After installing a Catch Can for my 2020 Super Duty Tremor. I was shock to find this!

That’s a bit bothersome…..wonder if all 7.3s do that? Maybe I’m misunderstanding….blow-by is oil and gases moving from the crankcase past the rings to the combustion chamber…right?
I must be missing something here?
I guess it just means you should pay a bit more attention to the oil level on a 7.3….no big deal
 
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That’s a bit bothersome…..wonder if all 7.3s do that? Maybe I’m misunderstanding….blow-by is oil and gases moving from the crankcase past the rings to the combustion chamber…right?
I must be missing something here?
Is it really that bothersome? With this much blow-by, it would amount to about 3/4 cup of oil loss over one oil change interval, which seems pretty modest for such a large engine.

Also, how important is it, really, to use a catch can on this port-injected engine? You're not running the risk messing up your direct cylider fuel injectors (since there aren't any). The gas will wash the oil from the intake and it'll just get burned up just as fast as it leave the crankcase, just like so many port-injected engines before it.
 
Is it really that bothersome? With this much blow-by, it would amount to about 3/4 cup of oil loss over one oil change interval, which seems pretty modest for such a large engine.

Also, how important is it, really, to use a catch can on this port-injected engine? You're not running the risk messing up your direct cylider fuel injectors (since there aren't any). The gas will wash the oil from the intake and it'll just get burned up just as fast as it leave the crankcase, just like so many port-injected engines before it.
The only impact I could see is that adding oil to the gas would potentially be lowering the octane and hurting performance and gas mileage.

It would be such a small amount though that it probably wouldn't be noticed.
 
That's actually not bad. Any big bore engine is going to have a decent amount of blow-by. About a cup of crapola in ~3500 miles is no problem.

I'm on the fence for getting one... wintertime freeze-up of the lines is a concern as my truck is parked outside.
 
I installed a UPR on my 7.3 gasser before embarking on our cross-country trip this summer. Drove 3200 miles from Tacoma to Cape Cod, towing 9500lbs and was impressed with the UPR's performance. There was 1/3 cup of oil in there. Checked it again after coming home (another 4500 miles) and even more in there. Every 7.3 gasser should have a catch can, especially if towing.
 
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That's actually not bad. Any big bore engine is going to have a decent amount of blow-by. About a cup of crapola in ~3500 miles is no problem.

I'm on the fence for getting one... wintertime freeze-up of the lines is a concern as my truck is parked outside.
The lines are there from the crankcase to intake regardless, the catch can is just added in-line. The lines that come with the UPR are much more insulated than the molded factory lines too FWIW.
 
If you break the 7.3 in (more than the 7 minutes of run time at the plant) with some zinc additive, so that you have the best ring seating, will it make a difference here?
Not an engineer here, but even with the rings seated, hot crankcase vapors that recirculate back into the intake from the valve covers will still have aerosolized oil particles in them that would condense in the presence of cooler air.
 
If you break the 7.3 in (more than the 7 minutes of run time at the plant) with some zinc additive, so that you have the best ring seating, will it make a difference here?
Not really. Drive cycle and behavior will have a bigger influence. ALL rings will leak down, and so will your valve stem seals.

High loads and high speeds will drive this more than anything else.
 
UPR was one of my first mods, after watching the Palm Beach Dyno vid of an intake with a bunch of oil in it and now this video. I'm convinced my $400 was well spent.
Ditto, That was the same video that convinced me to install one, also. Do you really need it, Probably not but I’d like to take care of my stuff and I’m planning on keeping the truck for a while. It’s not hurting the engine but helping it. So why not install one. Plus it‘s fun to get new toys for the truck.
 
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The lines are there from the crankcase to intake regardless, the catch can is just added in-line. The lines that come with the UPR are much more insulated than the molded factory lines too FWIW.
Insulated lines won't do squat for a -10°F, 10 hour cold soak. We get at least one night a year that cold.

I am more worried about the filter media freezing or the check valves freezing shut. As long as the lines drain back (as the OEM ones do) and the fluid can't settle in the hose, there should be no problems other than the can itself, valves, and filter media.
 
Ditto, That was the same video that convinced me to install one, also. Do you really need it, Probably not but I’d like to take care of my stuff and I’m planning on keeping the truck for a while. It’s not hurting the engine but helping it. I’d like to take care of my stuff and I’m planning on keeping the truck for a while. So why not install one. Plus it‘s fun to get new toys for the truck.
Amen brother!
 
That oil accumlation in the catch can from the video seems pretty par for the course, I was actually surprised to not see any water/fuel contamination in it as well. Blow-by is unavoidable, even on the best modern engines, and this is just proof that the PCV system is functioning as intended. Fuel contamination occurs mostly on cold start-ups when the engine runs a rich mixture to compensate for the lower cylinder temps which results in increased fuel blow-by. This along with any water condensation in the crank case from an engine cooling down on a cool night with decent humidity, and you've got a good mix of water/fuel/oil in the crankcase at start-up. As the engine is ran all this mixture churns and the water/fuel content boils/burns off as the oil heats up, and an in-line catch can simply catches the mix before it enters the combustion chamber to get burned off for emissions.

This oil mixture if directed back into the engine to be burned off does effectively lower the octane rating of the fuel used to burn it since its mixed with aersolized oil, but I would think on n/a motors it's not as big a deal knock-wise as it is for forced induction. Still though, catching the stuff directly and recycling it is much better for your motor and downstream exhaust components than burning it off is.

On another turbo'd vehicle of mine I've got a catch can for the two heads and another from the crankcase, it's pretty amazing how effective these systems are. No more oil film coating the inside of the intercooler, able to run a little more advance and higher boost at WOT without knock, they're definitely worth the money if you can keep up on them.
 
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