To Rebuild or not, but with no Experience with Engine Rebuilds
 

So my 2014 BRZ engine gave up on me with what I believe to likely be a connecting rod failure that catastrophically failed the engine by ripping open the top of the engine casing. I'm very strongly considering doing my own rebuild and, while I have done all previous work on the car myself, I've never done an engine rebuild and I'm hoping to get an honest reality check on whether that is perhaps a bridge to far.

Previous work I've done myself includes the following:

• Fully installed JRSC C30-94 system
• replaced clutch, clutch fork, and flywheel
• serviced brakes
• replaced suspension
• installed P-Tuning FlexFuel system including installing upgraded fuel injector and fuel pump

I have a fairly decent tool set, I generally consider myself to be fairly mechanically inclined and resourceful, and I try to research as much as I can before I take on a project. However, I've only learned through experience and haven't had any formal training. Being honest with myself, I would still consider myself to be a relative novice to moderately experienced. I also rely fairly heavily on the shop manual and the online community for bigger projects like this, which is a huge confidence boost.

Anyway, I'm wondering if, at the end of the day when all the money is spent and I'm hoping to find peace of mind, is an engine rebuild the sort of project that I should really just leave to a professional and just deal with the added labor costs? I know the easy answer is that going with a professional will probably make me feel better. But with the added cost of labor and stories I've read about shops messing things up or running into a problem they can't solve and saying they can't do more, I keep coming back to the likely oversimplified idea that, if I go with a strengthened shortblock and internals, rebuild and/or potentially upgrade my heads, slap it all together exactly by the book including the above power add-ons, and work with a reputable e-tuner, I should have a very good chance of success, right? However, I know there are about a hundred different things that can go wrong along the way that I may not have the experience to know about or time to fully research.

To that end, were I to fire up the rebuilt engine and something is straightaway problematic (e.g., rough idle, low power, doesn't start), 1) I can't imagine my tuner will be keen on helping me solve the problem beyond telling me what any codes that come up could mean and 2) I would probably end up bringing it to a shop to diagnose anyway so that I don't make it worse. And I have a hard time imagining any shop will want to even look at my engine if they don't feel they can be sure they know what I actually did in the first place.

Ultimately, I think doing a rebuild is the only other option to parting out the car and sending the rest to a salvage yard as I don't feel I have the experience, time, or money to spend on an engine swap to a different platform, even with an OTS kit like the K-power industries 86 swap kit. And it doesn't make sense to spend the money to go back to stock form if I'm not going to enjoy the car.

Anyway, I know I don't have to say this twice on this forum, but I'm looking for candid, honest opinions so thanks in advance for reading all that and taking time to respond!

Peace of mind went out the window as soon as the supercharger was added. An overly aggressive, or poor tune was most likely the culprit.

If you are already hedging with "don't have the time to fully research," don't do it. The engine requires super attention to detail as it is stacked together.

Even with my level of experience, I would start with a long block salvaged from a wrecked one that took a hit anywhere except the front. Swap them, and rebuild the original. Once finished, I'd swap them back out and keep the second, known good one as a spare for when the rebuild breaks again.

I second the notion that you doing a rebuild isn't a great idea. There are things so impossibly small that will make or break your build, this engine isn't forgiving in the slightest.

Just get a used stock longblock and have them swap it in. I don't think this engine ever comes back the same after being unsealed.

What if I were planning to go with something like an IAG built short block which I thought comes assembled with the internals, use a vendor to rebuild/upgrade the heads, and mate the heads to the block with new gaskets. Again, know I’m probably oversimplifying, but is it perhaps that straightforward?
Edit: sounds like it’s not.

If I can remove/install a transmission, seems like installing a used long block would be about on par in terms of difficulty, no? Would that not just be a matter of getting it in the engine bay, connecting things up, installing accessories, and mating it up with the transmission?

