Guest 73Turbo240z Posted October 4, 2005 Share Posted October 4, 2005 Alright this is the third attempt i've made at getting a WORKING solution for oil fittings... this time i went w/ a well know turbo parts supply company, and the stuff still isn't working, and i believe i've narrowed down why it isn't working as well... the block hole for the oil feed is 1/8" NPT... the inlet oil feed at my turbo is M12x1.5... i've solved the puzzle on the turbo side of the equation, however at the block things remain a royal PITA. This time i believe it's due to tapering... Exhibits A, B, and C.... on #1 you will see the stock nissan/datsun tee on the left, the aftermarket offering on the right. same for #2 and #3 is the mess of parts i'm trying to make work... as you can see the stock part has a tapering in the threads that is more aggressive than your standard 1/8" NPT thread offering from the aftermarket guys on the right... that being said, does anyone know where i can procure a Tee fitting that has this more aggressive 1/8" NPT thread tapering on the male end, w/ generic straight 1/8" npt female ports (2)? In discouragement i've placed an order w/ McMaster now to see if the Tee's they have have this tapering... this is getting VERY frustrating. Quote Link to comment Share on other sites More sharing options...
slownrusty Posted October 5, 2005 Share Posted October 5, 2005 Dude...the Nissan block is NOT 1/8" NPT...it is 1/8" BSPT...British Pipe Thread. Did I not send you the link on what I did? Take the stock Nissan Tee and drill it out: Weld in your new oil restrictor with -3 or -4 fitting, or take it to a Machine shop and let them do it: Here is everything welded and ready to go: Installed: Yasin Quote Link to comment Share on other sites More sharing options...
Guest 73Turbo240z Posted October 5, 2005 Share Posted October 5, 2005 Dude...the Nissan block is NOT 1/8" NPT...it is 1/8" BSPT...British Pipe Thread. Did I not send you the link on what I did? Yasin What did you use as a oil restrictor? or did the -4an fitting act as the restrictor once welded in? I've been pondering the welding it in place idea... only reservation about doing that is that i'm unsure what it takes to weld to what this is... looks like brass, i have a 220v mig w/ a bottle of argon... will that do the job or do i need to do somthing else? Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 5, 2005 Share Posted October 5, 2005 Have to agree, the block threads are NOT NPT, they are BSP (1/8-27 BSP I believe) For the restrictor, you can also use braze in the base fitting, and simply drill it out. For the inverted flare portion, as Yasin did, drilling and then adapting to something you CAN use is the easiest option. Welding is nice, but a threaded solution would also be possible. I forgot where I saw it, but there was a BSP "T" Fitting available, that would allow you to do essentially the same thing Yasin did, and still screw the stock sender in the end of it---I think it was for sale at Pegasus Racing in New Berlin WI... Was a Male-Female-Female "T" configuration in BSP. They deal a lot with English Ford stuff there, so they have some strange BSP fittings available. The feed to the turbo would simply be a BSP to AN-4 (with restrictor added) which should be available almost annywhere---a Parker Store would be a good place to look. A Brass or Aluminum BSP to AN fitting makes it really easy to tap the bottom of the fitting, and screw in an older Rochester Carburettor Jet to use as a restrictor, and makes it easy to change later if you want more/less oil. The Rochester jets were a standard machine screw thread---1/4-20 I believe, and their sizing in simple: a 50 jet is .050"! Good Luck! Quote Link to comment Share on other sites More sharing options...
Guest 73Turbo240z Posted October 5, 2005 Share Posted October 5, 2005 forgive the ignorance in the restrictors... but if i were to keep with the stock ZX T-tap, and add adapters after the fact, why would i need a restrictor, and why wasn't one present in the functioning design that datsun/nissan did in this T-tap from the get go? Quote Link to comment Share on other sites More sharing options...
slownrusty Posted October 5, 2005 Share Posted October 5, 2005 If you keep the stock Nissan Oil line, no restrictor required, if you upgrade to a braided steel line like I did, then a restrictor is required. I did as Tony mentioned...welded in the hole and then drilled it for the restrictor. The stock Nissan Tee is steel not brass, so is weldable. Fixed the pic above, did not realize I had the same pic twice. Regards - Yasin Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 5, 2005 Share Posted October 5, 2005 If you keep the stock Nissan Oil line' date=' no restrictor required, if you upgrade to a braided steel line like I did, then a restrictor is required. I did as Tony mentioned...welded in the hole and then drilled it for the restrictor.Regards - Yasin[/quote'] Who wants to keep the stock Nissan Line, though? LOL Quote Link to comment Share on other sites More sharing options...
