Datsun Roadster Forum-311s.org

No offense taken at all! What I reported was my personal experience in using the Mobile One filter, which does not allow for the use of the tube. The rattle was significantly longer despite the smaller size of the filter. By switching back to a Hastings and the tube, the rattle was much shorter, which suggested that the tube was doing its job to help keep the filter more full. I also always spin my engine for about 12 reps before firing (I have an ignition kill switch). Three pumps of the Dellortos, switch on and it fires right up with no rattle. That did not happen with the Mobile One filter regardless.

I believe the bigger issue is pressurizing the cam chain tensioner. The rattle seems to be caused more by this than rocker arms on the cam. By shimming the tensioner, most pre-start rattle sounds are gone, and what's there is very quiet. However, what sounded like "oil starvation" was longer without the tube. BTW, with my engine on the stand with the tensioner installed NO shims and without oil pressure (of course), when turning the engine over by hand the chain would go through this slacking then sudden tightening as the tensioner would be pushed in against its internal spring, which is not enough resistance. I watched the crank turn while the cam did not, radically changing cam to crank timing, and it wasn't just a little. What happens when the engine is being turned faster by the starter is unknown, but that rattling would suggest to me that what I observed is happening unless the tensioner is shimmed. So, regardless I suggest every U20 cam tensioner be shimmed!

Dumb question from a guy who has never taken apart a U20:
Does the timing chain use a hydraulic tensioner, or is it strictly a spring-loaded deal?
I remember from (decades ago) working on the L16 that it had a spring-loaded plunger attached to the tensioner shoe, but also used engine oil pressure to advance the shoe into the slack side of the timing chain. Just wondering if the U20 is the same...

I ended up with a new oil filter that would work with U20, maybe R16 without the tube. Anyone need it just PM me and just cover the shipping and I will send it ($5?)

TurboRagtop wrote: ↑Wed Oct 09, 2019 4:07 pm Dumb question from a guy who has never taken apart a U20:
Does the timing chain use a hydraulic tensioner, or is it strictly a spring-loaded deal?
I remember from (decades ago) working on the L16 that it had a spring-loaded plunger attached to the tensioner shoe, but also used engine oil pressure to advance the shoe into the slack side of the timing chain. Just wondering if the U20 is the same...

Correct. A little spring that doesn't do much, dominatly actuated by pressure. 2 tensioners though.

I Have factory new Nissan tubes in stock $10 each or 3 for $25 plus shipping

Ross
Sports imports

There you go..at 10 bucks, why would you not use it? Clearly the engineers at Nissan thought it was a good idea.

Agreed! Think I got mine from Ross years ago!

There's nothing like pulling off a filter and going, dammit, where's the tube? Sins of previous owners.

As I mentioned before, ALL of those components need to be present and correct.








For example, if P/N 8 is missing, as it was in my engine, the filter does diddly squat because the oil doesn't follow the right path inside the housing.

When I got my car it never had the Tube, and back then everyone was going on about the need for it well I finally found a correct pic of said tube , made one up and fitted it, the pic of the one posted is not quite correct, it has an angled cut and approx one third of the top is covered, but it still drains back after one day sitting idle, if my car sits for a week or so I crank the motor over till I get pressure before starting it..at least makes me feel better about it, been like it for 15yrs now...

sunbeam590 wrote: ↑Thu Oct 10, 2019 11:04 pm When I got my car it never had the Tube, and back then everyone was going on about the need for it well I finally found a correct pic of said tube , made one up and fitted it, the pic of the one posted is not quite correct, it has an angled cut and approx one third of the top is covered, but it still drains back after one day sitting idle, if my car sits for a week or so I crank the motor over till I get pressure before starting it..at least makes me feel better about it, been like it for 15yrs now...

They came in more than one version I believe. The one I have came out of an early roadster and I think they are the same in my other ones.

Ok, I started this tread by asking if the anti drain back tube was really necessary and a lot of folks weighed in. I asked the question because I didn’t want to introduce any new variable in my car’s oiling system unless I would benefit from adding one. So wanting the best for my car I bought one from Jim Tyler ( Datsun Restoration Products) and after an easy installation on my next oil change I note a difference in the time it takes my car to gain oil pressure and oil to reach my engine’s valve train. I also installed a Nissan filter (long version) that’s correct for my 67 SRL and still available at my local Nissan dealer # A5208-43G0A-01. Thanks 311 owners for your time and knowledge sharing to help me out. Rick

The pleasure is ours... we like to help.

Does anyone have dimensions for this tube? Length? ID / OD in both the end that inserts into the threaded portion of the filter mount and the end that extends into the filter itself?

Anyone? See my last post.