Max fuel pressure for Carter 3705 carbs?

[fmahannah]

Copied after the 64 head, some say that head was better but I liked 63 with the shafts on the spacers instead of pedestals. It’s a wonder those guides weren’t already setup for the perfect circle seals, and cut down for high lift cams. My exhaust never had seals put on just the intake. I had the helicore type bronze guide (the best imo) on both I E but they were tight and never leaked down the guide. Glad you found the culprit.

Yeah it had positive intake seals but just umbrellas on the exhaust. Will have both soon

I don't think there is much you can do about the location/build-up of oil and the drain backs.
I looked at it too and I agree that it can be a problem area.

It is a pain when every time you pull valve covers a stream of oil runs down your block and onto the exhaust, that is for sure

 

[steve340]

If you use guide seals you knock on to the outside diameter of the guide and effectively seal there the oil cannot build up that high.
But another thing to consider is there is a lot of oil flying around in the valve cover to lube the rockers and cool the valve springs. You probably need all that oil it is only a problem when it gets somewhere it should not be.
Make sure the valve guide is not loose in the head. I have seen that once or twice.

 

[Geoff 2]

Hate to be a wet blanket....but I would have the heads crack tested.
[1] Exh valves have new seals. Would not expect new-ish seals to leak so soon.
[2] It seems odd that oil leaking into an exh port would create blue smoke as soon as the engine is started & the engine is cold. What ignites the oil into smoke in a cold engine inside the exh port?
[3] Look for other areas that oil can get into the exh ports. Removable valve guides that were pressed in & cracked the head?

 

[fmahannah]

Hate to be a wet blanket....but I would have the heads crack tested.
[1] Exh valves have new seals. Would not expect new-ish seals to leak so soon.
[2] It seems odd that oil leaking into an exh port would create blue smoke as soon as the engine is started & the engine is cold. What ignites the oil into smoke in a cold engine inside the exh port?
[3] Look for other areas that oil can get into the exh ports. Removable valve guides that were pressed in & cracked the head?

New umbrella seals on exhaust valves, but those ride up and down with the valve and would not prevent oil laying in the head at that corner from getting past the guides.
Car does not smoke until water temp reaches 140-180

I am having them crack tested, all guides redone, and positive seals on exhaust

 

[fmahannah]

Update. The machine shop says all guides are within spec, no cracks either. I am having them install positive exhaust valve seals just in case.
I just took another look at the exhaust manifold from the passenger side. Only the #8 manifold port shows signs of oil traveling out of the
exhaust port and down into the exhaust pipe. Oil there is black from carbon and sticky. The other ports show only dry carbon.

The #8 cylinder exhaust port which happened to have the valve closed the last time I shut it off had oil laying on the back side of the valve.
Had it not been closed that oil would have run down into the chamber. The only source I can think of for oil on the back side of the valve
would be guides if there are no cracks? Oil lays deepest inside the valve cover at the rear and deep enough to reach the valve guide. Is it
possible the even if guide is in spec that oil would make it's way down the guide to the back side of the valve IF submerged in oil and
only using umbrella seals instead of positive seals?

I have seen other posts about oil in number 8 exhaust port on various forums so it does happen, but usually guides were bad.

Any ideas about a source for this oil would be appreciated. The only other thing I can think of would be valve cover gasket
leak at rear running down and somehow getting between the manifold gasket, but no sign of such a leak.

Thanks!

 

[Ceedawg]

Update. The machine shop says all guides are within spec, no cracks either. I am having them install positive exhaust valve seals just in case.
I just took another look at the exhaust manifold from the passenger side. Only the #8 manifold port shows signs of oil traveling out of the
exhaust port and down into the exhaust pipe. Oil there is black from carbon and sticky. The other ports show only dry carbon.

The #8 cylinder exhaust port which happened to have the valve closed the last time I shut it off had oil laying on the back side of the valve.
Had it not been closed that oil would have run down into the chamber. The only source I can think of for oil on the back side of the valve
would be guides if there are no cracks? Oil lays deepest inside the valve cover at the rear and deep enough to reach the valve guide. Is it
possible the even if guide is in spec that oil would make it's way down the guide to the back side of the valve IF submerged in oil and
only using umbrella seals instead of positive seals?

I have seen other posts about oil in number 8 exhaust port on various forums so it does happen, but usually guides were bad.

Any ideas about a source for this oil would be appreciated. The only other thing I can think of would be valve cover gasket
leak at rear running down and somehow getting between the manifold gasket, but no sign of such a leak.

Thanks!

View attachment 1326987

Magnaflux the whole port for cracks not just the guide, old heads were known to crack, who knows about the new ones. That’s a good seep into that manifold.

 

[fmahannah]

They fully crack tested both heads. Heads are Mopar reporduction max wedge heads, not originals

 

[steve340]

That pics shows quite a bit of raw oil were there should not really be any.
I remember all your plugs looked pretty fouled so I do not think the problem will be only in one cylinder.

