Oil pan baffle
 

After building many engines here, most of which went into track cars, we can unequivocally say that oil pan baffles are a good thing. Looking at OP (Oil Pressure) data for various builds over the years, we see only minor oil pressure drops in long high G braking events. We see significant drops in oil pressure under sustained 1G+ cornering however. The engine in Vegas which saw 32psi and 420+whp at Super Lap last year didn't have a baffle. I simply forgot to tell our engine builder to install one. As a result, we saw scary pressure drops during sustained cornering, eventually leading to a spun rod bearing. In comparison, data from a similar engine with baffle plate running similar boost for much longer (w2w) sessions so virtually no lateral G relative pressure drops. To date, we have only lost two motors on track. One was a severely lightened crank spun at 8500 rpm that lost a main bearing. The other was Vegas motor run without a baffle, data showing exactly what killed it.

There are a few good baffle plates on the market. An experienced engine builder can easily make one from sheet steel. We offer the Mazda piece on our site, which needs minor trimming to fit the BP sump. The Maruha also works and I'm guessing there are others. The OEM baffle is too small to work at sustained high G's. You may wonder how Spec Miata engines survive. The answer is they don't. The fastest specs in the country run expensive 0W20 1~1.5qts low, all in the quest for 130whp through the stock airbox, restrictir, manifold and ECU.
The front running SM engines make that power for 5-15hrs, not 100+hrs like most of you expect from your BP's.

I thought I read you intended to run heavier oil after experiencing the failure. Do you now believe it was solely the fault of the missing baffle?

Secondary question since you mentioned expensive oil- If absolute lap times were not as important as longevity, what oil would you choose for a 350whp+ track Miata?

Even name brand conventional oil will get the job done. It just has to be changed once more frequently and cannot be allowed to overheat. I have only ever used synthetics in all of my vehicles. I prefer Amsoil but that's paying for extra insurance. Even cheap mobile 1 will get the job done.

The decision to run heavier oil in Vegas was takentaken b we looked at the OP data.

Keep the windage tray too i'm assuming? I haven't been in a BP bottom end in a long time, but i do remember that thing being a huge PITA to get back together.

I know the oil pan in the boat has many baffles and a windage tray. I don't think it would stay alive without them. Especially with high G cornering.

We switched exclusively to NB2 bottom ends for the windage tray/MBSP (Main Bearing Support Plate) back in 2008. We don't have any OP datalog from before that so it's just an educated guess that the MBSP helps oil control. According to Mazda, the MBSP is an NVH thing to make the BP less buzzy. Cheaper than line balancing one presumes.

But yes, I see no reason to delete the OEM windage tray in any BP.

I have been running this setup with good results.
https://www.crank-scrapers.com/Mazda_BP_BF.html
Vince