Tip: Oil Lines

[civic31g]

This tip is really necessary for those looking to run an external oil pressure gauge or for those running a turbocharger or supercharger.

A question that comes up often is "what do I need?" and well that can vary. Honestly, to do it very clean and have everything as leak proof and "goof proof" as possible, using AN fittings and the proper stainless braided lines and fittings makes a world of difference. The difference between doing it right the first time (though doing it right may cost twice as much) and jigger rigging it can mean the difference between it working properly and engine failure due to oil pressure drop.

Many people find themselves making trips to the hardware store for brass MPT fittings that are most often used in natural gas or low-pressure fluid installs. The catch is, these products are made for household use and not specifically made for high performance automotive use. They cannot withstand large amounts of vibration and shock that is normal abuse to an engine and anything attached to it. The REAL drawback of using these hardware store parts is the fact they are not the same thread as automotive parts and can strip out fittings and/or leak under pressure which is no doubt what we want to avoid.

What you will typically do to feed these oil pressure gauges and/or turbochargers is remove the factory oil pressure switch which is basically a pressure activated switch that lights the oil pressure "dummy light" on the dash warning you in the event of low oil pressure. (This signals below roughly 15-20psi.) You will want to retain this switch as having the light along with a gauge is important, as you will likely put little attention to the gauge itself while at the racetrack or when driving hard elsewhere. To remove the stock pressure switch, you will need a 24mm socket that is fairly deep. Just pull the plug off the end and undo the switch from the block. Expect a mess of oil to come with it. Now here comes the reason you want to stay away from hardware store parts and why you need a metric adapter... Standard automotive fittings use an American NPT threaded fitting which is a 1/8" pipe thread with 27 threads per inch and is tapered to provide a better seal while Honda blocks use a 1/8" BSPT thread which is 28 threads per inch and also tapered. Although BSPT will screw into an NPT hole and vice versa, using an NPT fitting directly on the back of the block can damage the threads on the block itself which may release small metal shavings directly into the motor and that is bad. Instead, you will need a BSPT to NPT adapter fitting available from several companies including Autometer. (As pictured in brass)

So now you have removed your oil pressure switch from the back of the block (located next to the oil filter) and you have your metric adapter ready to screw in. What you will want to do is use a small dab of thread sealer which is typicaly white in color and has a paste like form. This is basically liquid Teflon, which unlike Teflon tapes, it stays in a liquidy paste form and will not clog the oil lines or any fittings in the event some of it may glob off into the oil flow. DO NOT use Teflon tape as it can block oil flow in the engine or other fittings which may result in oil pressure drop and engine failure! Apply some of the Permatex thread sealer around the threads of the fitting, smear it into the threads with your finger and wipe off any excess, then screw the fitting into the back of the block. You do not need to tighten it down very tight, just wrench it in with just enough force that it doesn?t want to vibrate loose on its own. Over tightening it may strip the threads and thus cause large headaches. (I typicaly tighten the fitting in the block until it is no longer easy to tighten with a short handle wrench. At that point I know it will not leak or vibrate off.)


(Pictured: Aeroquip 1/8" NPT to -4AN fitting *blue anodized aluminum*, 1/8" BSPT to 1/8" NPT adapter *brass*, 1/8" NPT to -3AN fitting *steel*)

Now that you have the proper BSPT to NPT adapter on the block, you can start working with standard NPT fittings from here out which means everything else should fit together nicely. (Please note: I suggest sticking to the same brand for all AN fittings and lines for everything to prevent problems.)

A quick intro to race fittings... AN stands for Army Navy because these fittings were designed for the government because they are reusable and require no thread sealer, so you don?t need to use any on the AN side of fittings. The NPT side of NPT to AN adapter fittings still requires a thread sealer. The size is indicated in fractions. A -4AN is roughly 4/16ths of an inch diameter hose. (The inner diameter of most -4AN line is more like 0.22" which is slightly less than 4/16ths.)

From your new NPT adapter, you can purchase a 1/8" NPT to -4AN fitting to run your stainless steel braided oil lines. Although you can use a -3AN line, -4AN is slightly larger and can flow more oil, plus it is less likely to clog. You will want to use thread sealer on the NPT side of the threads the same as you did on the BSPT adapter screwed into the back of the motor. Once that is ready, screw it into the adapter fitting and tighten it roughly as snug as the previous fitting. (You may need two wrenches to tighten the second fitting without over tightening the first fitting in the block.)

