Oil pressure sending unit question

[qsiguy]

Does anyone know the thread size for the oil pressure sending unit? Hoping to find it out without pulling it first. Working on a turbo project and need to install a T on that output.

[elwesso]

Does anyone know the thread size for the oil pressure sending unit? Hoping to find it out without pulling it first. Working on a turbo project and need to install a T on that output.

Is that going to be the turbo feed? The pressure unit has a realy weird thread size/pitch, not common at all from what I understand... Maybe for pipe sizes but I dont know...

Anyway, Ive seen these things on ebay that go in between the oil filter mount and the oil filter and allow you to get oil pressure there...

[John Dixon]

Pretty sure it's 1/8" BSPTThe hex head caps in the oilways might be more convenient, they're M18x1.75

[qsiguy]

I already have an oil filter sandwich plate but I've heard from some that have used them that they didn't always work to well so I'm checking into other options.

I have already spoken to multiple people who use the oil pressure sending unit port with a T and it works well. STS Turbo uses the oil pressure port as well for their kit so I know that is a good option.

John, can you explain where the "hex head caps" in the oilways are? That may be a good alternative as well. Also, I assume they are pressurized?

[Mettler]

They're right there, as part of the oil filter & pressure sender unit housing. Have a look from underneath, just a hex head plug which I'm sure was designed in there to allow for expanding the oil circuit.

I've read bad things about sandwich plates too, major oil pressure loss... not sure why, I'd theorise it's because of a choke point somewhere in there.

[SSDwellah]

Yeah Nissan has some weird tradition of using british size threads for their oil fittings. I had the same issue on my 240SX (KA24DE). BSPT is probably right, but I'm not sure on the size.

[canadiandrifter240sx]

It is 1/8 pipe thread i balieve it is 1/8 27 npt. I can check next time I am at the shop. I used the sending unit port on my KA-t ...it works well.

I built a block off plate that eliminates the VH oil houseing all together and uses AN -10 male weld in bungs to feed a remote filter mount. I may have these made and sell them in a group buy if there is interest for them.

Chris

[darinz]

I've cut the factory housing (the bit that filter is on that bolts to the block) and then threaded fitting into that. From there it feeds oil to a remote filter, then to the oil cooler. I have taken the turbo feed off the return line before it re-enters the engine.I've replaced the factory oil sender with an aftermarket obe and retapped the block to fit. It is now 1/8 bsp which fitts a lot more than the factory thread.

[John Dixon]

I removed the factory filter housing too as I've gone dry sump.Only thing I was thinking is if you keep the stock pump, isn't the pressure relief valve for it in that housing?

[qsiguy]

Ok, on the other end of the question. What are the oil return line options. Obviously tapping the oil pan or running a line into the valve cover are options but are there return line plugs like the pressure plugs you guys are talking about?

By the way this is for a rear mounted turbo installation so there will be a scavenging oil pump sending the oil back up to the motor so it doesn't really matter if it goes back in low on the engine. It would be nice to have a dedicated fitting for it so I didn't have to tap my valve cover or the oil filler cap for the return line.

[darinz]

Yeah it is but all it does is allow the oil to bypass the oil filter if that gets blocked!For the oil return I've welded a fitting into the sump, same place with every other turbo I've had. Except for my Mazda 6 which is so cramped (and under warranty) I haven't bothered to look to see where anything is.I'm running a T04z which is only getting 1 litre per min so not much oil to deal with anyway, but on the turbo on the motor I pulled out it was in the same place and that was a journel bearing T3 so much more oil to deal with.

[qsiguy]

I need to pull my valve covers anyway to replace the gaskets (leaking) so while they are off I think I'll drill/tap for a return fitting. The cap doesn't look like a viable option given the style of it.

[tiger]

hey sorry to resurect this old thread but can someone tell me what this thing is on the oil filter housing??

please check this thread for a picture!!!

zerothread?id=246471

[Raxephon]

hey sorry to resurect this old thread but can someone tell me what this thing is on the oil filter housing??

please check this thread for a picture!!!

zerothread?id=246471

Oil Pressure Relief Valve Assembly maybe?

[tiger]

yeah that's what i'm thinking... I guess it's important eh?

[darinz]

All it's doing is bypassing the oil filter if it gets to blocked. I've cut the housing before that (so have removed it) to enable the remote filter and oil cooler to be fitted. Does seem to have any effect as long as you change your filter regulary. I've fitted a far bigger filter as well.

[qsiguy]

I can't find it now but I seem to remember reading a post by Tech regarding the oil bypass assy. and that it would bypass under acceleration so the oil is only going through the filter at cruise or idle.

[tiger]

So, removing the spring would be a bad Idea? Your post kind adidn't make a lot of sense.. can you explain better?

[darinz]

I can't see how as it is only steel ball with a spring behind it. There is no control mech. etc. I could see how at high revs the pressure would be higher than the spring setting and so force it open.

[somedude]

the oil pressure relief valve doesnt bypass the filter. it is what sets your high pressure. oil pressure is good but too much can be a bad thing. when pressure gets to a certain point the ball is forced open and the excess oil goes back to inlet side of the pump.

spring pressure is your high pressure limit. bearing clearance is your low pressure

[tiger]

you rule! :-) Glad I put mine back in!