• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Max fuel pressure for Carter 3705 carbs?

4406bbl said:
I don't think it is you, maybe some bad parts. I have no answer for too rich with less pressure and the floats set lower. The only time I had flooding that bad with afb is with bad, usually loose needles and seats, or one time a guy rebuilt his avs and did not put the gaskets on the 2 seats.
Click to expand...
Seats and needles are new, but from a quadrajet kit. Perhaps they are not correct. I did put the gaskets in the seats though and completely removed the old ones
 
Last edited:
It is easy to check if the n/s are sealing after installation. Invert the airhorn & suck on the fuel inlet. If you can suck air, they are not leaking.

Both types of floats were used by Carter, smooth & corrugated, but I am not sure what change in float level dimension is reqd when swapping from one to the other. If you have the originals, submerge in some warm water for a few seconds. If they are leaking, you will hear sloshing from inside. If they test ok, re-use them.
 
Here is a video showing float differences. The smooth ones are what I got from quadrajet parts and are likely the same as edelbrock, the corrugated ones are what was in all five of my original carter 3705 carbs. I will test the originals to see if I have 4 good ones to use.

 
OK I just took the holley regulator out of the system thinking it might be bad, made no difference. So all that leaves is the floats so I will find 4 good ones out ofthe ones i have and swap them out and see what happens.
Other than that it would have to be something else that came from the kits like inlet needle and seat themselves or gaskets.
 
QJ needles I thought were shorter than AFBs. Do the inverted test I suggested in 162; that will tell you if the n/s are sealing.
 
Last edited:
I am not being smart but did you call the shop that did this motor, you said you had paper work. Frankly you are easter egging and shooting in the sky. Your fuel pressure has nothing to do with oil burning in motor. No relationship. You are at the point with so much changed and the very good possibility that this motor was a pos that bandaged together. Get it to a good mechanic. There has to be a good car club or mopar club in your area. Your 9 pages into this and you are in worse condition than when you started. And you are spending money on parts that don't fix your issue, other than the carbs.

Geoff, I don't know what to say about your advice. You are dismissing stuff yet you know nothing about the motor but what the op tells you. You have him buying **** and doing crap that has nothing to do with getting his car right. The wrong selection of valve seals for a Mopar can absolutely cause it to smoke and bad. Not only that, but the wrong springs with the seals can knock them off the guides; and his guides clearance can be too loose. But some how from Australia with no real knowledge of his motor you know that is not the problem. Running on one carb with a cross ram is dumb in my opinion and you risk running super lean on one bank. This is not an inline dual quad. You told him it was oil so where is the oil coming from? Do you pull carbs off a car with an oil leak? Are you just screwing with him for fun? Why do you want him to pull the carb if you believe it is an oil leak???

I feel for you and I hope you get your car fixed, but you need to attack this with some logic and recognize what effects your specific symptoms. It can't just be smoke with no source. A good mechanic will stick an af meter in your exhaust drive your car and can hone in on your problem even if he is just eliminating items. Like AF is fine carbs are good.
 
DS,
Get your facts straight pal. Of course I know nothing about the engine except what the OP tells me. Just like you...
I never advised Forrest to get any valve seals, so I don't know where your BS is coming from. Many engines do not have valve seals & they don't smoke.
I DID advise him to get a dist with adj vac adv & now his engine idles & doesn't stall in gear. Money well spent.
What other '****' did I advise him to get????????? I was the one that made suggestions to try & fix his carbs rather than buy another set...to save him money.
Apparently your limited knowledge did not allow you to understand the blocking off the carb with a gasket was to see if it was leaking fuel into the manifold { post #154} [ cardboard wet ], nothing to do with the oil problem.
 
I do apologize for exceeding some unpublished limit on the number of posts considered to be reasonable, but I thought that was what this forum was for, trying to get help with difficult or unusual problems from people who have more exerience in certain areas. Just for clarification here are some points:

1. When I first bought the car it was running rich at idle, idling at 1500 rpms, and not running well. Not having experience with dual carbs I took it to a long established local speed shop to have them tune it so that it idled at a more reasonable speed and hopefully not so rich. They reported that one of the carbs would not respond to mixture adjustments and needed to be cleaned and rebuilt. I was charged around $600 for a carb rebuild and timing adjustment. The only thing accomplished was the idle speed was down to around 1200 rpms. Still running rich and and of course mixture screws had no effect because transition slots were well exposed on both carbs. They never noticed or did not mention the blown out mixture screw seats.

