Building a blower-friendly head...

[trickyrix]

Well, I had a couple of thoughts the other day... first time in a long time ...

Anyhow, after I get all the requisite compression/leakdown checks done on my motor, I thought I would set about procuring/building a new head for my car. Ideally, I'd like to build 1.8 NA head with solid lifters (or good, new hydraulic lifters) and blower-friendly cams (zero-overlap, from my understanding). Alternately, I could use an NB head and intake, but I don't know what all is involved in getting the intake to work correctly in an NA car. Either way, I figure a little port and polish job might be in order as well.

All of which raises a few questions:

1) Does anyone make blower-specific cams for the Miata?

2) Will the stock ECU + Powercard be enough to compensate for cam changes?

3) Is there a solid lifter conversion for an NA head?
3a) Should I even worry about this?

4) What all is involved in swapping an NB head/intake into an NA?

I'd really appreciate some input from the seasoned vets out there... thanks!

[icepenguin66]

In order to put an NB head on an NA, you'll have to wire in a rpm switch into the ECU for the VICS control on the NB head. Mazda's V-tech sorta.

[boisking]

In order to put an NB head on an NA, you'll have to wire in a rpm switch into the ECU for the VICS control on the NB head. Mazda's V-tech sorta.

Or you could just use a head from an NB that does not have variable cam timing...from either a '99 or a Mazdaspeed. Putting a '99 head on a 1.8 NA is a popular upgrade, especially on supercharged cars.

[trickyrix]

Or you could just use a head from an NB that does not have variable cam timing...from either a '99 or a Mazdaspeed. Putting a '99 head on a 1.8 NA is a popular upgrade, especially on supercharged cars.

I know the later NB cars had variable cam timing, but the early ones have some sort of variable-length intake runners, right? I take it that feature is ECU-controlled and has a solenoid that needs to be triggered. Can this mechanism be disabled/removed or is it fairly easy to rig? I've poked around some and haven't found any specifics on the NB head swap. If I can sort it out, that sounds like the best way to go.

Also, what's the valve adjustment interval on an NB head?

[boisking]

I have never heard of any such device on a Miata. I know that it is used with sportbikes, but the intake system is shaped completely different and this would not be easily packaged in Miatas. I also do not know whether NA and NB 1.8 intakes use different bolt patterns on the mounting flange. Nonetheless, this system can be bypassed by just making the intake runners stationary and replacing the servo that controls it with a bracket. Your car has no controller for this type of system in the PCM.

[POS Racing]

I know the later NB cars had variable cam timing, but the early ones have some sort of variable-length intake runners, right?

Also, what's the valve adjustment interval on an NB head?

Yep, here is a picture for ya of a '99 -'00 intake, got no clue how it is signaled.

My owners manual sats to inspect the valve clearance ever 60,000 miles.


BTW. Great link -> http://members.aol.com/solomiata/MX5Engine.html

[juxt3r]

Rico,

As regards the cams, you might want to check with Jimmy at Fuji Racing. He apparently has easy access to a nice selection of cam profiles. There might be something in there that'll work for ya'. I'd recommend calling vs. just looking at the online specs, as they don't give ALL of the needed information.
Fuji Racing

Let us know what you find out!

As re: the head/VICS stuff, some folks have gutted the variable runner mechanism, others have used an rpm sensor of sorts to enable the butterflies at a certain rpm. If I recall correctly, some individuals also opt to use the 1.8 NA intake manifold to eliminate the whole issue.
There might also be a need to change out the fuel rail for one made for the 99-00 head, should you go that route. Check here in the various Power Mods forums for possible reading material.

Engine management, well, you'll get all manner of thought on that. Some will say that, if the powercard can do the trick, use it. Others state that the sooner you get a standalone, the better off you'll be in the long run, as it offers so much more adjustability for the car and its many functions. Something like a plug 'n' play Megasquirt or AEM EMS might be worthwhile, as any such creature will support (and hopefully help show gains from) any future power mods.

I know that's a lot of ifs and maybes, but perhaps some of it will help in your thought process of your upgrade path.

[trickyrix]

If I recall correctly, some individuals also opt to use the 1.8 NA intake manifold to eliminate the whole issue.
There might also be a need to change out the fuel rail for one made for the 99-00 head, should you go that route. Check here in the various Power Mods forums for possible reading material.

Hmmm... I'll do some checking, but it's my understanding that a 1.8 NA manifold won't mate to a 1.8 NB head - grrrr. And that's the situation that necessitates an NB head/intake (w/VICS) combo...

Of course... a gutted NB intake would solve all my worldly problems...




OK... so... we know that an NB intake has a snake pit of plumbing in it. But we don't quite know that it can be gutted and/or we don't know how that system can be made to work in an NA. I do know for a fact that an NB head will not bolt to an NA manifold - the ports and bolt patterns are different.

I'm still looking for the NB to NA head swap solution... this needs to happen muy pronto... as I am A) tired of ticking lifters, and B) wanting for supercharged power...

[channelmaniac]

Why don't you just port & polish the existing head, get a valve job done on it (maybe even with some larger valves), and put in some new lash adjusters and be done with it?

http://www.store.partsdinosaur.com/product974.html

They are cheap from there... I bought a whole set to use when I finally get around to rebuilding the old engine out of the Spec project car.

