Need help tuning a 6x2 on a 364 nailhead

Bought the complete setup from a company. 6 Rochester carbs with only the two middle ones functional. They installed it and it ran like ****, so I dropped it off at their shop and they had it for about a week. When I picked it up, they said it had a dead cylinder. after an additional $900, I couldn't even drive the car into the trailer. I brought it back to the shop and took a look at it. Well I found the vacuum port on the driver's carb was not plugged off, and after the engine is shut off, the driver's carb dumps fuel onto the ****erflies from I'm ***uming the discharge nozzles. Pulled the tops of the carbs and found that the driver's side float was 1/2 full of fuel so I got that taken care of. Then I noticed the float settings were different between carbs. Then I noticed the bases were different and the floats were adjusted according to the bases, but they put the wrong tops on the wrong bases. So I swapped those over and got the car running, but it still has issues. When I bring the R's up, it backfires out the exhaust. It starts backfiring around 3,000. It idles pretty ****ty as well but at least it's idling now.

So in a nutshell, after finding all of this stuff out that you would think would be mindless for someone who does this for a living, I'm wondering if I should tear completely into the carbs and double check everything. I ordered a carb book but it won't be here for a couple of days, what do you guys recommend?

 

AS you well know not everyone who calls themselves a "PROFESSIONAL" is desserving of that ***le.
Given what you've found out so far I'd DEFINITELY be taking them totally apart and double checking everything. Either that or find someone who really is good with carbs.

 

What are you running for a dist??stock?? points?? when we ues to run tunnel ram engines we found that the old points were junk.What you are saying is happens at 3 grand is what use to happen to us.Setups like this do need a hotter spark to run.Also you said that it only runs on the two middle carbs,Are the other carbs open to the intake? It might be taking in too much air from the outside carbs.Oh by the way very nice setup all the same.

 

have you checked it extremely well for leakage around the unused carbs?? maybe spray some brake/carb cleaner around the bases to check. have you sync'd the carbs to each other yet? they are probably out of balance. different bases usually flow different rates.

 

You didn't deal with Eelco did you?

 

As far as the spark, I installed a Pertronix in the stock distributor with new cap, rotor, plugs and wires. The outer carbs are blocked off with plates which I've checked for vacuum leaks. I don't think the carbs have ever been synced together. Could you run through the process Revkev6? I don't care to get into who I got the setup from as it doesn't matter to me much right now. I just want to get the car running correctly.

 

EELCO strikes again!!.............OLDBEET

 

Here is how I do it. The object it to get the same air flow through both carbs. Your linkage will be different but just disconnect it until you get them balanced. Once both carbs are flowing the same and it's idling where you want it, then you can hook the linkage back up.

Are you still running the same plugs after all the flooding problems? They sometimes clean up on their own but might still break down under a load.

 

Thanks for the help Tommy. Very informative. I did a little looking and found a carb synching tool similar to yours made by Schleyer, $30 through JC Whitney. I'll throw a new set of plugs in there just to eliminate the possibility of that being a problem.

 

Holley or edelbrock makes a tool called the "uni-sync". I think it's like $25 through summit or jegs and they won't **** you on shipping like JC Whitney.

 

I'm with Tommy, put some fresh plugs in it. Sure sounds like a lean backfire though. I don't know much about buicks, but I had a 56 bel-air with 3-2's on it. Functional. Am I understanding this right? One carb is feeding four cyls and the other four cyls? As Tommy said, I would pop the linkage off, back the idle speed screws off till the blades are closed. Open them an equal amount ( one turn, two, whatever) shut the idle mixture screws down, open them a couple turns and start it. Just make sure you do the same for both carbs when you do something to one do it to the other, baby steps back and forth. If the float levels are the same, both carbs are in good shape, no vacuum leaks, it should run. If one carb is open a little more than the other though, you will get a lean pop. They would have to be pretty far out of sync though I would say. Hook up your linkage and you should be close. JMO. Just make sure THOSE NON FUNCTIONING CARBS ARE SEALED OFF!! Or POP, POP, POP. !!!You'll never get it to run if they aren't. Lippy

 

In the process of getting a carb synching tool. I've been monitoring vacuum on both carbs and they're about the same with approx 15 inches of vacuum. Pulled a plug and it's black as coal...fuel pressure is about 5psi. I'm also having to advance the timing on the motor really far to get it to run, in the neighborhood of 24 which I'm ***uming is to compensate for the rich mixture.

