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tapping front cover for oil drain "na-t"

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Old Sep 21, 2010 | 10:41 PM
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TX tapping front cover for oil drain "na-t"

finishing my s4 6port turbo build . just wondering what size drain line you guys are running? and what size drill bit and tap you used . basically whats ur set up . thanks guys
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Old Sep 21, 2010 | 11:07 PM
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I think it would be better to just swap to the TII front cover. Just my 2 cents
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Old Sep 22, 2010 | 12:04 AM
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I run a -10 an which roughly equates too... roughly a 5/8th inch line.

I will grab my tool box later and see if I can find the tap I used although I used the oil pan
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Old Sep 22, 2010 | 11:00 AM
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If I didn't end up finding my Tii cover, I was just going to +1 Grappler's doing and tap the pan.

This has been done a kaBILLION time, with conventional engines, and I've probably done it 50, or so.

The only off-set thing that I recommend is to double wall the oil pan, where you tap and thread it. That way you don't have to worry about the threads pulling or shimmying around, due to vibration.
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Old Sep 22, 2010 | 11:03 AM
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I always tap the front cover 1/2npt below the OMP, The oil pan is thin and might leak.
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Old Sep 22, 2010 | 11:10 AM
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That's kinda what I was thinking.... I'll have to look at my spare NA housing to see, but I *THINK* there's a spot, in the casting, that actually thinner FOR this purpose.

Habit (and a bit of common logic)as pretty much shown that it's better to TnT a denser material than not. Though if it's not an option, make sure the thinner (in this case, the oil pan) has a double hull, so it doesn't flex, etc.
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Old Sep 22, 2010 | 11:17 AM
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Also keep in mind, That the oil needs to drain freely and not be blocked by oil sitting in the pan. Thats another reason why I always tap the front cover.
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Old Sep 22, 2010 | 11:46 AM
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One my 1st 6port turbo I did the oil pan and it technically worked but I don't know how efficient it was. There wasn't enough room for me to get it flat and I don't think it was fully above the oil. I went with the TII cover the 2nd and 3rd time around to save a lot headaches. Regardless I think tapping the N/A front cover would be better than the oil pan.
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Old Sep 22, 2010 | 12:03 PM
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Yup. If it can be done while NOT in the car, attached to the rest of the engine, that'd be preferable, as well (shaving bits).
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Old Sep 22, 2010 | 08:15 PM
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Either way works if you do it right in all honesty each has its pro's and con's but it all comes down to the individual tastes and opinions.
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Old Sep 22, 2010 | 09:58 PM
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Gigetty.
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Old Sep 22, 2010 | 10:02 PM
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Originally Posted by unek87
finishing my s4 6port turbo build . just wondering what size drain line you guys are running? and what size drill bit and tap you used . basically whats ur set up . thanks guys
-10AN works just fine. The flange is already cast into the front cover, more or less. Making a turbo drain is a piece of cake.

B
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Old Sep 22, 2010 | 10:08 PM
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I used -10. Tapping the front cover is easy. Just remove the oil pan and make sure no shavings get in there
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Old Sep 22, 2010 | 10:56 PM
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my bad i meant to say that i was tapping the front cover . i dont want to take the na cover off and replace with a t2 cover cause then i have to replace gaskets and crush washer and all that jazzy stuff plus its a straight shot on that flat area beside the omp . i just wanted to know what sizes i should use for the drill bit and the tap and what size line . thanks guys and hey frosty you have any pic's of ur setup ?
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Old Sep 22, 2010 | 11:03 PM
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i wouldn't drill and tap it on the car ur gonna get shavings and **** is gonna get fucked up
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Old Sep 23, 2010 | 12:04 AM
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+1. I think I mentioned that.... Hm.
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Old Sep 23, 2010 | 10:09 AM
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Ya know, if you are removing the oil pan, why bother tapping the front cover? Just weld a bung into the oil pan and avoid having to pull the front cover.
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Old Sep 23, 2010 | 10:02 PM
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well the the oil pan is dropped already so im not really worried bout shavings , plus when ever i drill on a engine my shop vac is right next to the spot sucking that **** up as i drill .

