Steve's unending Progress thread, Air compressor setup recommendations Options

[stephenaki]

I saw several pictures of different hook ups, some complex some very simple but I thought the whole point of the breather was to catch the oil then let it drain back into the motor. If she drains into the carbs, doesn't that kinda gum them up a bit?

there should be 4 ports.
one from each head. these are 'in'
one drainback to the case - this is kind of an in/out, as it relieves crankcase pressure in operation and provides a return path for collected oil, condensed from the mist.
one _vent_ to the air cleaner, to burn the partially oxidized blowby and some of the oil vapor. Some simply vent this to the atmosphere. I ran mine to the air cleaner, the way carbureted Porsche engines always were from the factory. With - I should note - a flame arrestor, because having an intake backfire propagate into the possibly combustible crankcase vapor is definitely A Bad Thing.

Yes, there are 4 ports. I have seen people use the two sides and one in the center blocking off the 4th. Now, I am running dual Dellorto 40 Carbs and the intake manifold on each one has a vent port.

There is one on each side; would these suffice for the "one from each head?" I assume that I will need to run one drain line back into the oil filler neck as there is a port already there.

If I run one line each from the side ports to the intake vent and then one to the oil filler neck vent, I have one port left. Here is what I am thinking.

Sorry for the crude drawing, will this work? She needs to pass inspection so I can ship her home. I will PCS this June and need to get her operational so I can put her on a boat headed back stateside.

I can probably create a "Y" junction and run a single line to the junction and then split them out to each carb on the top. Thoughts? Do I need to do this or will a three line system suffice?

[Cupomeat]

Sorry to join this thread late, but you need to port your breather box BEFORE the throttle venturies/butterfly plates or else you'll have your whole crank case in a partial vacuum and you'll be chasing mixture issues as the engine loosens up.

Don't use the manifold ports for this. You can use them to equalize between the two sides, but it is bad idea to use them for crankcase breathing.

Just think, if ANY gasket starts to leak (top of a valve cover or the breather tower for examples) then you'll start sucking air through them and your mixture will go lean.

I think the port they speak of is the HEAD breather port which is found on D-Jet cars and vents the gasses from each head.

I hope this helps.

[stephenaki]

Sorry to join this thread late, but you need to port your breather box BEFORE the throttle venturies/butterfly plates or else you'll have your whole crank case in a partial vacuum and you'll be chasing mixture issues as the engine loosens up.

Don't use the manifold ports for this. You can use them to equalize between the two sides, but it is bad idea to use them for crankcase breathing.

Just think, if ANY gasket starts to leak (top of a valve cover or the breather tower for examples) then you'll start sucking air through them and your mixture will go lean.

I think the port they speak of is the HEAD breather port which is found on D-Jet cars and vents the gasses from each head.

I hope this helps.

Hmm, OK, will look at other options. I'm looking at old photos and their are hoses running into what looks like a PCV valve. There is then a hose running from the PCV to an empty quart of oil container. The port from the oil filler neck also has a hose running from it to the empty oil container and no, I didn't do this, the Germans did!

I have a new NCO that is working in a sister ALE that is a school house instructor for the Army for mechanics. I'll enlist his help to come up with the best solution for this sucker.

Tomorrow I'll finish up the electrical, fuel lines and heater controls. All I'll have left is the breather box set up after that.

[SirAndy]

Sorry to join this thread late, but you need to port your breather box BEFORE the throttle venturies/butterfly plates

(IMG:style_emoticons/default/agree.gif)

The breather box needs to vent into the air-cleaner portion, not the intake runners. The oil vapors should go through the venturis, not bypass them.
(IMG:style_emoticons/default/shades.gif)

[DBCooper]

(IMG:style_emoticons/default/agree.gif) But do use a hose to connect those manifold vents on each side to the other. It smooths out side-to-side vacuum differences so the car idles a bit better.

[ArtechnikA]

There's a few concepts here, loosely related but they all come together.