For sure! Long block is doable. There are some differences in the layout of electrical parts, so make sure the replacement is compatible. I don't remember the cutoff years offhand, just that it's a thing. I think @DarkPira7e has had the pleasure of dealing with it. ;)

If you haven't done any kind of engine assembly before I don't recommend it. A boxer is just like any other engine but almost double the parts. If you don't have experience with FIPG it can be easily messed up and you are out an engine. Just look at the J02 recall thread, and that was all done by dealer techs. I've probably assembled hundreds of engines from cars to motorcycles and I am still very careful to check and double check on the FA's.

https://www.ft86club.com/forums/showthread.php?t=133306

i went this route and its really not as simple as you making it out to be. I was on the same boat as you. novice "mechanic"(meaning not real mechanic, does it for a hobby on my car), mechanically good, works on their own car and looks on the shop manual. i went through this and i would recommend finding a used longblock and swapping it out with your damaged one.



Yes, i think its about on par in terms of difficulty. i think pulling the motor is easier on these engine but yes its about the same.


if OP is replacing the whole complete longblock without swapping anything over from his old motor then it should work with 2013-2016 manual motors. there are some weird exceptions but generally if you got a 2013-2016 twin you should be able to swap it like plug n play. they changed the connectors and coil packs after 2015 so if you get a motor 2015+ just use everything on that motor. hopefully that makes sense enough. OH it matters if its manual or auto, so make sure the motor for was a manual if you need that.

Thanks all, this is a huge help and is why I appreciate this community so much. I still need to disassemble and remove the blown engine, but so far it is looking like I could probably reuse the alternator, A/C compressor, intake manifold, etc., but I'll be looking for both complete and bare long blocks. Although the top of the engine case got ripped open like a piece of paper, it's not looking like much else was damaged.

I'm pretty sure I know what the answer is to this next question and it's generally what I'm already leaning toward, but bear with me; going back to FI is not wise? Even though it's bonkers fun, the idea of eating the cost of used engine because I just couldn't help having more power is hard to stomach and seems a bit selfish. On the other hand, the failed engine was boosted in one way or another for about the last 55k miles and I've only ever done e-tuning so maybe I should have just gotten it tuned "properly" at a shop with a dyno. I understand that doesn't guarantee that you couldn't get a bad tune from a reputable shop if, say, someone's not having a good day or they just make a mistake.

Anyway, feel free to tell me to stop grasping at straws and just plan on enjoying the chassis with a stock motor for what it's worth.

Something else I would note FWIW is that before the last 17k miles, I had a Phantom ESC which, if your familiar with it would make about 4.5 psi of essentially instant boost as low as 2k to 2.5k RPM IIRC and would taper off to about 2.5 psi at redline. I've always been curious if that was unduly stressing the internals, particularly the con rods, but it didn't fail so alls good right? Fast forward to the JRSC in CARB form and then with FlexFuel, perhaps the fun I had with the ESC was enough to weaken the con rods? The reason I mention it is that I generally had a fantastic experience with Zach from CSG with the JRSC system and I've only read good things about CSG and Zach. So I'm biased in saying this, but I tend to think the tune was maybe not the problem and that it was something else, but at the same time I'll never know for sure.

YES! Thanks! I forgot about that. Not just the vacuum pump either. The upper pan (structural member of the block) is different.

oh yea the vacuum pump. yes the upper oil pan is lil different and the coolant crossover tube/pipe thing on top of the engine has another sensor for the autos. you can buy some plate to cover it.

that short block is trashed. maybe your heads are useable wont know until the teardown. i would put that on the back burner after you pull out the motor. id focus on trying to find a good longblock near you. yes, you can use those things, ac compressor, intake etc.. but generally most used long blocks will be complete and depending on location they range from 3-4.5k depending on mileage and whatnot.

We can't really decide if you should or shouldnt continue with FI. And we don't know the full story of your engine/car. who tuned it, who installed it, how much power it was running, how you actually drive it, how much boost etc...its rarer but NA motors fail without going into FI. for me, when i broke my fa20, i was pretty adamant about fixing it. i thought downtime would be like 6 months at most. nope it was like almost a year until i would fire her up. what im saying is when you go adding stuff past OEM, you shouldnt think about reliability. my car is far from OEM now and its alot of work just from a maintenance standpoint.

so many factors but if you did Flexfuel on top of FI then that's your main stressor. these FA20 needs to be kept below 280whp/300bhp to have somewhat of a resonable life. Generally you don't want any boost down low. belt driven superchargers like JRSC has that as a benefit