340 Duster oil looks milky

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Did the viscosity have a temperature associated with it? And was it called 'kinematic viscosity'? And the oil weight?

Seems like 4% fuel is a LOT....???
 
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nm9stheham said:
Seems like 4% fuel is a LOT....???
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Oh I dunno, it's only like 1 part in 25, right?
lol.
So if you fill a 25" tall tube, only the first inch would be gas, I mean if it separated out.
Or in the pan, it's only 23 ounces in 4.5 quartsUS.
Yikes!that's about 3 cups.How do you suppose that got in there?
 
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AJ/FormS said:
Oh I dunno, it's only like 1 part in 25, right?
lol.
So if you fill a 25" tall tube, only the first inch would be gas, I mean if it separated out.
Or in the pan, it's only 23 ounces in 4.5 quartsUS.
Yikes!that's about 3 cups.How do you suppose that got in there?
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Im no mathematecian or speller.
But 3 cups seems steep.
 
Should be under 0.5% A little higher than 1 is OK. typical of too much choke or similar..
Report Explanation | Blackstone Laboratories
9 is prob 9cSt @ 100 *C, which is would only be acceptable in a SAE 20 engine oil.
upload_2020-2-8_8-42-38.png

Viscosity Classifications
 
nm9stheham said:
Did the viscosity have a temperature associated with it? And was it called 'kinematic viscosity'? And the oil weight?

Seems like 4% fuel is a LOT....???
Click to expand...
I would say that at some point in time the carb float stuck and flooded into intake.
 
Mechanical fuel pump? Maybe a pinhole tear in the diaphragm.
 
Mattax said:
Should be under 0.5% A little higher than 1 is OK. typical of too much choke or similar..
Report Explanation | Blackstone Laboratories
9 is prob 9cSt @ 100 *C, which is would only be acceptable in a SAE 20 engine oil.
View attachment 1715466498
Viscosity Classifications
Click to expand...
That what I was driving at, Mattax.... Kinematic viscosity of 9-ish is low for a multigrade xW30 or xW40 weight at 100c.... which would correspond with the % gas in oil number.

But gas in the oil would explain why the oil is so filthy in the OP's pix... it has really cleaned out the engine! I'd pull the valve covers and make sure that varnish gunk has not started to form. Probably not, but long term gas-in-oil will reeeealy gunk up a crankscase.
 
RustyRatRod said:
Mechanical fuel pump? Maybe a pinhole tear in the diaphragm.
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Yep, or a dibbling leak in the carb allowing raw gas in the intake after engine shut off, and gas runs into the cylinders and past the rings. Too high a float might do it....

Happened to my /6 after some years of exactly that with the PO; he just was not aware. The first oil came out reeeeealy thin when I bought it, and the cylinders had to be bored .040" over to correct for all the severe bore wear from the repeated cylinder washings, especially #1.
 
nm9stheham said:
Did the viscosity have a temperature associated with it? And was it called 'kinematic viscosity'? And the oil weight?

Seems like 4% fuel is a LOT....???
Click to expand...
nm9stheham said:
Did the viscosity have a temperature associated with it? And was it called 'kinematic viscosity'? And the oil weight?

Seems like 4% fuel is a LOT....???
Click to expand...
i dont see anything about viscosity temperature, on the paper it says viscosity @100C and the oil weight is 10-30. When the old carb was on it we had to dump fuel down it to get it started but changed the oil once I smelled gas in it. Would changing oil once get all the gas out?
 
MOPARBURNEM said:
i dont see anything about viscosity temperature, on the paper it says viscosity @100C and the oil weight is 10-30.
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That's the answer.
Kinematic viscosity is measured in centi-Stokes. (cSt) 1 mm squared per second is the same measurement.
If you look at the chart I cut and pasted above, you'll see just one 30 the viscosity grade column. That means straight 30 and all multigrade 30s like your 10w-30 must meet the viscosity shown to the right. So a 10W-30 should be between 9.3 and 12.5 cStokes at 100*C (212*F).
Oil viscosity decreases greatly as the oil gets hotter. So the oil grades, or weights as many people call them, are a simpler way to classify them.
 
