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Mon Nov 12, 2018 3:42 pm

Engine is an AM code 1600cc (probably) DP engine in my '70 bug, stock '70 decklid
Bought the engine off craigslist so I could continue to drive my bug while it's main engine is down; I've put around 2k miles on it so far.
This engine appears to have significant blow-by, but it has alright power and runs well enough.

Except now it's blowing oil snot onto the paper air filter (K&N converted oil bath) and that's restricting airflow.

A few things,
- Engine does not have a thermostat or flaps.
- Bug is my daily driver; I moved ~ a month ago, which cut my ~25 min commute to ~15 min. So the engine has less time to warm up.
- I'm in NC, its' gotten significantly colder in the past few weeks. Morning temps 35 - 45F, Evening 40 - 50F.
- Normally I run 10w-30 Rotella synthetic blend, but this engine is a little leaky so I got a case of Havoline 10w-30 conventional at Costco and have run a few quarts through it.
- Oil is clean (if a bit dark) on the dipstick, so it's not contaminated.

I realize not having the thermostat + flaps and the shorter drive isn't helping things. But that's more than the normal coating the oil filler cap can get..
Wondering if some oil froths worse than others, would synthetic do any better?

Still have the stock oil bath from my other engine, it would likely tolerate the snot better than the paper K&N.
That said, the engine has a later oil filler with the bigger pipe so I was looking at getting it a matching stock paper filter aircleaner.
Those appear to inject the crankcase vent air post-filter, so while it probably wouldn't gunk up the filter I'm not sure I want the crud getting sucked into the carb.

Thoughts?

Mon Nov 12, 2018 3:58 pm

Ah. "Milk" out the crankcase breather. Generated by a cold engine, has very little to do with what type of oil is used. Run the engine nice and hot, long enough, and this goes away. I'd rather have this go into an oil bath cleaner than get all over a paper element.

Mon Nov 12, 2018 6:28 pm

The result of not having the thermostat~flaps assembly as engineered. With that system in place the white goo in general does not appear.
What I would do is change oil run that car out on the highway for 20 minutes and turn around and run back. The white goo will not be there.

Mon Nov 12, 2018 7:45 pm

Thanks guys
Figured it was related to the engine not warming up enough, I've had some on the oil cap in the past but never enough to coat the air cleaner and affect it running.
Guess it's a side effect of my custom air cleaner, neither stock option would be similarly affected.. though the stock paper version would throw the gunk down the carb.

My 'good' engine has working thermostat and flaps, wasn't planning to put much more into this one, though if it'll eliminate the sludge I'll think about it.

I can take it on an occasional longer highway drive, want to hazard a guess how long it'll take to build back up?
Once a week highway drive enough to keep it at bay?

Mon Nov 12, 2018 9:00 pm

When ever you drive it get it hot, like 60 MPH for 15 min.s or around town for 30 min.s . Running in the drive way for5 min.s is the worse thing you can do.

Tue Nov 13, 2018 8:00 pm

Could take the 'long way home' from work.

Or take the car out on a highway/longer drive through the 2 lane roads once a week.

If you'd like to keep that out of the filter/carb/air cleaner you could rig up a little oil breather box to catch it in.

Tue Nov 13, 2018 10:09 pm

"Once a week highway drive enough to keep it at bay?"

Depends on temp, humidity and amount of blow-by. Without a thermostat and flaps I would say it's not enough highway driving if you're driving it slow everyday.

Also, shake out the tube connecting the filler vent to the air cleaner when you return after a trip. The vent tube will also build with 'slime', freeze overnight (if parked outside) and then block your crankcase ventilation until it thaws, if it thaws.

Depending on oil level, speed and the amount of blow-by, I've had oil/mist get past the slinger and out behind the pulley with a frozen tube.