Now comes the tricky part. What you ideally want to do is have a matching size braided oil line with enough extra slack in it to allow for plenty of flex. Roughly 24" is more than enough room to allow for flex between the motor and the Tee fitting or manifold block attached to the firewall with the sensors mounted in that. You will need to buy the same size fittings and lines for everything as -3AN lines will not work with -4AN fittings and vice versa. You can buy these lines pre-assembled from several places or you can make your own using the proper fittings available from many performance shops. (Most shops will cut custom lengths of braided line for no extra cost. This is best as the line itself is a real pain to cut without a carbide cutoff saw.) You can attach this line to the AN fitting now located on the back of the block. You want to tighten it so that the fitting no longer moves freely. You do not need to tighten it much as the angle of the fitting itself provides the seal. Again, no sealer is required for the AN side of fittings or lines.

Now comes the part you can vary depending on what you need to do. Personally, I use one of my own "Super Manifolds" which can be used for vacuum/boost, fuel or oil lines. The "super manifold" has both 1/4" NPT and 1/8" NPT threaded holes meaning you can screw in the standard fittings without special adapters. These offer plenty of size options for different sized lines, pressure gauges, temp probes or oil feeds for turbochargers and superchargers. (Mine is pictured below with a 1/4" NPT to -4AN, 1/8" NPT to -4AN and a 1/4" NPT to 1/8" NPT adapter fitting plus the included stainless plugs in unused holes.) You CAN use a simple brass Tee fitting but run the risk of cross threading since most hardware store fittings are MPT threaded, and if you are going to run an oil feed for a turbocharger or supercharger or even a VTEC head on an LS-VTEC swap along with the pressure gauge and the factory pressure switch, you will need a Tee with at least 4 ports in it to allow one for the feed, one for each sensor and one for the output to the turbocharger, supercharger or VTEC head. (The "super manifold" I sell has 6 ports plus an input, more than enough for most any setup.)


(Pictured: Super Manifold V1 with 1/4" NPT to -4AN and 1/8" NPT to -4AN Aeroquip fittings and a brass 1/4" NPT to 1/8" NPT adapter.)

You will want to again use thread sealer on another 1/8" NPT to -4AN fitting and screw that into the tee block that you plan on using. Tighten it down with a wrench roughly the same as the fittings on the motor. Because the holes are tapered, it should tighten down and hold in place without much effort. Now you can use thread sealer on the oil pressure gauge sending unit and thread that into the tee block. And although using another adapter to revert the oil pressure switch threads to allow it to thread in properly would be ideal, I don?t believe anyone makes a reverse fitting allowing the switch to thread into an NPT hole so you will just have to put thread sealer on it and screw it in as much as you can without damaging the threads. You should still be able to tighten it so that it does not leak as long as you used thread sealer.

Now consider a mounting location for the tee block and sensors. Ideally you should mount it with screws or zip ties to the firewall or something attached to the firewall so that it doesn?t fall off and dangle as the weight could break the fitting right off of the back of the motor which would cause oil pressure loss and engine failure. Also consider the length of the wires for each sensor, specifically the stock sensor, as you cannot extend that wire easily. Now run the -4AN oil line into the finished tee block and tighten it down. Then plug the sensor wires up to the sending unit and the stock sensor. If you are running a line to the head or a turbocharger or supercharger, make sure those are properly attached and tightened. Recheck all fittings to be sure everything is tight and that the tee block is secure on the firewall with plenty of room for the oil line to flex when the engine moves. (I make a large loop with my oil line from the back of the motor to the tee block to allow for flex.)

