adding an after market oil pressure gauge

[mellow65]

on the EJ motor how do people add an after market oil pressure gauge. I have used those sandwich plates that you put between the oil filter and block and they work, but I am limited on space there. With a factory oil cooler and a skid plate (rally car) it would be putting the oil filter down lower then i would feel comfortable doing.

 

Has anyone ran a T off the stock location and maybe kept both stock and after market one working. Or maybe running some tubing from the stock location to a remote location or something.

 

I just don't know I am just looking for ideas right now.

[porcupine73]

Hi. Easiest way I have found (and done on several soobs) is to tee into the factory oil pressure switch under the alternator. Note: the threads are 1/8" BSPT (British standard pipe, tapered thread), so you need adapters if you are planning to use the US customary 1/8" NPT (national pipe, tapered thread). These threads are nearly the same and will thread somewhat into each other, but you are asking for leaks if you do so.

[porcupine73]

Forgot to add, you can get 1/8" BPST to 1/8" NPT adapters from many places, including my personal favorite http://www.mcmaster.com I also got some from amsoil before, which were simply Stewart Warner.

[mellow65]

ok not to sound like one of those people that don't bother to look, but man was i lost on that website. Any chance you could fill me in on some part numbers from that site. You know the fact that you have done this a few time, it will help me out quite a bit. I'm what you call not tube fitting smart.

 

or at least i can take what you gave me number wise and that BPST and NPT stuff and hit the hardware store and see what they got.

 

Would you just recommend just a brass fittings or something different.

[jreb10]

From the McMaster-Carr website:

 

Part Number: 4860K141

 

Shape

Adapter

 

Adapter Type

Female x Male Adapter

 

Pipe Size

1/8"

 

Pipe to Pipe Connection

BSPT Male x NPT Female

 

Material

Yellow Brass

 

Maximum Pressure (psi)

2900

 

Maximum Pressure Note

Maximum pressure is rated at 72° F.

 

Specifications Met

International Organization for Standardization (ISO)

 

ISO Specification

ISO 228 Class A, ISO 7.1

 

I used this adapter in my EJ22 when I installed an electrical oil pressure gauge. I also used two brass 45 degree street els and a brass tee to keep my transducer and the existing pressure switch well clear of the alternator. Coat all the threads with good quality high temp sealent.

[porcupine73]

Typically if you buy an autometer or any other such pressure gauge it is going to have 1/8" or possibly 1/4" NPT male thread.

 

You can search for mcmaster part # 4860K141 and 4860K151, or just jump to their catalog page 28.

 

Right on, you'd need this part to adapt the block 1/8" BSPT female to NPT:

 

First, the adapter set I have used in the past was sold by amsoil, stock #BP44, which were simply a set of adapters in a Stewart Warner box --> link Wherever you buy your gauge might have these adapters too; I have also gotten them in gauge adapter kits at pepboys.

 

4860K141

1 Each Brass Threaded Pipe Fitting, Bspt Male X Npt Female, 1/8" Adapter, 1" Length

 

Then if you want to keep the stock pressure switch as well, you need another adapter, i.e. 1/8"NPT male to 1/8" BSPT female:

 

4860K151

1 Each Brass Threaded Pipe Fitting, Npt Male X Bspp Female, 1/8" Adapter, 1" Length IMPORTANT NOTE: I am not sure this is the right part #. BSPP is british standard pipe, parallel thread - not sure if this will seal properly with a BSPT male

 

Also you might want to get some 1/8" NPT elbows, tees, nipples, etc or try to plan in advance how you're going to plumb it. There isn't a ton of room under the alternator to fit senders and such in down there, so I usually route the plumbing up behind the alternator and put my senders or whatever I'm doing there.

 

I'm going to give a lot of information here about the fittings, etc, because engine oil is mission critical to the engine. You really don't want any leaks.

 

For the 1/8" NPT elbows, tees, etc., I usually get the NPTF designation. These are also called 'dryseal'. It has a slightly modified crest and roots threading that makes it less likely to leak. You still need to use a thread sealant though.