 

Snowman, does it make any difference when you shut the idle mixture screws down? 24 deg timing? sheesh, I'd put the timing back where it belongs and figure out why it's rich. JMO. You are talking about 24 initial timing right? Lippy

 

Lippy, yep 24 with the vacuum adv. disconnected...I'll set it at 12 and see what I can do to get it to run.

 

Well I got it running on 12 degrees. The plugs helped out quite a bit. They've been ran on really rich for quite a while. I'm only getting about 14in of vacuum at idle, but I know the engine is kinda tired, so that's okay with me. It still seems to have a misfire at around 3k. Also if I stab the throttle, it will back fire out of the carbs.

 

Had a heck of a time getting my 4-94's on the y-block set up untill i got the uni-syn tool from speedway , cured all my problems , quick, easy and cheap.

 

I think for now I'm gonna let be until I get the Uni-syn this afternoon. No point in spinning my wheels. Thanks guys for all the help. I'd always prefer learning rather than paying someone else.

 

They have done a lot of work for me and did a great job. I think you need to find a new hobby. Some of us are really tired of your drama

 

Well I thought I would give you guys an update on the progress of the car. After I got the Uni-sync, I was unable to get the carbs sync correctly. Well I ended up dropping it off at the guys' shop that I got the setup from so he could mess with it on his dime. After a good month and no real progress, I went to go pick the car up. When I got there, the car could even drive under it's own power. As he was pulling it out of his shop, he s****ed the side of the car down some railing next to a loading dock taking some paint off of the rr quarter above the wheel arch. So then, the car was left there for him to take car of fixing the paint on the car as well.

After constant phone calls and excuses to failed promise dates I finally just told him I was coming to get the car (about two weeks ago). He told me at first he found one of the accelerator pumps sticking in the bore, so he used the base off one of the other dummy carbs after mic-ing it. Then during the rebuild he found that his employee who built the carbs forgot to install the power valves. He continued to de-jet the car all the way down to a custom made set of 36s! When I got there of course the car still wasn't running right and the paint fix was immediately noticeable. I had to once again winch the car into the trailer.

Once I got it back to the shop, I immediately noticed a couple of things as soon as I pulled it off of the trailer. The linkage to the p***enger carb was left disconnected and the throttle stop on the driver's carb was installed backwards. So after quickly fixing those things I was able to drive the car back into the shop. So I went back to the basics and started off by checking for vacuum leaks. Well the new base he put on the p***enger side carb has two small holes on each side near the rear mounting bolts that weren't plugged in any way. So I temporarily plugged them and continued. I found another leak on the driver's intake manifold. So I pulled it off and found what is in this picture...

I called the guy and told him what I found and of course his excuse was he was blind with frustration and he would send me a gasket right away. Well five days later and no gasket and no contact I called him and he said he had some on order and was expecting them any day. So I just made my own. Of course now the car is running super lean so I re-jet the carbs to a set of 40s and start from there. After I get it back together, I reset the timing and now I get around 21 in/hg of vacuum. Now that the car idles, I continue to try and sync the carbs. I can set the uni-sync to the p***enger carb and as soon as I set it on the driver's carb, it chokes out and dies. I check the idle mixture screws and they are back out to around 4 turns. I correct that issue and continue on. Well after double checking everything, I pull the plugs and give them a look. The p***enger side plugs are looking good but of course the driver's side are black. So I pull the tops off the the carbs and I think the remaining pictures will describe themselves as to what I found:

 

makes me want a vespa

 

Holly ****! I hope the 6 deuce set-up on my Cheby isn't as big a problem as you are having. I am plannin to run all 6, Yikes! I feel you pain man. Good luck.

 

That ****s, spending all the dough and getting garbage. Then the shop damages the body, installs junk parts etc...If it is who I think it is they have a bad rep on this board and others for similar concerns.
Do you still have a dead skip at idle? sounds like you may have gotten rid of it if vacuum is up to about 21"/h2o.
DId you have the motor running with a single carb before the 6 carb setup was installed? Just curious if the carbs are the only problem.
If you still have a skip at idle as well as backfire, you might want to pull the valve covers and make sure all the lifters/rockers etc.. are in good working condition. Also double check all the plugs and plugwires, firing order etc... Even if you had them right, did the shop move anything trying to find a solution?
Just cover the basics.
Next, get some good rebuild kits for the center carbs and do it yourself. Take your time and keep everything as clean as a hospital operating room. Once re***embled, turn the idle mixture screws in a little towards the lean side and start briging them out slowly. You might also want to bump the timing up a little to about 16-18 initial.
You will get this done in time and you will know how to do it the next time you build a similar project.
as far as the shop which damaged your car...I would be looking for someone to pay for the proper repairs needed on the body, and some of the $900 back you spent the first time for nothing.

 

This skip at idle is gone and it can rev pretty good, but the syncing shows that the carbs are way off side to side. I'm pretty sure it's an incorrect float level setting on the driver's carb. I'll fix that in the am and see what happens. As far as the shop damaging the car, I will be working out the details shortly. My focus is set on getting this car right. If I was to do this project again, I would have learned how to build the carbs myself, source the correct parts and keep people out of my shop, which is what I reccomend you do 28oakland. Hindsight is 20/20.

 

Sorry you had to find out this way...

 

.........................................uhhhh.......

 

Well, I corrected the float level on the driver's side carb and re-***embled the carbs. Ran the engine for a bit, which is getting a lot better but I've again noticed a couple of differences between the carbs. I'm still having trouble with the driver's carb when I put the uni-sync on it...it wants to choke out. So I got to looking down inside the carb while it running and notice d that when I increase the Rs, there are two pinholes in the discharge nozzle by the center mounting screw that fuel comes out of only on the driver's carb. So I popped the tops back off and noticed the driver's float is off again. Then compared floats and noticed they are different. There is also a br*** valve in the bottom of the fuel bowl, that too is different between carbs:


I'm going to correct the float again and put it back together and see what happens. Any ideas anyone?

 

I finally figured it out! I browsed around the net to find a service manual for these carbs since I left mine at home. When I pulled the carbs back off, the driver's float was ok this time. Then I started reading up on the fuel p***ages and vent and vacuum ports. After a little visual investigation I came across this hole (indicated by the red arrow).

This is where an idle vent valve would go, but in this case is plugged on the p***enger carb and left open on this side. This also explains the float level problem. When I put the uni-sync on the driver's carb, it creates an improper vacuum inside the bowl when this hole isn't plugged, thus overfilling the bowl and bending the float tang...also causing a rich condition. So I plugged that hole with my finger and what do ya know, I can sync the carbs!

 

So does it run OK now?

Nevertheless, this is about someone that is not giving up, and rather learn himself.

My hat's off to you, snowman.

Let us know.

 

Well I'm in the process of jetting the carbs now that they're correctly ***embled. When I got the car back, there was a set of custom 36s installed. I'm now up to 63s and the car is still running lean! With the 63s, it idles nice, free revs good, but when held at a constant high RPM or under load there is a lean stumble/miss. So I'm gonna try a bigger set real quick and see what happens. It's Friday night and I'm gettin ancy!

 

'Atta boy!! Good to see you are getting towards the end. A little tuning here and there and sounds like you should be good to go.
Glad to hear it is coming along well finally.