Ok thanks. I am thinking of just doing something real quick to see how it works out for now so i can get all the oil contained.

 

Like most CTD's, mine was dripping just enough to be aggravating - especially on my wife's new driveway. Not sure which was worse - the oil dripping or the wife complaining

I took an empty propane tank and popped out the valve and replaced it with a egr valve. Then drilled a hole in the side for a 1/2" hose barb brazed into the tank to connect the vent tube to. Drilling a hole in the bottom and brazing a valve into it allows me to drain the tank.
Crankcase pressure blows into the center of the tank, oil drops to the bottom and gasses exit thru the egr valve via 2' piece of 3/8" hose tucked between the frame and the cab.
Been on the truck about 4 yrs and I've emptied it twice ! Both times into the same 6oz jar. The jar is about 1/3 full now.
Never guessed that little bit of oil could spread into such large puddles - or cause so much trouble about a driveway

 

A bit of a re-attack but I'm pondering another issue.

I'm building another off-road rig ("Bud"), and I want to make it as 'submirsable' as possible. That said, I'm thinking about ways to route the vents - all of 'em (engine, tranny, diffs, t-cases) above the water line, which I'm figuring to be the top of the hood. Yeaaaah. So, that said, I'm thinking about routing all the vents into one central location, maybe even a drain-able (petcock) reservoir-style gig along the frame (kind of like a big sealed catch can) with a single main vent up and out along the backside of the cab. I'm also doing both a 'snorkle' style air intake similar to what I did on Nacho and for certain the truck will have a single stack on the back right side behind the cab.

My big question is...what would the effects be of plumbing the main vent upstream into the stack on the uphill end about 3 feet from the tip? The solids would accumulate in the reservoir and the fumes would be drawn up and out with the exhaust...ja? Would the exhaust pressure 'push' the fumes back into the vent system? I was hoping if the vent was angled 'upward' inline with the exhaust flow then the exhaust would actually be scavenging the vents out.

Thoughts?

- Sam

 

- bump -

Regarding the valve cover breathers - if I capped the tappet cover breather completely and relied on the valve cover breather only, what are some thoughts on that being enough of a breather system for effective crank case venting?

In other words, would a single valve cover breather be sufficient for a 6BT?

- Sam

 

No. There's not enough area in the drainback hole to let all the blowby out.

 

...so I gotta ask, what are thoughts on a pair of the breathers, like pictured earlier?

 

As an adjunct to the stock system, they are fine. I would not want to vent the whole engine through them.

 

A vacuum in the crankcase will actually increase horsepower. There would be less air in there for the pistons to push up and down, on top of the rings sealing better. I think using the exhaust would work better if it's plumbed out near the end of the pipe where the pressure starts to drop. It would have to plumb in after the air filter to pull any amount of vacuum to really do much besides contain vapors. I was going to try one on an Allis Chalmers I had but I couldn't find an electric or belt driven one rated for continuous use.

Hot Rod magazine did a test several years ago on a Chevy small-block, they lost 20 horsepower driving the pump and gained something like 70 when they hooked it into the crankcase.

 

I've been trying to figure out what the effects would be of simply running the stock breather hose up instead of down - what would be the effects of 'rotating' the tappet cover vent upward and out instead of downward and out? There might be some residual oil collecting in the vent tube/plumbing, but wouldn't that just run back into the tappet cover? Maybe I don't need the valve cover vent at all...?

 

The only effect would be oily gunk all over the top if the truck instead of underneath.

 

copy. I am planning to plumb the end of the vent into the air box but not directly into the turbo inlet tube itself. This way it'll be vented to the outside air and the engine intake should draw the smelly vapors enough to make it a non-issue.....should. Plus if the exit for the vent is on the outside of the filter then the filter should make for an effective barrier to whatever oil particles manage to make their way to the exit......should.
I can control the oily mess in the air box - it's going to be a fabbed piece under the p-side fender with an external louvered inlet - military style. It'll have a water (and oil) drain in case it rains, etc, and should be a perfect intake port and engine breather vent.

Thanks for the discussions.

 

That sounds like an OK plan but I have a couple concerns. If you run a paper filter, the oily mist is likely to clog it. Run oiled cotton like a K&N or AFE and that won't happen. Also when you run the plumbing, you can't have any low spots. They will collect water and freeze in cold weather, the pressure in the crankcase will then cause leaks.

 

water....that is a real good point. Hmmmm gotta ponder than'n. Thanks

 

Hey BC, a most learned and useful piece, definitely gets my vote for sticky, and X2 on BK's "valuable asset to the community" comment.

 

It would not be a good idea to vent the crank case into the inlet, either before the filter or after. The oil mist will coat the inside of your intercooler which has an insulating affect (oil traps heat energy) making your heat exchanger much less efficient. It will also coat the impeller with crud. The second issue is a high boost Cummins has a ton of blowby, and that much oil in your inlet could cause pre-ignition which would be very bad.
I vent mine with a catch can like this: