Wouldn't that be a cleaner install overall?

Just finished reading the whole thread because thinking about a VVT swap into my 94.

 

If you want to spend a bunch of time and money to convert your '94 to the inferior returnless system, be my guest

 

I'm making progress modifying my '94 oil pump to support a crank sensor. I drilled & tapped the cast boss for M6x1. It looks like the oil pump has a little vestigial lip inboard of the sensor mounting point. In the later crank sensor equipped NA's, it looks like this lip became a more pronounced reference point to locate the NA style sensors. Of course, I have a NB style sensor. From what I can tell, the NB pump and sensor configuration allow the sensor to basically pivot freely about the mounting bolt.

I'm going to have to trim that lip off to allow the sensor to seat flush. For those who have dealt with this sensor before, would I be better off giving the sensor enough clearance to pivot freely, or just enough clearance to sit flush but not be able to pivot really at all?

 

I would bolt up an OEM damper briefly before cutting anything. You may find that you need to space the sensor out to center it on the trigger wheel, vs. trimming the oil pump.

e: A bit of searching says that's probably wrong. You will need to trim the oil pump to locate the sensor properly. The location of that boss is also different, apparently, so you'll need to compensate for that in your trigger angle setting.

 

I ended up needing to both shave down the pad and add a washer to get the sensor centered on the trigger teeth.

here's the before shot. You can see that the protruding element is radiused.



here's the after shot. I had to file it down to 2mm and stick a 2mm washer behind the sensor.




here you can see where the trigger wheel teeth pass the sensor head. I basically just put the crank sprocket & pulley on the crank without the key so i could spin it against the sensor. That buffed shiny stripe is where the tooth rubbed against the sensor. FYI, the sensor head diameter is just about exactly 16mm if you are trying to center it.




The trigger angle correction sounds intimidating. I guess I'd better start researching that...

 

Same as what NA CAS users have to do, so not a big deal. NBs generally all use the same angle, but yours might not. Just something to check.

 

AKA "trigger wizard" + check timing with a light?

 

Yep. That is correct.

 

Awesome. That's pretty simple. I'll update whether this sensor location requires any correction in TS once I get there.

*UPDATE* I had to advance my timing with trigger wizard 5.5* to get the trigger wheel signal properly sinc'd

 

https://www.miataturbo.net/build-threads-57/ryephiles-loosely-guided-build-80222/page3/#post1189805

 

Yeah, I saw that after I decided to go the route I did (really nice build thread BTW). That AutoTechnik part is like $62 after shipping. I bought a whole metric tap & die set for $38 instead. Saving beer money & buying tools is more in line with my cheap bastard life philosophy anyway.

 

I would have gone your way too. I just ran across that today searching for how the crank sensor wires run. Saw your posts, figured that belonged in this thread.

 

So.. sanity check here. For those with early (real) oil pressure gauges who have done this swap. Does your oil pressure flutter as VVT engages?

 

yes, mine seems to. are you using a vvt oil pump?

 

Yep, Boundary VVT pump. Thanks!

 

What is your oil pressure at idle when full operating temp? I am assuming you have the full boundary pump with shimmed pressure regulator?

 

Yep. ~30psi warm @ idle.

 

Yes, in multiple cars I have done the swap in.

 

Dear Awesome miata gods,

I've read in the 1.8 swap guide from flying miata that if you go standalone you do not need to swap the fuelrails. and thus you have to convert to a non return style fuel system. What will be the best solution since I have the pnp pro for the 90-93 chassis and that the fuel rail is extremely hard to find where I live.

Very Kind regards,
Cedric

 

Your problem is easier to solve than you would think. Just add a fuel pressure regulator inline, with the return pipe connected to the return line and the outlet pipe connected to the returnless fuel rail. That way you're basically putting the fuel return where the original one is instead of next to the fuel tank. That's basically what the returnless system is: It has a constant pressure FPR next to the tank and a short return line.