75 280Z - Updating fuel feed & return lines in the engine bay

[HusseinHolland]

OK - so couple issues. One is that I have not been able to get the ProtunerZ rail CSV port to properly seal. They use a ORB-6 to AN fitting to seal the port. Problem is, they didn't cut a proper chamfer seat on that port (unlike the end ORB-8 ports). I've tried swapping fittings & o-rings, even adding a crush washer & thread sealant -doesn't matter it still seeps since the ring is being pushed out rather than into a recess as designed. It became easier to see today, since I now have the heat shield acting as a tray below

Lack of proper chamfer seat

I've sent pics to ProtunerZ, so we'll see what they say about it.

The other thing was that taking the rail in & out, I damaged 2 injector lower rings. The adaptor bungs also have no real chamfer to get the o-ring started when inserting, so, unless one is very careful the seals **** in the adapter as the rail is seated on the manifold, and the o-rings get cut in the process. I didn't really notice where the slightly irregular idle beat was coming from until I had the heat shield , as that reflects the sound of the air leak & sends it to you when standing on the driver's side. I couldn't tell exactly where it was coming from (injector or base adaptor) so I sprayed them with carb clean to isolate the air leaks to two injectors

I still removed the adaptors again & rechecked all the seat orings, they were all good

Back together again

Edited November 19, 2023 by HusseinHolland

[Zed Head]

Edit - actually I can't tell what the Protunerz site is saying.  It's not clear.  "6AN orb Fuel gauge port"?  See below.  Which is it?

I don't have much experience with AN threads fittings but the internet says it's a tapered thread flared fitting.  The Proturnerz site says that's a 6AN hole, if it's the hole you're using.

They mixed ORB with AN.  Easy to see a mix-up.  Full disclosure - I didn't even know what ORB was until just now.  Thank you internet...

https://protunerz.com/collections/fuel-rails/products/datsun-l-series-fuel-rail

https://en.wikipedia.org/wiki/AN_thread

https://hosebox.com/insights/orb-fittings-explained-selection-setup/

 

• CNC Anodized BILLET Fuel Rail with outer ORB-8 Thread, 6AN orb Fuel gauge port /cold start/pressure sensor.

 

 

Edited November 18, 2023 by Zed Head

[Zed Head]

My first instinct when I saw the hole was maybe it's a tapered pipe thread.  Following up on that, you could easily make it one.  They seal just fine with a bit of thread sealant.

[HusseinHolland]

44 minutes ago, Zed Head said:

Edit - actually I can't tell what the Protunerz site is saying.  It's not clear.  "6AN orb Fuel gauge port"?  See below.  Which is it?

I don't have much experience with AN threads fittings but the internet says it's a tapered thread flared fitting.  The Proturnerz site says that's a 6AN hole, if it's the hole you're using.

They mixed ORB with AN.  Easy to see a mix-up.  Full disclosure - I didn't even know what ORB was until just now.  Thank you internet...

 

21 minutes ago, Zed Head said:

My first instinct when I saw the hole was maybe it's a tapered pipe thread.  Following up on that, you could easily make it one.  They seal just fine with a bit of thread sealant.

It's 6 AN Male (which has a 37º flare seat) on one side, and ORB-6 (o ring seal) on the other. ORB -is not a tapered thread like NPT. The seat in the rail should have a chamfer for the o r-ing to compress into. The ORB-8 end seats had the proper chamfer, I didn't take any pics of the that

EDIT - ProtunerZ replied to my email - they are looking into it, they say they've not seen this issue before.

Edited November 18, 2023 by HusseinHolland

[Zed Head]

Not clear what you're saying, you showed a hole and an o-ring, and implied that hole was meant to be an ORB design.  The Protrunerz site doesn't clearly say say it's an ORB hole.  You're assuming it's an ORB hole.  That's the part that needs defining.  Looking at the ORB-8 at the end of the rail it's hard to imagine they'd forget to perform that operation on that hole.  But, who knows, maybe that's what happened.

I'm just here for the words...

I did find some other images though that imply it's supposed to be ORB.  But even they look a bit off.  Seems like the fitting is not seated.  Anyway, there are many ways.  Carry on.

[HusseinHolland]

6 minutes ago, Zed Head said:

Not clear what you're saying, you showed a hole and an o-ring, and implied that hole was meant to be an ORB design.  The Protrunerz site doesn't clearly say say it's an ORB hole.  You're assuming it's an ORB hole.  That's the part that needs defining.  Looking at the ORB-8 at the end of the rail it's hard to imagine they'd forget to perform that operation on that hole.  But, who knows, maybe that's what happened.

I'm just here for the words...

I did find some other images though that imply it's supposed to be ORB.  But even they look a bit off.  Seems like the fitting is not seated.  Anyway, there are many ways.  Carry on.

 

Thanks for the input, Zed Head. Yes, it should have the chamfer seat. That's the only way an ORB fitting can seal. They provide the ORB to 6AN fitting that is intended for the purpose, so it's not as if there could be an error in terms of the fitting used. The chamfer should have been cut as with the pic you found of the end seat.

[Patcon]

How hard would it be to just add the chamfer?

[HusseinHolland]

32 minutes ago, Patcon said:

How hard would it be to just add the chamfer?

Not sure I have a chamfer bit in the correct size. I don't want to do anything to the rail until ProtunerZ makes a determination. If they ask me to send the rail back, it won't be any good if I have modified it. If they suggest I do exactly that, rather than replace it with one properly seated, I will ask for a partial refund on the part. It's already dropped $45 from what I paid, due to their Black Friday Sale....

Edited November 18, 2023 by HusseinHolland

[Patcon]

I understand

It just seems like it would be childs play for you considering all the fabrication you done in the past.

[grannyknot]

It's possible that they sent you the wrong fuel rail, here is a pic from their website, it's blurry but you can see the chamfer on the fuel rail.

Also, your rail has threads, what are those for?

 

[HusseinHolland]

On 11/18/2023 at 7:50 AM, grannyknot said:

It's possible that they sent you the wrong fuel rail, here is a pic from their website, it's blurry but you can see the chamfer on the fuel rail.

Also, your rail has threads, what are those for?

 

ProTunerZ is sending me another rail. They said they will send one with a more obvious chamfer, as they do seem to be variations. Apparently none of them have a significant chamfer on the ORB-6 port, and they said I am the first one to indicate it is a problem. The "chamfer" such as it is on mine is not uniform, and where the thread is visible close to the surface is where the o-ring pushed out. Perhaps most ppl block it off instead of using it as an active port? I dunno. Anyway, I'll swap it out when the new one arrives.

The Allen heads are where the rail is bolted to the provided standoff brackets. The website illustrates the old brackets, which apparently bolted to the head/manifold studs (Yuk) - the new version bolts to the stock rail mount points.

[HusseinHolland]

Replacement rail came today.

Center port was no different than the first one, so I cut a chamfer with a countersink drill. Just went deep enough that the  o-ring compresses without any squeeze-out