The breather box is designed to relieve pressure from places it shouldn't be, but is. One is the crankcase. Positive pressure here is always bad, and all cars have some way of venting this pressure. In Ancient Tymes it was just routed to atmosphere. More recently (mid 1950's) it was necessary to route it back to the intake.

The other place pressure is bad, especially in boxer engines, is the valve covers. 914's are famous for blowing out valve cover gaskets, followed by all their oil. In some years of 914's - and I don't follow the /4's that closely so check the history somewhere - there are breather ports in the heads that lead to the rocker arm area. Lots of performance VW engines from before this time found ways to add breather ports to their valve covers.

If your heads have ports, use them. If not, you might want to find a way to add them, but at this point for you, it'd just be an unnecessary complication. Connect the crankcase breather - yes, that one at the oil filler - to one of the breather box ports, and the other to the AIRBOX. Or whatever you're using to keep rain out of the carb intakes. just (somehow) run the hose to a fitting that vents to the carb side of the air cleaner.

Moving on - if you think about boxer firing sequence, you see that adjacent cylinders fire consecutively. This means the first to fire has to start the air column moving through the venturis, making it run a little lean, and the second has the advantage of the moving air column's momentum (which is significant) and tends to run rich.

With single-throat carbs and manifolds, it's helpful to balance the airflow with a big pipe between the manifolds. That lets some of the vacuum from the other side of the engine keep the air column moving so the first-to-fire cylinder doesn't run so lean. VW has used this trick for a long some, back to at least the early twin-carb T-III engines.

So the _only_ place to connect the manifold ports is to each other. It will help a lot. If you can't arrange for an appropriate hose, plug the ports until you can find the right hose.

[stephenaki]

There's a few concepts here, loosely related but they all come together.

The breather box is designed to relieve pressure from places it shouldn't be, but is. One is the crankcase. Positive pressure here is always bad, and all cars have some way of venting this pressure. In Ancient Tymes it was just routed to atmosphere. More recently (mid 1950's) it was necessary to route it back to the intake.

The other place pressure is bad, especially in boxer engines, is the valve covers. 914's are famous for blowing out valve cover gaskets, followed by all their oil. In some years of 914's - and I don't follow the /4's that closely so check the history somewhere - there are breather ports in the heads that lead to the rocker arm area. Lots of performance VW engines from before this time found ways to add breather ports to their valve covers.

If your heads have ports, use them. If not, you might want to find a way to add them, but at this point for you, it'd just be an unnecessary complication. Connect the crankcase breather - yes, that one at the oil filler - to one of the breather box ports, and the other to the AIRBOX. Or whatever you're using to keep rain out of the carb intakes. just (somehow) run the hose to a fitting that vents to the carb side of the air cleaner.

Moving on - if you think about boxer firing sequence, you see that adjacent cylinders fire consecutively. This means the first to fire has to start the air column moving through the venturis, making it run a little lean, and the second has the advantage of the moving air column's momentum (which is significant) and tends to run rich.

With single-throat carbs and manifolds, it's helpful to balance the airflow with a big pipe between the manifolds. That lets some of the vacuum from the other side of the engine keep the air column moving so the first-to-fire cylinder doesn't run so lean. VW has used this trick for a long some, back to at least the early twin-carb T-III engines.

So the _only_ place to connect the manifold ports is to each other. It will help a lot. If you can't arrange for an appropriate hose, plug the ports until you can find the right hose.

Thanks for the discussion on this subject. It has definitely made me a lot smarter on this issue. Based on your and everyone elses comments, I believe I have a way ahead.

[stephenaki]

OK, got a lot of work done today. Got all but the battery hooked up, finished the heater box set up, had to pull the wires and re-route them. Luckily one of the guys on my team popped over cause he was bored and made it a lot easier with four sets of hands.

