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Well it turns out the engine i'm buying from MX-5 Plus has a hole in the sump.

Since Richard will need to replace it before I can get the engine picked up I thought I may as well get him to tap the sump to suit a turbo return line, should I have the cash to turbo the car in the future.

So .. since the engine is out of a car, and the sump will be off, what's the best fitting to get him to place in the sump and where should it be located?

flyinMiata wrote:The drain hole location is 2” below the upper lip and as far forward on the left side of the sump as possible, directly under the A/C compressor bracket (if so equipped).

They use a 3/8NPT-5/8” hose barb, should I do that and just block the barb until I need it, or get something threaded that I can screw a nut into and then screw a barb into later?

Dont do what Mazda did on the SP

What was that, so I know what NOT to do then

Not sure exactly but I think they drilled the sump then threaded it and screwed in a nipple but the sump material isn't thick enough so there's not enough thread to get a good seal.

Dave, Daniel at Mania has modified my sump to take a solid steel return line from the turbo to the sump, and has used flat plate on the end of the pipe with two bolts and a gasket to secure it:
something like this on the end...

Much neater solution than Mazda's on the SP and one that is relatively easily done with the sump out of the car. You wouldn't have to make a solid pipe if you don't have the turbo in place yet - you could join it with a rubber hose and clamps - and it is easy to blank the hole with a flat plate if not required.

Get something which you can screw something onto - Enzed or Pirtek may be able to advise. Getting something to clamp a rubber hose onto is a serious pain in the ass, as the rubber degrades over time due to the hot/cold cycles from using the engine.

I personally am getting my brass screw-in fitting changed to a fitting on which I can screw a steel braided line. It's overkill for an oil return line, but a) it'll stay reasonably flexible and b) not degrade over time.

You could get it done yourself, really. Just take the holed sump into Pirtek/Enzed and see what they can do for you.

Everyone's going turbo these days.

I'm not going turbo, well not for ages i'm way too broke to do the job properly.

But I may as well get the sump done while it's off.

You could get them to weld an alloy 3/8 NPT bung on it like Sabre says...that way you can just screw a speedflow hex head blocker into it until you are ready to attach a line to it. Don't forget to use hydraulic thread sealer on the blocker too.