Cam Caps and Journals Redoux

When my mechanic, as part of a job to replace the timing belt a few years back, found that the exhaust side cam caps where on the intake side and vice versa, I knew the engine wasn't long for this world. I also knew it might not die immediately. Much more recently, curious about what doom awaits us, the opportunity for looking more closely presented itself with a needed oil change. After pulling the oil filter (see earlier post) I got curious and removed the valve cover to have a look at the cam caps and the cams themselves.

What's hard to see in the picture above is a ridge on the cam about 1/4 way up. I think that was the source of the sparkles in the oil filter.

Sadly, in the process of reassembling that cam cap, I managed to shear the bolts. Had I not, I might have been able to run the car for a few thousand more miles before engine replacement. My thoughts were, it's probably better to replace the head now, than the whole thing later. The plans were to pull the head and find a replacement.  Replacment BP4W heads were about $900.

I found used BP4W engines for $1200 or so. 1.6l JDM's were a bit cheaper. A full-on rebuild was $4k. Any of those would require either $500 (?) in tools to do it myself or $1000+ to have it done.

Its also worth noting that many of the replacement heads and engines for this car are BP5As not the BP4Ws that the 1999 and 2000 miatas came with. The later are better heads. The former are engines from MX3s.