Opening Crank Case Vent Tube

[Uncle Laulau]

LauLau You dont need headers dont waist you money and time on them.

 

also untill you get the crank case open I would buy a long hose from the valve cover and routew it down back by the trans to ground so you dont suck in oil thru the carb(speed tape the bottom of aircleaner where elbow was)

 

Yah it looks like other things are breaking faster than I can get to em any hu. Don't you think they would provide some better breathing for the engine? If not, what about how fricken cool they look. Well to each his own, I have heard other people say the stock manifold is good enough. It's just another thing I can say I put on the car on my own, the long list of what's on this thing. I find that fun.

 

So you don't like running the valve cover vent into the carb. I have to say after cleaning it I really am close to getting rid of the connection, and letting it vent to air. I'm gonna check it after I open the crank case up correctly, and if it still blows oil it's gone.

[H5WAGON]

PO crap can make your head spin sometimes........

 

 

What about the timing marker...?

[Wide14u]

the timing marker is on opposite on the l20 then it is l16 and l18

[Wide14u]

or its deference in the year's

[banzai510(hainz)]

So you don't like running the valve cover vent into the carb.

 

I vent mine to the carb to keep the stink down. But if over oiling like you have Maybe route a hose down below the trans.This help keep oil spray off the fire wall also.

 

Once you get crank case pipe I would ike for a L16 set on the PVC hose ect....

 

The cost of having headers and best to have the ceramic coated(100-150$) other wise they look like shit.Then maybe they leak and soem are loud bell sounding.

Personally the cast ehaust man can handle 150hp. Far from what your going to do with a down draft and even most sidedrafts setups.

 

Plas they last a long time and DONT LEAK.

 

If you just got to have a header I say get the short tube one from Top End Performance for 150 then get it ceramic coated for another 150 to add maybe 3 hp power in the top end over 5kRPM but loose 2 hp in the drivablity range(low end)

[ggzilla]

You misunderstand the purpose of the tubes. One is to let fresh air in, the other to let the block air out. That's why it's called "positive" crankcase ventilation.

 

If you want minimal crankcase ventilation, then maybe you only need one of them. Just run a hose down slightly below the pan & crossmember a little bit, like on the 1963 vehicles.

[Uncle Laulau]

Man I stalled on a big intersection tonight, with my old lady! Man my dang coil wires keep wiggling free. I pinched them tight with pliers and they still fell off. At this rate my wife will never ride with me again. arg.

[wayno]

Man I stalled on a big intersection tonight, with my old lady! Man my dang coil wires keep wiggling free. I pinched them tight with pliers and they still fell off. At this rate my wife will never ride with me again. arg.

 

 

Are the wires your talking about the ones going to the distibuter electronic ignition? Do you have good motor mounts, does the engine move around a lot? Does your shift lever move a lot when you shift gears?

[Uncle Laulau]

Are the wires your talking about the ones going to the distibuter electronic ignition? Do you have good motor mounts, does the engine move around a lot? Does your shift lever move a lot when you shift gears?

 

I just got back from the movies I'm not an insomniac. All the wires jiggle off the coil and resistor once and a while. The shifter does not move nor are there any other signs of motor mount drama. I just need to go threw and do my wiring a bit nicer. I got new female ends to put on that should do it.

[DanielC]

It is a lot better if both tubes to vent the crankcase are hooked up. The carburetor is calibrated to take into account the "air leak" from the PCV valve. This sucks moisture, and unburnt gases out of the cranckase, and burns them. Because a good PVC system keeps the engine crankcase at a slight vacuum, the engine leaks a lot less oil, and stays cleaner. The tube on the top of the valve (cam) cover should be vented in to the clean side of the air cleaner. Air normally goes in this tube. You do not want dirty air being dumped on top of your camshaft.

 

I too believe you do not need headers. The stock l-16 exhaust manifold is one of the best flowing stock manifolds, on any car. It fits. It does not leak. It is not excessively noisy. It allows you to hook up the hot air stove to the air cleaner. This makes your Datsun run better in the winter, and warm up faster. I have actually had the carburetor ice up on a Datsun, and almost stall the engine, and I live south of Portland, OR. You drive in the same weather conditions I did. Got the money to buy the headers? Trust me, there are better things to spend the money on.

 

With electrical spade connectors, I often that a pair of pliers, and slightly squeeze together the curly clips on the female connector, to hold it on tighter. If is slides on easy, you need to do this. There is also a little dimple on the female connector, that goes into slight hole on the male connector, that snaps into place, and helps hold the connection together. You also want the wires supported as close to the part they are hooked up to. On the distributer, there is a clip that holds the wire, on the top left bolt that holds the fan shroud on the radiator. the distributer to coil primary wires then go to the radiator core support, above the headlight bucket, and then toward the back, on the left inner fender, and then drop down to the coil, just above the coil. I will try to get a picture later.