Aaron the reason why i havent done the pan is cause the oil pan is full of oil right . so that means the flow coming out the turbo would be blocked kinda right? i have my water pump off so that flat spot next to the omp is a straight shot since the lower water neck isnt there . and the reason why i was thinking of tapping the drain there is cause its higher then the pan but yet will drain into the pan with out any blockage . i mean the stock t2 is right in the same area right ? they most of put it there for a reason . also i wouldnt have to remove the front cover since the area i would drill at is clear of anything once the pan is removed .

also Aaron i wanted to say thanks for your lil web page .i've gotten some good info from there. also im still popping a few ideas in my head for feed . debating on either pulling it from the stock oil pressure sending unit and t-ing off , getting a adapter filter sandwich, or drilling and tapping the stock oil pedestal ?
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Old Sep 23, 2010 | 10:27 PM
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I've got an S5 NA cover that has the location for the return, but it isn't drilled out, yet (extra to go with the S5 Tii cover, I'm using).

As far as feed goes, I just installed a Lamco adaptor that would be your best option (also, you could run with an additional oil-pressure sending unit, or an oil temp gauge).

My recommendation is to keep the tapping to a bear minimum, if you can help it.
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Old Sep 24, 2010 | 08:18 AM
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yeah i know most don't like going the tapping route. its not that i'm trying to be a hard *** or anything i just like challenges, fabbing ,etc. now with the oil feed i may just go with the sandwich cause as you stated i get the extra ports . once i get this done all i need to really do is find the stock tmic piping and fab my down pipe

thanks guys for ur comments so far .
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Old Sep 24, 2010 | 12:57 PM
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the pan is the incorrect location for the drain, you will put more stress on the turbo oil seals with the backpressure in the drain pipe, if you don't wind up with turbo oil smoking issues right off the bat.
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Old Sep 24, 2010 | 01:34 PM
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The Tii oil pan has a pair of vertical baffles that kind of 'box-in' the return. As long as the return is ABOVE the sitting oil-level, in the pan, you'll have no problems. This has been time and time again on NA cars that hang a snail. It's just fine...

Of course, if your oil pan is THAT pressurized, there may be bigger problems than tapping it, to begin with.
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Old Sep 24, 2010 | 01:47 PM
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i don't ever recall seeing a baffle in the TII pans.

in fact out of curiosity i removed one just now to see where this baffle is, i can only assume you mean the one at the driver's side rear of the pan for the pressure regulator which is impossible to run a line effectively to that location for a turbo drain while keeping it from sagging at one point or another. that baffle is worthless as well anyways, it's just to keep the oil from covering the regulator.

the passenger side of the pan is just a horrible place for many reasons, mainly because of the angle of the pan on that side and getting a fitting to sit flush on it while staying above the standard oil level. even then a slight left hand turn covers the drain line with oil..

in short my statement stands, do the front cover if you want to do it the right way. i don't know why people are so hesitant to do it, TII front covers are not short in supply and a machine shop could do the job for a minimal charge if someone didn't want to take a chance screwing up their n/a cover(which are readily available in most wrecking yards). it just makes even less sense for people when they want to upgrade their turbo, i sure wouldn't want to damage my brand new $700-$2k turbo with shotty work.

the S5 n/a covers are a no brainer, they already have the oil drain boss right there, formed and ready to be drilled. the S4 cover just needs a pipe thread drilled and tapped which is even less work than modifying the oil pan..
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Old Sep 24, 2010 | 01:55 PM
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No disagreement, here. If he cover's off the car, then by all means do it that way.

Additionally, if they didn't have a baffle plate in the pan, then which of these is NA and which is TII?



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Old Sep 24, 2010 | 01:59 PM
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oil pressure regulator baffle at the wrong corner of the pan.. that baffle is worthless below the deck of the engine.

see the steep angles on the left side of the pan in the first picture? that is where the oil line would have to be welded to the pan at the left lower corner. a horrible spot for a bung, the worst on the pan due to the angle and how it will sit after it's welded in to be functional.

if by baffle you mean a low spot to clear the power steering rack? that won't keep oil from running to that area on a left hand turn after a shift and deceleration. the pan location may work fine if you are just doing 1/4 mile runs however.
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