Now that everything is connected, tight and secure, you can go ahead and test start the engine. (Please note: If you had much oil drain out when removing the pressure switch, you may want to check the oil level first and refill any lost oil.) The oil pressure light on the dash should light and then go away after a second or two as it will take a moment for the oil line to gain pressure. If for some reason the light does not turn off after a few seconds and you show very little or no oil pressure on the gauge, shut the engine off and check the connections both on the oil line and wire connections to be sure they are secure and no oil is leaking anywhere. (This would be very obvious if you have no oil pressure at all.) Depending on how the tee block is setup, you MAY need to run a small wire to ground the block to the car so that the gauges function properly. Usually the stainless braided line will be a perfectly fine ground but sometimes this isn?t the case. After checking everything, start the engine again and test for pressure. If the oil pressure light dims but you show no oil pressure on the gauge, you will want to retrace all of your wires on the gauge to be sure they are properly connected. If you show pressure on the gauge but the light stays on, the plug on the oil pressure switch may not be all the way connected.

Also, after you start the car the first time to be sure everything checks out, look at EVERY connection to be sure their are no oil leaks. Even the smallest leak over time can cause large headaches and a real big mess. If you have a leak, try tightening the connection. If that doesn't help, you may want to undo the fitting completely and apply more thread sealer or a bit of Teflon tape. If you do apply Teflon tape, be sure to leave the first few threads exposed so that the tape doesn't flake off into the oil flow.

(Pictured: Aeroquip AQP Racing Line)

Here is a listing of typical fittings you may need... (Note the * before a part name, this denotes a preferred part.)

Edit: Ok here is a list of what you will most likely need and suggested places you can buy these parts.

* Permatex Thread Sealer (0.6oz tube) should have a white pasty look to it. You can get the Permatex Thread Sealer at most auto parts stores for about $3 and the small tube will last a long time. Remember, a little bit goes a long way! You wont need to glob it on.

You can substitute that for ARP thread sealer but it is more expensive and slightly chunkier and less pasty though it doesn?t smell as bad. It is also harder to find unless you have a true performance parts store nearby. It does work very good however. This should cost about $6 for roughly a 3oz tube.

* Super Manifold V1 (made by me, as pictured above) This is the ideal option due to the number of ports and the flexibility of various sizes of NPT threads making any changes later "future proof" so you wont have to get under your car and replace it ever! $30 + shipping from me! ----> Super Manifold V1 <---- Order Here

You can substitute that for a brass MPT tee fitting from most hardware stores for about $6 BUT the NPT fittings may not thread in as well which could cause leakage and/or metal shavings to enter the oil flow. It is also limited to one feed in and two feeds out which means you can only send oil to the pressure switch and a gauge or the pressure switch and an oil feed for a turbo/supercharger or VTEC head, not all three. It also lacks any mounting holes while the Super Manifold V1 has two holes on the top ideal for small zip ties or screws.

* Aeroquip NPT to AN fittings (various sizes) Although you can use -3AN if you desire, -4AN would be ideal. These fittings can be ordered from a number of online performance parts dealers. (My personal favorites are www.SummitRacing.com and www.Jegs.com for great service with orders in the past.) The Summit Racing part number for 1/8" NPT to -4AN fittings is AER-FCM2001 and for a 1/4" NPT to -4AN fitting is AER-FCM2002. You will most likely need two AER-FCM2001, one for the engine side and one for the tee block side. If you are using the Super Manifold V1 that I offer, I would suggest using a 1/4" NPT to -4AN fitting on the manifold side so you can run the oil feed into the bottom port or one of the top two side ports. You would still want a 1/8" NPT to -4AN fitting for the engine side however.

You can also use Earl?s fittings or really any other brand NPT to AN fitting. Earls are also nice but tend to be slightly more expensive than Aeroquip. (Personally, I use Aeroquip for everything.)

* Aeroquip -4AN stainless braided line (Roughly 24" is good enough.) This is easy to work with and available in a 3 foot pre-cut length from Summit Racing for roughly $15 (Summit Racing part number AER-FCA0403). You may need a hacksaw or circular saw with a carbide blade to cut this to length if you prefer. I do believe Summit Racing can also ship custom lengths if you desire but I would suggest no less than 24" for a line from the engine to the tee block to allow for plenty of slack and enough length to be able to pull the whole thing over the engine if you need to service anything on it and about 36" for an oil feed for a turbo or supercharger. The matching fittings you will need are Summit Racing part number AER-FCM1101 for -4AN straight hose ends. These are somewhat tricky to assemble at first but once you understand how it goes together, it takes no more than 5 minutes to assemble the line from scratch. Again, you will need two hose ends for each line.