Has the exhaust cross - over in the intake got a crack or hole in it?

 

[fmahannah]

That pics shows quite a bit of raw oil were there should not really be any.
I remember all your plugs looked pretty fouled so I do not think the problem will be only in one cylinder.

Has the exhaust cross - over in the intake got a crack or hole in it?

There is no exhaust crossover in a max wedge intake. Plugs were fouled from rich carbs before the oil issues started

 

[steve340]

OK this is a strange one for sure.
What about a porosity in the head allowing oil to get down from the valve cover in to the exhaust port?
With the valve closed you could use a vacuum pump on that port.
Or make up a plate and fitting and put 40 psi of air pressure in there?

 

[Geoff 2]

Is there any oil in the #8 intake port?

 

[fmahannah]

Is there any oil in the #8 intake port?

No

 

[fmahannah]

OK this is a strange one for sure.
What about a porosity in the head allowing oil to get down from the valve cover in to the exhaust port?
With the valve closed you could use a vacuum pump on that port.
Or make up a plate and fitting and put 40 psi of air pressure in there?

I still think it has to be oil that accumulates in that end of the valve cover until it gets high enough to drain back getting past the guide and down the valve stem. But shop checked guides. Or past the guide itself between the guide and the head? Would a machine shop be able to check for that some way while they have the heads? Thanks.

 

[4406bbl]

Do you have a pic of the rear of that head with the valve spring removed? I wonder if the guides are shortened a lot creating the perfect storm for you. Like others here I have run with no seals and not had smoking issues. Yes oil sitting in a puddle above the guide will run down even in spec guides. Enclosed is a pic of a 906 head, guides are absolutely shot and the valve seals were all broken, but not smoke driving down the road, only on start up. Are you guides shorter than these, been 20 years since I had a few sets of those heads so I can't remember how they looked stock. I can't fathom oil running down an in spec exhaust guide enough to smoke because it is under pressure, but maybe I am wrong.

 

[steve340]

Thinking about it if the oil were coming down the inside of the valve guide - it would gather on the valve head. The engine would blow a cloud of smoke on start up. Due to pressure inside the cylinder the exhaust guide is not usually an easy source of oil when the engine is running.
No way that oil could end up at the top of the port and going down the exhaust pipe.

Are your valve guides cast in to the head or the replaceable type.
I have seen these loose in the head and the oil came down between the outside of the guide and the head. You could see raw oil like your picture
If this is the case do a test before you bolt the heads back on.

 

[fmahannah]

Do you have a pic of the rear of that head with the valve spring removed? I wonder if the guides are shortened a lot creating the perfect storm for you. Like others here I have run with no seals and not had smoking issues. Yes oil sitting in a puddle above the guide will run down even in spec guides. Enclosed is a pic of a 906 head, guides are absolutely shot and the valve seals were all broken, but not smoke driving down the road, only on start up. Are you guides shorter than these, been 20 years since I had a few sets of those heads so I can't remember how they looked stock. I can't fathom oil running down an in spec exhaust guide enough to smoke because it is under pressure, but maybe I am wrong.

View attachment 1327425

Exhaust guides have not been altered, intakes have been cut for positive seals

 

[fmahannah]

Thinking about it if the oil were coming down the inside of the valve guide - it would gather on the valve head. The engine would blow a cloud of smoke on start up. Due to pressure inside the cylinder the exhaust guide is not usually an easy source of oil when the engine is running.
No way that oil could end up at the top of the port and going down the exhaust pipe.

Are your valve guides cast in to the head or the replaceable type.
I have seen these loose in the head and the oil came down between the outside of the guide and the head. You could see raw oil like your picture
If this is the case do a test before you bolt the heads back on.

When I get the heads back I am going to test by putting oil into the valve cover area and seeing if any of it is able to get past the guides or seals before putting them back on

 

[Ceedawg]

View attachment 1327483

Exhaust guides have not been altered, intakes have been cut for positive seals

If that is a picture of your head there’s no way oil could puddle into the exhaust guide. Oil would run down to bolt first. Did you have gaskets on the exhaust manifold? Valve cover leaking down head into that port maybe?

 

[4406bbl]

Yes those look uncut, I don't think that would puddle oil above the guide boss once the engine is hot. Looks the same as the 906 head. Positive seals are fine but I don't think that is the problem. After an hours run time all the oil should be burned put off the head and manifolds and it should not oil smoke. With positive seals don't overthink it and tighten up the clearance....or you will stick valves.

 

[fmahannah]

If that is a picture of your head there’s no way oil could puddle into the exhaust guide. Oil would run down to bolt first. Did you have gaskets on the exhaust manifold? Valve cover leaking down head into that port maybe?

This is where the oil sits in the valve cover. Valve cover gasket is not leaking, new exhaust manifold gaskets from mancini racing