L18 Crankcase Breather Outlet - Need solution

[bertvorgon]

yes, that is correct. My waste gate is basically off the #4 area, so when everything is in full kill mode, there as a lot of radiant heat in that area. It was just as easy for us under engine building time, to just fit up a pipe and push it back into place.

You should be fine as long there is an air space between things.

[datzenmike]

Find an L20B engine. The block vent is up with a sharp bend and straight back. You could trim the bend off and pound into the side like yours and add a hose away from the hot pipes.



Find a Z series engine. Same as the L20B but wraps around the rear of the head and over to the right side. Again cut before the bend and mount on the side of the L18 block. If you run an oil catch can like Keith's just join the pipe cut off with a short length of hose and gear clamps.

[bertvorgon]

great pictures Mike.

that is what I did, take the 2 liter spigot, cut it, then fabbed the type from the other block, to go back behind the head.

[fivetengarage]

I was able to tap my block with a pipe tap for a threaded pipe bushing.Next was a pipe to A/N fitting.Lastly a swivel 90 degree A/N fitting with hose was attached and ran to a breather.

[zKars]

3/4 NPT tap? Officially needs a 59/64 drill, and I know that hole is real close to 1", yes?

[fivetengarage]

3/4 NPT tap? Officially needs a 59/64 drill, and I know that hole is real close to 1", yes?

3/4 NPT should be correct.

[Boy Blunder]

That would be the way to do it with the engine being built.

Also, the outlet on my block is not the same as yours. I will be looking into removing the pressed in breather pipe and having an AN fitting welded on to that after cutting it down.

[bertvorgon]

I could tell you the story of the FIRST time I filled the catch can........?

[Boy Blunder]

I could tell you the story of the FIRST time I filled the catch can........?

Feel free to enlighten me?

I'm not missing something here in regards to the earlier solution discussed in this thread: The removal of the outlet pipe, modifying it and then inserting it back into the block am I?

[bertvorgon]

Your doing fine, your path is correct.

Back in the 80's, at the season start of my second generation 2 liter, we blocked off the block breather hole. This was at the same time we tried a bigger and different camshaft profile, and, installed the spray bar.

Now, my season start was usually the Knox mountain hillclimb, 260 miles from home. So other than the drive from the shop, after the engine install, the drive up was the engine break in...dumb.

So, imagine a windy mountain road, hair pin corners, one after another, very quickly, ups and downs. For you locals, the Hope/Princeton, between East gate and Princeton. It is midnight, as we left late, 4 of us, me, Doug in his 5 liter Mustang, Campbell in his Pontiac Firebird, and, Roger and Jackie as support vehicle, in their Jeep. We come upon a Corvette, who is trucking along, but not at our pace. he sees us in his mirror, and picks up the pace, but, still basically holding us up. Doug and I push him, right on his ass, with him finally getting passed as there was no way he could out corner us. I of course was on full kill mode, hitting max boost as we exited the hair pin corners. Doug and I finally got a clear passing straight. just blowing him out of the water. We then proceeded to put some distance from him, just to prove the point. As I peaked on one of the hills, my oil light flashed...WHAT THE HELL.....? I pull over right away, get out, it is late, middle of nowhere. Doug pulls over, then a few minutes later, Roger and Jackie. I jump out of my bucket seat, into the chill of the mountain air, pop open my hood. Roger brings a flashlight, shining into my engine bay. In 2 seconds I see the catch can is full, and oil is pouring out, all down the passenger side wheel arch, frame, wiring...EVERYTHING on that side of the catch can. What the hell?! I pull the dipstck, nothing showing! What the hell?!

I realize that the sustained boost, coupled with the blocked off block, and the spray bar, has introduced a serious issue with my new motor. Long story short, luckily Roger has some spare oil as do I, we refill engine and drive at normal pace to Kelowna. I get up at crack of dawn and head to car wash, after having grabbed 6 cans of brake clean. What a mess, at least 4 litres of oil has gushed all over that side of the car. I spent 20.00 bucks at the car wash, plus emptied all 6 cans of brake clean. I disconnected the spray bar and plugged it, just running the normal factory oiling for the weekend.

To this day, 30 years later, I still have oil weeping from the frame. We opened up the block breather, and again to this day, I run a litre of oil low as indicated on the dip stick.

What is the issue...we think it is just the internal block pressure, due to high rpm, that gets a super pumping air flow situation, with an incredibly oil particle laden air, that under boost gets a very positive crank case pressure, thus just pumping that oil laded air out into the catch tank. Who knows how accurate the dip stick is, in the comp pan, as to how high the oil level really is, and what is going on that block breather channel in the block, specially under severe g-force loads. My car does corner very hard, even under acceleration out of tight corners, so even with the windage tray, we think the oil level is getting very high up that channel.

[Boy Blunder]

Your doing fine, your path is correct.

Back in the 80's, at the season start of my second generation 2 liter, we blocked off the block breather hole. This was at the same time we tried a bigger and different camshaft profile, and, installed the spray bar.

