Datsun Roadster Forum-311s.org

I modified my SU baseplate by cutting off the stock horns to accommodate aftermarket Velocity stacks. In that process I’ve lost the ability to connect the valve cover vent hose to baseplate. I’ve tried to route the oily mist with a catch can of various types but I’m always getting that thin mist of moisture and oil that clings around the engine bay. I’d like to feed it back into the intake to rid smell/mess. Should I connect it directly to one of the intake manifold plugs or run a PCV valve in between the hose and intake?

Can you post pictures of the modified base plate?

Guess my basic question is since the stacks lack the original bibs on each for the hose that routed vented gases back into the intake, should I go directly from valve cover to one of the taps on manifold or put a PCV inline? Would a PCV pressurize the block too much?

You could drill and tap the stacks for a brass nipple in each, and use the factory rubber "t"?

I'm a bit confused as to why you did that to the 2000 air cleaner. It had stacks. The 1600 has goofy bent stacks - I could see doing it with that design.

Different stacks and their lengths alter where you want power. The stock U20 is just ok. With bigger bore and SU mods fuller radiused stacks work better for my application.
The shorter ones wake up my mid/top end
I still have my original air box. The one pictured that I hacked was from a friend.

Just run it to the existing pipe, it will get sucked in.

I did that Greg with those itty bitty filters as many guys have done but there’s always a film of oil, even if it’s just a little. I would much rather reintroduce it back into the intake. Just need to know if it’s better just recycling it back or introducing a PCV. Don’t want smell and mess. It’s all about the engine bay tidiness is what I’m seeking.

I'd bet with the minimal intake there might be a problem with the vacuum leak on 1 branch .. ( carb syncro ).or Datsun might have put it in ...the vacuum port for pcv is always located in the plenum area of the intake
there was a mini pcv half the size of the common one some sun compacts used I forget which one

drill and tap the stacks for barbs for the stock rubber "t"?

What I’m trying to avoid. Venting to atmosphere will always result in misty oil. I’m not going to bugger up nice stacks and even if I did there will be a mist of oil at stacks. Has to be a way to recycle it back to intake. Just need to know if PCV is better than recycling it continuously back constantly.

What about to a good quality oil catch tank then back to airbox?

nismou20 wrote: ↑Tue Aug 25, 2020 10:03 pm What I’m trying to avoid. Venting to atmosphere will always result in misty oil. I’m not going to bugger up nice stacks and even if I did there will be a mist of oil at stacks. Has to be a way to recycle it back to intake. Just need to know if PCV is better than recycling it continuously back constantly.

Hells yes... it will not work ,just sucking the vent tube into the intake....would be a oil burner for sure you need the pulsing valve

The 240Z system is the same as what you did by cutting the stacks. They just route into the air cleaner and the suction takes care of the rest. It should work as you have it with the hose from the valve cover to the air cleaner.

I don't understand how the oil mist is making it out of the air filter. Are you running an air filter, or just the plate?

Peace,
Pat