PCV catch can; homebrew Condensator writeup
- Thread starter Spook50
- Start date
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When I was running the small catch can I consistently saw that city driving filled it faster than highway. There shouldn't be a change with the big catch can I'm now running but it is less obvious because I don't have to check it every fill up (so far I've got over 1,000 miles and it hasn't even reached the sight tube yet).
Are you seeing improved mileage as well?
Hey Spooky, Why dont you rig up a drain back system. Instead of a 1/4 NPT plug put another barb and gravity feed it back to the oil pan. Option #1 get a FJ 60 side cover and have it drain into the (FJ60) PCV opening or Option #2 weld a mall bung onto the side of the oil pan and put a barb on there.
Dynosoar
Dynosoar
- Thread starter
- #25
Hey Spooky, Why dont you rig up a drain back system. Instead of a 1/4 NPT plug put another barb and gravity feed it back to the oil pan. Option #1 get a FJ 60 side cover and have it drain into the (FJ60) PCV opening or Option #2 weld a mall bung onto the side of the oil pan and put a barb on there.
Dynosoar
With a check valve, this would be possible. But even with not even week-old synthetic oil, what's ending up in the PCV catch can is black as tar, so I'd rather that stays out of the engine once it leaves it. Obviously this is mostly oil from the crankcase that's ending up in there, but I've got no problem topping off occasionally as the catch can fills and is emptied. I'd rather top it off with clean stuff than let the dirty stuff drain back into it.
Joel, do you have any pics/info on your setup? I'm curious to see what you're using.
Not sure. At the point that I originally installed it I wasn't really keeping track. On my current engine I've never run it without it.
I will try and get some pics tonight. I need to take some pics of my new fan shroud and SPAL fans (all ready to drop in, just need to replace all the hoses and re-install everything).
Here is a link to a polished version of the catch can that I'm running. Why this one? Because I could get it in black. I hate bling under the hood. I almost painted my Ron Davis radiator black while it was out
Riss Racing Oil Catch Can (Polished) Riss Racing
- Thread starter
- #28
I will try and get some pics tonight. I need to take some pics of my new fan shroud and SPAL fans (all ready to drop in, just need to replace all the hoses and re-install everything).
Here is a link to a polished version of the catch can that I'm running. Why this one? Because I could get it in black. I hate bling under the hood. I almost painted my Ron Davis radiator black while it was out
Riss Racing Oil Catch Can (Polished) Riss Racing
Ohhh, this is interesting. I haven't seen these ones out there before. What material is the sight tube made out of? How do you break it down to drain it? Is there any internal baffling or anything like that to help the oil and sludge separate from the air?
Im thinking that like a gano filter(used to remove crud from rad.) ,given enough time the sludge should start to decrease in amount running synthetic oil. Mike
There is a thumb screw with an oil ring at the bottom for draining. It is filled with steel wool. The only downside is that the interior is not accessible to clean/replace the steel wool. The sight tube is plastic of some kind. You can get sights like this at McMaster/Carr if you want to fab your own catch can.
Like the homemade one better. MIke
- Thread starter
- #32
Damn, I don't like the steel wool idea. I think the best way to go is to have a simple can setup with the inlet being a pipe that reaches maybe a third of the way down into the can, and the exit being right at the top, so that residue will drip down the pipe but won't be drawn upward into the exit.
I might have to play around and see where I can get other separators that are about the same height as mine but a bit larger around, with integrated mounts. Be cool if I could find one that I could paint (the housing, not the bowl) to match my truck
These things are real easy to fabricate, especially if you have the technology to weld aluminum (although stainless or even mild would probably be fine). Sight tubes are cheap.I've got a TIG and considered this myself but I just have too many other projects up in the air.
Steel wool does seem to be a common air/oil separater medium, mainly I think because of how easy the actual filters clog and then then restrict all PCV flow which will then force everything back into the intake or out through gaskets. It seems to work just as well as the filter I had before, which was similar to the pictures at the start of this thread. If I made my own I was still going to use steel wool, I would just make it accessible.
Eventually I will cut the top (or bottom) off of what I've got and make it accessible
Steel wool does seem to be a common air/oil separater medium, mainly I think because of how easy the actual filters clog and then then restrict all PCV flow which will then force everything back into the intake or out through gaskets. It seems to work just as well as the filter I had before, which was similar to the pictures at the start of this thread. If I made my own I was still going to use steel wool, I would just make it accessible.
