I know this has been talked about before, but what do you guys think about taking the crank case gas/ preassure and have it suck into the exhaust. I use one of those venturi effect fitting they use on like dragsters and put close to the down pipe. put a check valve before it, and see if would work. what do you guys think. I gettung suck of my intercooler boots slipping off and oil getting in my turbo. that's not good for it.
crankcase preassure reroute
- Thread starter Goose_ss4
- Start date
Goofyexponent
Mentally Unstable..
Whynot? I know some drag racers and mud racers do the same thing. I fully intend on making a CDR block off plate and running a vent tube (RDT) on my rebuild.
Goofyexponent
Mentally Unstable..
That might cause some problems....BUT if you putyour fitting at a shallow angle to th pipe, it will pull and not push. Get what I am trying to say?
Don't have your fitting at a 90* angle to the pipe...but notch the fitting and weld it into the pipe at say a 30* angle so when you look into the fitting you are looking in the sae direction that the exhaust is flowing.
Don't have your fitting at a 90* angle to the pipe...but notch the fitting and weld it into the pipe at say a 30* angle so when you look into the fitting you are looking in the sae direction that the exhaust is flowing.
riotwarrior
Full Access Member
I was thinking this also, though with my idea slightly different.
I thought about some type of catch can, say a filter housing with no filter in it and a small petcock on the bottom. have the draft tube into the catch can and then the second tube into the downpipe at an angle.
Can catches and collects oil..tube draws the pressure out and evacs it?
Heck you could even hook the vacuum pump to the can and cause vacuum...don't know if it would work or not but you absolutely need a backfire check valve in that down pipe!
Anyone?
I thought about some type of catch can, say a filter housing with no filter in it and a small petcock on the bottom. have the draft tube into the catch can and then the second tube into the downpipe at an angle.
Can catches and collects oil..tube draws the pressure out and evacs it?
Heck you could even hook the vacuum pump to the can and cause vacuum...don't know if it would work or not but you absolutely need a backfire check valve in that down pipe!
Anyone?
G. Mann
Full Access Member
I see problems ahead with that arrangement. If the exhaust pressure is higher than crankcase pressure, you run the risk of pressurizing the crankcase with exhaust gasses, like at WFO. Not good.
If you indeed draw a vacuum, you run the risk of having to much and sucking the oil out of the engine... at WFO.... or just while you are driving normal.
In either case, the balance of pressure in the crankcase isn't as designed by IH, so something will happen that wasn't planned for by design. IMHO, better to have the CDR work as designed, and live with it.
If you indeed draw a vacuum, you run the risk of having to much and sucking the oil out of the engine... at WFO.... or just while you are driving normal.
In either case, the balance of pressure in the crankcase isn't as designed by IH, so something will happen that wasn't planned for by design. IMHO, better to have the CDR work as designed, and live with it.
Goofyexponent
Mentally Unstable..
I don't think it could pressureize the crank case. The exhaust gases would take the path of least resistance......out the 3" tailpipe.
I got the catch can set up now. not as good as you might think. you get alot of smoke, and when the filter get used alot it gets drench in oil. then oil gets everywhere, drips. that's why I an hoping the exhaust its going to burn it up, and since it moves alot of air at least it would blow it out tail pipe prety good
G. Mann
Full Access Member
With all respect, the laws of physics rule. If the pressure out the exhaust is greater than the pressure in the crankcase, you will get exhaust gases pushing into the crankcase. Regardless of the idea that a 3 inch exhaust pipe has no pressure, it does, and lots of it. Otherwise, how would you have enough to drive a turbo for instance?If you want to prove this to yourself, put a flat plate over the exhaust and try to hold it there.
The crankcase has the displacement pressure of the pistons moving up and down. The exhaust has the displacement pressure of the pistons moving up and down PLUS the explosion and expansion of the combustion gases to drive them up and down [thus move the truck forward].
If a venturi scavange system such as the OP suggests was a viable solution, IMHO, the highly paid engineers who designed engines would have put it into use long ago... they didn't... Instead, they devised a CDR system that injests the oil mist/air from crankcase to the intake to be burned in the cylinder,,, then sent out the exhaust. Hotter fire at ignition point, greater pressures, and cleaner burn off. I think they thought it through pretty good.
