That suck about what happen andi did the same thing and this is what happen to my connecting rods

 

I figure when I open my engine I'm going to find the same thing

I assume you're going to get forged Rods. If so, shoot me a pm

 

What's the advantage of the MSM piston over the piston used on the 99-00 Miatas. They're both 9.5:1 CR. What other changes did they make for the MSM?

I'm running a normally aspirated 1.8L for racing and I'm currently debating what pistons to get. The rules allow a .020" overbore and upping CR by 0.5:1. So I'm looking at 9.5:1 pistons. Not sure if I should go with Supertechs or stock 99-00 or MSM. Any opinions?

 

1) this thread is a yeard old
2) msm pistons are nothing special
3) get one of the sets of high comp pistons (n/a) or low comp pistons (f/i) from our sponsors

 

The MSM motor is mostly the same as the 99-00 motor with the addition of a plate that is supposed to tie the main bearings together to prevent flex. The intake cam is the one they used on the JDM motors, and it has a little more lift than the USDM 99-00 intake cam. If you can go .20 over, why not look into the aftermarket?

Wake up on the wrong side of the bed?

 

Maybe.

 

I'm considering aftermarket but there aren't many I've found that have a 9.5:1 CR. There's Supertech/Belfab, the 99-00 and MSM pistons. If there are others pleasr let me know.

Also since I race this car in long enduros (25 hours) as well as sprints I'm interested in longevity. Piston slap doesn't seem like it would be good for longevity (even though a good machinist can limit or eliminate it).

 

If you're n/a why not go higher? You could use the 10:1 from the newer nb's or even the 11+ from companies like supertec and a few others. I don't understand why you want specifically the 9.5:1 and not lower/higher depending on what your needs are.

If you're worried about slap get stock ones from a 01-05 with the 10:1 ratio.
If you're buying stock though I'd either get used ones for a good deal, or just get forged ones. Buying new stock pistons is almost as expensive as buying forged.

 

There are quite a few piston manufacturers. Most will make you anything you want for a little extra over what they stock. CP, Wiseco, JW, etc etc. Really though tenths of a point are meaningless.

Piston slap occurs cold, not hot. If you're running the car that hard, that long, then I'd probably want the bores a bit oversized, so there's going to be some slap when cold. It will tighten up once hot. Forged pistons aren't idiot-proof, but they're more durable than stock, and going oversized is a no-brainer.

 

I can't go higher than 9.5 or .020 becauser the rules don't allow it. Thanks for the input though guys.

 

Oh THAT'S why. Ok, at least it makes sense now.
In that case I'd look around for used 99-00 pistons. You can get them super cheap.

 

So we don't know the difference between the 99-00 and MSM pistons? They're definitely different part numbers.

 

FYI the MBSP can be had for cheap.

 

maybe they have different rings?

 

Rings aren't part of Mazda's part number, but I guess maybe the ring lands could be different on the piston as well.