ZX-Tex

iTrader: (15)

OK follow the link below for the pictures of the bearings. I could not find all of the bearings from the rods, and am not sure which ones came from where. But the one with the most wear (shiny surface) came from the destroyed rod so that could be post-failure.

Picasa Web Albums - John - connecting ro...

patsmx5

iTrader: (16)

I would say that bearing second from the right saw detonation. The way the shiny area is constricted to ONLY the center of the bearing is the tell tale signs of damage from detonation. Happen to be the bearing from the damaged rod? Bearing on the far left looks damaged too, but the damage isn't restricted to only the center.

rlogan

iTrader: (21)

So what components did you go with? Sorry if I missed it in the thread...we'll have to grab lunch. Glad the machine shop is working out...they are pretty good guys over there. If I do this turbo, I may go ahead and do the bottom end right on that new motor or the current block that's in it. I know I won't settle for 7-8psi for long and I hate pulling engines.

ZX-Tex

iTrader: (15)

Ryan! What's up? I got the Belfab 'HP kit'. More info here:
https://www.miataturbo.net/forum/t30899/

Believe me you will want to turn up the boost That 2560 is pretty sweet at 12+ psi.

Duffin worked out well; Russel and Donald are both good guys and from what I can see so far they did a good job. We'll grab lunch and I'll give you all the info about Belfab.

If you are conservative on the tune with the timing you may be OK with your current motor even at 12 psi. Plus your compression is 0.5 psi lower than mine (I think) if you have the stock 94-97 block.

patsmx5

iTrader: (16)

Bump.

ZX-Tex

iTrader: (15)

DOH! Missed it

ZX-Tex

iTrader: (15)

OK not to resurrect and old thread but I have some more recent information that I want to add that could be pertinent to this thread in case it is useful. It turns out that this motor quite possibly had an oil pump pressure relief valve that was malfunctioning. Though I never heard any rod knock or anything of that sort, it is possible at least that the rod bearings were not fully lubricated.

Though I can see how this could create a bending torque in an otherwise two-force-member (the Engineers know what I mean by that) I cannot say that this is what bent the rods for certain. It seems like the rods and crank would have really been torn up if there was enough friction in the big end rod bearings to create that much torque. I briefly had another crank from someone else's motor that had failed from known oil starvation. The crank had spun a bearing to the point where the crank was unusable.