oil pressure install help??

jmv

Member
:
2003 MSP #1475
I've had my oil pressure gauge all wired as far as the gauge goes, and its been in my pod for around 2 weeks, but i'm just getting to actually installing the sending unit (its electronic). Took off a bracket to get to where the stock switch sender is, got it out, and i have a BSPT (british standard pipe thread) to NPT (national pipe thread) adapter that fits into the standard hole (the engine and the stock switch are BSPT, the aftermarket sender and all the other fittings are NPT). I'm trying to keep both, so that i still have the dummy light in the dash. Problem is, the aftermarket sender totally dwarfes the stock switch, and i can't find any way to fit it in there, with the oil filter, intake manifold, and that bracket beneath them all being so close together. Can i use some other sending unit, or does it have to be a stewart warner to work with the stewart warner gauge?? Or, does anyone know another good way to do this??

Thanks a bunch for any help, i gotta get this taken care of by the end of this weekend, or i won't make it back to school, lol.
 
yeah, i had seen that. Thats where i got my parts for adapting NPT to BSPT, etc. My problem lies in the fact that i can't fit the aftermarket sender, and i didn't know if it would be possible to just use a different one that was smaller.
 
cthomp21 said:
http://cgi.ebay.com/ebaymotors/Oil-...iewItemQQcategoryZ6763QQitemZ8033036513QQrdZ1

I used an oil filter block adapter. It sandwiches in between the block and filter and has the correct fitting for attaching the gauge's sending unit.

You'll have to take a dremel and cut off about 1/2" worth of the "bolt" coming out of the block for the adapter to fit correctly.

I think I'm going to get one of these. Just today while doing an oil change I noticed signs of a bit of leaking around where the T is.

With this adapter can you still use the 626 oil filters?
 
cthomp21 said:
http://cgi.ebay.com/ebaymotors/Oil-...iewItemQQcategoryZ6763QQitemZ8033036513QQrdZ1

I used an oil filter block adapter. It sandwiches in between the block and filter and has the correct fitting for attaching the gauge's sending unit.

You'll have to take a dremel and cut off about 1/2" worth of the "bolt" coming out of the block for the adapter to fit correctly.


okay, did a bit more research on this, seems like it would be a viable option.... but exactly what bolt is it that you have to cut?? The large one that the oil filter screws on to?? That doesn't seem like something i'd want to do. Also, do you think its cool to go with an ebay one, vs like the Greddy one, which is $70, which i can't afford.
 
Yeah, you cut the bolt that the oil filter screws onto. You need to cut about 1/2" off of it. I used a dremel with a cut off wheel. The only difficult part is the small amount of space to work in, but it's not too bad.

The bronze bolt in the pic then screws onto the factory post holding the block adapter in place. The oil filter will screw onto the new bronze bolt.

You'll plug 2 of the 3 holes on the block adapter with the extra supplied NPT bolts. I used some teflon tape on them. The extra holes can also be used for an oil cooler or something else.

The gauge's sending unit should thread right into the remaining hole which is 1/8" NPT (the size of the autometer sending unit and probably the SW too).

I'm not sure if the 626 filter will fit. I'm just using the stock size filter right now. I'll be checking at the next oil change. The block adapter pushes the filter out about an inch.

I used the ebay block adapter. Everything is of very good quality and has worked well. I couldn't see paying twice as much for the greddy block adapter.
 

Attachments

  • 1132440534767_oil_adapter_all.webp
    1132440534767_oil_adapter_all.webp
    98.5 KB · Views: 731
You should be remote mounting the aftermarket sending unit. With it directly attached to the engine block, it will eventually break the brass fitting. You'll notice leaks starting before this happens though. What you should do it hook up a -6AN oil line and mount the sending unit on the frame/firewall/etc.
 
I think that'll be what i'll do. What do you have to do about grounding it though??
 
What do you mean grounding it? From what I know, you just hook up the signal wire to the sending unit and call it a day. I did this on my Lancer, I ghetto rigged it though. My pressure sender was zip tied to my AC lines and I never got around to properly mounting it with a C bracket to the fire wall.

Oil line should be -6AN. And then you would need a -6AN to 1/8 NPT fittings.

Check out this thread for my solution list for fittings and such needed to hook up aftermarket senders and keep the stock sender. Page 2 has my list and prices for fittings, and page 3 has a picture of how I would install everything.
 
Well, my understanding of the sender is that its a variable resistor, connecting the wire from the gauge to ground. If you were to touch the wire of the gauge straight to the chassis, you'd get a full reading, 100 psi, or whatever. If you were to hook it up to the sender with no oil, it wouldn't let any signal go through. As oil pressure increases, it adds more current or flow or whatever, giving you the reading. If you just screwed the thing straight into the engine block, it would ground itself, but if you connect it via hose, all its touching is that rubber or whatever material. Thats also why they reccomend not using the tape to seal the threads, but rather the paste-y stuff. At least, thats my understanding of it, is this innacurate??
 
Interesting theory, and I believe you are correct. I had mine hooked up using stainless lines and brass fittings, which may have grounded it, but either way it worked just fine. It read around 45psi at idle and up to about 90psi at WOT.
 
livelyjay said:
Interesting theory, and I believe you are correct. I had mine hooked up using stainless lines and brass fittings, which may have grounded it, but either way it worked just fine. It read around 45psi at idle and up to about 90psi at WOT.


ahh, okay, gotcha. I'll either try to get stainless hose, depending on how much it is, or just figure a way to solder a wire onto the threads higher up or sumthin.
 
livelyjay said:
Interesting theory, and I believe you are correct. I had mine hooked up using stainless lines and brass fittings, which may have grounded it, but either way it worked just fine. It read around 45psi at idle and up to about 90psi at WOT.

hey, where did you buy your fittings and lines at??
 
I bought the oil line and AN fittings from Summit Racing since they have flat rate shipping I figured it would be better to buy from them. The brass fittings I found at Home Depot, but they aren't going to have the BSPT adapters.

If you look back in the thread I have a link to a web site where I would buy all my fittings in the future (NPT and BSPT fittings, I don't think they have AN fittings).
 
yeah, i had already found that thread, and i've got the BSPT/NPT adapters in hand, i just wasn't sure where to find the AN fittings.
 
You can get AN from many different "motorsports" stores. TurfBurn carries them, as would a local shop. I just found buying them from Summit from the comfort of my chair a little easier.

My tee fitting was 1/4NPT, so I had a -6AN oil line, two -6AN to 1/4NPT fittings, and then two 1/8NPT female to 1/4NPT female adapters for the sending units (since they are all 1/8NPT male). There should be -6AN to 1/8NPT adapters available though, or you can just get a -4AN line, because I know there are -4AN to 1/8NPT fittings available.

EDIT:
I bought Earl's performance Auto-Flex hose. It looks like if you go with -6AN you can only go down to 1/4NPT, then you would need a brass adapter to go down to 1/8NPT. Or you could just get -4AN line because the AN adapters come in 1/8NPT sizes.
 
Last edited:
would there be any problems with going -4AN?? That seems like a better alternative, since my tee fitting is 1/8NPT, and i'm wanting to save as much space under there as possible.
 
I would say getting -4AN line would be better. It's cheaper (not by much though) and would require less fittings (less chance for leaks). You don't have to worry about oil volume either. If you were getting something where volume mattered (like a turbo feed line) then line size would matter.

Hope this has been helpful, and have fun with the install. People are usually pretty impressed when you do oil gauge installs yourself.
 
Back