Jump to content
HybridZ

Oil Pressure Sensor threads


Recommended Posts

I have searched this but to no prevail. I plan on running a turbo feed line from the oil pressure sensor location with a T-fitting. So I can still use my pressure sensor, and not have to drill and tap a hole in the pan. But I need to know the size of the hole and threads in the sensor hole. Can anyone tell me this?

Link to comment
Share on other sites

pipe thread doesn't work like that with the coarse thread and fine thread. pipe thread is tapered so that cranking it down creates a seal at the back end. what i would do is try to find a 1/8th npt adapter to run a -6an line to the turbo inlet, and get the largest drain you can fit. i belive that -6 line is 3/8", and a good return line size would be -8 which is roughly 1/2" in standard size. you can get bulkhead fittings like on a fuel cell that allow you to drill out the pan and and install the adapter to connect to the drain line. you'd probably want to epoxy it though just to be sure it doesn't leak.

Link to comment
Share on other sites

It is BSPT 1/8 - 28 TPI British Standard Pipe Thread. Not NPT (1/8 - 27 TPI) TPI is the pitch of the thread in threads per inch. They are two different threads. The pitch is very close, and cranking in a NPT fitting with sealant will (most of the time) work. Once.

 

BSPT fittings are hard to find in N America. The block can be retapped to 1/8 NPT easily.

 

AN3 line will work for the turbo, or 3/16 solid line. No way you need an AN6 supply line. 1/2 is the smallest I would use for turbo return to pan. AN8 or AN10 will work.

 

Doug

Link to comment
Share on other sites

Good point Doug. I knew they were close, and I know that one of the sizes match both size and thread pitch in both BSPT and NPT and I thought it was 1/8. Nevermind. You could also consider re-dieing the fitting to BSPT assuming the dies are easier to get a hold of than the NPT tap.

 

I run -3 turbo feed line and -12 return.

 

Dave

Link to comment
Share on other sites

Sorry for the bum advice savageskaterkid, i stand corrected on the feed line size. I thought I had read in maximum boost or somewhere that 3/8" was a good tube diameter, but if you guys are running 1/4" (-4) and smaller with no problems, then all the better since -4 hose is cheaper by the foot (at least here in tampa) than the other sizes. I haven't gotten my turbo installed yet, and am also in the process of putting together all the ancillary pieces to the system. 1/8th npt taps aren't that hard to come by in the states, you can get them at most hardware stores. i got one from harbor freight as part of a set.

Does the feed line need to be flexible on this engine, or could you use say one of those aftermarket brake lines that already has the 1/8" npt fittings on the end that you bend yourself?

Hey savageskaterkid, i reread your first post, and it sounded to me like you were going to try to avoid tapping the pan? You don't tap the pan for the feed line because there is no pressure there. You run the return line there so the oil can drain back into the system. That's why you want a larger drain line, to reduce the restriction to flow (unless you have a scavenger pump of some kind, gravity is what is getting the oil back to the pan), and you want to make sure that the drain is above the level of the oil in the pan so it doesn't get backed up, so i've been told.

Link to comment
Share on other sites

Sorry for the bum advice savageskaterkid' date=' i stand corrected on the feed line size. I thought I had read in maximum boost or somewhere that 3/8" was a good tube diameter, but if you guys are running 1/4" (-4) and smaller with no problems, then all the better since -4 hose is cheaper by the foot (at least here in tampa) than the other sizes. I haven't gotten my turbo installed yet, and am also in the process of putting together all the ancillary pieces to the system. 1/8th npt taps aren't that hard to come by in the states, you can get them at most hardware stores. i got one from harbor freight as part of a set.

Does the feed line need to be flexible on this engine, or could you use say one of those aftermarket brake lines that already has the 1/8" npt fittings on the end that you bend yourself?

Hey savageskaterkid, i reread your first post, and it sounded to me like you were going to try to avoid tapping the pan? You don't tap the pan for the feed line because there is no pressure there. You run the return line there so the oil can drain back into the system. That's why you want a larger drain line, to reduce the restriction to flow (unless you have a scavenger pump of some kind, gravity is what is getting the oil back to the pan), and you want to make sure that the drain is above the level of the oil in the pan so it doesn't get backed up, so i've been told.[/quote']

 

No problem at all, I got the piece no problem though. The point of this thread was to find out about the threads on the oil pressure sensor so that I can put a T-fitting in it so I can still use the pressure sensor and be able to run the feed line. Since the sensor reads there is pressure, then there should be no problem in the pressure sending oil up the line, correct? I do not want to drill and tap the pan for the feed line, just becuz it will be a PITA and a bit of a hassle with my limited tools. The return line will probly be fed right into the valve cover to tell you the truth, because of the ease to get it off and I can get the taps that I need for it. Would the valve cover be a good place for the return line?

Link to comment
Share on other sites

Whoa-Stop-Halt. You will be drilling your oil pan for the turbo oil return unless you have a scavenge pump to pump oil away from the turbo. Turbos need a big oil return line that gravity-feeds away from the turbo. If oil can't easily get away from the turbo, it will end up going around the bearings and seals(piston rings)in the turbo and into the intake airstream or the exhaust, creating big problems. The valve cover would not be a good place to try and return turbo oil.

 

For the oil pressure supply, the stock pressure sender hole is a great place to tee in for the turbo. That is where the factory teed in to supply the turbo on the ZXT. There is a nice little block on the ZXT engine that has the correct threads and a flare fitting for a rigid oil line to the turbo.

Seriously, Your best bet would be to get a ZXT engine with all the goodies and drop it into your S30.

 

Finally - You can't drill and tap the oil pan and get oil pressure because there is no oil pressure in the pan. It is created by the oil pump, which sucks oil out of the pan via the pickup and pumps it through the oil filter and into the main oil gallery in the block, which is where the oil pressure sender lives.

 

Doug

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...