Guest 73Turbo240z Posted October 5, 2005 Share Posted October 5, 2005 i don't care what line i use so long as it gets oil to the turbo... what are the do's and don't for this restrictor setup? i'm assuming it's a little more "specific" than stick somthing in the way of the oil path. i've never done somthing like this, so it's all new to me... anyway to gauge? shooting for a certain idling line pressure? Quote Link to comment Share on other sites More sharing options...
dragoontwo Posted October 6, 2005 Share Posted October 6, 2005 i don't care what line i use so long as it gets oil to the turbo... what are the do's and don't for this restrictor setup? i'm assuming it's a little more "specific" than stick somthing in the way of the oil path. i've never done somthing like this' date=' so it's all new to me... anyway to gauge? shooting for a [b']certain idling line pressure?[/b] Iirc, you don't want more oil pressure than you have pressure in the turbo. Quote Link to comment Share on other sites More sharing options...
slownrusty Posted October 6, 2005 Share Posted October 6, 2005 I STRONGLY recommend chucking the stock Nissan hard line and using a braided steel line -3 or -4 size. For the last time.... Block off the fitting completely with weld as per my photo...then drill out a .060" hole....TADAH....perfect size oil line restrictor. Now you are ready to roll. Yasin Quote Link to comment Share on other sites More sharing options...
240hoke Posted October 6, 2005 Share Posted October 6, 2005 I just ran a tap in my block with lots of grease on it to catch the filings and then cleaned it as best i could. The thread are so close it worked fine for me. Quote Link to comment Share on other sites More sharing options...
240hoke Posted October 6, 2005 Share Posted October 6, 2005 Also I am not running any type of restrictor... havent had any problems with it. Whats the purpose, to just keep to much oil pressure from the bearing and blowing through the seals? i ran mine long and hard for a year wihtout any issues what-so-ever Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 6, 2005 Share Posted October 6, 2005 The restriction of oil flow to the bearing is seal related, true, but there are very complex forces working inside highspeed turbomachinery that manny people are unaware of... too much oil can cause a measured decrease in spool up time, excessive frothing in the pan (causing intermittent cavitation of the MAIN pump in some cases!), seal leakage, oil consumption, high oil temperatures blah blah blah... By restricting flow, you get better heat transfer from the oil that IS going in there, and returning far less volume of frothing oil to the sump. Those are the two biggest issues after seals leaking. Quote Link to comment Share on other sites More sharing options...
240hoke Posted October 6, 2005 Share Posted October 6, 2005 Hurm injteresting, well sounds like i need to add a restrictor? Any idea on how much spool time is decreased? I think im gonna do some testing ill reinstall my oil feed how it is, dyno it, and then on the next run add the restrictor. has anyone done this before? Quote Link to comment Share on other sites More sharing options...
sims76 Posted October 6, 2005 Share Posted October 6, 2005 Just an FYI, I took the same approach as 240ZHoke and re-tapped my block using an NPT tap. I am also using a -3 AN steel braided line for the oil feed. I bought the turbo and line from James T. He suggested that the -3 feed was more prudent than the -4 for similar reasons that Tony D stated. No problems after 9 months and thousands of miles of aggressive driving with this setup. Quote Link to comment Share on other sites More sharing options...