2. The "restored" Carter carbs on it had damaged mixture screw seats. I contacted three pro carb restoration shops (all well known) and all three said they would not attempt to repair my carbs. So I found and purchased three unrestored Carter 3705s and used them to build two carbs with perfect mixture screw seats. To do this I purchased two rebuild kits and 4 floats specifically for my carbs from quadrajetparts.com

3. Just in case the issue with running rich was caused by excess fuel pressure I installed a Holley billet regulator. Did not help.

4. The only other part I bought was the distributor with vacuum advance recommended by Geoff and it did finally resolve my issues with idle roughness and stalling in gear. Was able to close up throttles and no longer expose transition slots so that mixtures could be adjusted.

5. The issue with smoking after a short drive happened after the above steps. I did not purchase valve seals I simply checked the condition of the existing ones while I had the covers off. A compression test, cooling system combustion gas and pressure test, leakdown tests showed no issues with rings or head gasket. I did replace the intake gasket and valve cover gaskets. After adjusting float levels lower and adjusting fuel pressure lower it is now running way rich at idle again and the smoke that results is pretty much identical to the smoke I had after my road tests, but it is really fuel and not oil when idling. The inside of the intake manifold has fuel puddles laying everywhere. There is even fuel in the carbs down in the slots where the weighted secondary valve sits. When idling there is no visible fuel dribbling coming out of boosters/venturis and tops of primary and secondary plates appear to be dry. Fuel must be coming out below the plates. If decreasing fuel pressure and lowering floats causes a car to run very rich at idle I would say that qualifies as an unusual problem.

6. If this was not a max wedge tribute I would have simply replaced the carbs with new ones and been done with it, but I am trying to keep the Carter carbs since you can't just go buy them off the shelf

Thanks for all the efforts to help but I don't want to stir up any issues here and will continue solving the problem on my own at this point

Thanks again.
 
Forrest No issue and no limit on your post, but without being very clear and specific as you are with the above post you seem to be chasing your tail. When do you want to get a fresh set of eyes on your car. The carb can not go richer if you lowered the float level and lowered fuel pressure. There can be other reason to have fuel in the manifold. So how do we know it is rich and smoke is from fuel? Not water/anti freeze or oil? If you drive down the highway and it bellow smoke that is not rich af. I standby my advice to get a mechanic that works on old cars and one that at least has an AF meter. Even taking to chassis dyno shop, just to let them tell you some parameters of your car at idle and midrange speed.
 
Last edited:
Geoff 2 said:
DS,
Get your facts straight pal. Of course I know nothing about the engine except what the OP tells me. Just like you...
I never advised Forrest to get any valve seals, so I don't know where your BS is coming from. Many engines do not have valve seals & they don't smoke.
I DID advise him to get a dist with adj vac adv & now his engine idles & doesn't stall in gear. Money well spent.
What other '****' did I advise him to get????????? I was the one that made suggestions to try & fix his carbs rather than buy another set...to save him money.
Apparently your limited knowledge did not allow you to understand the blocking off the carb with a gasket was to see if it was leaking fuel into the manifold { post #154} [ cardboard wet ], nothing to do with the oil problem.
Click to expand...

Geoff, it is you that needs to get your facts straight. Your on a mopar site not a GM, Pontiac, or exotic car site. You are way to full of yourself. You have the same selective reading you accuse others off. Mopars do need valve seals with stock heads. Certain seals like teflon don't always work well. So it is irrelevant what some other manufacture does. I never accused you of asking him to buy seals but you declared that can't be the problem. Your wrong. I also gave him a method to repair his carbs. I even gave him an offer to look at them on PM. I got an unsolicated email to be careful about you on another forum. Apparently you have made some outrageous comment on the A body forum. You almost seem to go out of your way to dismiss other peoples comments, advice. And Forest has followed most of your, and here we sit with the car in worst shape. Nothing has been a logical troubleshooting approach.

When you trouble shoot on a forum or via email, you have to ensure what you are being told makes sense too. If his carbs are leaking you can see it by simply taking them off one at a time after the run. Even an inline hemi with a leak will deposit the fuel under the faulty carb. You don't need to stick a cereal box over the manifold.
 
