Mistakes were made, my R34 Story

[Kinkstaah]

Yea I mean I know it exists, but finding (specifically) female BSPT to male NPT (i.e, to plug a Nissan OEM sensor into a 'standard' NPT port) was truly difficult. I don't think I'll recreate the setup I had in the past unless it's (possibly?) advisable with a stronger T piece made of steel, but who knows if the aluminium threads in the block become the next weak point etc.

Given it may need to be redrilled out and something tapped into it, it'll need to be Female BSPT to the something that ends uo coming out of the side of the block.

[Duncan]

yeah, so "something" should be -4 AN....to a hose....to a -4AN to NPT fitting

*edit* sorry, I surely have that backwards. The LS is from land of the free so it must be NPT at the block, and the Nissan sender is BSPT. But still, conceptually the same

[GTSBoy]

10 minutes on a lathe would be one way to achieve literally anything you want, too. (except for AN type stuff - just talking about M-F with BSP and NPT in any mix/combo).

[Kinkstaah]

I'm not quite understanding or I'm missing steps here, (I appreciate people are trying to inform my brain but I am of the dumb, especially today) - All I want to do is mount the male BSPT of the OEM sender into the system somewhere without it snapping the adapter via vibration.

The Nissan sender has a male 1/8 BSPT output. The block has a (very destroyed) 1/8 NPT input. I'm not really sure how a lathe assists with that, and also don't know anybody with a lathe, nor specifically what I would want to buy. I'm not really sure how adding additional adapters creates a better, more leak proof resilient seal here.

[Duncan]

Ahh. Well the block damage is a problem, you really need to run a tap or thread chaser through it to see if the threads can be saved, but any chips are likely to be bottom end bound which is bad.

Earls seem to have what you need if you want to stick with mounting direct on the block: https://rceperformance.com.au/parts/earls-straight-adapter-1-8-npt-male-to-1-8-bspt-female.html, but as I said above I'd recommend remote mounting the sender

[GTSBoy]

9 minutes ago, Kinkstaah said:

The block has a (very destroyed) 1/8 NPT input.

No it doesn't. It just needs an ezy-out to pull that broken bit of alloy out of the hole and presto chango - it will be back to being a 1/8" hole tapped NPT. as per @MBS206 recco.

10 minutes ago, Kinkstaah said:

I'm not really sure how a lathe assists with that

That would be for making what you had in alloy, in steel. If you wanted to do just that instead of remote mounting like @Duncan and I have been pushing.

A steel fitting would be unbreakable (compared to that tragically skinny little alloy adapter). But remote mounting would almost certainly be 10x better.

Small engineering shops abound all over the place. A lathe and 10 minutes of time = 2x six packs.

[GTSBoy]

And if you have to drill the oil block, then just drill it for 1/4" and tap it BSP and get a 1/8 to 1/4 BSP bush. The Nissan sender will go straight in and the bush will suit the newly tapped hole. And it will be real strong, to boot.

[Kinkstaah]

..this is the current state of that port.

I appreciate the info help (and the link to the Earls thing @Duncan). Though going by that it seems like 1/4 then BSP'ing it and using a bush may work.

I don't know where I'd be remote mounting the pressure sender... to... exactly. I assume the idea here is that any vibration is taken up by the semiflexible/flexible hose itself instead of it leveraging against the block directly.

I want to believe a stronger, steel bush/adapter would work, but I don't know if that is engineeringly sound or just wishful thinking given the stupendous implications of a leak/failure in this spot. What are the real world risks of dissimilar metals here? It's a 6061 Aluminum block, and I'm talking brass or steel or SS adapters/things.

[Duncan]

You are all good then, I didn't realise the port was in a part you can (have!) remove. Just pull the broken part out, clean it and the threads should be fine.

Yes, the whole point about remote mounting is it takes almost all of the vibration out via the flexible hose. You just need a convenient chassis point and a cable tie or 3.

[GTSBoy]

I wouldn't worry about dissimilar metal corrosion, should you just buy/make a steel replacement. There will be thread tape and sealant compound between the metals. The few little spots where they touch each other will be deep inside the joint, unable to get wet. And the alloy block is much much larger than a small steel fitting, so there is plenty of "sacrificial" capacity there.

Any bush you put in there will be dissimilar anyway. Either steel or brass. Maybe stainless. All of them are different to the other parts in the chain. But what I said above still applies.

[Kinkstaah]

1 hour ago, Duncan said:

Yes, the whole point about remote mounting is it takes almost all of the vibration out via the flexible hose. You just need a convenient chassis point and a cable tie or 3.

How do you propose I cable tie this:



To something securely? Is it really just a case of finding a couple of holes and ziptying it there so it never goes flying or starts dangling around, more or less?

Then run a 1/8 BSP Female to [hose adapter of choice?/AN?] and then the opposing fitting at the bush-into-oil-block end? being the hose-into-realistically likely a 1/8 BSPT male)

Is this going to provide any real benefit over using a stainless/steel 1/4 to 1/8 BSPT reducing bush?



I am making the assumption the OEM sender is BSPT not BSPP/BSP

[GTSBoy]

1 hour ago, Kinkstaah said:

Is it really just a case of finding a couple of holes and ziptying it there so it never goes flying or starts dangling around, more or less?

Yup. You can get creative and make a sort of "bracket" with cable ties. Put 2 around the sender with a third passing underneath them strapped down against the sender. Then that third one is able to be passed through some hole at right angles to the orientation of the sender. Or some variation on the theme.

1 hour ago, Kinkstaah said:

Then run a 1/8 BSP Female to [hose adapter of choice?/AN?] and then the opposing fitting at the bush-into-oil-block end? being the hose-into-realistically likely a 1/8 BSPT male)

Yes.... ummm, with caveats? I mean, the sender is BSP and you would likely have AN stuff on the hose, so yes, there would be the adapter you mention. But the block end will either be 1/8 NPT if that thread is still OK in there, or you can drill and tap it out to 1/4 BSP or NPT and use appropriate adapter there. As it stands, your mention of 1/8 BSPT male seems... wrong for the 1/8 NPT female it has to go into.

1 hour ago, Kinkstaah said:

Is this going to provide any real benefit over using a stainless/steel 1/4 to 1/8 BSPT reducing bush?

The hose will be better, because even with the bush, the mass of the sender will be "hanging" off a hard threaded connection and will add some stress/strain to that. It might fail in the future. The hose eliminates almost all such risk - but adds in several more threaded connections to leak from!

1 hour ago, Kinkstaah said:

I am making the assumption the OEM sender is BSPT not BSPP/BSP

It really should be tapered, but it looks very long in that photo with no taper visible. If you have it in hand you should be able to see if it tapered or not. There technically is no possibility of a mechanical seal with a parallel male in a parallel female, so it is hard to believe that it is parallel male, but weirder things have happened. Maybe it's meant to seat on some surface when screwed in on the original installation? Anyway, at that thread size, parallel in parallel, with tape and goop, will seal just fine.