Now, my season start was usually the Knox mountain hillclimb, 260 miles from home. So other than the drive from the shop, after the engine install, the drive up was the engine break in...dumb.

So, imagine a windy mountain road, hair pin corners, one after another, very quickly, ups and downs. For you locals, the Hope/Princeton, between East gate and Princeton. It is midnight, as we left late, 4 of us, me, Doug in his 5 liter Mustang, Campbell in his Pontiac Firebird, and, Roger and Jackie as support vehicle, in their Jeep. We come upon a Corvette, who is trucking along, but not at our pace. he sees us in his mirror, and picks up the pace, but, still basically holding us up. Doug and I push him, right on his ass, with him finally getting passed as there was no way he could out corner us. I of course was on full kill mode, hitting max boost as we exited the hair pin corners. Doug and I finally got a clear passing straight. just blowing him out of the water. We then proceeded to put some distance from him, just to prove the point. As I peaked on one of the hills, my oil light flashed...WHAT THE HELL.....? I pull over right away, get out, it is late, middle of nowhere. Doug pulls over, then a few minutes later, Roger and Jackie. I jump out of my bucket seat, into the chill of the mountain air, pop open my hood. Roger brings a flashlight, shining into my engine bay. In 2 seconds I see the catch can is full, and oil is pouring out, all down the passenger side wheel arch, frame, wiring...EVERYTHING on that side of the catch can. What the hell?! I pull the dipstck, nothing showing! What the hell?!

I realize that the sustained boost, coupled with the blocked off block, and the spray bar, has introduced a serious issue with my new motor. Long story short, luckily Roger has some spare oil as do I, we refill engine and drive at normal pace to Kelowna. I get up at crack of dawn and head to car wash, after having grabbed 6 cans of brake clean. What a mess, at least 4 litres of oil has gushed all over that side of the car. I spent 20.00 bucks at the car wash, plus emptied all 6 cans of brake clean. I disconnected the spray bar and plugged it, just running the normal factory oiling for the weekend.

To this day, 30 years later, I still have oil weeping from the frame. We opened up the block breather, and again to this day, I run a litre of oil low as indicated on the dip stick.

What is the issue...we think it is just the internal block pressure, due to high rpm, that gets a super pumping air flow situation, with an incredibly oil particle laden air, that under boost gets a very positive crank case pressure, thus just pumping that oil laded air out into the catch tank. Who knows how accurate the dip stick is, in the comp pan, as to how high the oil level really is, and what is going on that block breather channel in the block, specially under severe g-force loads. My car does corner very hard, even under acceleration out of tight corners, so even with the windage tray, we think the oil level is getting very high up that channel.

So, just a thought from my still learnig mechanical mind:
Do you think a dry sump system and the pump yo go along with it would alleviate your issues?
I wonder if this affects not only turbo L series bust also high rev builds. Rebello tells me my engine can make power up to 8800. Never been there but it is tempting to go over the 8k mark.

[bertvorgon]

I have no idea if a dry sump system would change things, it might, but I doubt it.

Most of the oil comes out the valve cover breather, which is weird that if I run the pan oil level lower,
it makes the difference. Who knows, I don't worry about it now, just run the oil a tad lower and I know I have no g-force issues with the oil pick-up in the comp pan.

We have wondered if the holes from the spray bar are an issue, they are a gnats eyebrow bigger than normal. This was due to the fact that when we first installed the spray bar, my camshaft got wiped out. It was pulled out and it turned out that whoever made it, never de-burred the holes...go figure...so the spray was missing some of the cam lobes. We hooked the solvent tank line up to it and right away saw the screwy pattern. We cleaned it up and checked the spray, all ok. Andy checks ALL spray bars now, before they are installed.

[datzenmike]

The valve cover outlet is poorly placed then. OK for stock use but excessive blow by picks up cam oil.

A much larger hole and pipe built into that front cover? the one just below the valve cover, would slow the air speed down allowing more 'time' for the droplets to stick inside the pipe. Perhaps plumbed upward towards the catch can so the separated oil could gravity feed back into the engine? Run this pipe above the spark plugs on the right side and have baffles in it.

Shield the valve cover from oil thrown off the cam. Like a windage tray for the oil pan. Hell as it is now oil is half way towards being ejected.

[Boy Blunder]

Mike,

I know on my setup the cam spray bar inlet is coming in on the right side. I think the issue outlined by keith is that this may be caused by the spray bar, especially one that may or may not be flowing more oil than intended.

[bertvorgon]

We did think of something like that. Most dry sump systems also have an "Oil Separator" built into the return tank, which takes the air out of the thrashed oil.

Once we tried the lower oil level, it was a non issue, so all that work required was just left on the bench so to speak, which was fine by me, as I have enough STUFF in the engine bay.

I would not say it is excessive blow by, as I burn no oil, nor would my engine builder tolerate that. It us just an air pumping issue, at high RPM, and your right Mike, the stock ( and still baffled ) separator in the valve cover fills with oil laden air, which them gets burped out the breather line.

It also only does it at sustained high RPM 7,000 - 8,000