Quad carb setup information help

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rod7515 said:
Ok, ill get it to him in the next week or so. Ill have him shorten it up about 6 degrees as you spoke of earlier to get me to 22*. I already let him know where I was looking to get to in base timing, the only problem would be if this distributor is not capable of being changed. Hopefully it will all work out. I really appreciate all the help and guidance. As I move forward there will be many more questions. Lol.
Thanks,
Rod
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Yep, there is the possibility you can’t adjust that distributor. That would suck. Keep us posted. This will be fun.
 
That would suck because then I might have to replace the ignition box as well. When I did the modifications to it they involved running all new wiring one piece of wire at a time. There fore the wiring may not be the correct color and I did not update any drawings as I went. Yes that wasn't smart but I kept telling myself I would and of course I didnt. Bottom line is hopefully that distributor is adjustable!
Rod
 
I received my pin set, drill set and a couple of pin vises today. Also got my Edelbrock unit sync as well. So I've got to fit the gage to either the plastic carb caps or the KRC metal cap. Was wondering what size hole you cut to fit the gage to a cap and how did you fasten it down? Also when you are using it once its mounted on a cap do you put a gasket between the cap and carb? I realize that I need to take care of the timing before I start with the uni-sync.
Rod
 
The hole in the cap has to be bigger than the hole in the Unisyn so the hole isn’t the restriction.

You can use Right Stuff silicone to stick the Unisyn to the cap.

You shouldn’t need a gasket, but I’ve been using a plastic cap. You can feel the engine suck the cap down on the carb. If you use the aluminum cap, you may need a gasket.
 
Took the car out for a ride today. I will say that it doesn't seem anywhere near as rich as it did on the first start. I have the throttle plates totally closed on both carbs and idle screws backed out off stops. It idles at about 900 rpms in gear. Its a little low but doesn't load up at all and will sit and run forever that way.
I want to get the distributor out and check to see if it can be changed but I need to wait another 2 weeks before it can be done. I the meantime I plan on moving the timing up to see how it handles more advance.
My edelbrock synchronizing gage came so I will get that assembled to the top lid and see if I can play with that awhile even tho I will probably have to do it again once the distributor is changed.
During my ride today the I noticed a slight boog around 2500 -2800 rooms while driving. Again its very slight. I also plan on adding my bungs in my exhaust to see what ratio I have. How do I know where to put them to get the best readings? Should I put one on each side?
This is all new to me so I really appreciate the but help.
As for the distributor how did you come to the 6* distributor change and is that still the number you think is best?
Thanks Rod
 
rod7515 said:
Took the car out for a ride today. I will say that it doesn't seem anywhere near as rich as it did on the first start. I have the throttle plates totally closed on both carbs and idle screws backed out off stops. It idles at about 900 rpms in gear. Its a little low but doesn't load up at all and will sit and run forever that way.
I want to get the distributor out and check to see if it can be changed but I need to wait another 2 weeks before it can be done. I the meantime I plan on moving the timing up to see how it handles more advance.
My edelbrock synchronizing gage came so I will get that assembled to the top lid and see if I can play with that awhile even tho I will probably have to do it again once the distributor is changed.
During my ride today the I noticed a slight boog around 2500 -2800 rooms while driving. Again its very slight. I also plan on adding my bungs in my exhaust to see what ratio I have. How do I know where to put them to get the best readings? Should I put one on each side?
This is all new to me so I really appreciate the but help.
As for the distributor how did you come to the 6* distributor change and is that still the number you think is best?
Thanks Rod
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What power valve are you using? That slight bog could be a lean spot because the power valve is opening too late or it could be a rich spot because it’s opening too soon. It could also be the secondaries opening a skosh too quick.

As for the 6 degrees...if we are talking about how I would do it, I’d start with 6 degrees of mechanical advance in the distributor. That’s all. Maybe 7 at the most.

When you have say 6 degrees in the distributor you double that because the crank is turning twice as fast as the cam/distributor. So that means at the crank you’ll have 12 degrees of mechanical advance.

So let’s just say you’ll end up at 35 degrees total, you’ll have 35 minus your 12 mechanical is 23 initial timing. If you end up at 34 total you’ll have 22 initial and let’s say you may end up with 36 total you’ll have 24 initial.

And I wouldn’t let the distributor add any mechanical advance until 2300-2400 rpm and it get it all in until 3300 or so.

That’s what I’d start with.
 
Rat, thanks for the reply. I put the 6.5 PV that came in the kit. I'm pretty sure i have a new set of 3.5 but that's a large jump. I can order a set of 4.5s and or 5.5s to have on hand. What would you go to?
Thanks
Rod
 
rod7515 said:
Rat, thanks for the reply. I put the 6.5 PV that came in the kit. I'm pretty sure i have a new set of 3.5 but that's a large jump. I can order a set of 4.5s and or 5.5s to have on hand. What would you go to?
Thanks
Rod
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I’d put a vacuum gauge on it and drive it and then see how much vacuum you have when it stumbles. If you are at (just guessing here) 16-17 inches of vacuum and it stumbles on tip in then I’d try a power valve that opens sooner. If the vacuum is lower you may need a later opening power valve.
 
Rat, I'm away for the weekend but next week I will check it out before I pull the distributor. Ill need to go get some of Pennsylvania $4.79 per gallon gas first. This is well beyond the highest in my 62.5 years of life. This government is trying their damndest to ruin the car hobby
Rod
 
Only $4.79? You lucky fella! We are paying $7.57 for low octane & $8.52 for hi octane. And prices are expected to rise....
 