Eventually I will cut the top (or bottom) off of what I've got and make it accessible
Oh and if you really want to see good air/oil separater design take a look at how sump tanks for dry sump oiling systems are designed. These need to separate the air from the oil without aerating the oil. Probably overkill but you could likely use the same design principle with a mid point entry and an exit on the top.
You could use PVC pipe as well.
Phil
Phil
- Thread starter
- #36
Fuel economy update
Well it's been five fillups, and I've put just under 1000 miles on the unit. It's caught what looks to be just over 2oz. of fluid in the bowl (I'm going to get an actual measurement when I empty it). What's interesting is that my fuel economy has been all over the place since I installed it. My first fillup got me 15.9 MPG, the one after that was just 12.3 (down to right what I was averaging before installation), then slowly working its way back up. It may be too soon after installation to get real numbers, but running the numbers so far I've gotten an average of 13.7 MPG. Still about 1 MPG better than before (would get about 13 on a real good day), but certainly not the 16 I got excited about initially. Still, for $25 and an afternoon's worth of work, I'd say it's well worth it. I'll keep checking my economy periodically and see if it keeps increasing or if it stays about where it's at now.
I'll be fogging my engine with Seafoam soon to get it all cleaned out for good, and I'll track my economy after that to see if I had enough crap built up to affect my economy.
Well it's been five fillups, and I've put just under 1000 miles on the unit. It's caught what looks to be just over 2oz. of fluid in the bowl (I'm going to get an actual measurement when I empty it). What's interesting is that my fuel economy has been all over the place since I installed it. My first fillup got me 15.9 MPG, the one after that was just 12.3 (down to right what I was averaging before installation), then slowly working its way back up. It may be too soon after installation to get real numbers, but running the numbers so far I've gotten an average of 13.7 MPG. Still about 1 MPG better than before (would get about 13 on a real good day), but certainly not the 16 I got excited about initially. Still, for $25 and an afternoon's worth of work, I'd say it's well worth it. I'll keep checking my economy periodically and see if it keeps increasing or if it stays about where it's at now.
I'll be fogging my engine with Seafoam soon to get it all cleaned out for good, and I'll track my economy after that to see if I had enough crap built up to affect my economy.
I think mile age should improve with time,slowly the can should start filtering more and more. My 62 gets 17.5 mpg but is all stock,Im going to try your idea and see what happens,but cleaner cruiser should equal cooler engine should equal better gas mileage. Mike
I think I'm going to build a new catch can simply to work on my welding skills. I'm going to do a internal baffled design (no steel wool). I'm also going to build two - one for the PCV and one for the "clean" side (intake to front of the valve cover). I was reading billavista's LS2 review on Pirate and LS motors have oil/air seperation baffling on both the PCV side and the clean side. This is because at WOT the blowby plus the lack of vacuum means that the PCV won't pull anything (or much). The extra pressue ends up reversing the clean path and blowing back into the intake. I believe this is why I still see trace amounts of oil in my intake tube.
This will be a good back burner project as soon as I get a new tank of argon.
This will be a good back burner project as soon as I get a new tank of argon.
Hey Spook, any extended results?
- Thread starter
- #40
I'm getting on average an ounce of oil/sludge every thousand miles. There's a LOT of water that gets caught in it from doing cold starts in the winter, since it doesn't heat up long enough (being seperate from the engine) to let the water evaporate out. I've been straining what I pour out of it just so I can find out how much actual oil and sludge is being caught in it, and since installation I've got about half a quart, maybe a little more. And it's all BLACK.
As far as fuel economy, I average about 13.5-14 MPG with stock gears and 31" mud terrains. Long trips are usually 1 MPG or so better. Overall it's a slight improvement, but IMO very much worth it for the principle of preventing buildup in the throttle body and intake manifold.
Best mileage I ever got was with stock 29" A/T tires, no electric fan and no PCV catch can, in early summer, averaging about 65 MPH for just over 200 miles. That was 17 MPG. I have to admit I'm very cuious to see what I'd get with what I've done now and stock 29" tires.
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