must've been the amount of timing you were running? 15psi is stock boost levels on the LNF.

How strong are these engines typically? It doesnt even look like the piston was showing signs of detonation.

The ring land is reportedly a weak point on these pistons when boosted. I think I was running too much timing, as the cell I ended up in was one that I didn't think I was going to end up in, so I hadn't given it as much thought regarding timing as I should have. Where the issue happened it was 200-205 KPA, 3100-3200 RPM, and about 14 degrees of timing. Other guys in endurance racing have lost bits like this at lower boost levels and lower timing levels.

I think wouldn't be surprised if the LNF has stock forged pistons.

Actually I did some research, everything is forged....EXCEPT the pistons lol. I bet they are hypereutectic or something, if that was a forged piston it probably would melt before it chunks up like yours did.

LNF, LE5, and LSJ are all hypereutectic AFAIK.

My car can't go, but at least it will be able to stop real quick...

:likecat:

Is that an off the shelf kit, or are you piecing it together? Looks good!

It's the big boy Trackspeed 11.75" superlite kit. We're going to be stocking these kits in short order.

Hi Nigel awesome build, Im sorry you are having some engine trouble. Hopefully a set of pistons will bring it back to life. I recently purchased a whole powertrain from a solstice gxp and plan on swapping it in my 2000 miata for track use. Your build thread answered some of my concerns like where to route the exhaust, but am still curious on what you did for some other things like:
What did you do for a clutch master cylinder for the AR5?
Did you have to modify the turbo outlet to fit under the hood?
What intercooler kit or piping are you using? I was thinking about using the Fab9 larger intercooler but not sure if the ebay piping is any good.
Are you using the factory turbo blow off valve or aftermarket?
What did you do for fuel lines and pressure?

Any info would be appreciated. I am thinking about doing a build thread here once I start the project(hopefully this winter)
Thanks

I haven't posted updates for a while, but I'm in the home stretch for getting this thing back up and running. I've made a couple of small tweaks in putting it back together, but in the end I opted to jump toss in another junk yard motor and be on my way.

First of all, the 2.0 is a cool choice here. I don't know of anyone whose done it yet, and you should expect to do a lot more cutting to make it fit. It's a direct injection engine, so fueling will be different than my setup, which is the port injected 2.4. The 2.0 can make great power in stock form and there is a solid aftermarket, unlike the 2.4 which is a bit of an orphan.

For the clutch master I got a kit from ecotecmiata. It included the master with an adapter, a hose of the right length, a few fittings, and a beefy adapter to join the AR5 to the Miata PPF. Fitment was okay, but it was quite reasonably priced so I'd go the same route if I was doing it over. I don't think they advertise it, but if you are buying your oil pan from them just ask.

Turbo outlet had to be cut and re-welded to fit

I'm using all eBay intercooler parts. I just reused my 2.25" piping and intercooler from my BP turbo setup. For the 300whp/300wtq I'm going for, I don't think it will be a big limiting factor.

I ran an aftermarket blow off valve and EBC that I carried over from my turbo BP setup, but then I found that the turbo does all that just fine. It's a Borg Warner and shares many features with the EFR including built in EBC and bypass valve. It works quite well.

For fuel I'm running a DW200 pump, stock returnless fuel lines at 60psi, and FF960 injectors. Again, all stuff that carried over nicely from the BP. I just had to run some extra fuel line and shielding to reach the other side of the engine bay. I just did run of the mill E85 compatible Continental fuel line.

Today is a sad day. My regular job has been quite demanding lately, so it took me 4 months to get the new (old) engine in and going. I put about 25 miles on it and I get rod knock. I was so looking forward to turning some laps this weekend at Miata Reunion. :mad:

That's terrible news. So sorry to hear!

Hope you get her up and running soon- though depending on your location, it seems like it might be a winter project.
Best of luck.
Dan

Darn im so sorry to hear that. Maybe you can piece together a good motor with what you have. Thanks for the info on your build. I sent a reply about your initial response but it doesnt look like it saved it? I am currently piecing parts together for mine. Once I start I will make a build thread.

It was good to see you again this weekend Nigel. I was looking forward to a ride in your car. Hopefully we both get our cars on the road soon.

Totally. I'm going fully forged, no holds barred, all-out, overbuilt, so much less likely to fail, allofit this time.

Just curious, I am doing the same exact swap in my NA. Who made your driveshaft and if its not asking to much what about did it run you.

I just had a local shop do it for me. It was about $600 I think, and I had to get an adapter from driftmotion for about $150.

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