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Old 12-22-2013, 06:00 PM   #1
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Default NPT vs BSPT oil feed confusion

Ok someone explain this to me, or at least tell me I'm over thinking things and stop stressing about this.

Our oil pressure sender to block connection is using a 1/8 BSPT thread.
Most stainless lines and fittings are 1/8 NPT.
The difference between those two is small, but enough for many people to say that a connection between the two "won't seal properly".

I've looked at BEGi and FM kits as well as many DIY setups and it seems that the brass or stainless "Tee" people are using is in NPT, the feed line is also npt, while the fitting into the block is BSPT to NPT.

So my question then: doesn't that mean that most people are screwing their oil pressure sensors, that have BSPT thread, into a NPT brass "Tee"?

Am I missing something?
Or do you just wrap teflon tape onto the thread and call it "good"? I'm pretty sure that's what I did on my previous setup, but now I'm kinda curious if I shouldn't try to source something more ideal?
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Old 12-22-2013, 06:14 PM   #2
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I honestly don't know what Bell and FM are supplying in their kits, however the correct part for this application will have a male 1/8 BSP thread for the block, a female 1/8 BSP thread for the sensor, and a female 1/8 NPT thread for the take-off. Example: Oil Feed Block BSP/NPT-BSP-NPT | Prl Motorsports
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Old 12-22-2013, 06:18 PM   #3
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Oh snap Joe, that is a cool fitting. I think I found what I'm looking for
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Old 12-22-2013, 06:59 PM   #4
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I used a block like that for my setup and it worked great:



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NPT vs BSPT oil feed confusion-picture%252520088.jpg   NPT vs BSPT oil feed confusion-picture%252520090.jpg  
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Old 12-22-2013, 07:35 PM   #5
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Tried to order one just now, they want $11 for shipping? Are they insane? lol
I'm going to send them a message and ask if they are willing to charge a non-retarded shipping price of say, 2-3 bux.
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Old 12-22-2013, 08:21 PM   #6
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I'm using a steel 1/8" BPST to 1/8" NPT and a steel 1/8" Tee. The oil line connects to the Tee with a 1/8" NPT to 4AN fitting. The bracket supports the weight of the whole assembly by attaching it to the intake manifold. I'm also using a VDO sender.

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Old 12-22-2013, 08:28 PM   #7
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isn't your vdo sender 1/8 bspt? in which case you threaded bspt into an npt Tee
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Old 12-22-2013, 08:31 PM   #8
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btw I think its funny how I'm overthinking these things nowadays. I guess the older you get the more you tend to do this. On my last setup I just screwed it all in, no questions asked, and it was a 1/8 NPT Tee, I know that for sure. LOL
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Old 12-22-2013, 08:48 PM   #9
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Quote:
Originally Posted by 18psi View Post
isn't your vdo sender 1/8 bspt? in which case you threaded bspt into an npt Tee
VDO pressure transducers are available in a wide variety of fitments, including M10, M12, M14, 1/8 NPT, 1/4 NPT, and 1/8 BSP.

Presupposing that he purchased the sensor from a US distributor, I'm guessing he got the 1/8 NPT version.

Pressure Sensors & Switches | Sensors | VDO Instruments and Accessories
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Old 12-22-2013, 09:19 PM   #10
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BSPP and 24* metric flare or death... oh wait, I'm not at work. I believe 1/8 BSPT is slightly smaller than 1/8 NPT and the same thread pitch so that the male BSPT will thread into a female NPT but the NPT only goes a couple threads into the BPST, not anywhere close to certain on that one. The TPI is 1 different which is like 0.5% different and the taper angle is identical.
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Old 12-22-2013, 10:20 PM   #11
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Quote:
Originally Posted by 18psi View Post
I'm going to send them a message and ask if they are willing to charge a non-retarded shipping price of say, 2-3 bux.
Eagerly awaiting the complaint thread where you bitch and moan about how "they never shipped it" or "USPS lost it" because you were too cheap to pay for decent shipping services.
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Old 12-22-2013, 11:02 PM   #12
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$5.80 anywhere in the US for up to 70 pounds. Tracking and $50 insurance included.