Got the exhaust on, pulled the driver seat out and installed the new seat adjustment handle. We'll see how long before it breaks based on comments from DD that I read when I looked up how to install the dang thing. Its the plastic handle.

So all I have left is to hook up the battery, run the breather lines, add oil, and time the motor. Tomorrow is put away all the Christmas stuff day so I won't get anything done tomorrow. Especially given the fact that we are moving in about 6 months so will go through everything to see what we can sell here in Germany before heading back stateside.

If I'm fortunate, I'll get to finish everything up on Monday. That being said and based on the plethora of comments for the breather, my plan is as follows.

1. Run a line from one intake port to the other per recommendations.
2. Drill and install a port on top of each carb lids and run lines from the sides of the CB breather to each carb.
3. Run a line from the front of the breather to the oil filler port and cap off the extra port on the breather.

Any issues with this plan? (IMG:style_emoticons/default/popcorn[1].gif) If all goes well, I'll have her registered by the end of this coming week. Provided the inspectors aren't fucktards. They got a new crew in and a couple of them are complete assholes who try to find ways to fail the 'Americans' cars during inspection. (IMG:style_emoticons/default/sheeplove.gif)

[ArtechnikA]

You really only need to vent the breather to one carb. More is just weight, expense, clutter, and stuff to go wrong. Pick whichever is closest.

If you want two for the symmetry, go for it, but it won't buy you anything.

[stephenaki]

You really only need to vent the breather to one carb. More is just weight, expense, clutter, and stuff to go wrong. Pick whichever is closest.

If you want two for the symmetry, go for it, but it won't buy you anything.

Sounds like a plan. I'll just use one and see how she goes. Not worried about the other stuff just need her running long enough for me to get her back stateside. Thanks.

[stephenaki]

Well, back to work after the new year and other than annoying retards who are trying to get me to do their job, were doing well. That being said...
She's done! Well relatively speaking.

Everything is assembled I just have to check timing. Unfortunately, she'll crank but isn't starting at the moment. She's getting fuel, I can see it squirting into the carbs when I move the throttle lever between the carbs.

Anyone got any hints or suggestions?
Here is the picture of what I did for the breather unit and the engine bay.

Necessity being the mother of invention, I had to route a hose between ports since I couldn't find any caps to close them off.


I rechecked all the wiring and everything is good and you can here her cranking but she just isn't starting. If I can get her started and make sure the timing is good then I can get her registered this week.

[ArtechnikA]

static-time to 6º BTDC and it will start, then go from there.
if it doesn't start there, your problem is not timing.

[stephenaki]

static-time to 6º BTDC and it will start, then go from there.
if it doesn't start there, your problem is not timing.

I'll give her a try tomorrow. Lets see how many Germans I can piss off; Sundays are 'don't do anything' days. You can do hobbies but they don't consider me working on the car a hobby even though I do. (IMG:style_emoticons/default/biggrin.gif)

[fastfingers]

I know you said you checked the wiring, and when I read you had trouble getting her started/running, it reminded me of an embarrassing personal experience for me about 30 years ago. So, not trying to insult here, just check the obvious. This is what happened to me.

I had just finished putting the heads back on and reinstalling a fuel injected 1974 2.0L. I remember worrying about checking everything on the fuel injection. I was so worried about it. After the engine was back in the car and everything was "ready" to go, it wouldn't start. I had a friend come over that weekend and we looked over all the potential trouble areas. So finally my friend says, looking at the wires running from the distributor to the spark plugs, are you sure you have this right, it looks wrong to him? I'm thinking, what, are you kidding me? How could I get something that simple incorrect after having put the rest of the engine back together? Well, he leans into the engine bay and just arbitrarily switched two of the plug wires.

The car started up easily and idled as smooth as a sewing machine. I never forgot that mistake.

[cwpeden]

I had my tachometer wire on the wrong terminal of the coil. That prevented start.

Same scenerio. Friend comes over after 2 days of trying....this isnt right....and away we go.

