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-   -   Rebuild good 99 head, or just put it on? (https://www.miataturbo.net/general-miata-chat-9/rebuild-good-99-head-just-put-43240/)

hustler 01-26-2010 09:01 PM

i said to keep it because IF everything checks out on lash and the valves are "dry," then the head is "good." Maybe I have this opinion now because the thought of spending more money makes me vomit.

webby459 01-26-2010 09:11 PM


Originally Posted by djp0623 (Post 512958)
Will the head guy have everything he needs with the 94-97 head gasket set? No sense in paying for it twice if I already have it.

He will have all the right gaskets, you probably know this already, but you will need the intake gasket from the 99 along with the plenum gasket if you separate the manifold and think this gasket needs replacement.

Good plan on getting the head done and great price on the work. Mine will definitely be costing more.

miatauser884 01-26-2010 11:41 PM


Originally Posted by hustler (Post 513900)
i said to keep it because IF everything checks out on lash and the valves are "dry," then the head is "good." Maybe I have this opinion now because the thought of spending more money makes me vomit.

I am getting close to this point. I'm just trying to make sure that I have as few problems as possible after the install. God I hope there aren't any large expensive surprises.

JasonC SBB 01-27-2010 12:20 PM

The most common problem in medium and hi miles heads is leaky exhaust valves.

Here's how to check it:

Lay the head on its side and point the exhaust ports up. Pick the 2 or 3 cylinders whose valves are closed and the lobes are pointing away from the valves. Pour some kerosene or thin oil or spirits into the ports. Watch for weeping into the combustion chamber. I'll bet you a donut some or most of the exh valves will weep, and the intake valves are fine.

If you get some weeping (but not dripping lol), the cheapass way to fix it is to lap the exhaust valves. This will improve your leakdown and increase the life of the valves. While your at it, check the guides by checking how much side to side play the exh valve heads have.

BTW of all the head porting trix the most bang for the buck is indeed to backcut the intake valves.
Next is to just pay extra for Supertech intake valves if the intake valves need replacing.
Next is a 3 angle job
Next is if the exh valves need replacing AND a 3 angle job is necessary, pay extra and get +1mm Supertech exh valves.
(Rebello tells me that +1mm intake valves need to have extra bowl work to make em flow better than standard.)
After that some mad skillz are necessary to do it right; bowl work is next bang for the buck, and that ridge in the short side when the air makes a turn.
Then teardropping the guides.

miatauser884 01-27-2010 02:25 PM

Just got the head back. It is much less exciting when not installing shiny new cams and valves. However, it is clean and will be easy to paint. Unfortunately, since it is going on my new motor immediately, I will not be able to judge and performance gain.

neogenesis2004 01-27-2010 02:46 PM

You are going to paint the cyl head? wtfz

miatauser884 01-27-2010 02:50 PM


Originally Posted by neogenesis2004 (Post 514245)
You are going to paint the cyl head? wtfz

Painting block and head with high temp engine paint. I fail to see the issue. Is it better to leave it unpainted? That's even easier to do. ;)

neogenesis2004 01-27-2010 02:58 PM

Its debatable, but the head operates at a higher temp than the block. Paint usually flakes off.


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