Max fuel pressure for Carter 3705 carbs?

[4406bbl]

I can't think of anything else. Maybe the bowl gasket overhangs the float bowl a little bit and rubs it. Float mechanically hits/sticks with side pressure somehow.

 

[Geoff 2]

Forrest,
What you have is oil smoke. It is NOT the carb, or the VA or the PCV. The max wedge [ MW ] intake does not use the bathtub sheet metal gasket that is used with regular big block intakes. The front & rear of the MW intake seals the valley area, with a cork type gasket. The intake face of the cyl heads are sealed with a composition gasket. I have an exploded view of the MW parts, & it shows this.
If the block has been decked, heads milled, or the intake has warped, the intake may have a gap between the heads & the intake, which the gaskets are not sealing. Oil slung up from the crank hits the underside of the intake & because there is vacuum in the intake, oil gets drawn [ sucked ] past the leaking gasket.
I said this many posts back now & this is the most likely cause of the oil smoke.

 

[Dragon Slayer]

This can be the valve guide seals as I mentioned before. Do you know what type they are? Pulling the valve cover and have a look.

 

[fmahannah]

So I have oil smoke and an intake full of fuel .... awesome. I guess I will just go ahead and pull the intake and the valve covers. Gaskets arrived today for these. I will let you know what I find. Thanks!

This can be the valve guide seals as I mentioned before. Do you know what type they are? Pulling the valve cover and have a look.

According to the build sheet they charged him for MAHLE Original B45403 and MAHLE Original B45343 seals, will know more when I pull valve covers.
Is there any way to get these wedge valve covers off without having to pull the intake? They did not use allen head valve cover bolts so I can't get to all of them.

Thanks

 

[Geoff 2]

Forrest.

Just to add to post #142.
- I would not use the cork end gaskets. Cork belongs on a Model T...Use silicon.
- old gaskets removed, sit the intake in place; measure the gap between intake & head, for both sides; make sure the intake gaskets are thick enough. No good trying to seal a 0.070" gap with 0.060" gaskets....
- do NOT use silicon around the int port openings. Any petrol from a carb flooding etc will turn silicon into jelly. Use Permatex/Loctite #3 non-hardening cement or Loctite 515/518 gasket maker.
- to stop any wicking up of oil past the intake bolt threads, use Loctite 567 pipe sealant. Clean male/female threads first with lacquer thinners for a good seal.

 

[fmahannah]

Forrest,
What you have is oil smoke. It is NOT the carb, or the VA or the PCV. The max wedge [ MW ] intake does not use the bathtub sheet metal gasket that is used with regular big block intakes. The front & rear of the MW intake seals the valley area, with a cork type gasket. The intake face of the cyl heads are sealed with a composition gasket. I have an exploded view of the MW parts, & it shows this.
If the block has been decked, heads milled, or the intake has warped, the intake may have a gap between the heads & the intake, which the gaskets are not sealing. Oil slung up from the crank hits the underside of the intake & because there is vacuum in the intake, oil gets drawn [ sucked ] past the leaking gasket.
I said this many posts back now & this is the most likely cause of the oil smoke.

Would oil getting past the intake seals be enough to make the car not respond to the accelerator unless it is slowly pressed allowing the car to catch up? Note it only behaves this way once the smoke has started, not before.

Thanks

 

[fmahannah]

Forrest.

Just to add to post #142.
- I would not use the cork end gaskets. Cork belongs on a Model T...Use silicon.
- old gaskets removed, sit the intake in place; measure the gap between intake & head, for both sides; make sure the intake gaskets are thick enough. No good trying to seal a 0.070" gap with 0.060" gaskets....
- do NOT use silicon around the int port openings. Any petrol from a carb flooding etc will turn silicon into jelly. Use Permatex/Loctite #3 non-hardening cement or Loctite 515/518 gasket maker.
- to stop any wicking up of oil past the intake bolt threads, use Loctite 567 pipe sealant. Clean male/female threads first with lacquer thinners for a good seal.

I bought intake gaskets but the ends are cork. Where can I find a set with silicone ends that you would recommend?

Thanks

 

[4406bbl]

The silicone will be in a tube that you squeeze into place. I like permatex right stuff brand for this. I have never seen intake valve seals cause hesitation like that, just smoke, and have seen them deteriorated down to failure.

 

[4406bbl]

On the loctite 518 it is designed for metal to metal connections, it dries from the absence of air. It may work but I don't know. With an intake paper gasket I would use permatex #2 tube or #3 brushable.