If your lazy, you can substitute that for pre-assembled -4AN lines in custom lengths from this site here ----> www.bakerprecision.com though I cant vouch for their service or quality as I never ordered from them before. They use Earl?s lines and have crimped on fittings, which are just as good, but I?ve had a crimped on fitting pull off a line before. (Personally, I don?t like mixing and matching brands of fittings and lines but it shouldn?t be a problem as long as your not mixing the braided line brand with another brand of hose ends.)

Lastly, you will want a BSPT to NPT adapter for the back of the block. This is critical and you shouldn?t screw an NPT fitting directly into the block or else risk stripping the threads, cause an oil leak or worse, metal shavings in the engine.

* Autometer brass BSPT to NPT adapter (I'd prefer steel but brass is ok.) The Summit Racing part number is ATM-2269 and you will only need one of these. It is a bit pricey at almost $11 each but you really shouldn?t go without it. I believe another company makes one that is steel instead but I?m not aware of their part number.

There you have it... That is basically what you need to make a proper oil line from the engine to an oil pressure gauge sender and/or a tee block for a turbo/supercharger or VTEC head feed.

(Pictured: Super Manifold V1 with Autometer 100psi pressure sending unit, Honda oil pressure switch, -4AN oil feed in, -4AN oil feed out to a Vortech supercharger.)

Q&A section:

Q: Why do I need braided lines, why can?t I just use rubber hose and barbed fittings?
A: Due to the pressures in the oil system, most rubber hose alone cannot withstand the high pressure and heat from the oil system. The last thing you want to fail in your engine bay is an oil line, which could cause oil pressure loss and engine failure or even worse, a fire! Braided lines can withstand over 1000psi and are safe over 450? which is clearly higher than your oil will ever reach. The fittings also screw together which is added safety to prevent a line from blowing off or leaking.

Q: Why not just use a tee block on the back of the engine and hang the sending unit and pressure switch directly on that?
A: Due to the amount of shock and vibration the engine gets on a daily basis, that added weight hanging on by a brittle brass fitting and fine threaded aluminum in the engine could cause it to break off or strip the threads and pull out while driving causing engine failure and/or a fire.

Q: Why use a billet aluminum "Super Manifold" over a less expensive brass tee fitting from my hardware store?
A: The Super Manifold V1 has the proper NPT threads on it to allow for a tight leak proof fit. It is also made from 6061 aircraft quality billet aluminum and has a durable black anodized finish to help it blend into your engine bay. Brass is also brittle and can crack over time. Plus fittings often found at hardware stores use a MPT threads that is slightly different than NPT, which can cause leaks or poor fitment. The Super Manifold V1 also has 6 ports plus an input and includes plugs for unused ports. A brass tee only has 2 ports plus an input and includes no plugs. To feed the oil pressure switch, a pressure gauge, an oil temp probe and a turbocharger or supercharger, you would need to mix and match several tee's together which makes the chances for leakage higher and buying that many different parts adds up to the cost of the Super Manifold V1 anyhow.

Q: If I do it right, how much will all the parts cost roughly?
A: You can get the Super Manifold V1 for $30 plus shipping and the rest of the parts for roughly $50-70 plus shipping online for a grand total of under $100. With that, you get piece of mind knowing you'll never have to replace any of that again and you'll never worry about an oil leak either.

Q: I've read you can get an aluminum "manifold" from another company online for less?
A: True, their is another company that sells hardware, however their manifold isn?t designed for automotive use and due to its design and shape, to run both the pressure switch, oil pressure sending unit for a gauge and an oil feed line in and an oil feed line out to a turbo or supercharger, you would have to purchase a larger manifold to allow for spacing of each device. Plus you would have to order the proper plugs to plug unused holes at an extra cost. Add it all up and you have a larger, less attractive setup that is less flexible for future add-on's, and it will end up costing nearly the same amount as the Super Manifold V1 which includes everything you need, plus the design has holes on three sides which allows for bulky sending units. (Remember those cheep 6 plug power strips you used to use for your computer? Yea, you could get like 2 transformers into it plus one regular plug for your computer. Not a good design at all! Neither is the alternative "manifold" from an online hardware retailer.)



from clubsi.com

[cynosurecivic]

damn good article, but im tired while reading it and i got lost somewhere. haha, i'll come back leter. once again, seems like a good article.