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Pulling a VVT engine for swap into my NA8

Hi all

Next weekend I'm going to be pulling an 03 VVT engine out of a car to eventually swap into my 95 NA8 (driven by an MS3), and I want to make sure that I get everything I need while I'm there. Apart from everything attached to the engine that doesn't need to be removed to pull it, what else should I try to grab?

So far, my short list consists of the plugs and wiring on the harness side for:
* VVT actuator
* Cam angle sensor
* Crank angle sensor
* TPS
* IAC

Is there anything on the fuel system side of things I should try to get? It seems that people reuse their NA8 fuel rails, injectors and FPR. How about the cooling side? I understand people also reuse the NA8 coil pack and wires, but if I have access to the car, would it be worth trying to use the newer COP's? What else would I need for that?

Thanks!

Can't use the NA fuel rail, the mounting tabs between NA8 and NB1/2 are different. Can't use the NA8 coil pack, it doesn't fit on the back of the head with the VVT oil line in the way. I've made several posts on the topic on exactly what parts you need, just search for "VVT swap" posts by my username.

I was just about to suggest searching Savs posts for detailed info.

beat me to it :party:

Okay, I had your second link saved but not the first one. Thanks for the links and the quick replies.
As I am starting from a 1.8 car, does this look correct?

Quote:

-Use the coolant temp sensors from your 1.8 motor and install them in the new motor. You won't use the front thermoswitch (for your fans), the MegaSquirt will control the fans.
-Wire the OEM cam/crank sensors into your factory CAS plug (use pigtails from the '01 harness)
-Use the '03 ignition coils wired into the 1995 wiring. This will require deleting the ignitor, but it isn't too difficult to get going.
-Use the alternator from a 1994-1997 Miata and enlarge/replace the 1.6 ring connector to fit with no modifications?
-Rewire your injector harnesses using pigtails. The AEM 30-1710 (90-95 plug and play) has internal circuitry set up for the 90-93 non-CA batch fire cars, and hooking the VVT solenoid up to INJ#9 will cause one of the injectors to lock wide open. Since your non-CA '93 harness won't have provisions for injector 3/4 in the OEM harness, you will pull from one of the middle connectors on the AEM for controlling all 4 injectors. Not exactly sure what to do here. Will come back after more searching. From what I see, the standard MS3 has logic level ignition outputs. Some searching indicates that this is what the 03 COP's are looking for, in addition to 12v, tach and ground. Is this accurate?
-Use your OEM oil pressure sender, it will replace the smaller dummy sender in the '01 motorKeep '03 pressure sender, since mine is dummy as well, or replace with real sensor
-Use the '01 throttle body, it draws air for the IAC from inside itself which makes plumbing the IAC easier (as in, you don't have to do it at all). Use pigtails for the TPS and IAC connectors and wire them into the factory harness. Wiring diagrams are your friend here.
-Use the '01 intake manifold and a '99 fuel rail with a 1.6 FPR turned upside down in place of the OEM fuel rail damper. The return line will come up and around the intake manifold right above the injectors to the factory fuel line. Get the connector from the '99 rail, slice the hardened plastic line off, and slip a standard rubber fuel hose over it so you still have the proper connector for the feed line. Do I need to go find a 1.6 FPR or will the one in my car work? Are there any problems with the lower fuel pressure from the '95 fuel system feeding the 03 injectors?

For the 95 if you only have 3 coil pack wires then you can just combine the 95 and 03 coil pack harnesses but depinning all the coil connectors and putting the pins and wires from the 95 harness into the 01+ harness.

For the 95 the alternator needs no mads, bit just bolts up

IIRC the dummy switches are the same

I forget the fpr thing I think the 1.8 fpr doesnt fit. There's no problem with the pressure though.

I have pictures of the fuel rail setup.

You need a NB1 fuel rail (~$100 from Mazdaspeed) and a 1.6L FPR.

Attachment 235558

Kraftstoff Druckregler Original

Or you can get a EUDM NB1 fuel pressure regulator - for instance at ILMotorsport.

Pretty sweet. Also $100 euros for something that can be had for <$20 from any Miata junkyard in the country.

Meh, who cares about some Euros.... ;-)

Quote:

Originally Posted by Dunning Kruger Affect (Post 1156224)

I have pictures of the fuel rail setup.

You need a NB1 fuel rail (~$100 from Mazdaspeed) and a 1.6L FPR.

https://i.imgur.com/BtKwP.jpg

Thanks, that's very useful.

So do I run the 95, 99 or 03 injectors? A friend of mine burnt a valve on his car (99 engine in an NA6 car) and thought it was a result of the lower pressure from his 1.6 FPR. He runs an adjustable FPR with HP walbro now. Any comments on that?

Your friend attempted to run a '99 motor on stock NA6 electronics, presumably? Not smart. If your friend hadn't run the engine lean, it wouldn't have burnt a valve. The reduced fuel pressure had nothing to do with it.

The later 99+ injectors are a better design, so stick with those and control the fuel properly with a standalone.

Quote:

Originally Posted by Savington (Post 1156849)

Yep, MS3 is the plan, but he was running an MS2. Must have been in the tune then, because you're right, if your AFR is okay it seems that the fuel pressure shouldn't matter that much (just might have to run a higher duty cycle given the same size injector?)

Quote:

Originally Posted by Uncle Humjaba (Post 1156938)

Yep, you've got it. The higher fuel pressure will give you better atomization, but if the AFRs are good it doesn't matter what the fuel pressure is (within reason).

Awesome, thank you.

Another question. It appears that the thing to do is to delete the MAF, add a GM IAT and tune via speed density. Is there a reason that Miata folks don't tune with mass air? When learning to tune on my Subaru, there was some talk of converting to speed density because it's pretty easy to peg the stock MAF, but I don't see that happening on a naturally aspirated Miata. I'm interested in having a well-mannered car in varying conditions since I drive to and from the track, and it seems that mass air is the better way to do that.

The stock miata MAF, even the 1.8 ones create quite a restriction in the intake tube and removing its worth a few HP. Swapping to a GM maf that doesnt pose a restriction is more work than just going speed density.

That makes sense. I'm trying to figure out where to put the IAT in my NA engine without fussing with the intake tube.

On the bright side, picked this up today:
https://www.miataturbo.net/attachmen...ine=1408315786

That engine looks really clean.

If you check out my red car build thread, you can see the airbox I built. I mounted my IAT to the airbox right next to the air filter. Works great with MS.

^ Thanks, I'll look through it.

Another - what's the difference between the 99 fuel rail and the 01? Why won't the 01 work? It looks like there's some interference issues between the 99 rail and the VTCS intake manifold but I can file that down if needed.
2001 into 1994, fuel rail questions - MX-5 Miata Forum

And for my future reference
[NA] VVT Swap - parts list help - MX-5 Miata Forum

Some more questions...
This motor I pulled has 55k miles. Would it be a good idea to do the timing belt and water pump while I've got it out? Did they ever fix these or is it still recommended to do them every 60k? What about the clutch?

Also, I have the header and down pipe(?) that came off the 03. Is it possible to fit this header/pipe together with my 95 exhaust, or do I have no choice but to buy an aftermarket 94-97 header?