So I think I'm going to pull the distributor this weekend and take it to have the mechanical advance redone. Before I do this should I move my timing up to 22-24 initial and drive it to get it hot then make sure it will crank without kicking back? Just want to make sure I don't miss any steps I should check first.
Thanks, rod
 
rod7515 said:
So I think I'm going to pull the distributor this weekend and take it to have the mechanical advance redone. Before I do this should I move my timing up to 22-24 initial and drive it to get it hot then make sure it will crank without kicking back? Just want to make sure I don't miss any steps I should check first.
Thanks, rod
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Yes.
 
Well a few months have passed and I haven’t had a chance to complete this task. It’s funny how life gets in the way. Tonight I was able to take the time to balance the 2 carbs as well as move the initial timing up to 20*. Took it for a short drive after it sat idling for about 20 minutes while I adjusted the carbs. Probably a total running time of 40 minutes. I turned it off and let it sit for about 20 minutes before trying to restart it. Cranked over fine so this weekend I will add4 more degrees of initial and see how it cranks. If ok I will be pulling the distributor next week to have it recurved. My apologize for not getting this done sooner. Thanks for all the help.
Rod
 
So today I moved the distributor up to 24* then 26* and no issues starting at all. Since moving the timing the car runs cooler and is definitely using less fuel. So I ready to pull the distributor out and hopefully it can be recurved. I will ask for him to reduce from the mechanical advance of 10* now to 6* going forward. Once that’s done we can start on the carb updates. Again thanks for your help with this.
Rod
 
Pulled the distributor out tonight. Going to drop it off tomorrow to see if it can be recurved. I’ll update as I have information.
Rod
 
Dropped off the distributor today and hoping he can recurve it. Once its done i can get back on track to adjusting the carbs.
Rod
 
Rod,
You are doing the right thing: getting the ign timing correct BEFORE touching the carbs. So many people do it the other way round & get into trouble....
 
Thanks Bewy. I’ve gotten great guidance from Rat Bastid (Tim) during this tune up. I look forward to getting to the carbs and making the changes needed to make this set up work correctly. Had a slight set back yesterday when the trans cable broke but should have a new one early next week.
Rod
 
Update on distributor curve change: the pro form distributor was able to be recurved. He called me tonight and told me that he gave me 7* of distributor advance (14* at crank) at 3400 rpm. I ask him what it had before he made the change and he said more then 14*. That would be all but 28* at the crank. Going to go pick it up tomorrow. Cost was $85 to have it done. He did advise that if the distributor gave me any problems he would recommend going to a Chrysler distributor to replace it. Says he is sure it would work with the pro form ignition box I have. I’ll get the distributor back in but I also need to replace and modify the trans shifter cable routing first so I don’t have the same broken cable issue in the future.
Rod
 
rod7515 said:
Update on distributor curve change: the pro form distributor was able to be recurved. He called me tonight and told me that he gave me 7* of distributor advance (14* at crank) at 3400 rpm. I ask him what it had before he made the change and he said more then 14*. That would be all but 28* at the crank. Going to go pick it up tomorrow. Cost was $85 to have it done. He did advise that if the distributor gave me any problems he would recommend going to a Chrysler distributor to replace it. Says he is sure it would work with the pro form ignition box I have. I’ll get the distributor back in but I also need to replace and modify the trans shifter cable routing first so I don’t have the same broken cable issue in the future.
Rod
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Damn that guy works way too cheap.
 
Picked up the distributor today. Took it straight to the garage and put it in. Started it up and left it get to operating temp. Set timing at 23*. Total comes in at just about 3400 rpm’s to 37*. I’m going to need to paint some lines on crank as my eyes aren’t as good as they once were. But it looks like I should be good. Now I need to replace the trans cable before starting on carbs but with a holiday weekend coming and a vacation week it’s going to be delayed a week or so. I just don’t think I will get a chance to work on it this week. Maybe if rain comes tomorrow I can sneak into garage. Let’s hope.
Rod
 
So just a quick update on where I’m at before I left for the week. I did get back to the garage but not for very long. I was able to pull the old trans cable out, I dropped the trans pan to change fluid and filter and got pan back on but that’s as far as I got. Now for the week of relaxation.

Once I get the cable back in my plan is to drive the car and get some idea if the timing needs a tweak and also what kind of vacuum I have at different RPM’s and throttle positions. Does anyone have a routine or drive method to get the best info? Also before the distributor change it had a hesitation when adding harder then normal throttle and I thought maybe it was the secondaries coming in to soon. When I built these carbs I bought the diaphragm spring kits and I used the lightest spring that came in the kits. Which one would you have started with. And of course I may need to do some changing to the metering blocks as well. I guess this is where the true tuning begins.
Thanks Rod
 
Start with the middle spring. If it takes the hesitation out, you can go to the next lighter spring until it just gets that hesitation then go back one stiffer spring. It’s been forever since I’ve done a TR with VS carbs. I used to buy the tops for the vacuum can that you can hook a hose up between the two carbs. Not saying that’s an issue, but 1984 is a long time ago.

The best thing to do it have someone ride with you to write down important things you need to see relative to vacuum readings. Like gear, MPH, RPM etc.

That way you can get an idea of where you are as far as idle jet, T slots, transition or on the mains. You can also get a good idea where you need to be for power valve opening.
 
HOLY CRAP ON A CRACKER! Wow. I just looked up those covers. Holley part number 20-28. Summit gets 116 bucks for that part number. It used to be 2 in the kit but it doesn’t specify if it’s two of them buggers or just one.

If it’s a pair of them that’s not all that bad for 2022 prices but dayum. I’m thinking 30 dollars each. Not 58.

The vacuum cans should be hooked together. It says it gets them to both open at the same time. That COULD be part of the hesitation. You have one carb opening the secondaries sooner than the other one. That generally pisses a carb right off.
 
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