Who makes the nicest catch can kit??

SS502 · February 6, 2019

4 hours ago, 3tspapat said:

That RXP can is HUGE! is it really HUGE or just looks like it?

So you had to cut Joe's nice bridge line for his CSS sytem to put in a T to bring to the small RXP can?

It’s not small but here is a reference for you.

Grumpy Bear · February 7, 2019

5 hours ago, SS502 said:

Anyone know what the term "space velocity" plays in all this or why it matters?

SS502 · February 7, 2019

14 minutes ago, Grumpy Bear said:

Anyone know what the term "space velocity" plays in all this or why it matters?

Well speaking mathematically it’s a formula that is too complex for me to even type, in practical, meaningful terminology it means “I haven’t got a clue”. Please share but I’m going to bed because I don’t want to have nightmares trying to decipher it tonight! I will read and be in a much better frame of mind to comprehend this in the morning ?

DenaliStone · February 7, 2019

I found this on Facebook Marketplace. The guy is asking $50 for it. It looks to be one of the original RX cans. He claims to have the hoses and other stuff for install. Would you guys run a used can for ~$100 after I drive to get it, or should I spend the additional $$ for a new one?

Edited February 7, 2019 by DenaliStone
Cleared extra picture from post.

SS502 · February 7, 2019

28 minutes ago, DenaliStone said:

I found this on Facebook Marketplace. The guy is asking $50 for it. It looks to be one of the original RX cans. He claims to have the hoses and other stuff for install. Would you guys run a used can for ~$100 after I drive to get it, or should I spend the additional $$ for a new one?

Good question...I will send a picture to the folks a RXP and see if it is truly an original...the RX (stickers) looks pretty clean/new to me. My other concern is even if this is an early RX (not sure RX and RXP association/relations) the cans have evolved with better flow rates, separation media inside and fittings. This can also appears to have no way to get inside of it, who knows what, if any, kind of baffles/chambers/crud or who know what is inside that thing. IF it is an original (or maybe even a prototype) I'd be buying it for my garage! I love old and unique stuff, even things as simple as a catch can.

Edited February 7, 2019 by SS502

SS502 · February 7, 2019

3 hours ago, DenaliStone said:

I found this on Facebook Marketplace. The guy is asking $50 for it. It looks to be one of the original RX cans. He claims to have the hoses and other stuff for install. Would you guys run a used can for ~$100 after I drive to get it, or should I spend the additional $$ for a new one?

I'm told it looks like an old Tracy Lewis can that was called RX up until 2014. From there the story gets into a bunch of legal/trademark/patent/company disputes. I won't post them because I don't have first hand knowledge and am not about to slander anyone or a company without 100% proof or evidence to support it. With that said, I would probably not use it simply due to the advancements is filtering media and airflow designs in ALL the newer systems on the market. This in no way is saying it's a bad design or that Mr. Lewis doesn't make a good product. If they are willing to ship it, I'd buy it for reasons posted earlier.

Grumpy Bear · February 7, 2019

11 hours ago, SS502 said:

Well speaking mathematically it’s a formula that is too complex for me to even type, in practical, meaningful terminology it means “I haven’t got a clue”. Please share but I’m going to bed because I don’t want to have nightmares trying to decipher it tonight! I will read and be in a much better frame of mind to comprehend this in the morning ?

Ever watch them draw numbers for the lottery? Ping Pong balls ‘fluidized’ by a steam of air. At the top of the chamber is a tube where air is always exiting but blocked by another tube within the tube. The balls flutter and fly about until the exit it unblocked. That tube is several orders of magnitude smaller in cross section but it flowing the exact same amount of air. Any ball that gets near the exit is carried up that tube by the increase in ‘space velocity’.

Space velocity is in simple terms air volume divided by the area of the conduit. If that tank is 10 square feet and the flow rate is 10 cfm then the space velocity is 1 FPS. If the tube were say ¼ square foot then the space velocity in the tube for 10 cfm would be 40 fps. Forty times faster. These units are ‘actual’ not ‘standard’.

Engineers like to make things complicated so we look smarter than we really are.