Guest 73Turbo240z Posted October 6, 2005 Share Posted October 6, 2005 I STRONGLY recommend chucking the stock Nissan hard line and using a braided steel line -3 or -4 size. For the last time.... Block off the fitting completely with weld as per my photo...then drill out a .060" hole....TADAH....perfect size oil line restrictor. Now you are ready to roll. Yasin i didn't gather that from your prior posts... welding up slag then drilling it out wasn't what i interpreted, sounded like you were saying find a pre-sized disc, weld it in, then weld the new AN fitting on... saying it how you did just then is much simpler to deal with, i can do that... any choice drill bits to use, names to look for, since i can't say off hand if i've ever seen bits listed by diameter as small as .060? Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 6, 2005 Share Posted October 6, 2005 "any choice drill bits to use, names to look for, since i can't say off hand if i've ever seen bits listed by diameter as small as .060?" Well, if you buy a Rochester #60 Jet, and simply tap the bottom of a threaded NPT(BSP) to AN-4 Adapter you don't have to worry about the orifice drill, do you? And you can change orifice size for about $.75... As for the line size, I was advised -3 was a better choice as it was .187" ID, almost identical to the .196" line that Nissan Supplies. One other item to think about is if you are feeding a -4 line straight through a -4 adapter, you basically have a .250" hole in the oil system blowing back to the sump. This can cause oil starvation in hard righthanders. I have lost a turbo in a hard right hand sweeper, passing under boost. if you drive hard, and do not run an accumulator for oil supply you are on borrowed time on anything but a ball-bearing turbo! They WILL trash in an instant from that air bubble travelling through the line! A large line---just like when going to a gauge, transmits a pressure drop IMMEDIATELY to the turbo. When I set up the restriction on my old Corvair (and the VW for that matter) the restriction was placed AT the turbine supply fitting, using the larger -4 line as somewhat of an accumulator, full of pressure right up to the turbo. Most Industrial Stationary Turbo Machinery will run your restriction as close to the point of use as possible to minimize effects of pressure fluctuation, and keep a steady stream of cooling oil on the componentry while at speed. Using a -4 Feed Fitting you can thread the "cone end" and stick your jet in there, also! The spool up differential is plotted in a lab on a scope trace---chances are you will not see it in seat of the pants driving. It IS a concern when designing the oil supply system for the turbo, though. It is measurable, and only mentioned because it indicates the excess oil is COSTING horsepower to turn meaning the exhaust turbine is roking harder to turn the compressor than it needs to. Remember Nissan is betting that the line will get coked up and restricted through owner neglect---which is why they called for replacement of the oil supply line at EVERY turbo changeout! Coking in the supply line has trashed more than one turbo, and is kind of a built in restrictor after about 50 to 75K miles of operation of a careless operator! On a -3 line, a restrictor is not nearly as important as a unfettered -4. And my preference from past installations is to install it at the turbo for the aforementioned reasons, if at all possible. Quote Link to comment Share on other sites More sharing options...
HadesOmega Posted October 8, 2005 Share Posted October 8, 2005 wow purdy. if you having so much trouble with the oil T why don't you get a stock one? that's what I was gonna do when i was planning to turbo my NA engine. Quote Link to comment Share on other sites More sharing options...
Guest 73Turbo240z Posted October 9, 2005 Share Posted October 9, 2005 wow purdy. if you having so much trouble with the oil T why don't you get a stock one? that's what I was gonna do when i was planning to turbo my NA engine. i have a stock one, and about a bazillion other fittings too now.. i think i found a working solution, i searched ebay for the rochester jets and couldn't find em, i found other .060 jets on summit, i also found a .060 oil restrictor w/ 1/8" npt male/female setup that i ended up factoring in.. once all the parts arrive and i can verify i found a working solution i'll make a post about it. Quote Link to comment Share on other sites More sharing options...
dragoontwo Posted October 9, 2005 Share Posted October 9, 2005 as to my previous comment on pressure, I was wrong. a good minimum hot idle pressure is 5psi. and a good minimum max load pressure is 25 psi. if you exceed 65-70 psi however, you may start to push oil pass the seals. remember these are minimums, and were taken from the book Maximum boost. Quote Link to comment Share on other sites More sharing options...
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