Tapping Oil/Water Ports on VVT Block
 

Has anyone attempted to tap the oil/water bosses (where the NA's have tapped holes) while the block is at the machine shop?

I believe JoeP had a thread about it several years ago and for oil the decision was made that it would be next to impossible to do correctly. Searching should find the thread.

Correct and correct.
Also we discussed it at least twice afterward.

But you should attempt to do it and report back, OP.

To be fair, not everyone has been here for years, and it can be quite difficult to locate some threads. Hell, it took me a while to find that specific thread, and I knew what to look for, since I posted it. And when I did finally find it, the specific image I posted which illustrated the point was dead. (Fuck you, ImageFrame.)

So chill. :D


Water is easy- you're just going through a few mm of metal into an open jacket.

Oil would be next to impossible to do correctly. The casting is still there, but they passage to feed it is missing in the later blocks. You'd have to drill a very narrow passage several inches through solid iron to hit the passage which feeds the rear main bearing all the way on the other side of the block. Deviate by just a degree or two and the block is trash. I'd attempt it only if I had a CNC milling machine to make the cut with.

As I said, the original image is long gone, but I managed to find a very low-quality preview cached in Google Images. Here's the problem:

https://www.miataturbo.net/attachmen...1&d=1413767318



While searching for that, I also came across am image of my dog taken while she was in the process of dying:

https://www.miataturbo.net/attachmen...1&d=1413767318

just turn the boost up and vent a passage out naturally

Does anyone know the thread pitch on the oil port on vvt motors? I wonder if one could simply use a double banjo bolt to feed the turbo from same source.

https://www.miataturbo.net/attachmen...ine=1413817991

On VVT motors the VVT oil line uses the same port that the oil pressure sensor uses. You simply add the same type of Tee that you would use on 96-00 miatas to run the oil feed line off of.

Thanks Joe.

I did some searching on the topic, but due to the unusual nature of the question I didn't come up with anything. I'm sad to hear that only the water port would be available to be tapped, but I genuinely appreciate sharing the knowledge. I'll update the thread as it moves along especially if I do move forward tapping the water port. My '95 block has me spoiled.

**Sorry to have made you relive the passing of the pup. I often find that I like mine more than most humans these days.

BTW, it looks like I joined a few years before Mr. 18psi, so by that correlation I should have know about it. In the same respect, its not a common topic and we are all trying to better the cause.

I cried.

Is this photo better?

http://i.picoodle.com/e7dhchp7.gif

I was looking for an alternative to the tiny 1/8" bspt for a feed. I was using a -6AN per efr technical document. But also this was my discrete way of asking for the thread pitch so I could drill the side of my 94 block for the vvt hardline.


Also, another option instead of tapping for coolant is just using the port on the back of the head that's normally capped of with a crush washer and bolt to the right of the outlet housing.

Ironically, it's been more than a year and my sister still has the damn thing in the freezer at home. Every time they try to get around to burying it on the backyard, there's some excuse about why it's to rainy or too cold or whatever... I have a weird family. :)

When I get home today I will see if I can find any pictures of how I have my VVT setup done on my 94 block. If you have a 94 block, can you just not use the oil feed port on the drivers side?

I sort of laughed at keeping a dead dog in your freezer, then I realized my uncle keeps a dead alligator head frozen in his freezer. He has had it for several years and he uses it as a gag for when new people come over to the house. He will be out grilling and tell them to go into the freezer and grab the tin foil wrapped head and open it up and bring it to him. Many many people have screamed upon opening it.

I was going to use this for the turbo lol. I want to make this motor nice and clean. I also have a bit more faith in the hard lines unless it's not drilled/tapped perfectly perpendicular.

Know the thread pitch of the banjo on the vvt oil port? The bolt itself is still in transit but I'll be dropping by the machine shop today for final parts dropoff otherwise I'd measure it myself

iirc 1/8" BSPT

Joe, I've seen SO MANY of your old posts with broken ImageFrame links it hurts.

I've considered doing this, has anyone actually done this?

That would be glorious! Please post up findings :bigtu:

Tha BANJO is not 1/8" BSPT. The BLOCK banjo is probably 1/8" BSPT but the banjo that holds the 2 VVT oil feed lines behind the head is not. What you actually want is this magic:

This is the source thread: https://www.miataturbo.net/diy-turbo...y-turbo-76423/

Alas, no actual mention of thread pitch. M10x1.0 is just a quess

Just to alleviate confusion, I'm moving to a VVT motor from the factory motor that came in my '95 (which has the aforementioned ports).

Thanks for continued contributions. :)

ohh right I confused the two since they're right next to each other.

that one JKav used is glorious

Where the oil pressure "sender" screws in to the VVT motor is 1/8" BSPT. I can't confirm the threads in the block. 18psi may very well be correct.

Agreed. I believe he had it custom machined. I would pay 20 internet monies for one of these if someone had a run of these manufactured. For serious.

Edit: Shit, I'm sorry. That's JKavs BLOCK bolt. It may in fact be 1/8"BSPT. My apologies for spewing misinformation.

Yea the pressure sender port is bspt but since the hardline attaches to the block, the vvt motor will have a straight thread into the oil galley.

Mystery continues.