Suggestions for a Miata head rebuild?

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pardsbane
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Suggestions for a Miata head rebuild?

Post by pardsbane » Sun Feb 20, 2011 2:52 pm

Hi Guys,

Last fall I discovered the head gasket had blown on my '96 track Miata. Now I'm trying to figure out what to do about. I could do a basic head gasket job, but although the car isn't worth much, it seems silly to spend all that labor and put the old basic head back on. A build head from Flying Miata can cost anywhere from 1200 to 2500, so I'm not sure what to do.

I plan on using the car for track days, autocrosses, and street driving in the summer, and I'll probably keep it for at least a few years.

I guess I'm just looking for thoughts and ideas, or if anyone knows alternative vendors to Flyin' Miata I should check out for go-fast internal parts, let me know. Flyin' Miata offers a pretty big menu of options, which ones would people recommend? Can I get the machining done cheaper locally?

Thanks!

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Re: Suggestions for a Miata head rebuild?

Post by CP » Sun Feb 20, 2011 9:53 pm

A brand new crate motor from Mazdaspeed is around $3000.
-Cy
99 Spec Miata (SM/STU/STL/EP)
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pardsbane
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Re: Suggestions for a Miata head rebuild?

Post by pardsbane » Mon Feb 21, 2011 1:55 am

Does participation in COM competition or A/X clubs count for a MazdaSpeed membership? I hadn't thought of sourcing a whole new engine...

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MiataSteve
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Re: Suggestions for a Miata head rebuild?

Post by MiataSteve » Mon Feb 21, 2011 8:18 am

pardsbane wrote:Does participation in COM competition or A/X clubs count for a MazdaSpeed membership? I..
Yes it does! http://www.mazdamotorsports.com/membershipinfo.htm

You could try to source a used engine.
http://www.expolineauto.com/
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breakaway500
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Re: Suggestions for a Miata head rebuild?

Post by breakaway500 » Mon Feb 21, 2011 9:25 am

If it ran fine before the head gasket failure,and funds are tight,you could check the head to make sure it is not warped (easy/inexpensive to do) and bolt it back on as is.(using new gaskets/head bolts/timing belt etc) Unless you do other supporting modifications,an expensive ported head will offer minimal gains,if any. If the overall engine was tired prior to the HG failure,it may be time for a complete new/used replacement. If you only plan on a few track/autocross events and a few k. miles of street use,the original engine repaired may be the best route to go,economically speaking.. :wink:
It's not what you drive, it's how you drive. "Lap times matter"

pardsbane
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Re: Suggestions for a Miata head rebuild?

Post by pardsbane » Mon Feb 21, 2011 12:13 pm

I hadn't thought of going the whole new engine route... would an '01 engine fit in a '96? Its just an NB engine at that point right? When swapping in a new (used) engine, how do you evaluate the engine before dropping it in to make sure its in good condition?

One frustrating thing about this is I had just replaced the timing belt, water pump, and all the seals, etc, just before the gasket blew, so ripping it apart or replacing the engine would mean all that work was wasted, but I guess no matter what I do it would be wasted...

-Josh

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Re: Suggestions for a Miata head rebuild?

Post by CP » Mon Feb 21, 2011 12:42 pm

The 01+ engines had a variable valve timing setup or something like that. This may mean differences in the wiring harness in the engine bay and differences in the ECU. Good low end torque but they're dogs on the top end which is why you don't see any of them in SCCA racing. Look for a 94-97 1.8 engine. The 99-00 engines had dual runner intake manifolds that the earlier cars didn't and may not work for your application either. Leos at Expoline can probably tell you what will work and what won't.
-Cy
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2011, 2013, 2014 NER STU Champion

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Re: Suggestions for a Miata head rebuild?

Post by jeffw » Wed Feb 23, 2011 12:01 am

CP wrote:A brand new crate motor from Mazdaspeed is around $3000.
Actually, much less than that for a NA 1.8L engine.