RJ

[Adam Payrot]

If you want the 99 head, all you need is this to activate the VICS

http://www.msdignition.com/rpm_7.htm

The 8950, and then one of these, I forget what the VICS window is (should be easy to find, look at a 99 dyno and see where the little extra power comes in).

http://www.msdignition.com/rpm_10.htm

The whole swap is pretty much the same as putting on a 94-97 head. I think that the EGR is slightly different, but that's all I can remember.



One thing to note... If you plan on getting an ECU before you get the 99 head, you might not need the MSD unit. Some ECU's have an RPM-selectable switch built-in that will do the exact same thing.


If you haven't seen it yet:
http://users.telenet.be/miata/englis..._head_swap.htm

[MadMerv]

I have never heard of any such device on a Miata. I know that it is used with sportbikes, but the intake system is shaped completely different and this would not be easily packaged in Miatas. I also do not know whether NA and NB 1.8 intakes use different bolt patterns on the mounting flange. Nonetheless, this system can be bypassed by just making the intake runners stationary and replacing the servo that controls it with a bracket. Your car has no controller for this type of system in the PCM.

Why bother to even post on a subject you obviously know nothing about???????

[trickyrix]

If you want the 99 head, all you need is this to activate the VICS

One thing to note... If you plan on getting an ECU before you get the 99 head, you might not need the MSD unit. Some ECU's have an RPM-selectable switch built-in that will do the exact same thing.

I had planned on sticking with the stock ECU and adding a Powercard with the blower. But would the addition of an NB head throw things too far out of whack for my electronics?

[Titus]

I had planned on sticking with the stock ECU and adding a Powercard with the blower. But would the addition of an NB head throw things too far out of whack for my electronics?

If you want to get into the head and cams, you really would be best served with an aftermarket ECU. This will allow you to adjust fuel and timing to be ideal for the mods you have, bump the redline up, and add a level of safety via knock sensing. I went blower followed by ECU. If I was to do it again, I would have gone with an ECU first.

[trickyrix]

If you want to get into the head and cams, you really would be best served with an aftermarket ECU. This will allow you to adjust fuel and timing to be ideal for the mods you have, bump the redline up, and add a level of safety via knock sensing. I went blower followed by ECU. If I was to do it again, I would have gone with an ECU first.

Is an aftermarket ECU a plug-n-play operation, or am I looking at lots of scary wiring? Remind me to pick your brain about that on Wed nite...

[Titus]

Is an aftermarket ECU a plug-n-play operation, or am I looking at lots of scary wiring? Remind me to pick your brain about that on Wed nite...

Yes.

There are a few different plug and play ECUs for your car (MSPNP, LINK, AEM, Hydra), but none of them are really as PNP as they all imply. Yes, they do plug in to the stock wiring harness in place of the stock ECU, and yes, they may even be able to start the car without doing anything more. The problem is, all of the extra benefits you get from an aftermarket ECU require wiring. Some of these include-

• Air Temperature sensor to allow the ECU to adjust timing based on the temperature of the air entering your intake manifold.
• MAP sensor to allow you to get rid of the restrictive AFM or MAF sensor.
• Knock sensor to allow the ECU to listen for detonation and pull timing if it hears it.
• Wide ban O2 sensor to allow more accurate fuel monitoring and adjustment while in boost.
• Wiring for more advanced fan control
• Conversion to sequential fuel injection (applies to my 1.6, don't think it applies to 1.
• RPM trigger, if you want the ECU to control VICS on a '99 head.

I run a LINK on my '92 and I am happy with it, but I plan on getting the sell expensive MSPNP for my Se7en. The Hydra is best of breed when it comes to plug and play ECUs for the Miata, but they know it and charge for it. AEM is popular outside the Miata community and might be the easiest to find a local shop with experience tuning it, but it also has the least Miata specific support on the net.

[johnwag]

OK... so... we know that an NB intake has a snake pit of plumbing in it. But we don't quite know that it can be gutted

It can be gutted. Lookie HERE.

[trickyrix]

Veddy interesting...

BTW, I just found a blurb on Miata.net about swapping '99-'00 cams and solid tappets into an NA head - apparently it can be done... hmmmmmmmmm.

All you have to do is use slightly thicker shims when setting the lash...

Link

Anybody ever tried this or will I be the first?

[Titus]

Veddy interesting...

BTW, I just found a blurb on Miata.net about swapping '99-'00 cams and solid tappets into an NA head - apparently it can be done... hmmmmmmmmm.

All you have to do is use slightly thicker shims when setting the lash...

Link

Anybody ever tried this or will I be the first?

I believe the biggest improvement of the '99 head was it's flow characteristics. I'm not sure why you would want to bring over the cams and tappets, but leave the improved flow on the table. If you are going to do it, go all the way!

[trickyrix]

I believe the biggest improvement of the '99 head was it's flow characteristics. I'm not sure why you would want to bring over the cams and tappets, but leave the improved flow on the table. If you are going to do it, go all the way!

Well, that's a good point that I wasn't aware of... but there's a mention in that blurb I read that they ditched the CAS at the back of the head, and I wasn't sure if mine could be adapted or not.

[Adam Payrot]

Well, that's a good point that I wasn't aware of... but there's a mention in that blurb I read that they ditched the CAS at the back of the head, and I wasn't sure if mine could be adapted or not.

Yes, it can be. You just use your 1.8 valve cover IIRC (though, I think it's possible to use the 99 VC too, I think there's a cover back there that bolts in/out, it's been forever since the last time I looked into all this). The 99 exhaust cam still has the proper notches for the 90-97 CAS.