How to identify whether pistons/rods have been changed

[Whoodoo]

I bought my '15 BRZ without any records and it had a lot of work done to it (vortech supercharger w/2.87 pulley, injectors, pump, catch can, full exhaust, etc). I want to determine whether it has had aftermarket rod and pistons installed. I had a borescope that I tried to stick into the oil pan drain hole and spark plug hole, but it was too big to fit into both so I couldn't really see anything.

How would you suggest I move forward? Is there enough room to get around the intake valve with the same scope? Maybe there are some telltale signs of the heads being removed?

[Strife26]

Well safe boost is 8lbs on turbo. I don't know superchargers, but if they have more than the average power, there is a good chance the internals are upgraded.

That's not to say you can't get away with higher boost on stock internals. I just wanted to offer one possiblity in determining if the internals were upgraded.

What is the alleged whp when you bought it?

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[Fred E]

It's rather unlikely that anyone traded in a supercharged car with a built engine without first swapping the engine out for a stock one. However, the 2.87" pulley is quite smaller than the original pulley and spins the blower to over 12 psi, so I'd be concerned about the extra wear by the high boost level on a stock engine.

A built engine would also be considerably noisier, especially during a cold start, due to the piston slap. If you can record the sound of a cold start, it should be fairly easy to tell if the engine has forged pistons.

[Whoodoo]

The history of the car according to carfax was that it was repossessed from the first owner then sold at auction to the small dealer that I bought it from. I have no idea what the claimed hp is, but I can tell you that it gets up to just over 10psi at 7k rpm. I haven't seen 12psi, but I also don't like to hit redline because it tends to shorten the life of the serpentine belt. I'm not afraid to do the oil pan, but I'd like to explore easier alternatives first.

[DrButtDrugs]

Got money to supercharge your car but can't pay the loan smh

[strat61caster]

Originally Posted by DrButtDrugs

Got money to supercharge your car but can't pay the loan smh

Quite a few cars that have been built and are on the market for less than a new one, or even a lightly used car.

OP took the risk of buying an unknown quantity and is trying to figure it out, better to start investigating now rather than throw a tantrum when it blows up in a few months.

I'd be trying to identify the tune/tuner, that may lead you to someone who has documentation for the car far quicker than figuring out if the pistons are stock or not. If it's a canned (off the shelf) Vortech tune, maybe the internals weren't touched and just the pulley added.

[Irace86.2.0]

You could remove the manifold or a spark plug, and use the scope to look inside.

[jflogerzi]

I would buy a stock pulley and install it. Take the car to a local shop that can dyno the car. Based on the mods, I am betting the original owner was probably running E85. These cars can handle higher boost as long as the fuel is there hence upgraded injectors and pump and E85. Did you get the ecutek dongle and cable? If not get that car tuned ASAP by a solid company in the area. Who knows how good the tune is. I hope you got a hell of a deal as that thing could be a ticking time bomb.

[chaoskaze]

^^ listen to what he said

[Irace86.2.0]

What is so bad about 12psi? My Harrop kit with an 85mm pulley is hitting 12-13 at redline, and I am on 91. The stock Edelbrock kit comes with an equivalent 82-83mm pulley, and it comes with a 91 tune and a warranty. Why is everyone freaking out about this psi level?

If the car isn’t equipped with a flex fuel system then it probably didn’t run e85 unless the previous owner pulled that and nothing else. Also, what size port injectors are there? That will probably give some insight, but not necessarily. Furthermore, if the car is running fine on 91 then it is tuned for 91 because if it was tuned for e85 only then the car would be running super rich. Why tell him to run to a dyno tuner? Borrow a friend’s ECUTEK so you can check the tune.

[Whoodoo]

I guess I'll address a few things at once here...

Tried the borescope down the spark plug hole but it was too big to fit inside.

Definitely not tuned for e85 because it runs fine on gas and it doesn't have a flex fuel kit.

I don't have the cable or dongle, nor are there any Ecutek tuners anywhere near where I live.

I don't know how big the injectors are - does anyone know how to identify them? I assume they are Deatschwerks because the pump is, but I can't see any markings on them just looking at them.

[Akari]

Sounds like you scored a nice deal finding one sold at auction with a supercharger.

I'd do a few things if I were you. First, just visually start looking for signs that the engine was removed. Bolt heads obviously tightened multiple times, things not aligned exactly the same as previous spots(especially motor mounts), odd scratches on accessories, etc. If there's no sign that it was ever removed, it likely is just stock. If there are, then continue your quest to see if it's been built.

Second, figure out how dangerous the current setup is. Longevity around FI is highly dependent on proper tuning. I'd at minimum get(or borrow) an ECUTek setup, see what you can figure out about what tune is on there, and datalog to make sure it's not running in a dangerous condition.

Someone else can likely confirm, but I believe ECUTek licenses are stored in the ECU, so you'd just need a cable/dongle.

[x808drifter]

Get an oil analysis.

[gtengr]

Check the valve cover and timing cover bolt heads for wear marks.