Do you have a second set of eyes to help out?

[Dave_Darling]

Check to see if you have spark. An extra plug can help with that. If not, troubleshoot the ignition system.

--DD

[stephenaki]

Thanks all, I have a friend of mine coming over this morning. He was a school house instructor for the Army mechanic school. After doing some research on setting static timing to 6 deg BTDC it occurred to me that I may not have installed the distributor correctly and have a misaligned drive gear.

I will begin the process this morning of making sure I have TDC marked correctly on the impeller as the mark is not clear and I am not totally sure it is right. Once I get that sorted, I will re-install the distributor and then have my buddy explain the nuances of setting static timing. I did forget to mention that the PO installed a petronix kit so there are no points. Hopefully, I'll have her up and running today, wish me luck!

[stephenaki]

Houston...we have ignition! (IMG:style_emoticons/default/piratenanner.gif) (IMG:style_emoticons/default/piratenanner.gif) (IMG:style_emoticons/default/piratenanner.gif) (IMG:style_emoticons/default/piratenanner.gif) (IMG:style_emoticons/default/drunk.gif) (IMG:style_emoticons/default/drunk.gif) (IMG:style_emoticons/default/cheer.gif) (IMG:style_emoticons/default/cheer.gif) (IMG:style_emoticons/default/cheer.gif)

So after about 3hrs of trial and error, Paul, my buddy, and I finally got the dizzy set up properly. Once we got that aligned properly...tada! She starts up and runs like a champ. I had to adjust the idle as she was running at about 300 rpms but once that was fixed she held a steady and smooth 1500 rpms.

We delved into the dynamic timing next and got her smoothed out. So what are the finishing touches? I need to recheck shift rod adjustment and clutch adjustment, she wasn't going into gear very smoothly. I then need to make sure the emergency brake is adjusted to ensure it locks when they put her on the machine.

I'll work on that this week if I get a chance; I'd do more work today but I am woefully late on completing a report for an investigation I was tasked with a while back so I have to dedicate the rest of today to that.

Once I get her past inspection and registered I need to take her over to the shipping guys to get a preliminary assessment on what I need to do to get her ready for shipment back stateside. The backup plan if they are too difficult is to send her back the way she came. This would mean a road trip to Sigonella, Italy to put her on a Navy ship that is going back stateside and, since it looks like I am now locked in for Norfolk, VA as my next assignment, I'll be right where the ship will drop the car off. So far, things are going well, hopefully my luck holds. (IMG:style_emoticons/default/biggrin.gif)

[Cairo94507]

Very cool and congratulations on getting the heart beating.

[stephenaki]

OK, so I did the gear shift rod adjustment then checked the clutch pedal, she still needs a couple of minor tweaks. So, go to start her, she isn't quite responding, could be the fact that it is 37 friggin degrees outside. After a while she begins to catch and then nothing. Kinda like she got stuck. OK, put her in 5th, push! She rolls and it feels like something unstuck itself. Get back in, crank her, she starts! Not sure what was sticking.

When i'd crank her it was like someone grabbed the flywheel for a sec then let go. Any ideas?

So, I get her running and warmed up, time to take her for a spin. She seems to be shifting OK, not great but OK. She goes into gear smoothly I just don't think I have the rod from the stick back to the rear set quite right yet. Then...she sticks and I get a high idle at 3000 RPM. (IMG:style_emoticons/default/sad.gif) Let off the gas and she keeps high idling. The problem is somewhere with the carbs. On a positive note, no oil leak or transmission fluid leak that I could find after driving her around for about 30 minutes.

Just gotta figure out the idle, the gearshift and clutch adjustment I can figure out without any issues. I really wish the PO hadn't taken the FI system out. Hopefully I can figure these last bits out so I can get her through inspection. Once that is done then I just gotta make sure she is clean and ready for the shipment back to the states. Frustrating to say the least. (IMG:style_emoticons/default/headbang.gif)