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-   -   Whats your opinion on this NB1 Cylinder Head? (https://www.miataturbo.net/engine-performance-56/whats-your-opinion-nb1-cylinder-head-109024/)

funster 01-27-2024 02:28 PM

Whats your opinion on this NB1 Cylinder Head?
 
Here's a '99 head, how does it look? The cam has some yellowish glazing on it, not sure if it got hot due to low oil or something. Any advice on checking if the bearings are in good order? Got this used so want to break it down and check everything out before using. Was told it had been resurfaced, and everything is stock.

Thanks for any insight, appreciated.

F
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sonofthehill 01-28-2024 10:22 PM

Cams don't look too unusual to me. Pull the cams if you are concerned about the bearing surfaces, see if your finger nail catches any of the grooves.

funster 01-29-2024 10:56 AM

I haven't been able to inspect all the lobes nor the bearing surfaces. Will definitely pull the cam. Thanks for the opinion and suggestion. Appreciate it.

LeoNA 01-29-2024 11:42 AM

Check the straightness and pressure test for leaks. Use a straight edge to confirm that it has not been over heated and warped. Check the top across the spark plug wells and VC gasket area. A very good check is to remove the valve train, cam seals and install the cams to see if they spin freely.

funster 01-29-2024 12:50 PM

Thanks, following on all but this part. "Check the top across the spark plug wells and VC gasket area" Would you clarify?

LeoNA 01-29-2024 01:25 PM

These cylinder head's have parallel surfaces, top and bottom. If the head has been surfaced it will be flat on the functional side so this surface cannot be used to tell if the head has been warped. Using the top surface you can check to see if it is warped. If it is then the cams will not spin freely, and the head is no good.

funster 01-29-2024 02:11 PM

Ahhh, got it. Thanks!


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