Mattax said:
That's the answer.
Kinematic viscosity is measured in centi-Stokes. (cSt) 1 mm squared per second is the same measurement.
If you look at the chart I cut and pasted above, you'll see just one 30 the viscosity grade column. That means straight 30 and all multigrade 30s like your 10w-30 must meet the viscosity shown to the right. So a 10W-30 should be between 9.3 and 12.5 cStokes at 100*C (212*F).
Oil viscosity decreases greatly as the oil gets hotter. So the oil grades, or weights as many people call them, are a simpler way to classify them.
Click to expand...
Thanks for the education, I’m learning as I go. I’m getting impatient but know what that leads to. I just really want to get this sorted so I can finally drive it. Do you think it’s possible there was still that much fuel still in it even after I changed the oil and swapped another carb on it. I did also notice the other day I had a crack on the ceramic of one of the plugs so maybe it wasn’t firing well in that cylinder and letting gas through to the oil??
 
Some pumps are bolted together and can be open up and see the diaphram condition.
 
MOPARBURNEM said:
Thanks for the education, I’m learning as I go. I’m getting impatient but know what that leads to. I just really want to get this sorted so I can finally drive it. Do you think it’s possible there was still that much fuel still in it even after I changed the oil and swapped another carb on it. I did also notice the other day I had a crack on the ceramic of one of the plugs so maybe it wasn’t firing well in that cylinder and letting gas through to the oil??
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The fuel in th eoil is from whenever that oil was run.
If you didn't use Blackstone, then go to whomever it was and get their analysis explanation. if you have doubts, then ask if if 4.4 is 4.4% or .044 % Huge difference.
if you can smell it in the oil then I think you know the answer.

IMO a misfiring cylinder is probably not going to dilute the oil to 4.5 %
The fuel pump is moer likely. Float bowls set way to high. Dumping fuel down the carb from a can. All more likely causes
 
Mattax said:
The fuel in th eoil is from whenever that oil was run.
If you didn't use Blackstone, then go to whomever it was and get their analysis explanation. if you have doubts, then ask if if 4.4 is 4.4% or .044 % Huge difference.
if you can smell it in the oil then I think you know the answer.

IMO a misfiring cylinder is probably not going to dilute the oil to 4.5 %
The fuel pump is moer likely. Float bowls set way to high. Dumping fuel down the carb from a can. All more likely causes
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I’m gonna call them tomorrow, to make sure it was water and not antifreeze then I’ll ask them about that as well.
 
In my few experiences with gas in oil, it takes a fair amount of fuel in the oil to smell it. So the 4% could be residual... or the sign of a slow seepage of fuel.

Look down the carb when idling and make sure there is no fuel visibly dribbling down the throats. And then shut it off, and make sure no fuel is dripping down the carb. Check the floats. What carb?

Stock type fuel pumps are pretty cheap.
 
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nm9stheham said:
In my few experiences with gas in oil, it takes a fair amount of fuel in the oil to smell it. So the 4% could be residual... or the sign of a slow seepage of fuel.

Look down the carb when idling and make sure there is no fuel visibly dribbling down the throats. And then shut it off, and make sure no fuel is dripping down the carb. Check the floats. What carb?

Stock type fuel pumps are pretty cheap.
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Ok I’ll look for that, it’s a Edelbrock 1407 750
 
I just got off the phone with them and they said there wasn’t any antifreeze and the water they spoke of was more than likely condensation, also they said the fuel content should actually only be around 1-2% since it runs lower compared to diesel (they are set up for diesel testing)
 
MOPARBURNEM said:
I just got off the phone with them and they said there wasn’t any antifreeze and the water they spoke of was more than likely condensation, also they said the fuel content should actually only be around 1-2% since it runs lower compared to diesel (they are set up for diesel testing)
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A lot of fuel going through that 750 cfm Carb could be the culprit for a 340
 
I installed an air compressor style water trap in the PCV line on my 408 Magnum. It's one of those cheap, plastic air compressor water separators, but it is very effective at trapping the condensation that would have otherwise gone straight into the induction.

During the cold season (if you can call it that here) I have to drain nearly a 1/4 cup of water weekly. My car is pretty much a daily driver, so it gets a regular mix of short and medium length road use.

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oil trap.JPG


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jbc426 said:
I installed an air compressor style water trap in the PCV line on my 408 Magnum. It's one of those cheap, plastic air compressor water separators, but it is very effective at trapping the condensation that would have otherwise gone straight into the induction.

During the cold season (if you can call it that here) I have to drain nearly a 1/4 cup of water weekly. My car is pretty much a daily driver, so it gets a regular mix of short and medium length road use.

View attachment 1715467760

View attachment 1715467762

View attachment 1715467761
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That’s a wonderful idea, believe I’ll look into one.
 
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