 

NPTF thread fittings are compatible with NPT thread fittings.

 

For thread sealant, I just used teflon tape and didn't have any problems.

 

I have also used the Permatex high temp thread sealant and it works very well on brass fittings, especially if you use their 'activator' first (though the activator is like $10 for a little spray can). You MUST let the Permatex stuff harden at least 24 hours before applying pressure I have noticed or it will likely spring a leak.

 

Also with the Permatex, only the part down in the threads hardens. Any excess that you see left outside the fitting will not harden (just so if you use it and wonder why it doesn't seem to be hardening). You can just wipe off the excess.

 

Do not apply sealant to the first one or two male threads, otherwise the sealant may end up inside the plumbing and contaminate your process fluid (engine oil in this case).

 

For material, brass is fine. It may corrode slightly greenish I have noticed, maybe brass has copper in it I don't remember. You could go stainless, chrome, etc if you wanted but that's just more $$.

 

When you assemble the brass fittings, you might want to research first the proper tightening procedure. These fittings should NOT be tightened to a specific torque. You are supposed to thread the fitting finger tight, then there is a specific range of TPFT (turns past finger tight) you are supposed to use.

 

The correct number of TPFT varies on thread type and size. I think for 1/8" NPT&BSPT it is 2-3 turns but I would have to double check.

 

The correct number of TPFT gives the proper number of threads of engagement for a leak free seal. (You need sealant because these tapered thread fittings have a spiral leak path between the thread crests and roots.)

 

Mcmaster brass fittings will be fairly well machined for leak free fits. (I have noticed on black&galvanized pipe from home depot you often have to crank it another turn or two past the designated TPFT to prevent leaks; the threads just don't seem to be so good on some of them.)

 

And that's about it!

 

The rest of this thread is my rant about mcmaster.

<rant>Also I love http://www.mcmaster.com They have a huge selection of hardware and such, they do not abuse you on shipping, have no minimum order, I have never ordered an item they did not have in stock, they sell in small quantities, plus they have several warehouses so if you live near enough to one you get your stuff the very next day even by ups ground. All these factors make them a great supplier for the hobbyist, though probably most industrial companies order from them regularly.

 

McMaster typically doesn't tell you the manufacturer of the item on the web site. However I have been pleasantly surprised when I ordered something expecting a generic product and received a nice name brand such as Parker for fittings, Armstrong for impact sockets, etc.

 

Some of their main competitors would be mcjunkin, msc, and grainger, and to a degree fastenal.

 

Also McMasters web site is cleanly laid out, and they have a lot of technical information available, i.e. different metal alloys, material compatibility, fastener grades, thread types, etc, etc</rant>

 

Here's a pic of the plumbing nightmare in my '00obw:

[Skip]

Yo Porc, nice write up and thanks for the

documentation.

 

If I remember correctly, when Davebugs and I were testing

the OP on the Leg from 'ell

There is an adapter the oil pressure switch screws into

that is then screwed into the block - this is the factory

set up on the early Leg.

 

When he removed this factory part, the threads in the block

were the same as a spark plug - straight not tapered,

used a copper washer to seal.

 

This part might be easier to find localy than a britsh pipe

standard fitting.

 

Hey now - part

Porc you using some form of pre oiler ....

The tank with the solenoid valve in the back ground.

 

Or you sneeking some NOS in there??????

[porcupine73]

Hm maybe the earlier legacies used a straight thread on the block with a sealing washer. I know on my '96 and '00 there was no sealing washer on the pressure switch, it had this whitish RTV like goop on the threads.

 

Some things I saw said you can seal BSP-parallel threads with sealant if you want to seal against the threads, or use a sealing washer.

 

Yes that is a preoiler there, that's a canton/mecca 1 quart accusump with a 12V solenoid valve. Also there is an amsoil bypass oil filter. No NOS yet, though that recent post about a wet shot sneaky peat setup has me thinking...haha

[Skip]

thanks Porc,

 

I'm sorry I was not more specific

the switch/sender does have the British thread as

you correctly say.