Dave7.3
Diesel ******
If a venturi scavange system such as the OP suggests was a viable solution, IMHO, the highly paid engineers who designed engines would have put it into use long ago... they didn't... Instead, they devised a CDR system that injests the oil mist/air from crankcase to the intake to be burned in the cylinder,,, then sent out the exhaust. Hotter fire at ignition point, greater pressures, and cleaner burn off. I think they thought it through pretty good.
No offense, you have an interesting take, but this doesn't exactly seem to be the case... The Ford engineers designed the CDR system for emission reasons. It is a no brainer especially when you look at heavy machinery. I've been around plenty over the last decade and ALL of them (no matter the make or model or year) have had an RDT.
Venturi effect? Really...how is that helpful with a farm tractor for instance that moves under 1mph while baling hay? No need to add complication here.
Also, as far as a catch can, this webpage has a pretty good design with a low resistance measurement to back it up:
http://www.guzzle7pt3.com/ccv1.php
I got sick of playing in oil while working on my 6637 air filter project and have since taken off the CDR to run an RDT system. I can get some pictures here actually... be back in a few.
phazertwo
Die Summer DIE!
I made a flame thrower this way... it was awesome, and works REALLY REALLY well!
What was said above about the higher pressure exhaust moving into the crank case no matter what the angle that the RDT was input is wrong according to my experiment.
My experiment: get some air 3/8, or 1/2 pex tubing. Get some 1/8 or 5/32 pex tubing. poke a hole in the 3/8 in the pex tubing just big enough for the smaller tubing. Shove 6 inches of the smaller tubing into the smaller tubing (so that it is inside the lager tubing traveling in the same direction as the flow of air in the larger tubing). Stick the other end of the small tube in a bucket of what ever you want (I chose rubbing alcohol because it starts on fire nicely) than hook the end of the larger hose to an air compressor (I have an air gun with a 1/8NPT threads on it that I hook at 1/8 to 3/8 pex adapter to) and let her rip! it will draw what ever is in the bucket out, and spray it all over the place!!
Anyway, thats fun and all but the moral of the story is a simple one. MOVING AIR HAS LESS PRESSURE THAN STATIC AIR! Just look at aircraft wing design, its does the same thing and it causes enough pressure under the wing to keep a 747 off the ground!
What G. Mann said is VERY true in a CLOSED system where the air has no where to go, however once you give it somwhere to go it will take the path of least resistance, which is right out the tail pipe! The only problem will be a really restrictive muffler, but it would have to be pretty restrictive!. Also placing the RDT before the turbo would probably cause an issue as well.
My $.02 stick it in the exhaust at a shallow angle and RUN IT!
Dave7.3
Diesel ******
Here are a few pics of the new setup I'm running. Originally welded my fitting positioned so that it ran next to my water pump hose and down to the frame before putting the CDR back on for the turbo. With more recent events, I plumbed it back the other way with a copper 90* fitting and capped the end with folded piece of steel wool. Seems to flow pretty well from my test run, might reduce the amount of steel wool though (4 layers).
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
greg_a_morton
Full Access Member
I can see wool higher up in the tubing but why at the end? Any thing in the tubing will add back pressure and cause more oil to end up on the ground. That is what has happened so for with my experiments with my truck. I bought from another member a banks blow by piece to use 1" tubing and I am going to my air filter to suck it in the engine. My engine has good power and good compression but seems to have a good amount of blow by and it looks awful coming out from under the truck. My thinking is if I mount the elbow at the end of the air filter on the cone it will not has as much vacuum to suck oil in as if it was in the air tubing up closer to the turbo. Oh well if it sucks a little oil in the engine since its running on 50% oil anyway!
Dave7.3
Diesel ******
Um, you do realize the stock CDR system vents into the intake system right before the turbo, right? Anyway, unless you leave the RDT vented loosely into the engine bay, I don't think you will have to worry about that.
As I mentioned before, if the plain RDT vent system works great for engines twice the size of ours...why not our trucks?
I admittedly am not a fan of plumbing the RDT into the exhaust though. I've got enough oily parts to wrench on without an exhaust being included. Besides, doesn't that setup spray oil out the tailpipe just like stacks would that have water in them? I guess everyone has their opinions, like not liking the sight of the venting vapor sitting in traffic (haven't had that problem myself)... but I do like keeping things simple.
-Dave
