510farmer Posted June 27, 2015 Report Share Posted June 27, 2015 After finding a crack on my lower housing by my sender unit I looked around, and I was able to find a brand new one by searching the Nissan part # We'll after getting it everything is exactly the same as the old. EXCEPT! The the side of the housing where the little hose barb fitting comes out. My old one had a pipe size of 25/64 unknown thread pitch The new one looks to be 63/128 unknown thread pitch I tried a 1/4 SPT and it goes in about 11/2 threads than stops I did find a metric. Bolt with a 20 thread pitch that would screw in but felt a smidge loose Is this a BPT? I would post pics but I have windows 12,000 and it hates photo bucket Any help Thx farmer 1 Quote Link to comment
DanielC Posted June 27, 2015 Report Share Posted June 27, 2015 This page has a chart on the difference between BSP, and American pipe threads. http://pipeandhose.com/?q=node%2F2 For a 1/4 pipe, American has 18 threads per inch, British has 19 threads per inch. Quote Link to comment
510farmer Posted June 27, 2015 Author Report Share Posted June 27, 2015 Thx Dan But does the stock housing come with BSPT? Quote Link to comment
DanielC Posted June 27, 2015 Report Share Posted June 27, 2015 Does the fitting from the old thermostat housing screw in to the new housing? Quote Link to comment
510farmer Posted June 27, 2015 Author Report Share Posted June 27, 2015 Does the fitting from the old thermostat housing screw in to the new housing?NoThe old one measures at 25/64 The new one measures at 63/128 Should the fittings be BSPT? Quote Link to comment
datzenmike Posted June 27, 2015 Report Share Posted June 27, 2015 I don't think so. Only the oil pressure sender is BSPT. On anything else it's metric threads isn't it Daniel? The bolts that hold the housing to the head and studs for the cover are M8 Quote Link to comment
Stoffregen Motorsports Posted June 27, 2015 Report Share Posted June 27, 2015 Buy yourself a 1/4 or 3/8 or whatever NPT tap and update it to modern, widely available, NPT threads. Any Kragen or Pep Boys or O' Douche Bag's store will have a NPT nipple on the shelf. Don't beat your head against the wall trying to keep it original. Drive it! Quote Link to comment
510farmer Posted June 27, 2015 Author Report Share Posted June 27, 2015 Buy yourself a 1/4 or 3/8 or whatever NPT tap and update it to modern, widely available, NPT threads. Any Kragen or Pep Boys or O' Douche Bag's store will have a NPT nipple on the shelf. Don't beat your head against the wall trying to keep it original. Drive it! Ya that's always a option,,,,,,But with all this Datsun knowledge on here No one knows what the size or thread pitch This could be? Thx farmer Quote Link to comment
Stoffregen Motorsports Posted June 27, 2015 Report Share Posted June 27, 2015 I think Mike is right and that it is metric taper pipe thread. Here is a good tech sheet http://mdmetric.com/tech/thddata22-1.pdf What are you going to do with this info? I really doubt you'll be able to buy MTP fittings easily here in the states. If you do find them, let us know where. 1 Quote Link to comment
banzai510(hainz) Posted June 27, 2015 Report Share Posted June 27, 2015 I get spare housing just for when the sender brecks 1 Quote Link to comment
510farmer Posted June 28, 2015 Author Report Share Posted June 28, 2015 I get spare housing just for when the sender brecksLol HainzIt not the sender hole it's the hose barb hole I'm going to bring it to my machinist friend so we can find out the exact thread and size Do it right or not at all! Farmer Quote Link to comment
Stoffregen Motorsports Posted June 28, 2015 Report Share Posted June 28, 2015 I bet he tells you to tap it NPT. 1 Quote Link to comment
650savag Posted June 28, 2015 Report Share Posted June 28, 2015 You stated the pipe size was 25/64 ". Do you have a thread gauge to measure the tpi (threads per inch)? It sounds like 1/8 th npt to me. The od of the nipple is .405 " which is a tad larger than 25/64th. 1/8 npt - 27tpi. Quote Link to comment
650savag Posted June 29, 2015 Report Share Posted June 29, 2015 http://rs161.pbsrc.com/albums/t207/650savag/Mobile%20Uploads/image_1.jpg~320x480 Quote Link to comment
Stoffregen Motorsports Posted June 29, 2015 Report Share Posted June 29, 2015 1 Quote Link to comment
Stoffregen Motorsports Posted June 29, 2015 Report Share Posted June 29, 2015 1/8 BSPT is 1/8-28. That's more likely what it is. 1 Quote Link to comment
650savag Posted June 29, 2015 Report Share Posted June 29, 2015 I believe this is the same part I replaced several years ago and I wound up getting a ss 1\4 npt nipple and put Teflon tape on the threads and screwed it in as far as I could and torqued it down good and it sealed fine. I will take a pic tomorrow. 1 Quote Link to comment
650savag Posted June 29, 2015 Report Share Posted June 29, 2015 This is what I did on my 78-620. I threaded a 1/4 NPT nipple into the lower housing, then used a 1/4" ss Tee to hook up my two hoses. The heater hose fits good on the 1/4" nipple but I had to use a stainless steel tubing fiting for the top (smaller) hose. I had all these fittings available to me (fringe benefits) at the time so I was not out any cost. I don't really know how much they would be to purchase them. Quote Link to comment