 

The adapter I was speaking of is screwed into the block

the sender screws into this - must be only early EJ's.

(1995 in question here)

 

Thanks for the pre oiler info looks kewl.

 

I'm watching Pesty's post also.

NOSit

We need your picture posting expertise.

[porcupine73]

Ah ok yes I understand. I think I did see this sort of adapter on my soobs too but I don't remember for sure.

[mellow65]

 

Thanks for all the info.

 

Where did you get the soft lines? I need to do some calling around here to find some better hardware stores that have more fittings. I hit a couple local parts places and they didn't even have the BSPT stuff.

[porcupine73]

Hello. The soft lines are hydraulic hose that came with the amsoil bypass filter kit. They have some hydraulic fitting called JIC that kind of threads onto the hose. Normal hose barb type connections are not suggested for engine oil.

 

If you want to buy your adapters locally, pepboys might be a place to check out. I bought their meter fittings kit a few years ago, it was like $8 and i think it had the two fittings you'd need (along with a bunch of other metric and assorted fittings).

 

Also at certain Carquest stores I have noted a fairly good selection of such fittings.

[mellow65]

after figuring out that web site it was cake to find what i was looking for. i got drawn out, at least in my head, what i needed to use both sensors. now i need to go measure it out in the car and see if my idea will fit.

 

I at least made me a list of what i needed so i can print it out and bring it with me out to the stores.

[MorganM]

Anyone happen to know the McMaster part number for a Tee that will go into 4860K141 ? I want to have an oil pressure guage sending unit in one side of the Tee and the idiot light sending unit in the other side.

[cobcob]

Anyone happen to know the McMaster part number for a Tee that will go into 4860K141 ? I want to have an oil pressure guage sending unit in one side of the Tee and the idiot light sending unit in the other side.

 

4860K451 for the Tee and you'll also need one of the following to adapt the Tee into your block. 4860K601

 

I would take the 4860K601 and thread that into your block, put the vertical leg of the T onto the end of that part and then put your idiot light onto one side of the T and the 4860K141 with your other pickup into the other end of the T. Is that what you're thinking?

I don't know for sure if you'll have enough room to do that so measure first!

Edited May 11, 2010 by cobcob

[porcupine73]

Would 4860K451 work? It says the thread type is BSPP. I always get the threads confused, but I think that's parallel or uniform threads. I don't know if that will seat properly with BSPT which is a tapered thread. You might also want to check out 4978K121, which is the tee in 1/8" BSPT.

[MorganM]

Great thanks for the part numbers!

[cobcob]

Two types of threads are distinguished:

Parallel ('straight') threads, BSPP (British Standard Pipe Parallel Thread), which have a constant diameter; denoted by the letter G. A variant of this thread is BSPF (British Standard Pipe Fastening Thread), This thread is identical to the BSPP with the exception of its name.

 

Taper threads, BSPT (British Standard Pipe Taper Thread), whose diameter increases or decreases along the length of the thread; denoted by the letter R.

 

 

These can be combined into two types of joints:

Jointing threads: These are pipe threads where pressure-tightness is made through the mating of two threads together. They always use a taper male thread, but can have either parallel or taper female threads. (In Europe, taper female pipe threads are not commonly used.)

 

Longscrew threads: These are parallel pipe threads used where a pressure-tight joint is achieved by the compression of a soft material (such as an o-ring seal or a washer) between the end face of the male thread and a socket or nipple face, with the tightening of a backnut.

[porcupine73]

Jointing threads: These are pipe threads where pressure-tightness is made through the mating of two threads together. They always use a taper male thread, but can have either parallel or taper female threads. (In Europe, taper female pipe threads are not commonly used.)

 

Ah that is interesting, thanks for the useful added info for the thread. I always thought the parallel threads needed an o-ring to seal (like the longscrew thread you described or ORB fittings). I wonder for the female thread which is the better choice (parallel or tapered)?

[Turbone]

2 brass L's, a nipple and a union, all 1/8" from Home Depot.

Used teflon tape and theres no leaks. Its angled back into the corner so it will clear the alternator.