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-   -   Need head advice. (https://www.miataturbo.net/engine-performance-56/need-head-advice-51248/)

Zabac 09-02-2010 10:56 AM

Need head advice.
 
Looking to buy a 99/00 head that I desparately need from a reputable seller.
Seller states that the head is slightly warped:
"Slightly warped (just under 15 thousandths), but have been told by the CarQuest machine shop off German Town road that it can be fixed just fine for less than 100."
Give me the grain of salt!

Thanks,

Daniel

jedduh01 09-02-2010 12:05 PM

I wouldnt be worried about a slight warped, Any head I pull and replace, goes to the machine shop and gets flattened anyways ... Just costs hundred bucks. Those heads however have been know to eat up cam journals from the bottom end going bad. Inspect closely. Do some research on what causes the damage and what to look out for there. I read about another local Charlottean (Miatamania) that got a a bad 99 head unuseable. Also depends on price before machine work needed. Perhaps a second opionion / warranty options.

Goodluck Dan

Zabac 09-02-2010 12:40 PM

"Cylinder head, valves, keepers, springs, retainers, lifters. No cams, gears, valve cover or sensors."
Price is right and i have a connection with a good local machine shop for all the work.
With no cams in place, how can I inspect for the journal damage? just look for scoring? but bearings are probably removed as well...
It is a reputable seller, so i'm wanting to take the chance...

Rallas 09-02-2010 12:50 PM

Check those cam journals! If there is obvious damage you should be able to see scoring marks. Also measure the diameters to see if they are within spec.
A machine shop can remove enough material to get a badly warped head flat again but the cam journals can't be fixed, a few thousanths misalignment can cause issues. That overall misalignment is alot harder to measure and is the reason why I have walked away from two seemingly cheap heads. The cost between a cheapie head and one that is in good shape usually isn't that much. Unless you get it for free that is.
You risk eating up good cams too if you are supplying your own cams, which can add to the risk of running a warped head.
Just my :2cents:

webby459 09-02-2010 01:09 PM

Cam journal damage is very obvious, ask how I know.

My machinist said he could fix mine by 'dusting' the caps and journal towers then align-boring the journals again. Then, either source different cams or polish the old ones down a bit. Sounds like voodoo, I probably wouldn't do it, but it's there as a possibility. The work exceeds the price of another used head, I'm sure. BTW, price on new head from mazdaspeed wasn't that bad, either, iirc.

SlideRuler 09-02-2010 01:34 PM

I think the most painless, though possibly a tiny bit more expensive option, would be this:

http://flyinmiata.com/enginebuilder/head.php

I'd rather pay a bit more for quality and ease of replacement than deal with any warpage or any other BS.

Zabac 09-02-2010 01:44 PM

Can you test the alignment without the cams? I'd assume so...
I guess best bet is to make conditional purchase, pending my shops approval.

My mashinist is pretty good, done lots of work for me and my friends, so I trust his word, and he's beyond reasonable, that's why I can't just pass on this head.

Savington 09-02-2010 01:48 PM

Have a shop check the cam journals, if they spec out and it really is only .015" warped (instead of that being a "guesstimate" and oh oops its .040 out) then it's probably OK.

Zabac 09-02-2010 01:52 PM


Originally Posted by Savington (Post 624935)
Have a shop check the cam journals, if they spec out and it really is only .015" warped (instead of that being a "guesstimate" and oh oops its .040 out) then it's probably OK.

That's what I'm thinking.
We'll see what shop says, but the head is only $140, can't resist at that price.


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