BDL
Well-Known Member
Basic question is this... Why is there sludge on the passenger side of my 1966 Poly Head 318 and none on the driver side?
Here's the background... I set out to do a simple thing yesterday: Stop the exhaust leaks so the wife and I can actually feel comfortable taking the boys out in the Charger without ending up smelling like exhaust. Well, I accomplished that. But, the lack of exhaust noise revealed serious valve train noise. So, I got to rectifying that. That's where the day went wrong.
There seems to be a debate on what the correct valve lash should be for the poly 318. I first set the valve lash to 0.008 intake / 0.012 exhaust after finding that recommendation online. Hmph. That setting was working great on the driver side and really seamed to quiet the poly down. But, as I removed the valve cover from the passenger side, I noticed sludge. I said to myself, wait... I didn't see sludge on the driver side. And I went about setting the lash on the passenger side while I pondered what could have caused the sludge.
Anyway, as I adjusted the passenger side, the engine ran progressively worse. When I started out with the adjustments, all I needed to do to start the engine was reach in and bump the ignition. But, by the time I was done, I was climbing in and playing around with the gas every time. And... The engine sounded like complete garbage when I did finally get it to run again. "It must be down two or three cylinders (more)" is what I thought.
That caused me to second guess the 0.008i/0.012e recommendations. So, I did more checking... I found three other recommendations: 0.010i/0.018e; 0.012i/0.022e; & 0.028i/0.032e. GRR. I chose to go through the whole valvetrain again with a larger gap to see what would happen. As expected, the valvetrain noise returned. However... I didn't get my cylinders back.
So... Without getting into the engine, I wonder what's going on in there. Did I bend pushrods? Do I have "burned valves?" Is there just too much garbage built up on the valves causing them not to seat? Is there too much blowby on the passenger side that's causing the sludge in the valvetrain?
I may need to disclose a few things. The 318 Poly I have been using for the past couple years was plucked straight from the junkyard. I did not pull it apart. I only flushed the cooling passages, changed the oil, poured a bit of oil down each spark plug hole and cranked and pumped the ol' Stromberg 2-barrell until it started. (I know... Poor Poly
) As you can imagine, it has Never run correctly. But I considered myself lucky to have a full 6 or 7 of the 8 available cylinders. Yeah. It was that bad at first. But, remarkably, it got better with time. I did take the time to take compression readings on all cylinders before I tried to crank it and then again after I ran it for a while. The initial compression readings told me that there was a reason I only had 6 or 7 cylinders. One cylinder had absolutely zero compression, another cylinder had only 80 psi and the other six hovered between 125 and 140 psi. I adjusted the valve lash at that time and was able to successfully bring the cylinder with zero pressure to somewhere closer to 80 psi. Also, the one that started out around 80 psi was raised to about 120 psi. Although the compression was better the second time I took the measurements, it never did completely even out across all 8 cylinders. The worst cylinder measured around 110 psi and the best cyl was around 150 psi.
Before I "fixed" it this weekend, the engine fooled people into thinking it had a hot cam (though it was hard to hear through the exhaust leaks and valvetrain noise). Now, it's easy to tell that it's just a terrible sounding engine.
The Charger may be down for the rest of this season... But she will be far better when she returns to the road. ...I've got the numbers matching Poly 318 in the front of the garage just begging to be machined and built.
Here's the background... I set out to do a simple thing yesterday: Stop the exhaust leaks so the wife and I can actually feel comfortable taking the boys out in the Charger without ending up smelling like exhaust. Well, I accomplished that. But, the lack of exhaust noise revealed serious valve train noise. So, I got to rectifying that. That's where the day went wrong.
There seems to be a debate on what the correct valve lash should be for the poly 318. I first set the valve lash to 0.008 intake / 0.012 exhaust after finding that recommendation online. Hmph. That setting was working great on the driver side and really seamed to quiet the poly down. But, as I removed the valve cover from the passenger side, I noticed sludge. I said to myself, wait... I didn't see sludge on the driver side. And I went about setting the lash on the passenger side while I pondered what could have caused the sludge.
Anyway, as I adjusted the passenger side, the engine ran progressively worse. When I started out with the adjustments, all I needed to do to start the engine was reach in and bump the ignition. But, by the time I was done, I was climbing in and playing around with the gas every time. And... The engine sounded like complete garbage when I did finally get it to run again. "It must be down two or three cylinders (more)" is what I thought.
That caused me to second guess the 0.008i/0.012e recommendations. So, I did more checking... I found three other recommendations: 0.010i/0.018e; 0.012i/0.022e; & 0.028i/0.032e. GRR. I chose to go through the whole valvetrain again with a larger gap to see what would happen. As expected, the valvetrain noise returned. However... I didn't get my cylinders back.
So... Without getting into the engine, I wonder what's going on in there. Did I bend pushrods? Do I have "burned valves?" Is there just too much garbage built up on the valves causing them not to seat? Is there too much blowby on the passenger side that's causing the sludge in the valvetrain?
I may need to disclose a few things. The 318 Poly I have been using for the past couple years was plucked straight from the junkyard. I did not pull it apart. I only flushed the cooling passages, changed the oil, poured a bit of oil down each spark plug hole and cranked and pumped the ol' Stromberg 2-barrell until it started. (I know... Poor Poly
) As you can imagine, it has Never run correctly. But I considered myself lucky to have a full 6 or 7 of the 8 available cylinders. Yeah. It was that bad at first. But, remarkably, it got better with time. I did take the time to take compression readings on all cylinders before I tried to crank it and then again after I ran it for a while. The initial compression readings told me that there was a reason I only had 6 or 7 cylinders. One cylinder had absolutely zero compression, another cylinder had only 80 psi and the other six hovered between 125 and 140 psi. I adjusted the valve lash at that time and was able to successfully bring the cylinder with zero pressure to somewhere closer to 80 psi. Also, the one that started out around 80 psi was raised to about 120 psi. Although the compression was better the second time I took the measurements, it never did completely even out across all 8 cylinders. The worst cylinder measured around 110 psi and the best cyl was around 150 psi. Before I "fixed" it this weekend, the engine fooled people into thinking it had a hot cam (though it was hard to hear through the exhaust leaks and valvetrain noise). Now, it's easy to tell that it's just a terrible sounding engine.
The Charger may be down for the rest of this season... But she will be far better when she returns to the road. ...I've got the numbers matching Poly 318 in the front of the garage just begging to be machined and built.
okay okay sorry... Seriously though it sounds like it definitely just needs a good going-through... but maybe you could try seafoam or a similar cleaner in the meantime? An oil system cleaner may be more helpful..
