Hunt mag look alike in my 289 Ford. It started to do just as you describe, then a few weeks later, hit the key nothing. It was if I had jumped a timing gear, backfired like crazy. Took it out put my points back in with a MSD 6AL box behind it. Haven't had a problem yet. I think its a fairly well electronically shielded box so that it wont mess with a pacemaker.

 

Actually that conversion would work very well. BUT you would need a couple trigger wires coming out somewhere ( the easy part) and you would need to run a external coil lead into the distributor cap.The distributor cap for a Vertex with external coil is approx $90.
I would be more than happy to convert one if someone wanted it done....

 

After reading the threads with the broke of poor performing units, i would like to make a hamb board offer.
I think the fix is to make the unit work by using a external ignition coil. The pertronix controller will work fine if you remove the coil. My mag shop friend down the street here in indianapolis has the kit to convert the vertex cap to external coil or i think we can hide this coil wire inside the housing and come out the bottom of the case where it wouldnt hardly be noticed. Once we do a couple we can write up a step by step fix for these broken units that would work very well in a hot rod.
Best of both worlds run good and reliable and look like a mag!!!
What ya think???

 

thats what i was thinking, youd actually be only adding 1 wire and a coil wire, should be easy to hide, you can add a second post so it matches where the hot lead went originaly.
jeff