And that is far from the cheapest way to ship something like that.
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Old 12-22-2013, 11:15 PM   #13
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Quote:
Originally Posted by Savington View Post
Eagerly awaiting the complaint thread where you bitch and moan about how "they never shipped it" or "USPS lost it" because you were too cheap to pay for decent shipping services.
USPS, UPS, and Fedex have all lost stuff for me, fucked me over on how long things were going to take, and messed around delivering (like giving stuff to my neighbor).

They ALL suck... might as well go for cheap.

BTW Joe... that fitting is gold! I hope Vlad has some success with the shipping.
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Old 12-22-2013, 11:28 PM   #14
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$5.80 anywhere in the US for up to 70 pounds. Tracking and $50 insurance included.

And that is far from the cheapest way to ship something like that.
USPS small flat rate used to not include tracking, so it was basically no better than First Class Mail. With tracking included, it's not a bad option, if you have good mail service in your area. $5.80 is still more than $3, though.

At the risk of channeling my inner Joe Perez, I looked up whether it would actually be possible to put 70lbs of stuff into a USPS small flat rate box. The best I was able to come up with would be filling the box with pure iridium, which still misses the mark by about 8.4lbs.
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Old 12-22-2013, 11:40 PM   #15
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Quote:
Originally Posted by Savington View Post
At the risk of channeling my inner Joe Perez, I looked up whether it would actually be possible to put 70lbs of stuff into a USPS small flat rate box. The best I was able to come up with would be filling the box with pure iridium, which still misses the mark by about 8.4lbs.
I was thinking that was impossible as I posted it.
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Old 12-23-2013, 12:06 AM   #16
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I ended up getting a BSPT tee from McMaster and welding a flared fitting on the end that supplies oil to the turbo
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Last edited by HHammerly; 12-23-2013 at 12:33 AM.
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Old 12-23-2013, 01:15 AM   #17
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Quote:
Originally Posted by Savington View Post
Eagerly awaiting the complaint thread where you bitch and moan about how "they never shipped it" or "USPS lost it" because you were too cheap to pay for decent shipping services.
Quote:
Originally Posted by Savington View Post
USPS small flat rate used to not include tracking, so it was basically no better than First Class Mail. With tracking included, it's not a bad option, if you have good mail service in your area. $5.80 is still more than $3, though.

At the risk of channeling my inner Joe Perez, I looked up whether it would actually be possible to put 70lbs of stuff into a USPS small flat rate box. The best I was able to come up with would be filling the box with pure iridium, which still misses the mark by about 8.4lbs.
I'm not at all too cheap.
But,
I absolutely REFUSE to pay a bs price for anything, and shipping is one of those things. We're talking about a fitting here, that is smaller than your *****, that can fit literally into a regular envelope. I can deal with $5.80, but not $11. Call it what you will.
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Old 12-23-2013, 01:41 AM   #18
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Quote:
Originally Posted by 18psi View Post
that can fit literally into a regular envelope, get torn open by sorting machines, disappear into a USPS sorting facility never to be seen again, which will then make me complain to the vendor and post a bad review about them "never shipping my fitting and stealing my money and killing my dog"
FTFY. Just because it fits in an envelope doesn't mean it belongs in an envelope.
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Old 12-23-2013, 02:54 AM   #19
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Quote:
Originally Posted by Savington View Post
FTFY. Just because it fits in an envelope doesn't mean it belongs in an envelope.


I must agree though, sometimes companies charge outrageous shipping costs. You just gotta
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Old 12-23-2013, 02:57 AM   #20
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sick burn bro
Except I never said to mail it in an envelope, I'm saying even a full blown priority with insurance and tracking package won't cost $11, and that's why they won't get my business. I'm sure I can source that fitting elsewhere though, for under $20 total.

But back on topic....
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