 

[fmahannah]

New intake gasket installed, letting it sit overnight and will test drive tomorrow. Could not really see any sign that the intake gasket had been letting oil past it but you never know.
Valve stem seals looked fine and still flexible.

 

[Geoff 2]

I doubt that leakage past the valve seals is causing smoke. Some engines only had an o ring on the valve stem for oil control.....& didn't blow smoke.

It sounds to me like you rushed the job. Did you check as I suggested to see what the gaps were between the head & intake, to make sure the gaskets would compress some? Sealant on the bolt threads?
As for the cork end seals, do not use them. Use a thick layer of silicon.

 

[fmahannah]

Just thinking out loud here about the changes I made to the car before it started the smoking after driving...

Is it possible that adding a holley pressure regulator with no return line to the system with the carter mechanical fuel pump when under load might overpressurize the system and blow the needles out of the seats?
Thanks

 

[fmahannah]

I doubt that leakage past the valve seals is causing smoke. Some engines only had an o ring on the valve stem for oil control.....& didn't blow smoke.

It sounds to me like you rushed the job. Did you check as I suggested to see what the gaps were between the head & intake, to make sure the gaskets would compress some? Sealant on the bolt threads?
As for the cork end seals, do not use them. Use a thick layer of silicon.

Yes I checked everything off your list and used right stuff on the ends per various examples I found online.

 

[fmahannah]

Test drive result after intake gasket changed .... same exact behavior as before. Drive a mile, turn left, smoke starts and engine runs very poorly so I limp it home
And again what smells like fuel laying in intake around bolts when looking through access plugs, entire intake interior seems wet.

Later I am going to remove the holley pressure regulator just in case and take another test drive, I still think it might be fuel related and other than the carbs themselves that is the only fuel system component that I changed.
Before I replaced the carbs, distributor, and added the regulator the only issue I had was running rich at idle. No exhaust smoke after or during highway driving, so I have to assume it is something I changed

 

[4406bbl]

As others have said try lowering the pressure down and see what happens before you remove it. I would check the floats for binding, push them side to side, see if maybe a bowl gasket overhangs and rubs/snags it, floats are level, and if nothing is found lower the floats 1/4" and see what happens.

 

[fmahannah]

Ok floats don't seem to be binding, not sitting crooked, replaced all four with new ones again. Set fuel pressure all the way down to 3 lbs. Running rich at idle again, definitely fuel, no need to test drive.
It was not running rich at idle before replacing the floats and dropping the fuel pressure.

Set float height from 3/8 inch down to 5/8 inch so inlet should be closing sooner, but now it is even richer at idle than it was before. Makes no sense to me when changes that should make it better make it worse.
I iwsh these had sight holes to dee actual fuel level while running.

Turned mixture screws in hoping they were too rich now, not the case as turning them in a half turn and waiting a minute would eventually stall the car.

Honestly I am ready to admit defeat and flatbed the car to someone else and telling them to do whatever it takes and call me when it is ready

Thanks for trying to help out, but obviously I am doing something wrong here

 

[Geoff 2]

Try running with just one carb. Get a Cornflakes box or similar, fold it over for double thickness. Punch out 4 holes for the mounting studs & fit under one carb. Of course disconnect the throttle linkage. Leave the fuel line hooked up. Get it running & see how the idle is. Remove the cardboard & see it is dry. Repeat with the other carb.

 

[4406bbl]

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.

 

[Geoff 2]

Just a bit of levity after 157 posts....

I worked for 3M for 27 years; one of their service manuals had a loooonoog list of troubleshooting tips for a particularly troublesome area of this machine. The final tip: pray for divine intervention. True, not a joke!! Someone had a sense of humour....

 

[fmahannah]

Try running with just one carb. Get a Cornflakes box or similar, fold it over for double thickness. Punch out 4 holes for the mounting studs & fit under one carb. Of course disconnect the throttle linkage. Leave the fuel line hooked up. Get it running & see how the idle is. Remove the cardboard & see it is dry. Repeat with the other carb.

I might have to try that! If both carbs are flooding even that would tell a story. At this point I will try anything. I have rebuilt and restored seven AMC Javelins and have never had this much trouble with fuel systems.

One thing I noticed though is that the AFB floats I bought from quadrajet parts have smooth sides and seem less tall than the stock ones that have grooves in the sides. I also bought their rebuild kits.
Anyone know of a different source for kits and floats for Carter 3705 carbs that may not be as generic?