[jon521]

so what is this line running to my vent? also, should i unplug my vent? my valve vent is running to my air filter, and is pushing out air, thats how it should be right?

 

[ggzilla]

The engine should not be pushing out much air. If you cup your hand around the rocker cover vent, you should not be able to see any vapours. If you do, the rings are excessively worn.

 

Yes, you should unblock that pipe and connect it back to the PCV valve.

 

The small line is for the fuel tank vent, I believe. Does your 521 have one of these on the firewall?

[jon521]

The engine should not be pushing out much air. If you cup your hand around the rocker cover vent, you should not be able to see any vapours. If you do, the rings are excessively worn.

 

Yes, you should unblock that pipe and connect it back to the PCV valve.

 

The small line is for the fuel tank vent, I believe. Does your 521 have one of these on the firewall?

 

where is my pcv valve at?

 

i do have one of those on my wheel well

[ggzilla]

I dunno where your PCV valve is.

 

But LauLau's look like it is missing. Isn't it supposed to be on the intake manifold just under the carburetor?

[jon521]

hhmm....what if i just unplug it and run it down by the trans like hainz said? that would work too right?

[wayno]

Laulau's PCV valve is missing and the intake manifold access is plugged off. He has made a hole venting the block to the outside air, it is probably adequate as the PCV valve doesn't suck that much air, volume wise.

[yello620]

hhmm....what if i just unplug it and run it down by the trans like hainz said? that would work too right?

 

No, it needs to be Positive. IE: it needs to have manifold vacuum sucking on it. But the Pcv valve controls how much airflow it gets.

[ggzilla]

yes, it works, it's what my pickup has, a hose that runs down to just below the crossmember.

 

But the PCV system is better, better for the engine, better for the environment. Smells better too.

[wayno]

hhmm....what if i just unplug it and run it down by the trans like hainz said? that would work too right?

 

 

I have a question that needs to have a clear answer, where does that tube coming from the engine side case go in the photo below.

If it goes to the cabarator, it needs a PCV valve, one of the reasons for a PCV valve is it is a oneway valve, if the engine backfires threw the carbarator, the PCV valve does not let it ignite the crankcase vapors inside the engine block. I beleave it is better to vent to the atmosphere, than to connect it to the carb without the PCV valve.

[jon521]

wayno, do you mean the smaller line that comes from the case breather and runs towards the foreground of the picture and get kinda blurry? that line runs to this:

 

 

 

 

 

 

[wayno]

Ok, that's good, not the carb without the PCV valve. The capped off part of that tube is supposed to go to the intake manifold via the PCV valve.

[jon521]

Ok, that's good, not the carb without the PCV valve. The capped off part of that tube is supposed to go to the intake manifold via the PCV valve.

 

 

altho my breather on my valve cover runs straight to the clean side of my air filter, but it doesnt need a valve there does it?

 

so it is better to unplug it and run it free to the atmosphere with no pcv valve than it is to leave it plugged?

 

 

[ggzilla]

my breather on my valve cover runs straight to the clean side of my air filter, but it doesnt need a valve there does it?

 

That hose is a special one -- it has a spark arrestor in it. Do not use a plain straight-through hose.

 

There is a lot of careful engineering that went into our Datsuns, although they appear simple they are sophisticatedly simple. I'm not sure why people throw parts away without fully understanding how it works.

 

Here's one from my datsun sedan:

 

 

so it is better to unplug it and run it free to the atmosphere with no pcv valve than it is to leave it plugged?

Yes it is better to vent the block. Even though the rocker cover is vented, it is still good to vent the block so the engine don't have to push air from bottom to top.

[jon521]

Wow you guys are the best. I have a straight hose from my valve cover to my air filter right now, so I think I will disconnect it from there get one of those small cone air filters to put on the valve cover vent. As for the case vent, I will probably run a line down towards towards the trans. Thanks for all the help! Even tho this isn't even my thread haha

[Uncle Laulau]

The learning never ends, it seems. Truck was hesitating and hard to start after it was warm. I experimented with removing the valve cover vent hose from the air intake on the weber. When I removed the hose water drops came out of the tube, water! Looks like condensation was getting sucked into the carb making it super hard to start after it was hot. So I'm leaving that vent open to the air. Probably get little filter for it, as long as this fix stays fixed. A bit of duct tape on the outside of the air filter to block the old vent entrance and we are golden. We shall see how this works, happy 4th of July.