In our example something under 1 fps the balls lay on the bottom and present as a ‘solid’. At 10 fps, they ‘fluidize’ and at 40 fps they can be “transported”. The exact velocity to reach each point can be obtained experimentally by observation and measurement in lieu of that complicated formula you found in your search.

Okay so the next question is going to be, doesn’t the size and weight of the ball dictate the rate of velocity it will take to transport that ball? Yes! And a few other items about the gas stream as well such as exact composition and temperature.

In a running motor all variables that effect this ‘transport’ space velocity number are in a constant state of flux unlike Ping Pong balls in an air stream. That can be used to the designers advantage or it can escape his notice, which by the way is the difference between an effective system and one that is not. I has NOTHING to do with how pretty it is or how well it is manufactured.

Shall I continue?

3tspapat · February 7, 2019

yes please do! I don't deal with air, I deal with water but the dynamics are very similar!

Grumpy Bear · February 7, 2019

15 minutes ago, 3tspapat said:

yes please do! I don't deal with air, I deal with water but the dynamics are very similar!

Love your tag line by the way. Okay, moving on then.

Smokey Yunick once put a window in the side of a motor to look in real time what the crankcase area looked like under load and rpm and found it to be torrid. (Brit meaning). A cloud of microscopic oil droplets whipped about in a hurricane. Naturally the degree of the storm rested on RPM and oil volume in the air space. Think paint being sprayed X 100. The oil scrapper and knifed crankshafts the result of those studies. For us we just need to know that it varies from near nothing to quite the display in the crankcase area.

The path to the rocker box area is torturous and that fine atomized mist is coalesced to larger droplets that the air streams velocity can not carry fully except under certain conditions. Low vapor velocity and large particle size hinder carryover. Under heavier loads the manufactures assist in oil retention with some variety of oil separation; baffles, demister pads etc. pre PCV system and of course any that remains entrapped is carried and hopefully burned.

Let's go back to the lottery machine. You've seen a similar device for adverts from vacuum cleaners where the ping pong ball is suspended in mid air over the exhaust tube? Hopefully you have. Once suspended there are two ways to get the ball to fall. Remove the air source OR direct it to the larger chamber where the space velocity is low enough to no longer keep the ball suspended.

Thing is there is a law of motion that says things in motion tend to stay in motion and visa versa. Meaning that the space velocity must be reduced to something lower than what it took to suspend it initially. That is called it's 'disengagement velocity'. It really is a rather large space.

If you pick back through all of this you will see that there are two sides to the equation. The side that generated the mist and the side that disengages it.

Catch cans of the sizes show do not work on the principle of 'space velocity'. They work on the principle of 'coalescence'. Combine droplets together to create enough mass the air stream can not support it thus become trapped in the provided space below whatever separating device is being employed. That could be Chevrons, staggered baffles (labyrinth), porous medias, even media wools. There are other means and methods as well but to stay on point....

The fact the designer of this can employs 2 in series tells me he is aware a single stage system of this size really is ineffective. That is a plus even before I know what is inside it. He has his thinking cap on. Great! Wonder what's in it?

Shall I continue or do you have enough?

SS502 · February 7, 2019

I'm good I sure hope you're using a normal keyboard...would hate typing all that on a phone Thank you for the in depth explanation.

3tspapat · February 7, 2019

Wait...don't go yet...the RXP system shown does have 2 catch cans, but they are not in series (confirm @SS502) right? One is for the clean side (valve vent lines) and the other is for the PCV. Now if we follow by the multi-stage in series principle (or baffles, compartments, etc.), I believe that most of the better designed cans do have small separation chambers inside and also the wool to allow the floating oil particles to coalesce.

So if what you say holds true, then the little oil filter CSS units definitely would not function as well as the catch can unit no?

Reading all that also reminded me of that catch can shoot out where 2 cans were used in series and the amount captured in each based on position (1st in series or second) was used to determine the more effective can.

FWIW, all that @Grumpy Bear typed, we just put into a program in our computer and it tells us what size baffles, how many, etc. to get solids to drop out, and we do use baffles, chambers, etc in series. But now we're going back nature's way of filtering water...so now we use mixed soil media, plants and bacteria.

