FOUND: Crankcase Breather Tube for L28

[grimlynsan]

Hi guys,

 

I went to Bunnings today and bought all manner of tubes, plumbing fittings, curtain rods, anything that looked roughly the right diameter (don't have verniers).

 

Turns out a wardrobe rail (23.5mm) is too small, and a plumbing fitting is too big (25mm) so I am guessing it's a 24mm tube that I need.

 

Does anyone have one of these, preferably in Brissy?

 

I need this so that I can connect a catch-can...

 

Thanks,

 

Lee

[Zedman240®]

Do you need the metal tube that goes into the block and not the rubber hose that goes to the airbox? Might have one floating around..

[grimlynsan]

Do you need the metal tube that goes into the block and not the rubber hose that goes to the airbox? Might have one floating around..

 

Wow that was quick. Yeah I am just after the metal pipe part. I'm going to run an adapter and hose from that to a catch can.

[grimlynsan]

This bit

[dat2kman]

You bring your bits of metal tubes around, and i can put them in the lathe and turn them down to a slight interference fit.

 

Or, i can have good look through the eleventy eleven boxes in the shed, for a proper one.

[grimlynsan]

Or, i can have good look through the eleventy eleven boxes in the shed, for a proper one.

 

If you wouldn't miiiinnnnd...... That way I can avoid postage, AND I get to look at your Roadster again! Plus I'd like to have a proper one :-)

[peter t]

You bring your bits of metal tubes around, and i can put them in the lathe and turn them down to a slight interference fit.

 

Or, i can have good look through the eleventy eleven boxes in the shed, for a proper one.

That's what I did Lee, bought a brass hose director from the hardware shop and rolled it around the grinder to get it to fit then stuck it in with sticky stuff. Bit rough but works and no one see it anyway.

[grimlynsan]

FOUND. Thanks Jason!

 

Although it is a bit shabby... will have to paint it red

[d3c0y]

I've got a welsh plug in mine much to Lee's horror. He wouldn't believe me its ok  :-\

[grimlynsan]

I've got a welsh plug in mine much to Lee's horror. He wouldn't believe me its ok  :-\

 

Remember I was saying it had to do with pressure and stuff.

[d3c0y]

Yeah i know that. I literally just double checked with PMC and he said you don't need it.

 

 

It's basically an emissions add-on. You get better bottom end lubrication without it.

[grimlynsan]

In no way questioning PMC but for reference I got my info here

http://www.enginebasics.com/Engine%20Basics%20Root%20Folder/Crankcase%20Ventilation.html

Something to do with ring seals from memory. I don't profess to understand how it works.

[dat2kman]

Better bottom end lubing? What a load of bollocks.

You end up with a wall of air trying to pass up the front timing case cover, along with air pressure going up the rear of block head oil drain hole.

At front, with an engine at high rpm, you end up with a waterfall type flow of oil teying to pass down via timing cover, as the rear of head drain is full.

We need the oil up in the valveteain to keep it all cool.

 

With puston ring blowby, six pustons reciprocating and a crankshaft rotating it is a veritable mist of oil droplet laden air in the bottom end.

 

The lower block breather is the large size it is for a reason. It in stock form, ultimately passes this pressurised air back into the induction system.

 

This is why crank scraper plates/blades are a very usefull item, they provide more horsepower, and pull oil out of the whipped up air in the bottom.

 

For sale L28 Crank scraper add coming up!

[d3c0y]

OK better bottom end lubrication maybe a stretch, ill give you that and the other reason my motor doesn't have one is because of the long stroke the rods come too close to contacting the breather pipe.

 

In reference to the link ,since an L doesn't have oil squirters, you need the crank throw off to help lubricate the wrist pins and the pistons so you don't want to eliminate the oil droplets flying around the crank case too much. Pete was telling me how he was rebuilding an L currently that had a vacuum pump installed on it and it starved the bottom end and cam of lubrication (didn't have an oil spray bar installed).

 

End of the day i've been told it doesn't need it and i have to believe my engine builder or the bases of my datsun life is a lie.

 

I guess with the crank scraper you are still getting throw off front the crank, just not below it.

[grimlynsan]

Last weekend I managed to get the new crankcase breather tube sorted. I know for most people, the crankcase breather tube is one of the most important components to consider in your Datsun restoration, and it is for you that I provide this account of progress so far.

 

I gave it a wee sand with an old file I had and some sanding blocks I had left over from sanding a wall. Then I whacked on some machinery paint I had left over from etch priming my front door frame on the house.

 

And now it looks the business!

 

If only the other engine bay bits looked so nice!

 

Lee

[d3c0y]

Factory bro, the cement in the pits at QR thanks you.

[grimlynsan]

I don't know... Looks kinda artful to me...

[d3c0y]

I see a flock of bats flying over the mangroves at dusk 

[grimlynsan]

So, another Saturday has passed and I have done some more work on the Z. I am of course delighted to share with you all the progress made on this most exciting topic!

 

Now the tube has been painted, I tapped it in with a hammer, using some wood to protect it.

 

Then I needed some hose to get the tube to the new catch can so off to Repco I went. Here's the issue, the crankcase breather tube is 24mm and largest hose you can get is much smaller than that, not to mention the fact that the input for the catch can is really small.

 

So after staring at everything available for quite some time, I managed to assemble:

 

• an AU Ford radiator hose (fits over the 24mm breather tube and has 2 bends which were useful in getting the best alignment).
   
  
• 1m heater hose
  
• 3cm of slightly larger heater hose (small slice I got for free, need it to step up from the 1/2" adaptor to the 24mm rad hose)
   
  
• 1/2 to 1/4 inch brass adaptor
  
• clamps
   
  

Picture 1 shows the parts lined up.

 

Picture 2 shows the rad hose with a 80 degree bend on the tube with the adaptor fitting.

 

After some fiddling I got this all to fit alright, but my idea of putting the filter on the catch can is not possible because the filter fouls on the hose! [Picture 3].

 

So I am still not finished.

 

I'd like to connect the breather on the tappet cover to the same can, using the other connection, but then there is nowhere for the air to escape. So I'm thinking I will drill a hole in the top of the catch can and then use one of the spare fittings that came with it, weld it in there somehow [Pic 4] and then put the filter on that. Then I will be sorted! All I need is some way to weld aluminium and it should one day look like the final Pic 5!