The problem is finding someone near him that will work on his car. Most will throw kits in, not make any progress and charge him a fortune. I think his engine is ok from the tests he has done....but the carbs have a leak. I was going to mention is starts after he makes a left turn, could it be as simple as no weights on the accelerator pump check balls and after a left turn it starts siphoning fuel out of the squirters but he now says it does it at idle again which tells me those are not the issue. He really needs to find someone that knows older afbs inside and out and send them to them, I doubt most shops know much about these carbs anymore. Dragon has offered to look at your carbs, I would take him up on the offer. I think if you get the carbs right the rest will be a lot easier. I assume when you had the intake off you looked at the intake ports and valves in the heads and there was no oil. Even with good compression rings can be bad, being washed by fuel is never good, but it still should run right with the compression you have. It would be crazy to rebuild the engine until you know the carbs are right.
 
I still do not think you can jump to the carb though you have to fix the leak. Venturi screws can loosen, gasket pinched. Top screws tightened equally and no pinch on air horn gasket. Distributor not firing properly, fouled plugs. He was talking about a cold exhaust before this last symptom and the blue smoke only at speed. So those things resolved? Even with the smaller floats if you lowered the level of fuel and your only at 5psi it should not flood. But certainly, need to check the needles and make sure they seal. Small particles can prevent proper closing.
You can't keep jumping to new issues without properly resolving original symptoms. Even if it went rich now, that heavy smoke at speed on the highway was not a rich carburetor, was it? It had to be anti freeze or oil. It was repeatable for a while and now it is gone. How is that possible unless there is leak sealant in the anti freeze and oil additives.
Left hand turn also moves oil to the passenger side head intake gasket inside valley. It moves fuel towards the primary of the passenger carb, and moves fuel to the secondary of the driver carb. Which carb is soaking in fuel, driver or passenger or both?
 
Ya I see your point. I know if it was me that engine would not be run again without seeing both of those carbs run properly on another engine, one at a time or a single 4bbl put on the 426 with a known good carb.
 
DS,
- Instead of sitting behind cowards castle, produce the 'outrageous' email so I can comment on it. I am betting it is from someone who got booted off FABO. If I made outrageous comments I would have got a warning or booted off & I got neither. I have only been a member a short time, see how many 'likes' I have. How many likes have you got???? I am on many forums & have been kicked off one.
- you are still wrong on valve seals. I pointed out how other brands use an o ring that is contained within the v/spring retainer...& that is the only seal that is used. I made no other mention of valve seals that should be used. If you think Mopar is somehow special from other engines that work without seals, please enlighten us....the Mopar umbrella seals often crack/fail but the engine doesn't smoke; valve guide/stem wear will be a factor.
- the disgraceful veiled slur about where I live [ Australia ]. As if I wouldn't have useful information to contribute, when ALL of us are contributing via the web, not in person. The place where the info comes is immaterial, what matters is the accuracy. For the record, one of my close friends owned a 63 Max Wedge Ramcharger, complete with alum front end, the only one in the country for many years. I still have one of the Carter carbs #3447 hanging on my wall....
- yes, I am guilty of dismissing advice when I know it is BS.
- Forrest has followed my advice & his car is in worse shape? You liar. His car now idles & doesn't stall after taking my advice on ign timing. You conveniently ignore the fact that he seems to have more than one issue, & not related. So of course we are moving between issues.
- more BS from you in post 170, & yes I am dismissing it as such: antifreeze smoke is white, & the smoke in the pics is clearly blue.
- just because YOU didn't like the cereal box idea doesn't mean it will not work. It is actually a most EFFECTIVE way to see if there is a porosity or other leakage problem & takes but a few min.
- your problem is you are jealous. You have been king of the kids on this forum in this area & now some one comes along, who God forbid, might know more than you do & you feel threatened.
 
If anyone is still interested, here is the current status. The new flooding issue at idle was being caused by the new float slightly hitting the vertical metal tab that sits under it and kept it from closing completely.
Noticed this when swapping the original floats back into the drivers side carb. Those tabs were bent on the carbs I rebuilt and I had straightened them up when they did not want to go through the top gasket cleanly.

Now with that out of the way I took another test drive. Only went about a half mile before the "blue/gray" smoke started again. Came home and shut it off and restarted, but this time it kept smoking.
Now it smokes (pretty sure its oil) all the time. Not a good sign for sure.

