Does this part work at all?
 

A question for the forum's engine gurus:

Does this work on an engine as it's advertised here: eBay Motors: Crank Scraper: Mazda Miata MX5 1.8 1.6 Race Proven (item 380084712206 end time Dec-25-08 06:32:36 PST)

or is this not worth it?

Thanks.

Yeah, 6HP is easy. They help power mainly at higher RPMs. If you looked at a dyno plot with and without they'd pretty much be the same up to 5K, then HP would increase exponentially to redline to a gain of ~10HP or so, depending on how high you rev. To me, it's worth it for 60 bucks if it fits correctly.

Cool; thanks Pat.

I was thinking that if it was worth it, I'd buy it to install when I build my engine later on. I'm not pursuing more hp (though that's a bonus). I was thinking about it as additional protection for my engine.

It's not gonna protect your engine really. It just reduces windage. Might help keep oil in the sump a spec more, but that's not a problem in the first place.

I have one in the OTM, but it came standard.

I just picked one up for my engine just because I had some left over funds in my budget, and I figured why not. I can see how it would help at higher rpms. We already have windage trays, so why not add a scraper. Maybe it will add a seat of the pants gain (If I can ever get the damn thing running).

Let me know the fit when you install it please.

Thanks

In case someone is looking to get one for a later Miata or one they've fitted with a MBSP, the design is different, and more expensive. These are sold on MiataRoadster.com as well.

Will do Rafa. I started to get the teflon version, but decided it was probably overkill. Plus I couldnt find info on how to break it in. Seems like you would end up with a pan full of teflon flakes, which doesnt sound good to me. I expect the normal version will need some minor tweeks for perfect fitment, since clearances need to be within probably .010-.020 to work best.

It looks like it comes pretty damn close to the end of the rods as well, so if you are running non-stock rods expect to need to do some work there to get it to fit.

I would imagine in a custom/aftermarket bottom end setup, teflon is probably the way to go since its forms exactly to the parts with a break in period.

Wouldnt the action of scraping oil from the crankshaft counterweight also cause some fluid friction? I know the scraper doesnt actually touch, but it seems like the fluid on the weights slamming into a flat surface (the scraper) would also cause minor drag since it would all puddle upside down in the corner betweem the weight and the scraper. Wonder how it would be improved by making the edges of the scraper angles like a cutting edge/ramp at maybe 45 degrees to the counterweights. Would give the oil somewhere to sling to instead of just getting slung and trapped against the edge of the scraper. Might be trying to fix something that isnt a problem, just something I was thinking about.

Of course it would cost more to make since it would no longer be flat, and it would also be easier to get bent out of shape and possibly rub.

NA6C-guy; a point to to take into account.

Im running stock rods, unfortunately, no 2.0 stroker :crx:

If you're that concerned about it, spend the extra $$$ and get the crank knife-edged. It eliminates the need for the scraper, reduces drag and frothing in the oil bath and reduces rotating mass...