MS6 -- possible oil drain line solution?

[Code Monkey]

Some of you may remember my epic fail at installing a GTX3071. In this post, I sketched my ideal routing of the oil return line.

A few weeks ago I was on a Gayata forum searching for parts and I saw power steering stuff for sale:



This is what caught my attention:



The seller e-mailed me another picture:



and I had this thought that maybe, maybe we could use it on the block side for the oil return line.

The part arrived Saturday and here is what the flange looks like superimposed on my earlier sketch:



Now, onto some measurements and comparisons.

The stock oil return line's orifice is 0.5856", the Miata's one is 0.5120", the third flange, same as Treadstone here sans the integrated o-ring, is 0.505". I am not concerned about the smaller than stock diameter as virtually all aftermarket flanges are 1/2" ID.

The bolt holes on the Miata flange are a bit too close and will have to be elongated, should be easily doable. The flange is super thin compared to the stock line, I have no idea if this is a problem, most likely shorter bolts will have to be used. The line should clear the TC easily, but it is still possible that it would run too close to the block. A -10an line with a clamp fits very snugly and there should be no leaks.

I do have a spare block and a spare stock EM, maybe one of these days I will grab another turbo and test my theory. Or perhaps someone who is in the middle of a build will jump on it.

The Miata part # is 32-5M0 and goes for $21.95. As you can see in the diagram, there is an o-ring if needed -- it is an extra $17.70 as part of a seal kit -- but I am sure we can source just an o-ring at a cheaper price. Another possibility is to shave the flange so it is perfectly flat but I am not sure if there is enough material.

To complete the line on the turbo end, we can use the above mentioned Treadstone flange, or, if an angle is required, a combination of this and this, as such:



@phate; @Tomas; @torquemaniac;

[torquemaniac]

Dustin make (or used to make) nice custom oil return line from the OEM line...see here : HOW TO: TOP MOUNT TURBO SET UP!!

This is the easiest option in my opinionm, unless you are crazy like me and want full custom shit

[Turbo_Steve]

And this guy from a subaru fits the turbo. Could be a match made in heaven.

[torquemaniac]

Nice option, but the real deal killer is the section that bolt to the block (low profile 80 degree bend)!

[Mazdazilla6]

That really is a killer idea! I'll definitely keep it in mind when I build my engine this coming year.

[rob ms6gt]

Nice find! You may have something there. I noticed the flanges on our egr tube match as well. I couldn't do anything with it tho. Right now I am using this

Amazon.com: Fragola (206010) #10 60° Push Lock Hose Fitting: Automotive

Amazon.com: Fragola (206010) #10 60° Push Lock Hose Fitting: Automotive
Amazon.com: Fragola (206010) #10 60° Push Lock Hose Fitting: Automotive

[Code Monkey]

The EGR line will not work as it angles back into the block, this is documented in my fail thread.

Kozmic could make a kill if they come up with a solution that fits many turbos.

[rob ms6gt]

Any updates?

[torquemaniac]

Some kind of corrugated stainless steel line could be your ticket...here is some examples :

Falcon Stainless, Inc. :: Price List for all Water Connectors

This kind of line is really nice...its flexible yet strong, will keep the bends you give it and can withstand high temp

[Code Monkey]

Originally Posted by rob ms6gt Any updates?

No updates so far.

A couple months ago, I started bugging my shop about putting my spare engine on a stand so that I could snag Thanksgiving or Christmas deals on rods/pistons. They missed the Thanksgiving and then Bill, my mechanic, got burned and hospitalized after his race car caught on fire so I did not want to push the matter any further. I am taking my speed6 to the shop this week and will ask them about the engine again, I think Bill may be already back working.

Originally Posted by torquemaniac Some kind of corrugated stainless steel line could be your ticket...

You know it is about the flange and a tight turn that any line has to make to clear the TC.

[torquemaniac]

Originally Posted by Code Monkey You know it is about the flange and a tight turn that any line has to make to clear the TC.

I can ship you my rev.A fitting if you want to try it out (its of no use to me)

Just pay shipping!

[avesfan101]

Lol you used all of my pictures!

I don't think this is a great solution. Prone to leakage. You could weld a AN fitting onto the end of that and call it a day.


I never had an issue with this set up.


That's a picture my uncle took a long time ago. That's a gt28 IWG. The problem on the speed 6 becomes even more of a pain with an ewg housing on the turbo itself. Like in my picture above.

[torquemaniac]

With the right clamps and hose, I dont think there will be leakage...the oil drain line is a low-pressure ''system''

[avesfan101]

Originally Posted by torquemaniac With the right clamps and hose, I dont think there will be leakage...the oil drain line is a low-pressure ''system''

You might be right but those clamps over time are naturally going to loosen up. Also as the hose "breaks in" and become softer and more ply able the clamp will no longer be tight.
Better bet is AN fittings.

Even push lock fittings would be better.

[torquemaniac]

Here is my oil drain fitting solution (block side) : a nice and shiny custom stainless elbow fitting

[Code Monkey]

^ Dude, assuming the angles work, you should seriously run some sort of a group buy.

Edit: If you could make the flange a tad thinner, that would help with getting to that cursed lower bolt....