I don't think Mazda likes us to quote prices, but lets say about 25% less :-)
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StephanAlfa
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Re: Suggestions for a Miata head rebuild?

Post by StephanAlfa » Wed Feb 23, 2011 9:21 am

I have a spare Alfa engine that you can use .. that way you'll be getting a "little" closer to driving a real vs a fake Alfa ... :lol: :lol: :lol: :lol: :lol:
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MiataSteve
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Re: Suggestions for a Miata head rebuild?

Post by MiataSteve » Wed Feb 23, 2011 9:36 am

StephanAlfa wrote:I have a spare Alfa engine that you can use .. that way you'll be getting a "little" closer to driving a real vs a fake Alfa ... :lol: :lol: :lol: :lol: :lol:

"The lady, er, Alfa Driver doth protest too much, methinks." :lol: :lol: :twisted:
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breakaway500
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Re: Suggestions for a Miata head rebuild?

Post by breakaway500 » Wed Feb 23, 2011 9:47 am

Or..replace the whole car...for $2500... http://worcester.craigslist.org/cto/2228539506.html
It's not what you drive, it's how you drive. "Lap times matter"

pardsbane
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Re: Suggestions for a Miata head rebuild?

Post by pardsbane » Sun Feb 27, 2011 11:11 pm

Yeah... I might need to replace the whole car... Unfortunately that link to CL you posted above is gone.

I stored my car on dollies this winter pushed to the side in my garage and yesterday I went out and did a shell game swapping cars around to get it ready to go to a shop for the head gasket, and when I jacked the car up, the rocker panel just collapsed:

http://www.flickr.com/photos/offthehill/5483704206/

Now I need to decide to repair the rockers and headgasket, or replace the car and swap all the safety equipment. I'm not sure which is better in the long run.

I know this problem is super common. Can anyone recommend a place to do the rocker repair?

This year was supposed to be the year of low cost, no-maintenance, all driving...

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breakaway500
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Re: Suggestions for a Miata head rebuild?

Post by breakaway500 » Mon Feb 28, 2011 9:47 am

Rust sucks to fix.What you can see is usually only the tip of the iceberg. If you keep an eye on Craigslist,early Miata deals pop up pretty regular,but you have to move fast. I have bought two NA 1.8 Miatas off CL in the last year,both were <$2.5k,rust free and under 120k miles,so it is very possible to find them.I missed a couple more by mere minutes. :shock: Mazda has built over 900,000 Miatas to date..so they are out there,and they do hold up quite well. :sunny: :sunny:
It's not what you drive, it's how you drive. "Lap times matter"

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Re: Suggestions for a Miata head rebuild?

Post by paultg » Tue Mar 01, 2011 1:43 pm

viewtopic.php?f=6&t=3113
Looks like you have a 1.8L car though. Humm..
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Re: Suggestions for a Miata head rebuild?

Post by WillM » Wed Mar 02, 2011 10:22 pm

It is hard to tell from that one picture, but the underside of your Miata looks pretty CLEAN. To me, I would think it is a keeper. Other than the engine, is it in good mechanical shape? How's the transmission? Does it have a Torsen?

Before taking things apart, a leak-down test and compression test are in order. They will help you determine what is wrong with the engine, and how extensive the damage might be.

A good, low-mileage motor should be around $1,000-1,300. If you want to stay in SS or ST, you can swap in a 1994-1997 Miata engine. Upgrading to a 1999-2005 motor would push you into SPC, if you are not there already, and the newer motors would really want an aftermarket ECU to control them correctly, especially if you want to control the variable cam found in the 2001-2005 motors.

Expolines is a great source for local Miata parts. I bet Leos has a few engines on hand right now.

That said, if all you need is to change out the head gasket and skim the head, that would be your cheapest fix. Unless, of course, you did all of that, put everything together, and then discovered that you had a tweaked a valve seat or guide.
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