L18 Crankcase Breather Outlet - Need solution

[Boy Blunder]

Good afternoon everyone. In my process of bringing my E Prepared 510 out of retirement... I am sorting through all sorts of stuff.

While I have the electromotive header and Mikuni's off the car, I can see that I will want to update how the crank breather vent was done.



Google Drive link to image:
https://drive.google.com/file/d/0B2oyfp ... sp=sharing

As you can see, I have this image taken with the Electramotive header still on the car. This shows just how tight the clearances are. Currently the crank case vent is just covered with steel mesh, and as you can see it does let oil blow by. After doing some research, I know that I would like to have the system set up to where I have a proper catch tank that routes the crank case breather and the valve cover vent.

Speaking with Mr. Ermish- His solution is to weld an AN bung fitting on the crank vent and all is right in the world.

The backyard mechanics solution is to just attach a rubber hose to the outlet and be done.

However... I don't believe either of these will work. Considering the tight clearances and the general common sense of saying "NO" to cutting the pipe off thus allowing metal shavings into the bottom end of this racing engine... I am open to ideas on how to solve this issue.

I can tell you that this engine is a .30 over L18 with a knife edge crank and rods with a lot of love in them. Cosworth pistons hitting the 14:1 CR mark. Rebello built head and the cam spray bar mounted.

This car also is equipped with an Accusump ( mechanical valve).

I am open to any ideas on how to make the best of this and do it proper without throwing oil everywhere and running the risk of unwanted oil pressure issues.

[okayfine]

Pic is not working for me.

[Boy Blunder]

Hmm..

When i first submitted the post I had the link go dead from google drive. I then copied the link location and used that link, and then the image appears within the post for me now.

I also added the link to the google drive as well, you should be able to follow the link to the image. Let me know if this doesn't work.

Thanks for looking.

[okayfine]

Picture:

Oil Leak.jpeg (95.12 KiB) Viewed 5332 times

[okayfine]

Will you be able to get around that nipple to completely weld an AN fitting on there? If so, then you could cut that nipple down using a tube cutter without introducing metal bits to the ID/engine innards.

If not, I don't see regular rubber hose holding up to the exhaust heat. It'd need some sort of protective sheath, or AN line if you can find the right ID so it will fairly easily slip over the nipple.

[Boy Blunder]

Regarding the Welding:

I don't know how to weld, and I'm pretty sure JB weld will not do the trick.

I do think that there may be an idea in using an open ended stainless braided hose with a clamp..

[okayfine]

If the block isn't going to come out, then welding is going to be problematic for a couple reasons, even if you're not doing it.

[datzenmike]

I assume this is not for the street then? That pipe is just pressed in, you could remove it and work on it. No you can't just run a hose down and out as anything blown out would get on the track surface. If a bung is welded onto it, the fumes can only then escape from the valve cover vent which would normally go to a catch can.

If for the street, you should connect the block vent to a PCV valve, even if you have to drill and tap the intake to fit one. The benefits are a cleaner engine, less engine smells, longer life and longer between oil changes.

[Boy Blunder]

That is news to me...

The crank case vent pipe is pressed into the block? How easy is it to remove?

If I can remove it and re insert it than I believe the end solution is to do just that. Remove it, shorten it and weld a 90 degree AN fitting on it and run braided hose to a catch can.

And no, this car is not street legal. Weights in at 1830lbs with ballast (to meet regulations).. no headlights and no creature comforts and sits on goodyear slicks

[zKars]

Removal is "easy" if you have access. Clamp a bigish vise grip on to it and bang on the vise grip with a hammer to pull it straight out.

Attach the vise grip by clamping it straight onto the lip, with the vise grip handle pointing in same orientation as the pipe centerline, not around the outside. Your not going to twist it, just pull it straight out. Clamp the vise grip so it leaves a raised nub on the handle in a position where you can bang it with the hammer.

[datzenmike]

That is news to me...



If I can remove it and re insert it than I believe the end solution is to do just that. Remove it, shorten it and weld a 90 degree AN fitting on it and run braided hose to a catch can.

Well a lower outlet to a catch can's not really needed as it will breathe through the valve cover vent. It's much higher on the engine and less likely to expel oil fog.

[bertvorgon]

Just a comment on the block breather...and this is just my experience.

yes, if you can, the fitting can wiggle out, then you can weld and extension on it, that is what I did.

As my motor does see very high RPM ( 7,500 - 8,000 ), I can still get a LOT of oil "fog" out the breather in the valve cover, and that is with the block breather in place. We have pondered over why, as I have a windage tray, etc, and the line from the block is very large. I still have the factory baffle in the valve cover also, so what does that tell you about the air displacement going on the the block! we thought it was maybe a turbo issue with blow by, but, at it's worst..HIGH RPM...was at the slaloms with very little boost. It too have a spray bar, so the amount of oil up top is considerable.

My ultimate solution ( I have a Nissan comp oil pan ) was to run an INDICATED 1 liter low on the dip stick. Why does that work...who knows...as it is not a crank issue...the oil is coming out the valve cover hose. Andy has run into that in a couple of other cars.

As you have a race car, my advice would be to retain the block breather, so as to allow the whole system to be able to breath as much as possible.

I had my catch can fill up once, when I first put the spray bar on...holy crap did that make a mess of the engine compartment, and after 20+ years, I still have oil weeping out of the seams on the passenger side, where my catch can is. At least it will never rust there!

[Boy Blunder]

Just a comment on the block breather...and this is just my experience.

yes, if you can, the fitting can wiggle out, then you can weld and extension on it, that is what I did.