510farmer Posted June 29, 2015 Author Report Share Posted June 29, 2015 All right I have found out what it is Savag- it on the lower thermostat housing on a L16 different part than your pictured But thx Ok so is everyone ready Lady's and gentlemen It is 1/4 BSPT......... 1/4 20 pitch does fit but it is loose 1/4 inverted flare thread works but is loose So after my machinist friend and I determined the thread The Bspt is 19 threads per inch That's why the standard npt starts to go in but stops We found a fitting I could work with at a hydraulic shop Another Dato! Mystery solved Thx for the help Farmer 1 Quote Link to comment
Stoffregen Motorsports Posted June 30, 2015 Report Share Posted June 30, 2015 I had to buy a 1/4 BSPT tap last year for a TJM air locker install. Never thought I'd need one of those... So you need the fitting (nipple) or the tap? Quote Link to comment
510farmer Posted June 30, 2015 Author Report Share Posted June 30, 2015 I had to buy a 1/4 BSPT tap last year for a TJM air locker install. Never thought I'd need one of those... So you need the fitting (nipple) or the tap? No I'm good I found parts at a hydraulic shop , that should workWhat gets me is Are there more threads on the engine other than the few we know about that are actually BSPT That folks are cramming NPT into Because like stated earlier NPT would start about 1 1/2 turns Farmer 2 Quote Link to comment
Stoffregen Motorsports Posted June 30, 2015 Report Share Posted June 30, 2015 Well I'm sure there are a lot of guys trying to fit them, but the only right way to fit a NPT fitting in the BSPT hole is to run the NPT tap into it. Really, it's not a problem. If it were a head bolt or some fastener that is removed regularly exercising the threads often, it may not be acceptable to do this method of retapping, but we're talking about something that gets installed, with sealer, and then never removed again, unless it gets old, rusted and broken. My comment earlier about beating your head against the wall...what I meant was, why take all the time to have your machinist friend help you figure out the thread pitch and then take even more time to try and find the exact right part with corresponding thread pitch? A NPT nipple can be got at any auto parts store, online car parts store, Ace hardware, etc. You can get them that look pretty darn close to OEM Nissan and if they ever fail, off to the hardware store to buy another. No time wasted at all and not even remotely resembling a hack job. 1 Quote Link to comment
510farmer Posted June 30, 2015 Author Report Share Posted June 30, 2015 Well I'm sure there are a lot of guys trying to fit them, but the only right way to fit a NPT fitting in the BSPT hole is to run the NPT tap into it. Really, it's not a problem. If it were a head bolt or some fastener that is removed regularly exercising the threads often, it may not be acceptable to do this method of retapping, but we're talking about something that gets installed, with sealer, and then never removed again, unless it gets old, rusted and broken. My comment earlier about beating your head against the wall...what I meant was, why take all the time to have your machinist friend help you figure out the thread pitch and then take even more time to try and find the exact right part with corresponding thread pitch? A NPT nipple can be got at any auto parts store, online car parts store, Ace hardware, etc. You can get them that look pretty darn close to OEM Nissan and if they ever fail, off to the hardware store to buy another. No time wasted at all and not even remotely resembling a hack job. I understand and that was a option I just wanted to know what it was, more of a personal goal I guess you would say And now when some one comes up with the same question, there is a answer Just like your answer in my oil thrower question thread Got to keep feeding the dato data base Thx Farmer 3 Quote Link to comment
Stoffregen Motorsports Posted June 30, 2015 Report Share Posted June 30, 2015 Understood. I was concerned that you did not get what I was trying to describe. But you got it. 1 Quote Link to comment
650savag Posted June 30, 2015 Report Share Posted June 30, 2015 I din't tap mine out but I could have. I have some pipe taps in the shop and several size tap handles. I worked maintenance in plants for years and was a machinist and tool and die maker for 16 years before retiring in 2013. I knew enough about fitting tapered pipe fittings that if it screwed in by hand 1 1/2 turns that I could make it seal with teflon tape and tightening the crap out of it. If you look at my pics you can tell the nipple that is in the housing did not screw in as far as the end that is screwed into the tee but it sealed and hasn't leaked a drop in about 10 years so for me it was a Happy Ratsun ending that cost me nothing but an hour or two of my time! I understand if someone wishes to use the OEM parts and searches to find the exact size that it calls for. I certainly respect that and it may help someone in the future who runs in to this same issue. For me, it's all about what works and what is the least hassle for me to get the job done and get my truck going again. I knew that I had the option, if it did not seal, to back it out and run a 1/4 NPT tap in there about 5-7 rounds and then I know it would seal. I got lucky and it was close enough to the right size and TPI that it worked without tapping it out! 1 Quote Link to comment
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