I will gladly test in the future my new and Nature Approved catch can using baffles, mixed soil media, plants and bacteria. I just need to get a loaner from the dealer to do this

SS502 · February 7, 2019

2 minutes ago, 3tspapat said:

Wait...don't go yet...the RXP system shown does have 2 catch cans, but they are not in series (confirm @SS502) right? One is for the clean side (valve vent lines) and the other is for the PCV. Now if we follow by the multi-stage in series principle (or baffles, compartments, etc.), I believe that most of the better designed cans do have small separation chambers inside and also the wool to allow the floating oil particles to coalesce.

So if what you say holds true, then the little oil filter CSS units definitely would not function as well as the catch can unit no?

Reading all that also reminded me of that catch can shoot out where 2 cans were used in series and the amount captured in each based on position (1st in series or second) was used to determine the more effective can.

FWIW, all that @Grumpy Bear typed, we just put into a program in our computer and it tells us what size baffles, how many, etc. to get solids to drop out, and we do use baffles, chambers, etc in series. But now we're going back nature's way of filtering water...so now we use mixed soil media, plants and bacteria.

I will gladly test in the future my new and Nature Approved catch can using baffles, mixed soil media, plants and bacteria. I just need to get a loaner from the dealer to do this

They are not in series, the larger can has chambers (5) and 100 micron media baffle, the CSS (small can) side just has 100 micron media. The idea behind the small can (I believe) is that with the older CSS, the dirty oil vapors went through a coalesce sequence, then letting cleaner air minus whatever oil/contaminates to the air box. The small can traps those same oil/contaminates and allows that same cleaner air to the air box but instead of allowing oil/contaminates to drip back into the valve cover and ultimately back into the oil, it is trapped for removal.

SS502 · February 7, 2019

Now with all this said, I am going to shut up and color. I do not design, sell or supply parts to or for anyone. I just buy what I feel is going to best suit my wants/needs/desires. I believe I said in one of my first posts in these forums that even if the catch can (any brand) doesn't do a darn thing, it's my belief they do, but even if they don't; it's my truck, my money, my choice and it might just help me get an extra minute of sleep at night. Trust me, when Mother Nature starts waking you up at 4:30 am every darned morning, that extra minute far outweighs the cost of a catch can

SS502 · February 7, 2019

26 minutes ago, 3tspapat said:

Wait...don't go yet...the RXP system shown does have 2 catch cans, but they are not in series (confirm @SS502) right? One is for the clean side (valve vent lines) and the other is for the PCV. Now if we follow by the multi-stage in series principle (or baffles, compartments, etc.), I believe that most of the better designed cans do have small separation chambers inside and also the wool to allow the floating oil particles to coalesce.

So if what you say holds true, then the little oil filter CSS units definitely would not function as well as the catch can unit no?

Reading all that also reminded me of that catch can shoot out where 2 cans were used in series and the amount captured in each based on position (1st in series or second) was used to determine the more effective can.

FWIW, all that @Grumpy Bear typed, we just put into a program in our computer and it tells us what size baffles, how many, etc. to get solids to drop out, and we do use baffles, chambers, etc in series. But now we're going back nature's way of filtering water...so now we use mixed soil media, plants and bacteria.

I will gladly test in the future my new and Nature Approved catch can using baffles, mixed soil media, plants and bacteria. I just need to get a loaner from the dealer to do this

Would be nice to make a can/system that could take the crud that is collected in the can, using bacteria and engine block heat to convert it into a bio-fuel then use that bio-fuel to run my lawn mower...but it's a moot point for me, I own an EGO mower

Grumpy Bear · February 7, 2019

Remember there are two sides to the equation and I was asked, (off line) IF I thought cans in general were a waste.

There are guys like me that use the motor so lightly that the vent line never gets a hint of oil. There are guys that tow heavy and/or at elevation at lower gearing and faster speeds that keep the second stage of the oil pump active and rpm up whose vapor load will be the other end of the scale. There are cans that work and cans that do not.

So, if you have a need, use one but use one that works.