So considering that the compression tests seemed to pass, the intake gasket was replaced, combustion gas in radiator test passed as did cooling system pressure test, what might be the cause of buring oil from startup to shutdown, both cold and hot?
I know it is likely bad news, what else could it be?

Could a compression test with engine warm have shown different results? It now smokes old or warm but wrose when warm I think.
Would a leakdown test on each cylinder tell me anything new?
Can a head gasket let oil into combustion chambers but not affect the cooling system?
Would sticking rings cause oil burning and would they have shown up in compression tests?

If anyone has ideas they are all appreciated. More than likely this is at the point where I just send the car to a Mopar shop in Atlanta and wait to be told a rebuild is needed :(

Note this car was restored between 2003-2005. Since that time it has only been driven 2500 miles or so. That means it has mostly been stored. Worst thing you can do to a car. Adding this info just in case that might shine a light on possible causes.

Thanks!
 
Last edited:
Is it smoking both sides or confined mostly to one side?
Normally a head gasket leak is getting water into the oil or both ways. You have one channel up to the heads for oiling valve train. That is the only pressurized section close to water jacket.
You have to go back and check all the usual suspect again. It is possible you washed out a cylinder or more with the leaking carbs.
Check PCV, look inside intake, pull the plugs and inspect, redo the compression test. Rings/cylinder wall and the head valve seals/guides are the only real source if the intake/pcv is ok. Especially if there is no oil/water mixing. No mixing would be good integrity of the head gasket and block/head between water and oil channels.
I am not a compression test expert but there are procedures in doing them to ensure your comparing each cylinder properly, and I do think you can still pass but have faulty oiling rings and smoke.
 
Dragon Slayer said:
Is it smoking both sides or confined mostly to one side?
Normally a head gasket leak is getting water into the oil or both ways. You have one channel up to the heads for oiling valve train. That is the only pressurized section close to water jacket.
You have to go back and check all the usual suspect again. It is possible you washed out a cylinder or more with the leaking carbs.
Check PCV, look inside intake, pull the plugs and inspect, redo the compression test. Rings/cylinder wall and the head valve seals/guides are the only real source if the intake/pcv is ok. Especially if there is no oil/water mixing. No mixing would be good integrity of the head gasket and block/head between water and oil channels.
I am not a compression test expert but there are procedures in doing them to ensure your comparing each cylinder properly, and I do think you can still pass but have faulty oiling rings and smoke.
Click to expand...

Smoke seems to be both sides, does have H pipe in exhaust though. Maybe slightly more on drivers side. I think it would be odd for anything major to go wrong on both banks at the same time?

No water in oil, no oil in water, no combustion gases or bubbling in cooling system.

When I look inside intake with borescope there is fuel around bolts, but where in there should I try to gt the scope to see signs of oil leaks?

Please explain PCV check method? Valve is clean as is the hose. I would think it should be dirty? It does have slight suction on valve at idle. If the rings are not sealing, wouldn't there be tons of blowby that would need to be handled by PCV system?

For compression tests I followed procedures, same rotations per cylinder, etc. I did not do leakdown tests but I can

Could valve guides/seals cause smoking all the time if they were really bad?

Thanks
 
I am going to say the rings are gone, had this happen on a stock car motor when we crashed and swapped the radiator, it ran a little hot and started smoking, compression was fine hell it won the feature, but the rings were done. We ball honed it in the car and it was back to normal for the next week. Gas wash down and overheating kills rings.
 
1 other thing, it says they notched the block for valve relief, if they went too far the ring may be going above the notch, this assumes it is smoking all the time.
 
You must log in or register to reply here.

Similar threads

Houle #382
11 PSI fuel pressure at the carb
Replies
18
Views
2K
Dragon Slayer
D
Macdon221
Carter 4429 Whistling and Rich...Help!
2
Replies
35
Views
2K
Macdon221
Macdon221
captain clank
CARTER AFB L8 3447SA
Replies
13
Views
2K
GTX JOHN
G
MIKESPOLARA
  • Locked
FOR SALE 1963 FURY 426 MAX WEDGE TRIBUTE $39900
Replies
0
Views
2K
MIKESPOLARA
MIKESPOLARA
fmahannah
Alternative carbs and linkage for max wedge?
2 3
Replies
53
Views
8K
Geoff 2
G
Auto Transport Service
Back
Top