As my motor does see very high RPM ( 7,500 - 8,000 ), I can still get a LOT of oil "fog" out the breather in the valve cover, and that is with the block breather in place. We have pondered over why, as I have a windage tray, etc, and the line from the block is very large. I still have the factory baffle in the valve cover also, so what does that tell you about the air displacement going on the the block! we thought it was maybe a turbo issue with blow by, but, at it's worst..HIGH RPM...was at the slaloms with very little boost. It too have a spray bar, so the amount of oil up top is considerable.

My ultimate solution ( I have a Nissan comp oil pan ) was to run an INDICATED 1 liter low on the dip stick. Why does that work...who knows...as it is not a crank issue...the oil is coming out the valve cover hose. Andy has run into that in a couple of other cars.

As you have a race car, my advice would be to retain the block breather, so as to allow the whole system to be able to breath as much as possible.

I had my catch can fill up once, when I first put the spray bar on...holy crap did that make a mess of the engine compartment, and after 20+ years, I still have oil weeping out of the seams on the passenger side, where my catch can is. At least it will never rust there!

Thanks for chiming in!

FYI- When I bought the car I was told the car would make peak power around the 7500 mark, after that your basically just spinning. When I called and spoke with Dave Rebello about the head to find out more about what was done ( As the car came with tons of receipts and documentation, pretty awesome in its own right!)- I went over the head build with Dave. Dave explained he's really had a specific build for an all out AutoX/Slalom engine package for a long time now - and with the cam he chooses the power will peak at about 8800 RPM .

Personally, I have followed the previous owner/mechanics advice and kept my right foot rev limiter to the 7500 mark ( the car has no rev limiter ).

Anyways, I run a very similar oiling setup to you Keith. I run the Datsun Competition oil pan and the cam spray bar as well, and as stated before I have an Accusump mechanical valve setup as well - I believe an extra 2 quarts. I find your "Mystery oil issue" interesting - as I wonder if this is something to do with the engine internal pressures and how the oil pan is baffled. I know that when I first fire up my race engine COLD, the engine will hover around the 80psi mark and then drop to the 25-35psi mark when finally warmed up at an idle that I have tuned to around 1200 RPM to smooth it out. Of course what any of this means I am still green compared to you old and wise farts - but this is just my own radical L series temperament.

Back to the Crank Breather Outlet-

What size of fitting did you weld onto the pipe? I believe that this is the way to go- if I can get that pipe out of the block without damaging it.
Also- how did you go about getting that pressed in pipe back in the block once done modifying it? I only ask as I'm sure others know what may seem very simple can sometimes be complicated and very easy to Fubar when not thought through properly.

[bertvorgon]

I actually did not weld a fitting on, as the heat that close even to an aeroquipe line, would have been to much in my case. So, we just made a 3/4" diameter piece that got welded onto the existing stub, and formed around the back of the block/head area, ending where you see it in the picture with the clear line, so there is flex as the engine moves. That might be tough for you, just depends on clearances.

I too see 80+ PSI cold, then it drops to and indicated 60 PSI hot, with an idle of around 20PSI indicated.
We attribute this to the fact that my pressure gauge comes off a distribution block for BOTH the spray bar and turbo feed. My higher volume oil pump is shimmed also, so we know the oil pressure is actually higher than indicated. Also, with 13 years on the last motor, when it was dismantled, it was in excellent shape, so we knew that oil pressure was not an issue. I run my idle at around 1,000 RPM. I think the spray bar, because of the volume of oil it moves, and most of us take our oil pressure off from that feed, have a bit more pressure than indicated.

I think we just used some lock-tite when we put it back in. I have had no weeping issues at all.

I only used my rev potential if a gear change was going to be a waste of TIME, as I usually shifted at 7,000. My reason was the load helped the turbo out a bit and once I was passed 4,500 RPM, I was in a good usable torque range. My short 4:62 gears sure help also.

[Boy Blunder]

I actually did not weld a fitting on, as the heat that close even to an aeroquipe line, would have been to much in my case. So, we just made a 3/4" diameter piece that got welded onto the existing stub, and formed around the back of the block/head area, ending where you see it in the picture with the clear line, so there is flex as the engine moves. That might be tough for you, just depends on clearances.

I too see 80+ PSI cold, then it drops to and indicated 60 PSI hot, with an idle of around 20PSI indicated.
We attribute this to the fact that my pressure gauge comes off a distribution block for BOTH the spray bar and turbo feed. My higher volume oil pump is shimmed also, so we know the oil pressure is actually higher than indicated. Also, with 13 years on the last motor, when it was dismantled, it was in excellent shape, so we knew that oil pressure was not an issue. I run my idle at around 1,000 RPM. I think the spray bar, because of the volume of oil it moves, and most of us take our oil pressure off from that feed, have a bit more pressure than indicated.

I think we just used some lock-tite when we put it back in. I have had no weeping issues at all.

I only used my rev potential if a gear change was going to be a waste of TIME, as I usually shifted at 7,000. My reason was the load helped the turbo out a bit and once I was passed 4,500 RPM, I was in a good usable torque range. My short 4:62 gears sure help also.

I'm going to assume you fabbed up a hard line pipe due to the immense heat generated by having a turbo manifold?

I know when talking to Troy Ermish about the issue he said he just welded on a bung and ran stainless braided. I would hope that this would do for an N/A application with the Nissan Comp header like we run. Even some overkill would be some general racing insulation for the hose that you can find from Pegasus Racing and the like.